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Definition: Interferometric Synthetic Aperture Radar | Open Energy
Open Energy Info (EERE)
Interferometric Synthetic Aperture Radar Interferometric Synthetic Aperture Radar Jump to: navigation, search Dictionary.png Interferometric Synthetic Aperture Radar Interferometric Synthetic Aperture Radar (InSAR) utilizes SAR images from two different time periods to generate maps of surface deformation. The technique can potentially measure millimeter-scale changes in the Earth's surface.[1][2] View on Wikipedia Wikipedia Definition Also Known As InSAR, IfSAR Related Terms Synthetic Aperture Radar, radar, sustainability References ↑ Synthetic Aperture Radar Interferometry to Measure Earth's Surface Topography and Its Deformation (Burgmann et al. 2000) ↑ Improved Visulaization of Satellite Radar InSAR Observed Structural Controls at Producing Geothermal Field Using Modeled Horizontal Surface Displacements(Opplinger et al. 2006)
Synthetic Aperture Radar -- Sandia National Laboratories
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Information Contacts Synthetic Aperture Radar Sandia synthetic aperture radar image of Washington, DC Sandia synthetic aperture radar image of Washington, DC Sandia synthetic...
Synthetic Aperture Radar Interferometry
E-Print Network (OSTI)
Synthetic aperture radar interferometry is an imaging technique for measuring the topography of a surface, its changes over time, and other changes in the detailed characteristics of the surface. By exploiting the phase of the coherent radar signal, interferometry has transformed radar remote sensing from a largely interpretive science to a quantitative tool, with applications in cartography, geodesy, land cover characterization, and natural hazards. This paper reviews the techniques of interferometry, systems and limitations, and applications in a rapidly growing area of science and engineering.
Paul A. Rosen; Scott Hensley; Ian R. Joughin; Fuk K. Li; S�ren N. Madsen; Senior Member; Ernesto Rodr�guez; Richard M. Goldstein
Synthetic Aperture Radar Imagery -- Sandia National Laboratories
Synthetic Aperture Radar Imagery Sandia has collected and real-time processed over 400,000 synthetic aperture radar images. The following is a selection of imagery available for...
Definition: Synthetic Aperture Radar | Open Energy Information
Aperture Radar Aperture Radar Jump to: navigation, search Dictionary.png Synthetic Aperture Radar Synthetic-aperture radar (SAR) is an active microwave remote sensing technology that measures the phase difference between a radar wave emitted from an antennae attached to a satellite or aircraft to generate high-resolution images of a surface.[1] View on Wikipedia Wikipedia Definition Also Known As SAR Related Terms radar References ↑ Synthetic Aperature Radar: Systems and Signal Processing (Curlander and McDonough - 1991 - book) fue LikeLike UnlikeLike You like this.Sign Up to see what your friends like. l cell, Retrieved from "http://en.openei.org/w/index.php?title=Definition:Synthetic_Aperture_Radar&oldid=493069" Category: Definitions What links here Related changes
Mapping Surface Currents and Waves with Interferometric Synthetic Aperture Radar in Coastal Waters: Observations of Wave Breaking in Swell-Dominant Conditions
Science Conference Proceedings (OSTI)
Airborne and spaceborne interferometric synthetic aperture radars (InSARs) produce surface velocity measurements at very high spatial resolutions over a large area. The data allow construction of the velocity strain field for highlighting ocean ...
Paul A. Hwang; Jakov V. Toporkov; Mark A. Sletten; Steven P. Menk
InSAR | Open Energy Information
InSAR InSAR Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: InSAR Details Activities (11) Areas (10) Regions (2) NEPA(0) Exploration Technique Information Exploration Group: Remote Sensing Techniques Exploration Sub Group: Active Sensors Parent Exploration Technique: Radar Information Provided by Technique Lithology: Stratigraphic/Structural: Geophysical Monitoring Hydrological: Can give indications about subsurface geothermal fluid flow Thermal: Dictionary.png InSAR: Interferometric Synthetic Aperture Radar (InSAR) is a remote sensing technique that can be used to accurately measure ground displacement. Other definitions:Wikipedia Reegle Introduction InSAR is a radar technique used in geodesy and remote sensing. This geodetic method uses two or more synthetic aperture radar (SAR) images to
Spotlight-Mode Synthetic Aperture Radar: A Signal Processing Approach
From the Publisher:Spotlight-mode Synthetic Aperture Radar: A Signal Processing Approach describes an important mode of synthetic aperture radar (SAR) imaging, known as spotlight-mode SAR. By treating the subject via the principles of signal processing, ...
Paul Thompson; Daniel E. Wahl; Paul H. Eichel; Dennis C. Ghiglia; Charles V. Jakowatz
Definition: InSAR | Open Energy Information
Definition Definition Edit with form History Facebook icon Twitter icon » Definition: InSAR Jump to: navigation, search Dictionary.png InSAR Interferometric Synthetic Aperture Radar (InSAR) is a remote sensing technique that can be used to accurately measure ground displacement.[1] View on Wikipedia Wikipedia Definition Interferometric synthetic aperture radar, abbreviated InSAR or IfSAR, is a radar technique used in geodesy and remote sensing. This geodetic method uses two or more synthetic aperture radar (SAR) images to generate maps of surface deformation or digital elevation, using differences in the phase of the waves returning to the satellite or aircraft. The technique can potentially measure centimetre-scale changes in deformation over spans of days to years. It has applications for
Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) |
Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) Author Parviz Tarikhi Published N/A, 2010 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) Citation Parviz Tarikhi. Synthetic Aperture Radar Persistent Scatterer Interferometry (PSInSAR) [Internet]. 2010. Tunis, Tunisia. N/A. [cited 2013/09/17]. Available from: http://parviztarikhi.files.wordpress.com/2010/05/3psinsar-i-parviz_tarikhi.pdf Retrieved from "http://en.openei.org/w/index.php?title=Synthetic_Aperture_Radar_Persistent_Scatterer_Interferometry_(PSInSAR)&oldid=682949"
Synthetic aperture radar processing with tiered subapertures
SciTech Connect
Synthetic Aperture Radar (SAR) is used to form images that are maps of radar reflectivity of some scene of interest, from range soundings taken over some spatial aperture. Additionally, the range soundings are typically synthesized from a sampled frequency aperture. Efficient processing of the collected data necessitates using efficient digital signal processing techniques such as vector multiplies and fast implementations of the Discrete Fourier Transform. Inherent in image formation algorithms that use these is a trade-off between the size of the scene that can be acceptably imaged, and the resolution with which the image can be made. These limits arise from migration errors and spatially variant phase errors, and different algorithms mitigate these to varying degrees. Two fairly successful algorithms for airborne SARs are Polar Format processing, and Overlapped Subaperture (OSA) processing. This report introduces and summarizes the analysis of generalized Tiered Subaperture (TSA) techniques that are a superset of both Polar Format processing and OSA processing. It is shown how tiers of subapertures in both azimuth and range can effectively mitigate both migration errors and spatially variant phase errors to allow virtually arbitrary scene sizes, even in a dynamic motion environment.
Doerry, A.W. [Sandia National Labs., Albuquerque, NM (United States). Synthetic Aperture Radar Dept.
Inversion of synthetic aperture radar interferograms for sources...
Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field Jump to: navigation, search OpenEI Reference...
What is Synthetic Aperture Radar? -- Sandia National Laboratories
What is Synthetic Aperture Radar? Environmental monitoring, earth-resource mapping, and military systems require broad-area imaging at high resolutions. Many times the imagery must...
Estimating Urban Canopy Parameters Using Synthetic Aperture Radar Data
This paper introduces a remote sensing�based approach to rapidly derive urban morphological characteristics using radar satellite data. The approach is based on the expectation that the magnitude of the synthetic aperture radar (SAR) backscatter ...
Indumathi Jeyachandran; Steven J. Burian; Stephen W. Stetson
Inversion of synthetic aperture radar interferograms for sources of
Inversion of synthetic aperture radar interferograms for sources of Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field Authors Bill Foxall and D. W. Vasco Published Journal Journal of Volcanology and Geothermal Research, 2008 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field Citation Bill Foxall,D. W. Vasco. 2008. Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie
Synthetic Aperture Radar Movie Gallery -- Sandia National Laboratories
Synthetic Aperture Radar Movie Gallery Synthetic Aperture Radar Movie Gallery This gallery features movies of Sandia National Laboratories' synthetic aperture radar imagery of Albuquerque, New Mexico and Washington, DC. Sandia's Twin-Otter SAR produced these high-resolution stripmap images in real time. (Note: The movies below have been downsampled greatly to make them suitable for viewing on the world wide web. These movies are not recommended for modems of speeds less than 56 kbps due to their large file sizes.) Albuquerque, NM Area Movies Sandia National Laboratories' Twin-Otter SAR produced these Ku-Band 0.3 and 1.0 meter resolution images of Albuquerque, NM in real time. Synthetic aperture radar movie of west Gibson Blvd 0.3 meter airborne synthetic aperture radar movie from I-25 to Maxwell along Gibson Blvd. (Length: 30 seconds)
Wavefront reconstruction of elevation circular synthetic aperture aperture radar imagery using a cylindrical Green's function
Elevation Circular Synthetic Aperture Radar (E-CSAR) is a novel radar modality used to form radar images from data sets acquired along a complete or even a segment of a cylindrical geometry above a given scan area. Due to the nonlinear nature of the ...
Daniel Flores-Tapia; Gabriel Thomas; Stephen Pistorius
A Butterfly Algorithm for Synthetic Aperture Radar Imaging
In spite of an extensive literature on fast algorithms for synthetic aperture radar (SAR) imaging, it is not currently known if it is possible to accurately form an image from N data points in provable near-linear time ...
Demanet, Laurent
Simultaneous Measurement of Ocean Winds and Waves with an Airborne Coherent Real Aperture Radar
A coherent, X-band airborne radar has been developed to measure wind speed and direction simultaneously with directional wave spectra on the ocean. The coherent real aperture radar (CORAR) measures received power, mean Doppler shifts, and mean ...
William J. Plant; William C. Keller; Kenneth Hayes
Synthetic aperture radar and interferometry development at Sandia National Laboratories
Environmental monitoring, earth-resource mapping, and military systems require broad-area imaging at high resolutions. Many times the imagery must be acquired in inclement weather or during night as well as day. Synthetic aperture radar (SAR) provides such a capability. SAR systems take advantage of the long-range propagation characteristics of radar signals and the complex information processing capability of modern digital electronics to provide high resolution imagery. SAR complements photographic and other optical imaging capabilities because of the minimum constrains on time-of-day and atmospheric conditions and because of the unique responses of terrain and cultural targets to radar frequencies. Interferometry is a method for generating a three-dimensional image of terrain. The height projection is obtained by acquiring two SAR images from two slightly differing locations. It is different from the common method of stereoscopic imaging for topography. The latter relies on differing geometric projections for triangulation to define the surface geometry whereas interferometry relies on differences in radar propagation times between the two SAR locations. This paper presents the capabilities of SAR, explains how SAR works, describes a few SAR applications, provides an overview of SAR development at Sandia, and briefly describes the motion compensation subsystem.
Detecting and monitoring UCG subsidence with InSAR
The use of interferometric synthetic aperture radar (InSAR) to measure surface subsidence caused by Underground Coal Gasification (UCG) is tested. InSAR is a remote sensing technique that uses Synthetic Aperture Radar images to make spatial images of surface deformation and may be deployed from satellite or an airplane. With current commercial satellite data, the technique works best in areas with little vegetation or farming activity. UCG subsidence is generally caused by roof collapse, which adversely affects UCG operations due to gas loss and is therefore important to monitor. Previous studies have demonstrated the usefulness of InSAR in measuring surface subsidence related to coal mining and surface deformation caused by a coal mining roof collapse in Crandall Canyon, Utah is imaged as a proof-of-concept. InSAR data is collected and processed over three known UCG operations including two pilot plants (Majuba, South Africa and Wulanchabu, China) and an operational plant (Angren, Uzbekistan). A clear f eature showing approximately 7 cm of subsidence is observed in the UCG field in Angren. Subsidence is not observed in the other two areas, which produce from deeper coal seams and processed a smaller volume. The results show that in some cases, InSAR is a useful tool to image UCG related subsidence. Data from newer satellites and improved algorithms will improve effectiveness.
Mellors, R J; Foxall, W; Yang, X
Use of Synthetic Aperture Radar in Finescale Surface Analysis of Synoptic-Scale Fronts at Sea
The viability of synthetic aperture radar (SAR) as a tool for finescale marine meteorological surface analyses of synoptic-scale fronts is demonstrated. In particular, it is shown that SAR can reveal the presence of, and the mesoscale and ...
G. S. Young; T. N. Sikora; N. S. Winstead
The Rhine Outflow Plume Studied by the Analysis of Synthetic Aperture Radar Data and Numerical Simulations
The dynamics of the Rhine outflow plume in the proximity of the river mouth is investigated by using remote sensing data and numerical simulations. The remote sensing data consist of 41 synthetic aperture radar (SAR) images acquired by the First ...
Katrin Hessner; Angelo Rubino; Peter Brandt; Werner Alpers
Observations of Bora Events over the Adriatic Sea and Black Sea by Spaceborne Synthetic Aperture Radar
Bora events over the Adriatic Sea and Black Sea are investigated by using synthetic aperture radar (SAR) images acquired by the advanced SAR (ASAR) on board the European satellite Envisat. It is shown that the sea surface roughness patterns ...
Werner Alpers; Andrei Ivanov; Jochen Horstmann
Synthetic Aperture Radar as a Tool for Investigating Polar Mesoscale Cyclones
Polar mesoscale cyclones are intense vortices that form in cold, marine air masses poleward of major jet streams and frontal zones. Synthetic aperture radar (SAR) should be considered as a potential tool for the study of polar mesoscale cyclones ...
Todd D. Sikora; Karen S. Friedman; William G. Pichel; Pablo Clemente-Col�n
InSAR At Coso Geothermal Area (2000) | Open Energy Information
source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » InSAR At Coso Geothermal Area (2000) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: InSAR At Coso Geothermal Area (2000) Exploration Activity Details Location Coso Geothermal Area Exploration Technique InSAR Activity Date 2000 Usefulness useful DOE-funding Unknown Exploration Basis To determine ground subsidence using satellite radar interferometry Notes Interferometric synthetic aperture radar (InSAR) data collected in the Coso geothermal area, eastern California, during 1993-1999 indicate ground subsidence over a approximately 50 km 2 region that approximately coincides
InSAR At Desert Peak Area (Laney, 2005) | Open Energy Information
InSAR At Desert Peak Area (Laney, 2005) InSAR At Desert Peak Area (Laney, 2005) Exploration Activity Details Location Desert Peak Area Exploration Technique InSAR Activity Date Usefulness not indicated DOE-funding Unknown Notes InSAR Ground Displacement Analysis, Gary Oppliger and Mark Coolbaugh. This project supports increased utilization of geothermal resources in the Western United States by developing basic measurements and interpretations that will assist reservoir management and expansion at Bradys, Desert Peak and the Desert Peak EGS study area (80 km NE of Reno, Nevada) and will serve as a technology template for other geothermal fields. Raw format European Space Agency (ESA) ERS 1/2 satellite synthetic Aperture Radar (SAR) radar scenes acquired from 1992 through 2002 are being processed to
The Measurement of Precipitation with Synthetic Aperture Radar
The radar equation for the measurement of precipitation by SAR is identical to that for a conventional radar. The achievable synthetic beamwidth, ?s, is proportional to ?v/U, the ratio of the spread of the precipitation Doppler spectrum to the ...
David Atlas; Richard K. Moore
Modeling Collapse Chimney and Spall Zone Settlement as a Source of Post-Shot Subsidence Detected by Synthetic Aperture Radar Interferometry
Ground surface subsidence resulting from the March 1992 JUNCTION underground nuclear test at the Nevada Test Site (NTS) imaged by satellite synthetic aperture radar interferometry (InSAR) wholly occurred during a period of several months after the shot (Vincent et al., 1999) and after the main cavity collapse event. A significant portion of the subsidence associated with the small (less than 20 kt) GALENA and DIVIDER tests probably also occurred after the shots, although the deformation detected in these cases contains additional contributions from coseismic processes, since the radar scenes used to construct the deformation interferogram bracketed these two later events, The dimensions of the seas of subsidence resulting from all three events are too large to be solely accounted for by processes confined to the damage zone in the vicinity of the shot point or the collapse chimney. Rather, the subsidence closely corresponds to the span dimensions predicted by Patton's (1990) empirical relationship between spall radius and yield. This suggests that gravitational settlement of damaged rock within the spall zone is an important source of post-shot subsidence, in addition to settlement of the rubble within the collapse chimney. These observations illustrate the potential power of InSAR as a tool for Comprehensive Nuclear-Test-Ban Treaty (CTBT) monitoring and on-site inspection in that the relatively broad ({approx} 100 m to 1 km) subsidence signatures resulting from small shots detonated at normal depths of burial (or even significantly overburied) are readily detectable within large geographical areas (100 km x 100 km) under favorable observing conditions. Furthermore, the present results demonstrate the flexibility of the technique in that the two routinely gathered satellite radar images used to construct the interferogram need not necessarily capture the event itself, but can cover a time period up to several months following the shot.
Foxwall, W.
InSAR observations of aseismic slip associated with an earthquake swarm in the Columbia River flood basalts
's Hanford Site. Data from the seismic network along with interferometric synthetic aperture radar (In of the swarm. By modeling the InSAR deformation data we constructed a model that consists of a shallow thrust detected nearly 40 years ago in and around the Hanford Nuclear Site located in the eastern YFB [Pitt, 1971
Basics of Polar-Format algorithm for processing Synthetic Aperture Radar images.
The purpose of this report is to provide a background to Synthetic Aperture Radar (SAR) image formation using the Polar Format (PFA) processing algorithm. This is meant to be an aid to those tasked to implement real-time image formation using the Polar Format processing algorithm.
Doerry, Armin Walter
Moving target indication via RADARSAT-2 multichannel synthetic aperture radar processing
With the recent launches of the German TerraSAR-X and the Canadian RADARSAT-2, both equipped with phased array antennas and multiple receiver channels, synthetic aperture radar, ground moving target indication (SAR-GMTI) data are now routinely being ...
S. Chiu; M. V. Drago�evi?
A model for forming airborne synthetic aperture radar images of underground targets
Synthetic Aperture Radar (SAR) from an airborne platform has been proposed for imaging targets beneath the earth`s surface. The propagation of the radar`s energy within the ground, however, is much different than in the earth`s atmosphere. The result is signal refraction, echo delay, propagation losses, dispersion, and volumetric scattering. These all combine to make SAR image formation from an airborne platform much more challenging than a surface imaging counterpart. This report treats the ground as a lossy dispersive half-space, and presents a model for the radar echo based on measurable parameters. The model is then used to explore various imaging schemes, and image properties. Dynamic range is discussed, as is the impact of loss on dynamic range. Modified window functions are proposed to mitigate effects of sidelobes of shallow targets overwhelming deeper targets.
Doerry, A.W.
A digital ASIC implementation of a video filter for synthetic aperture radar
Two GaAs ASICs have been designed and implemented for a synthetic aperture radar which eliminate the dc bias in the sampled video data and increase the signal to noise ratio by summing the data across consecutive bursts. The High Pass Filter and Presummer ASICs process data at a maximum sample rate of 170 MHz and 125 MHz respectively. The chips are fully ECL and TTL compatible. The high pass filter is packaged in GigaBit's standard 132-pin ceramic package, while the presummer is packaged in TriQuint's standard 196-pin ceramic package. The presummer has been successfully tested in a prototype synthetic aperture radar at Sandia National Laboratories. The high pass filter has been successfully tested in a high speed test fixture. These ASICs provide flexibility and low power consumption at data rates previously unattainable with comparable hardware. 1 refs., 4 figs.
Remund, B.L. (Sandia National Labs., Albuquerque, NM (United States)); Chow, J.; Salinas, J. (GigaBit Logic, Newbury Park, CA (United States))
Comparison of Synthetic Aperture Radar�Derived Wind Speeds with Buoy Wind Speeds along the Mountainous Alaskan Coast
Satellite-borne synthetic aperture radar (SAR) offers the potential for remotely sensing surface wind speed both over the open sea and in close proximity to the coast. The resolution improvement of SAR over scatterometers is of particular ...
C. M. Fisher; G. S. Young; N. S. Winstead; J. D. Haqq-Misra
Manual and Semiautomated Wind Direction Editing for Use in the Generation of Synthetic Aperture Radar Wind Speed Imagery
Previous studies have demonstrated that satellite synthetic aperture radar (SAR) can be used as an accurate scatterometer, yielding wind speed fields with subkilometer resolution. This wind speed generation is only possible, however, if a ...
George S. Young; Todd D. Sikora; Nathaniel S. Winstead
Characteristics of Ocean Surface Winds in the Lee of an Isolated Island Observed by Synthetic Aperture Radar
Characteristics of ocean surface winds around an isolated island are examined in relation to atmospheric stability using a synthetic aperture radar (SAR) and rawinsonde sounding observations. The SAR-derived winds on 22 May 2009 indicate a low-...
Osamu Isoguchi; Masanobu Shimada; Hiroshi Kawamura
Multifrequency and multistatic inverse synthetic aperture radar, with application to FM passive radar
This paper deals with the imaging of a moving target using a multifrequency and multistatic radar consisting in one receiver and several narrowband transmitters. Considering two hypotheses about the studied target, we derive two multistatic inverse synthetic ...
Guillaume Ginolhac; Fran�oise Schmitt; Franck Daout; Philippe Forster
The Evolution of Convective Storms from Their Footprints on the Sea as Viewed by Synthetic Aperture Radar from Space
SEASAT synthetic aperture radar (SAR) echoes from the sea have previously been shown to be the result of rain and winds produced by convective storms; rain damps the surface waves and causes echo-free holes, while the diverging winds associated ...
David Atlas; Peter G. Black
A 500 MHz phase generator for synthetic aperture radar waveform synthesizers
A GaAs Phase Generator ASIC has been developed using GigaBit's SC10000 standard cell library which produces the quadratic phase necessary to generate a linear-FM chirp waveform. Fully functional chips have been fabricated using a 3-layer metal, 0.9 {mu}m gate E/D-MESFET process. Measured maximum accumulation rates vary from 450 MHz to 590 MHz. The chip is fully ECL and TTL compatible and is packaged in GigaBit's standard 132-pin ceramic package. The phase generator has been successfully tested in a prototype synthetic aperture radar at Sandia National Laboratories. Sample rates as high as 800 Msamples/sec have been synthesized using two phase generator/sine ROM combinations in parallel driving a TriQuint TQ6112 DAC. 5 refs., 5 figs.
Remund, B.L. (Sandia National Labs., Albuquerque, NM (United States)); Srivatsa, C.R. (GigaBit Logic, Newbury Park, CA (United States))
Applications of Radar Interferometry to Detect Surface Deformation in
Applications of Radar Interferometry to Detect Surface Deformation in Applications of Radar Interferometry to Detect Surface Deformation in Geothermal Areas of Imperial Valley in Southern California Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Applications of Radar Interferometry to Detect Surface Deformation in Geothermal Areas of Imperial Valley in Southern California Abstract InSAR (interferometric synthetic aperture radar) is applied in Imperial Valley of southern California to detect and characterize surface deformation in existing geothermal fields, possible future geothermal developments, and around faults. The data used are from the Envisat satellite, collected over the period 2003-2010. The specific InSAR technique applied, SqueeSARTM, identifies permanent and distributed scatterers (PS and DS), which play the role of numerous benchmarks
Encounter of Foehn Wind with an Atmospheric Eddy over the Black Sea as Observed by the Synthetic Aperture Radar Onboard Envisat
Foehn wind blowing through the Kolkhida (Kolkheti) Lowland in the southwestern Caucasus (western Georgia) was observed on an Envisat synthetic aperture radar (SAR) image as it encountered an atmospheric cyclonic eddy over the Black Sea on 13 ...
Werner Alpers; Andrei Yu. Ivanov; Knut-Frode Dagestad
The northern Tien Shan of Central Asia is an area of active mid-continent deformation. Although far from a plate boundary, this region has experienced 5 earthquakes larger than magnitude 7 in the past century and includes one event that may as be as large as Mw 8.0. Previous studies based on GPS measurements indicate on the order of 23 mm/yr of shortening across the entire Tien Shan and up to 15 mm/year in the northern Tien Shan (Figure 1). The seismic moment release rate appears comparable with the geodetic measured slip, at least to first order, suggesting that geodetic rates can be considered a proxy for accumulation rates of stress for seismic hazard estimation. Interferometric synthetic aperture radar may provide a means to make detailed spatial measurements and hence in identifying block boundaries and assisting in seismic hazard. Therefore, we hoped to define block boundaries by direct measurement and by identifying and resolving earthquake slip. Due to political instability in Kyrgzystan, the existing seismic network has not performed as well as required to precisely determine earthquake hypocenters in remote areas and hence InSAR is highly useful. In this paper we present the result of three earthquake studies and show that InSAR is useful for refining locations of teleseismically located earthquakes. ALOS PALSAR data is used to investigate crustal motion in the Tien Shan mountains of Central Asia. As part of the work, considerable software development was undertaken to process PALSAR data. This software has been made freely available. Two damaging earthquakes have been imaged in the Tien Shan and the locations provided by ALOS InSAR have helped to refine seismological velocity models. A third earthquake south of Kyrgyzstan was also imaged. The use of InSAR data and especially L band is therefore very useful in providing groundtruth for earthquake locations.
Mellors, R J
Three-dimensional subsurface imaging synthetic aperture radar (3D SISAR). Final report, September 22, 1993--September 22, 1996
The concept developed under this applied research and development contract is a novel Ground Penetrating Radar system capable of remotely detecting, analyzing, and mapping buried waste containers from a mobile platform. From the testing and analysis performed to date, the 3-D SISAR has achieved the detection, accurate location, and three-dimensional imaging of buried test objects from a stand-off geometry. Tests have demonstrated that underground objects have been located to within 0.1 meter of their actual position. This work validates that the key elements of the approach are performing as anticipated. The stand-off synthetic aperture radar (SAR) methodology has been demonstrated to be a feasible approach as a remote sensing technique. The radar sensor constructed under this project is providing adequate quality data for imaging, and the matched filters have been demonstrated to provide enhanced target detection. Additional work is on-going in the area of underground propagation and scattering phenomena to provide enhanced depth performance, as the current imaging results have been limited to a few feet of depth underground.
SWIMSAT: A Real-Aperture Radar to Measure Directional Spectra of Ocean Waves from Space�Main Characteristics and Performance Simulation
The project SWIMSAT aims to measure the directional spectra of waves from space using a real-aperture radar with a low-incidence, conical-scanning beam. This system�s design is based on airborne versions developed in France and the United States. ...
Dani�le Hauser; Elbatoul Soussi; Eric Thouvenot; Laurent Rey
Inversion of synthetic aperture radar interferograms for sourcesof production-related subsidence at the Dixie Valley geothermalfield
We used synthetic aperture radar interferograms to imageground subsidence that occurred over the Dixie Valley geothermal fieldduring different time intervals between 1992 and 1997. Linear elasticinversion of the subsidence that occurred between April, 1996 and March,1997 revealed that the dominant sources of deformation during this timeperiod were large changes in fluid volumes at shallow depths within thevalley fill above the reservoir. The distributions of subsidence andsubsurface volume change support a model in which reduction in pressureand volume of hot water discharging into the valley fill from localizedupflow along the Stillwater range frontal fault is caused by drawdownwithin the upflow zone resulting from geothermal production. Our resultsalso suggest that an additional source of fluid volume reduction in theshallow valley fill might be similar drawdown within piedmont faultzones. Shallow groundwater flow in the vicinity of the field appears tobe controlled on the NW by a mapped fault and to the SW by a lineament ofas yet unknown origin.
Foxall, B.; Vasco, D.W.
Inversion of Synthetic Aperture Radar Interferograms for Sources of Production-Related Subsidence at the Dixie Valley Geothermal Field
DOE Green Energy (OSTI)
We used synthetic aperture radar interferograms to image ground subsidence that occurred over the Dixie Valley geothermal field during different time intervals between 1992 and 1997. Linear elastic inversion of the subsidence that occurred between April, 1996 and March, 1997 revealed that the dominant sources of deformation during this time period were large changes in fluid volumes at shallow depths within the valley fill above the reservoir. The distributions of subsidence and subsurface volume change support a model in which reduction in pressure and volume of hot water discharging into the valley fill from localized upflow along the Stillwater range frontal fault is caused by drawdown within the upflow zone resulting from geothermal production. Our results also suggest that an additional source of fluid volume reduction in the shallow valley fill might be similar drawdown within piedmont fault zones. Shallow groundwater flow in the vicinity of the field appears to be controlled on the NW by a mapped fault and to the SW by a lineament of as yet unknown origin.
Foxall, W; Vasco, D
Use of INSAR in surveillance and control of a large field project
In this paper, we introduce a new element of our [1] multilevel, integrated surveillance and control system: satellite Synthetic Aperture Radar interferometry (InSAR) images of oil field surface. In particular, we analyze five differential InSAR images of the Belridge Diatomite field, CA, between 11/98 and 12/99. The images have been reprocessed and normalized to obtain the ground surface displacement rate. In return, we have been able to calculate pixel-by-pixel the net subsidence of ground surface over the entire field area. The calculated annual subsidence volume of 19 million barrels is thought to be close to the subsidence at the top of the diatomite. We have also compared the 1999 rate of surface displacement from the satellite images with the surface monument triangulations between 1942 and 1997. We have found that the maximum rate of surface subsidence has been steadily increasing from -0.8 ft/year in 1988-97 to -1 ft/year in 1998-99. The respective rates of uplift of the field fringes also increased from 0.1 ft/year to 0.24 ft/year. In 1999, the observed subsidence rate exceeded by 4.5 million barrels the volumetric deficit of fluid injection.
Patzek, T.W.; Silin, D.B.
Use of Synthetic Aperture Radar (SAR) for geologic reconnaissance in Arctic regions: An example from the Arctic National Wildlife Refuge, Alaska
Satellite-based synthetic aperture radar (SAR) can provide an additional remote-sensing tool for regional geologic studies in arctic regions. Although SAR data do not yield direct information on rock type and do not replace traditional optical data, SAR data can provide useful geologic information in arctic regions where the stratigraphic column includes a wide range of lithologies, and bedrock exposures have been reduced to rubble by frost action. For example, in ERS-1 SAR data from the Arctic National Wildlife Refuge (ANWR) of the northeastern Brooks Range, Alaska, carbonate and clastic rocks can give remarkably different radar responses on minimally reprocessed SAR data. The different radar response of different lithologies can specifically the size and angularity of scree in talus slopes. Additional postacquisition processing can both remove many of the negative terrain effects common in SAR data and enhance contrasts in bedrock lithology. Because of this ability to discriminate between gross lithologic packages, the ERS-1 SAR data can be used to provide a regional view of ANWR and a detailed look at specific areas. A mosaic of ERS-1 SAR data from all of ANWR provides a synoptic view of the regional structural framework, such as the anticlinoria of northern ANWR and the different allochthonous units of central and southern ANWR. Higher resolution ERS-1 SAR data of the Porcupine Lake area can be used to examine specific structural and stratigraphic problems associated with several major structural boundaries.
Hanks, C.L.; Guritz, R.M. [Univ. of Alaska, Fairbanks, AK (United States)
Synthetic Aperture Radar (L band) and Optical Vegetation Indices for Discriminating the Brazilian Savanna Physiognomies: A Comparative Analysis
The all-weather capability, signal independence to the solar illumination angle, and response to 3D vegetation structures are the highlights of active radar systems for natural vegetation mapping and monitoring. However, they may present ...
Edson E. Sano; Laerte G. Ferreira; Alfredo R. Huete
Final Report: Detection and Characterization of Underground Facilities by Stochastic Inversion and Modeling of Data from the New Generation of Synthetic Aperture Satellites
Many clandestine development and production activities can be conducted underground to evade surveillance. The purpose of the study reported here was to develop a technique to detect underground facilities by broad-area search and then to characterize the facilities by inversion of the collected data. This would enable constraints to be placed on the types of activities that would be feasible at each underground site, providing a basis the design of targeted surveillance and analysis for more complete characterization. Excavation of underground cavities causes deformation in the host material and overburden that produces displacements at the ground surface. Such displacements are often measurable by a variety of surveying or geodetic techniques. One measurement technique, Interferometric Synthetic Aperture Radar (InSAR), uses data from satellite-borne (or airborne) synthetic aperture radars (SARs) and so is ideal for detecting and measuring surface displacements in denied access regions. Depending on the radar frequency and the acquisition mode and the surface conditions, displacement maps derived from SAR interferograms can provide millimeter- to centimeter-level measurement accuracy on regional and local scales at spatial resolution of {approx}1-10 m. Relatively low-resolution ({approx}20 m, say) maps covering large regions can be used for broad-area detection, while finer resolutions ({approx}1 m) can be used to image details of displacement fields over targeted small areas. Surface displacements are generally expected to be largest during or a relatively short time after active excavation, but, depending on the material properties, measurable displacement may continue at a decreasing rate for a considerable time after completion. For a given excavated volume in a given geological setting, the amplitude of the surface displacements decreases as the depth of excavation increases, while the area of the discernable displacement pattern increases. Therefore, the ability to detect evidence for an underground facility using InSAR depends on the displacement sensitivity and spatial resolution of the interferogram, as well as on the size and depth of the facility and the time since its completion. The methodology development described in this report focuses on the exploitation of synthetic aperture radar data that are available commercially from a number of satellite missions. Development of the method involves three components: (1) Evaluation of the capability of InSAR to detect and characterize underground facilities ; (2) inversion of InSAR data to infer the location, depth, shape and volume of a subsurface facility; and (3) evaluation and selection of suitable geomechanical forward models to use in the inversion. We adapted LLNL's general-purpose Bayesian Markov Chain-Monte Carlo procedure, the 'Stochastic Engine' (SE), to carry out inversions to characterize subsurface void geometries. The SE performs forward simulations for a large number of trial source models to identify the set of models that are consistent with the observations and prior constraints. The inverse solution produced by this kind of stochastic method is a posterior probability density function (pdf) over alternative models, which forms an appropriate input to risk-based decision analyses to evaluate subsequent response strategies. One major advantage of a stochastic inversion approach is its ability to deal with complex, non-linear forward models employing empirical, analytical or numerical methods. However, while a geomechanical model must incorporate adequate physics to enable sufficiently accurate prediction of surface displacements, it must also be computationally fast enough to render the large number of forward realizations needed in stochastic inversion feasible. This latter requirement prompted us first to investigate computationally efficient empirical relations and closed-form analytical solutions. However, our evaluation revealed severe limitations in the ability of existing empirical and analytical forms to predict deformations from undergro
Foxall, W; Cunningham, C; Mellors, R; Templeton, D; Dyer, K; White, J
InSAR At Salton Sea Area (Eneva And Adams, 2010) | Open Energy Information
Eneva And Adams, 2010) Eneva And Adams, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: InSAR At Salton Sea Area (Eneva And Adams, 2010) Exploration Activity Details Location Salton Sea Area Exploration Technique InSAR Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown References Mariana Eneva, David Adams (2010) Modeling Of Surface Deformation From Satellite Radar Interferometry In The Salton Sea Geothermal Field, California Retrieved from "http://en.openei.org/w/index.php?title=InSAR_At_Salton_Sea_Area_(Eneva_And_Adams,_2010)&oldid=400447" Category: Exploration Activities What links here Related changes Special pages Printable version Permanent link Browse properties 429 Throttled (bot load) Error 429 Throttled (bot load)
Use of Synthetic Aperture Radar (SAR) to Identify and Characterize Overwintering Areas of Fish in Ice-Covered Arctic RIvers: A Demonstration with Broad Whitefish and their Habitats in the Sagavanirktok River, Alaska
In northern climates, locating overwintering fish can be very challenging due to thick ice cover. Areas near the coast of the Beaufort Sea provide valuable overwintering habitat for both resident and anadromous fish species; identifying and understanding their use of overwintering areas is of special interest. Synthetic aperture radar (SAR) imagery from two spaceborne satellites was examined as an alternative to radiotelemetry for identifying anadromous fish overwintering. The presence of water and ice were sampled at 162 sites and fish were sampled at 16 of these sites. From SAR imagery alone, we successfully identified large pools inhabited by overwintering fish in the ice-covered Sagavanirktok River. In addition, the imagery was able to identify all of the larger pools (mean minimum length of 138m (range 15-470 m; SD=131)) of water located by field sampling. The effectiveness of SAR to identify these pools varied from 31% to 100%, depending on imagery polarization, the incidence angle range, and the orbit. Horizontal transmit�vertical receive (HV) polarization appeared best. The accuracy of SAR was also assessed at a finer pixel-by-pixel (30-m x30-m) scale. The best correspondence at this finer scale was obtained with an image having HV polarization. The levels of agreement ranged from 54% to 69%. The presence of broad whitefish (the only anadromous species present) was associated with salinity and pool size (estimated with SAR imagery); fish were more likely to be found in larger pools with low salinity. This research illustrates that SAR imaging has great potential for identifying under-ice overwintering areas of riverine fish. These techniques should allow managers to identify critical overwintering areas with relatively more ease and lower cost than traditional techniques.
Brown, Richard S.; Duguay, Claude R.; Mueller, Robert P.; Moulton, Larry; Doucette, Peter J.; Tagestad, Jerry D.
Synthetic Aperture Radar Applications -- Sandia National Laboratories
and innovative ideas are developed. While SAR is often used because of its all-weather, day-or-night capability, it also finds application because it renders a different...
Hidden Markov Models for Multi-aperture SAR Target Detection
THE OHIO STATE UNIVERSITY GRADUATE SCHOOL NAME: Flake, Layne R. QUARTER/YEAR: SP 95 DEPARTMENT: Electrical Engineering DEGREE: M. S. ADVISER'S NAME: Krishnamurthy, Ashok K. and Ahalt, Stanley C. TITLE OF THESIS: Hidden Markov Models for Multi-aperture SAR Target Detection This thesis proposes a new multi-aperture synthetic aperture radar (MASAR) automatic target detection (ATD) algorithm that uses hidden Markov models (HMMs) to exploit the anisotropic nature of radar returns from man-made objects. Specific HMM structures are developed to represent target and clutter pixels based on the way their radar returns vary at different aspect angles. The HMM ATD algorithm is subjected to a preliminary evaluation using simulated MASAR imagery. The HMM ATD algorithm displays better detection accuracy than the best alternative ATD method while requiring at least two orders of magnitude less calculations. Adviser's Signature Department of Electrical Engineering Acknowledgments I thank my adviser...
Layne R. Flake; Ashok K. Krishnamurthy; Stanley C. Ahalt; Adviser' s Name Krishnamurthy; Ashok K; Stanley C
NIST Aperture area measurements
... particularly critical, for example, in climate and weather applications on ... of aperture areas used in exo-atmospheric solar irradiance measurements; ...
Rotating Aperture System
DOE Patents (OSTI)
A rotating aperture system includes a low-pressure vacuum pumping stage with apertures for passage of a deuterium beam. A stator assembly includes holes for passage of the beam. The rotor assembly includes a shaft connected to a deuterium gas cell or a crossflow venturi that has a single aperture on each side that together align with holes every rotation. The rotating apertures are synchronized with the firing of the deuterium beam such that the beam fires through a clear aperture and passes into the Xe gas beam stop. Portions of the rotor are lapped into the stator to improve the sealing surfaces, to prevent rapid escape of the deuterium gas from the gas cell.
Rusnak, Brian; Hall, James M.; Shen, Stewart; Wood, Richard L.
High-Frequency Skywave Radar Track of Tropical Storm Debra
Tropical Storm Debra was tracked over a 31 h period in the Gulf of Mexico using the Wide Aperture Research Facility (WARF) high-frequency (HF) skywave radar in California. In contrast to the first WARF skywave radar tracking experiment in which ...
Joseph W. Maresca Jr.; Christopher T. Carlson
ARM - Measurement - Radar Doppler
W-Band (95 GHz) ARM Cloud Radar MMCR : Millimeter Wavelength Cloud Radar RWP : Radar Wind Profiler 50RWP : Radar Wind Profiler (50 MHz) WACR : W-Band (95 GHz) ARM Cloud Radar...
Apodizer aperture for lasers
An aperture attenuator for use with high power lasers which includes glass windows shaped and assembled to form an annulus chamber which is filled with a dye solution. The annulus chamber is shaped such that the section in alignment with the axis of the incident beam follows a curve which is represented by the equation y = (r - r.sub.o).sup.n.
Jorna, Siebe (Ann Arbor, MI); Siebert, Larry D. (Ann Arbor, MI); Brueckner, Keith A. (La Jolla, CA)
InSAR At Medicine Lake Area (Poland, Et Al., 2006) | Open Energy...
Medicine Lake Area (Poland, Et Al., 2006) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: InSAR At Medicine Lake Area (Poland, Et Al., 2006)...
Aperture center energy showcase
Sandia and Forest City have established a Cooperative Research and Development Agreement (CRADA), and the partnership provides a unique opportunity to take technology research and development from demonstration to application in a sustainable community. A project under that CRADA, Aperture Center Energy Showcase, offers a means to develop exhibits and demonstrations that present feedback to community members, Sandia customers, and visitors. The technologies included in the showcase focus on renewable energy and its efficiency, and resilience. These technologies are generally scalable, and provide secure, efficient solutions to energy production, delivery, and usage. In addition to establishing an Energy Showcase, support offices and conference capabilities that facilitate research, collaboration, and demonstration were created. The Aperture Center project focuses on establishing a location that provides outreach, awareness, and demonstration of research findings, emerging technologies, and project developments to Sandia customers, visitors, and Mesa del Sol community members.
Torres, J. J.
Three-Dimensional Air Motions over the Baiu Front Observed by a VHF-Band Doppler Radar: A Case Study
Upper-tmpospheric three dimensional air motions have been observed for the first time during the Baiu period in 1984 by using a 46.5 MHz Doppler radar in Japan. This radar, called the MU radar, operates with an antenna aperture of 8330 m2 and ...
Shoichiro Fukao; Manabu D. Yamanaka; Toru Sato; Toshitaka Tsuda; Susumu Kato
Deformation Trend Extraction Based on Multi-Temporal InSAR in Shanghai
Abstract: Shanghai is a modern metropolis characterized by high urban density and anthropogenic ground motions. Although traditional deformation monitoring methods, such as GPS and spirit leveling, are reliable to millimeter accuracy, the sparse point subsidence information makes understanding large areas difficult. Multiple temporal space-borne synthetic aperture radar interferometry is a powerful high-accuracy (sub-millimeter) remote sensing tool for monitoring slow ground deformation for a large area with a high point density. In this paper, the Interferometric Point Target Time Series Analysis method is used to extract ground subsidence rates in Shanghai based on 31 C-Band and 35 X-Band synthetic aperture radar (SAR) images obtained by Envisat and COSMO SkyMed (CSK) satellites from 2007 to 2010. A significant subsidence funnel that was detected is located in the junction place between the Yangpu and the Hongkou Districts. A t-test is formulated to judge the agreements between the subsidence results obtained by SAR and by spirit leveling. In addition, four profile lines crossing the subsidence funnel area are chosen for a comparison of ground subsidence rates, which were obtained by the two different band
Jie Chen; Jicang Wu; Lina Zhang; Junping Zou; Guoxiang Liu; Rui Zhang; Bing Yu
Analysis of PS InSAR Monitoring Result of Beijing Subsidence
Urban subsidence causes more concerns in China recently. PS InSAR technique is a very useful method for surface deformation detection. We selected Beijing as study area. Being the capital of China, Beijing suffered from ground subsidence for a long time. ... Keywords: urban subsidence, PS InSAR, COSMO-SkyMed, high resolution
Dong Jiang; Mario Costantini; Tingwu Chen; Zikuan Zhou; Chunqing Ge; Jiangbing Cao
Surface deformation analysis over a hydrocarbon reservoir using InSAR with ALOS-PALSAR data
InSAR has been developed to estimate the temporal change on the surface of Earth by combining multiple SAR images acquired over the same area at different times. In the last two decades, in addition to conventional InSAR, ...
?ahin, Sedar Cihan
Simplified Active Array L-Band Radar for Atmospheric Wind Profiling: Initial Results
A simple approach is presented to implement an active aperture radar with a constrained beam-forming network that is adequate enough to generate multiple beams for atmospheric wind profiling. In this approach, elements of the antenna array are fed ...
P. Srinivasulu; P. Yasodha; A. Jayaraman; S. N. Reddy; S. Satyanarayana
InSAR At Dixie Valley Geothermal Field Area (Laney, 2005) | Open Energy
Laney, 2005) Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: InSAR At Dixie Valley Geothermal Field Area (Laney, 2005) Exploration Activity Details Location Dixie Valley Geothermal Field Area Exploration Technique InSAR Activity Date Usefulness useful DOE-funding Unknown Notes Localized Strain as a Discriminator of Hidden Geothermal Systems, Vasco and Foxall, 2005. Recent work has focused on (1) collaborating with Alessandro Ferretti to use Permanent Scatterer (PS) InSAR data to infer strain at depth, (2) working with Lane Johnson to develop a dynamic faulting model, and (3) acquiring InSAR data for the region surrounding the Dixie Valley fault zone in collaboration with Dr. William Foxall of LLNL. The InSAR data have been processed and an initial interpretation of the results is
The Coupling of Gravity Waves and Turbulence at White Sands, New Mexico, from VHF Radar Observations
Doppler spectra taken with the VHF Doppler radar at White Sands Missile Range are used to describe the winds and turbulence for 10 days in March?April 1991. The large power aperture product of this radar provides excellent data coverage in 150-m ...
G. D. Nastrom; F. D. Eaton
Sparse aperture endoscope
An endoscope which reduces the volume needed by the imaging part thereof, maintains resolution of a wide diameter optical system, while increasing tool access, and allows stereographic or interferometric processing for depth and perspective information/visualization. Because the endoscope decreases the volume consumed by imaging optics such allows a larger fraction of the volume to be used for non-imaging tools, which allows smaller incisions in surgical and diagnostic medical applications thus produces less trauma to the patient or allows access to smaller volumes than is possible with larger instruments. The endoscope utilizes fiber optic light pipes in an outer layer for illumination, a multi-pupil imaging system in an inner annulus, and an access channel for other tools in the center. The endoscope is amenable to implementation as a flexible scope, and thus increases the utility thereof. Because the endoscope uses a multi-aperture pupil, it can also be utilized as an optical array, allowing stereographic and interferometric processing.
Fitch, Joseph P. (Livermore, CA)
An endoscope is disclosed which reduces the volume needed by the imaging part, maintains resolution of a wide diameter optical system, while increasing tool access, and allows stereographic or interferometric processing for depth and perspective information/visualization. Because the endoscope decreases the volume consumed by imaging optics such allows a larger fraction of the volume to be used for non-imaging tools, which allows smaller incisions in surgical and diagnostic medical applications thus produces less trauma to the patient or allows access to smaller volumes than is possible with larger instruments. The endoscope utilizes fiber optic light pipes in an outer layer for illumination, a multi-pupil imaging system in an inner annulus, and an access channel for other tools in the center. The endoscope is amenable to implementation as a flexible scope, and thus increases it's utility. Because the endoscope uses a multi-aperture pupil, it can also be utilized as an optical array, allowing stereographic and interferometric processing. 7 figs.
Fitch, J.P.
Finding Large Aperture Fractures in Geothermal Resource Areas Using a
Finding Large Aperture Fractures in Geothermal Resource Areas Using a Finding Large Aperture Fractures in Geothermal Resource Areas Using a Three-Component Long-Offset Surface Seismic Survey Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Finding Large Aperture Fractures in Geothermal Resource Areas Using a Three-Component Long-Offset Surface Seismic Survey Project Type / Topic 1 Recovery Act: Geothermal Technologies Program Project Type / Topic 2 Validation of Innovative Exploration Technologies Project Description Because fractures and faults with sub-commercial permeability can propagate hot fluid and hydrothermal alteration throughout a geothermal reservoir, potential field geophysical methods including resistivity, gravity, heatflow and magnetics cannot distinguish between low-permeability fractures and LAF's (Large Aperature Fractures). USG will develop and test the combination of three-component,long-offset seismic surveying, permanent scatter synthetic aperture radar interferometry (PSInSAR) and structural kinematic analysis as an integrated method for locating and 3-D mapping of LAF's in shallow to intermediate depth (600-4000 feet) geothermal systems. This project is designed to test the methodology on known occurrences of LAF's and then apply the technology to expand an existing production field and find a new production field in a separate but related resource area. A full diameter production well will be drilled into each of the two lease blocks covered by the geophysical exploration program.
InSAR At Brady Hot Springs Area (Laney, 2005) | Open Energy Information
source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » InSAR At Brady Hot Springs Area (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: InSAR At Brady Hot Springs Area (Laney, 2005) Exploration Activity Details Location Brady Hot Springs Area Exploration Technique InSAR Activity Date Usefulness not indicated DOE-funding Unknown Notes InSAR Ground Displacement Analysis, Gary Oppliger and Mark Coolbaugh. This project supports increased utilization of geothermal resources in the Western United States by developing basic measurements and interpretations that will assist reservoir management and expansion at Bradys, Desert Peak
Advanced InSAR Techniques for Geothermal Exploration and Production | Open
Advanced InSAR Techniques for Geothermal Exploration and Production Advanced InSAR Techniques for Geothermal Exploration and Production Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Advanced InSAR Techniques for Geothermal Exploration and Production Abstract InSAR is a remote sensing tool that has applications in both geothermal exploration and in the management of producing fields. The technique has developed rapidly in recent years and the most evolved algorithms, now capable of providing precise ground movement measurements with unprecedented spatial density over large areas, allow, among other things, the monitoring of the effects of fluid injection and extraction on surface deformation and the detection of active faults. Multi-interferogram approaches have been used at several geothermal sites in the US and abroad.
InSAR At Redfield Campus Area (Oppliger, Et Al., 2008) | Open Energy
Campus Area (Oppliger, Et Al., 2008) Campus Area (Oppliger, Et Al., 2008) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: InSAR At Redfield Campus Area (Oppliger, Et Al., 2008) Exploration Activity Details Location Redfield Campus Area Exploration Technique InSAR Activity Date Usefulness useful DOE-funding Unknown Notes Along with the GIS, an InSAR deformation study was conducted from a suite of previously created interferograms from 1993-2005. Jet Propulsion Laboratory's Repeat Orbit Interferometry processing software Package (ROI_PAC) was used in the formation of approximately 35 interferograms considered for use in this study. All InSAR pairs were systematically screened to determine those suitable for further processing based on signal-to-noise and data integrity around the Redfield campus and Steamboat
Nelson, "Magnetic Properties of the ALS noosler Synchrotron23,1989 Dynamic Aperture of the ALS Booster Synchrotron C.H.DYNAMIC APERTURE OF TIlE ALS BOOSTER SYNCIIROlRON� CharI""
Kim, C.H.
Monitoring and characterizing natural hazards with satellite InSAR imagery *, Jixian Zhangb
-temporal RADARSAT-1 and ERS backscattering signatures of coastal wetlands at Southeastern Louisiana. Photogrammetric. Monitoring dynamic water-level changes in wetlands improves hydrological modeling predictions-level changes in wetlands Both L-band and C-band InSAR imagery can be used to measure water-level changes
the Large Aperture GRB Observatory
The Large Aperture GRB Observatory (LAGO) aims at the detection of high energy photons from Gamma Ray Bursts (GRB) using the single particle technique (SPT) in ground based water Cherenkov detectors (WCD). To reach a reasonable sensitivity, high altitude mountain sites have been selected in Mexico (Sierra Negra, 4550 m a.s.l.), Bolivia (Chacaltaya, 5300 m a.s.l.) and Venezuela (Merida, 4765 m a.s.l.). We report on the project progresses and the first operation at high altitude, search for bursts in 6 months of preliminary data, as well as search for signal at ground level when satellites report a burst.
Bertou, Xavier [Centro Atomico Bariloche (Argentina)
The Large Aperture GRB Observatory
The Large Aperture GRB Observatory (LAGO) is aiming at the detection of the high energy (around 100 GeV) component of Gamma Ray Bursts, using the single particle technique in arrays of Water Cherenkov Detectors (WCD) in high mountain sites (Chacaltaya, Bolivia, 5300 m a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m a.s.l). WCD at high altitude offer a unique possibility of detecting low gamma fluxes in the 10 GeV - 1 TeV range. The status of the Observatory and data collected from 2007 to date will be presented.
Allard, D; Asorey, H; Barros, H; Bertou, X; Castillo, M; Chirinos, J M; De Castro, A; Flores, S; Gonz�lez, J; Berisso, M Gomez; Grajales, J; Guada, C; Day, W R Guevara; Ishitsuka, J; L�pez, J A; Mart�nez, O; Melfo, A; Meza, E; Loza, P Miranda; Barbosa, E Moreno; Murrugarra, C; N��ez, L A; Ormachea, L J Otiniano; P�rez, G; Perez, Y; Ponce, E; Quispe, J; Quintero, C; Rivera, H; Rosales, M; Rovero, A C; Saavedra, O; Salazar, H; Tello, J C; Peralda, R Ticona; Varela, E; Velarde, A; Villase�or, L; Wahl, D; Zamalloa, M A
Diffraction smoothing aperture for an optical beam
The disclosure is directed to an aperture for an optical beam having an irregular periphery or having perturbations imposed upon the periphery to decrease the diffraction effect caused by the beam passing through the aperture. Such apertures are particularly useful with high power solid state laser systems in that they minimize the problem of self-focusing which frequently destroys expensive components in such systems.
Judd, O' Dean P. (Los Alamos, NM); Suydam, Bergen R. (Los Alamos, NM)
Ion mobility spectrometer with virtual aperture grid
An ion mobility spectrometer does not require a physical aperture grid to prevent premature ion detector response. The last electrodes adjacent to the ion collector (typically the last four or five) have an electrode pitch that is less than the width of the ion swarm and each of the adjacent electrodes is connected to a source of free charge, thereby providing a virtual aperture grid at the end of the drift region that shields the ion collector from the mirror current of the approaching ion swarm. The virtual aperture grid is less complex in assembly and function and is less sensitive to vibrations than the physical aperture grid.
Pfeifer, Kent B. (Los Lunas, NM); Rumpf, Arthur N. (Albuquerque, NM)
Radar | Open Energy Information
Radar Radar Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Radar Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Remote Sensing Techniques Exploration Sub Group: Active Sensors Parent Exploration Technique: Active Sensors Information Provided by Technique Lithology: Stratigraphic/Structural: Detect fault and ground movement Hydrological: Can give indications about subsurface geothermal fluid flow Thermal: Dictionary.png Radar: Radar is an active-sensor remote sensing tool used to detect small changes in ground movement at geothermal locations. Other definitions:Wikipedia Reegle Introduction RAdio Detection And Ranging (RADAR) is used in a wide variety of applications. In remote sensing applications, the source of the radio waves
Geologic interpretation of space shuttle radar images of Indonesia
The National Aeronautics and Space Administration (NASA) space shuttle mission in November 1981 acquired images of parts of the earth with a synthetic aperture radar system at a wavelength of 23.5 cm (9.3 in.) and spatial resolution of 38 m (125 ft). This report describes the geologic interpretation of 1:250,000-scale images of Irian Jaya and eastern Kalimantan, Indonesia, where the all-weather capability of radar penetrates the persistent cloud cover. The inclined look direction of radar enhances subtle topographic features that may be the expression of geologic structures. On the Indonesian images, the following terrain categories are recognizable for geologic mapping: carbonate, clastic, volcanic, alluvial and coastal, melange, and metamorphic, as well as undifferentiated bedrock. Regional and local geologic structures are well expressed on the images.
Sabing, F.F.
Shock wave absorber having apertured plate
The shock or energy absorber disclosed herein utilizes an apertured plate maintained under the normal level of liquid flowing in a piping system and disposed between the normal liquid flow path and a cavity pressurized with a compressible gas. The degree of openness (or porosity) of the plate is between 0.01 and 0.60. The energy level of a shock wave travelling down the piping system thus is dissipated by some of the liquid being jetted through the apertured plate toward the cavity. The cavity is large compared to the quantity of liquid jetted through the apertured plate, so there is little change in its volume. The porosity of the apertured plate influences the percentage of energy absorbed.
Shin, Yong W. (Western Springs, IL); Wiedermann, Arne H. (Chicago Heights, IL); Ockert, Carl E. (Vienna, VA)
Shin, Y.W.; Wiedermann, A.H.; Ockert, C.E.
Solar Central Receiver with an Irising Aperture
Variable sun elevation, azimuthal and declination angles with the time of day, and seasons of the year respectively, give variable projected image size defects produced by field site concave mirrors on the central cavity receiver's aperture entrance. If the aperture is small, it will be inefficient for periods when the solar isolation is inclined due to spillage. However, if the aperture is large, it will be inefficient for periods when the solar isolation is normal, due to excess heat radiation and convection losses. Thus, the fixed aperture area size is a compromise between ideal sizes for different conditions. The end result is a loss of efficiency as a function of time of day and seasons of the year. This research presents an approach to maximize the interception factor on the receiver entrance, with reducing the heat losses by radiation and convection through its aperture area. A central receiver system, having a down-looking cavity with an irises aperture is being proposed for application in rich environmental solar conditions, utilized solar flux insolation throughout the day on the city of Kuwait. Solar tower focusing collector with a cavity type receiver having a fixed area aperture at the entrance is presented for comparison with the proposed technique. This collector is proved to be less efficient than the suggested design. The isiring cavity receiver with a variable area aperture provides an approximately constant efficiency regardless of the time of day or season of the year. The end result is the proposed system shows improved performance and capability. However, over the life-time of installation these advantages of the proposed system should overweigh its disadvantages of additional cost due to extra automation.
Galal, T.; Kulaib, A. M.; Abuzaid, M.
Downhole pulse radar
A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole. 7 figs.
Chang, Hsi-Tien
A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole.
Chang, Hsi-Tien (Albuquerque, NM)
Imaging Structure With Fluid Fluxes At The Bradys Geothermal Field With
Imaging Structure With Fluid Fluxes At The Bradys Geothermal Field With Imaging Structure With Fluid Fluxes At The Bradys Geothermal Field With Satellite Interferometric Radar (Insar)- New Insights Into Reservoir Extent And Structural Controls Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Imaging Structure With Fluid Fluxes At The Bradys Geothermal Field With Satellite Interferometric Radar (Insar)- New Insights Into Reservoir Extent And Structural Controls Details Activities (1) Areas (1) Regions (0) Abstract: We present a new example of Interferometric Synthetic Aperture Radar's (InSAR) remarkable utility for defining an operating geothermal reservoir's lateral extent and hydrologically active fracture systems. InSAR reveals millimeter-level surface change due to volume change in the reservoir and overlying aquifer systems caused by fluid pressure reduction
Radar transponder apparatus and signal processing technique
An active, phase-coded, time-grating transponder and a synthetic-aperture radar (SAR) and signal processor means, in combination, allow the recognition and location of the transponder (tag) in the SAR image and allow communication of information messages from the transponder to the SAR. The SAR is an illuminating radar having special processing modifications in an image-formation processor to receive an echo from a remote transponder, after the transponder receives and retransmits the SAR illuminations, and to enhance tile transponder`s echo relative to surrounding ground clutter by recognizing special transponder modulations from phase-shifted from the transponder retransmissions. The remote radio-frequency tag also transmits information to the SAR through a single antenna that also serves to receive the SAR illuminations. Unique tag-modulation and SAR signal processing techniques, in combination, allow the detection and precise geographical location of the tag, through the reduction of interfering signals from ground clutter, and allow communication of environmental and status information from said tag to be communicated to said SAR.
Axline, R.M. Jr.; Sloan, G.R.; Spalding, R.E.
Radar remote sensing of the lower atmosphere
on the observed radar clutter power. Marine ducts and theiron observed radar clutter power. Marine ducts and their
Karimian, Ali
Doppler Radar Observations of Mammatus
Observations of mammatus-like cloud features associated with a convective rain shower were obtained using a vertically pointing 8-mm-wavelength Doppler radar. The radar's excellent sensitivity and resolution allowed even very weak, finescale ...
Brooks E. Martner
A Physically Based Radar Simulator
There is a growing use of multiparameter radars for observation of the atmosphere and, in particular, for remote sensing of rain. Radar systems have the undeniable advantage of being able to monitor very large areas with a single installation in ...
Carlo Capsoni; Michele D�Amico
ARM - Measurement - Radar polarization
polarization polarization ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Radar polarization The temporal and geometric behavior of the electric field vector of an electromagnetic wave transmitted or received by a radar system, e.g. elliptical polarization, differential reflectivity, phase shift, co-polar correlation coefficient, linear depolarization ratio. Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CSAPR : C-Band ARM Precipitation Radar
Very Large Aperture Diffractive Space Telescope
A very large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass ''aiming'' at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The magnifying glass includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the magnifying glass, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets.
Hyde, Roderick Allen
Definition: Radar | Open Energy Information
Radar Radar Jump to: navigation, search Dictionary.png Radar Radar is an active-sensor remote sensing tool used to detect small changes in ground movement at geothermal locations. View on Wikipedia Wikipedia Definition Radar is an object detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio waves or microwaves which bounce off any object in their path. The object returns a tiny part of the wave's energy to a dish or antenna which is usually located at the same site as the transmitter. Radar was secretly developed by several nations before and
A Comparison of Radar Reflectivity Estimates of Rainfall from Collocated Radars
Radar reflectivity�based rainfall estimates from collocated radars are examined. The usual large storm-to-storm variations in radar bias and high correlation between radar estimates and rain gauge observations are found. For three storms in ...
Edward A. Brandes; J. Vivekanandan; James W. Wilson
Dual aperture dipole magnet with second harmonic component
An improved dual aperture dipole electromagnet includes a second-harmonic frequency magnetic guide field winding which surrounds first harmonic frequency magnetic guide field windings associated with each aperture. The second harmonic winding and the first harmonic windings cooperate to produce resultant magnetic waveforms in the apertures which have extended acceleration and shortened reset portions of electromagnet operation.
Praeg, Walter F. (Palos Park, IL)
Praeg, W.F.
Compact high precision adjustable beam defining aperture
The present invention provides an adjustable aperture for limiting the dimension of a beam of energy. In an exemplary embodiment, the aperture includes (1) at least one piezoelectric bender, where a fixed end of the bender is attached to a common support structure via a first attachment and where a movable end of the bender is movable in response to an actuating voltage applied to the bender and (2) at least one blade attached to the movable end of the bender via a second attachment such that the blade is capable of impinging upon the beam. In an exemplary embodiment, the beam of energy is electromagnetic radiation. In an exemplary embodiment, the beam of energy is X-rays.
Morton, Simon A; Dickert, Jeffrey
CRTF Real-Time Aperture Flux system
The Real-Time Aperture Flux system (TRAF) is a test measurement system designed to determine the input power/unit area (flux density) during solar experiments conducted at the Central Receiver Test Facility, Sandia National Laboratories, Albuquerque, New Mexico. The RTAF is capable of using both thermal sensors and photon sensors to determine the flux densities in the RTAF measuring plane. These data are manipulated in various ways to derive input power and flux density distribution to solar experiments.
Davis, D.B.
Optimal Maneuvers for Distributed Aperture Imaging Systems
Interest in space-borne, distributed multi-aperture interferometric systems is driven by a need for continuously sustained imaging with high resolution. Amplitude interferometry systems measure the Fourier components of the image corresponding to the wave vectors (locations in the so-called u-v plane) that are proportional to the relative positions of the apertures. Imaging to specified resolution demands measurement of the Fourier components with adequate signal-to-noise ratio over the interior of a disk in the u-v plane (the resolution disk). In this paper we concentrate on the case in which interferometric measurements are made while the apertures are changing their relative positions. This work discusses heuristic maneuvers and strategies for a system of two space-borne telescopes to cover the frequency plane while optimizing a cost function that includes both a measure of image quality and propulsive effort. The current study is motivated by previous research in which the optimization problem was formulated and the first-order necessary conditions (FONC) derived. The earlier work obtained short time horizon solutions to the FONC for various simple situations, but the complexity of the integro-differential equations for optimal maneuvering have heretofore prevented solution for an optimal maneuver for the entirety of the imaging process. In place of a direct attack on the FONC, the present work investigates various heuristic approaches to minimizing the cost function in the discretized state and discretized time domains in a hexagonal coordinate system. Using three classes of coverage rules, experimentation with a variety of maneuver strategies involving two apertures has led to a number of time-optimal or fuel-optimal solutions based on the initial conditions of the spacecraft. This thesis shows that an optimal maneuver can be determined from the starting positions of the spacecraft and that a self-spiral class of motion seems to be the most beneficial for long term strategies. Future work may focus on strategies for interferometric systems with more than two apertures and with a finer mesh of the hexagonal coordinate system.
Fitch, Danielle
The Operational Weather Radar Network in Europe
The operational weather radar network in Europe covers more than 30 countries and contains more than 200 weather radars. The radar network is heterogeneous in hardware, signal processing, transmit/receive frequency, and scanning strategy, thus making it ...
Asko Huuskonen; Elena Saltikoff; Iwan Holleman
Tornado Damage Estimation Using Polarimetric Radar
This study investigates the use of tornadic debris signature (TDS) parameters to estimate tornado damage severity using Norman, Oklahoma (KOUN), polarimetric radar data (polarimetric version of the Weather Surveillance Radar-1988 Doppler radar). ...
David J. Bodine; Matthew R. Kumjian; Robert D. Palmer; Pamela L. Heinselman; Alexander V. Ryzhkov
Millimeter Wave Cloud Radar (MMCR) Handbook
The millimeter cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar possesses a doppler capability that will allow the measurement of cloud constituent vertical velocities.
KB Widener; K Johnson
How Radar Works | Open Energy Information
2013 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for How Radar Works Citation Institute For Geophysics. How Radar Works...
Sub-aperture piston phase diversity for segmented and multi-aperture systems
Phase diversity is a method of image-based wavefront sensing that simultaneously estimates the unknown phase aberrations of an imaging system along with an image of the object. To perform this estimation a series of images differing by a known aberration, typically defocus, are used. In this paper we present a new method of introducing the diversity unique to segmented and multi-aperture systems in which individual segments or sub-apertures are pistoned with respect to one another. We compare this new diversity with the conventional focus diversity.
Bolcar, Matthew R.; Fienup, James R
Ultrasonic radar and its applications
A rangefinder is a device that measures distance from the observer to a target, for the purposes of surveying, determining focus in photography, or accurately aiming a weapon. Some devices use active methods to measure (such as sonar, laser, or radar); ... Keywords: PIC, radar, rangefinder, surveying, target, ultrasonic, weapon
Mansoor-Ul-Hassan Siddique
A Marine Radar Wind Sensor
A new method for retrieving the wind vector from radar-image sequences is presented. This method, called WiRAR, uses a marine X-band radar to analyze the backscatter of the ocean surface in space and time with respect to surface winds. Wind ...
Heiko Dankert; Jochen Horstmann
Beam profiles from multiple aperture sources
Using a rapidly convergent approximation scheme, formulas are given for beam intensity profiles everywhere. In the first approximation, formulas are found for multiple aperture sources, such as a TFTR design, and integrated power for rectangular plates downstream for Gaussian beamlets. This analysis is duplicated for Lorentzian beamlets which should provide a probable upper bound for off-axis loading as Gaussian beamlets provide a probable lower bound. Formulas for beam intensity profiles are found everywhere. In first approximation, formulas are found for downstream intensity of multiple sources and integrated power for rectangular plates.
Whealton, J.H.
Vacuum aperture isolator for retroreflection from laser-irradiated target
The disclosure is directed to a vacuum aperture isolator for retroreflection of a laser-irradiated target. Within a vacuum chamber are disposed a beam focusing element, a disc having an aperture and a recollimating element. The edge of the focused beam impinges on the edge of the aperture to produce a plasma which refracts any retroreflected light from the laser's target.
Benjamin, Robert F. (Los Alamos, NM); Mitchell, Kenneth B. (Los Alamos, NM)
ARM Climate Research Facility Radar Operations Plan
Roles, responsibilities, and processes associated with Atmospheric Radiation Measurement (ARM) Radar Operations.
Voyles, JW
The Atmospheric Imaging Radar: Simultaneous Volumetric Observations Using a Phased Array Weather Radar
Mobile weather radars often utilize rapid-scan strategies when collecting observations of severe weather. Various techniques have been used to improve volume update times, including the use of agile and multibeam radars. Imaging radars, similar in ...
Bradley Isom; Robert Palmer; Redmond Kelley; John Meier; David Bodine; Mark Yeary; Boon-Leng Cheong; Yan Zhang; Tian-You Yu; Michael I. Biggerstaff
Effects of Radar Beam Shielding on Rainfall Estimation for the Polarimetric C-Band Radar
Radar reflectivity (Zh), differential reflectivity (Zdr), and specific differential phase (Kdp) measured from the operational, polarimetric weather radar located in Trappes, France, were used to examine the effects of radar beam shielding on ...
Katja Friedrich; Urs Germann; Jonathan J. Gourley; Pierre Tabary
Very high numerical aperture light transmitting device
A new light-transmitting device using a SCIN glass core and a novel calcium sodium cladding has been developed. The very high index of refraction, radiation hardness, similar solubility for rare earths and similar melt and viscosity characteristics of core and cladding materials makes them attractive for several applications such as high-numerical-aperture optical fibers and specialty lenses. Optical fibers up to 60 m in length have been drawn, and several simple lenses have been designed, ground, and polished. Preliminary results on the ability to directly cast optical components of lead-indium phosphate glass are also discussed as well as the suitability of these glasses as a host medium for rare-earth ion lasers and amplifiers.
Allison, Stephen W. (Knoxville, TN); Boatner, Lynn A. (Oak Ridge, TN); Sales, Brian C. (Knoxville, TN)
Polarimetry for Weather Surveillance Radars
This paper is an overview of weather radar polarimetry emphasizing surveillance applications. The following potential benefits to operations are identified: improvement of quantitative precipitation measurements, discrimination of hail from rain ...
Dusan S. Zrnic; Alexander V. Ryzhkov
Radar Reflectivity of Cumulus Clouds
The relationships between the radar reflectivity factor Z and significant physical cloud parameters are studied from a dataset collected with an instrumented aircraft in non- or very weakly precipitating warm clouds. The cloud droplet populations ...
Henri Sauvageot; Jilani Omar
Radar Calibration: Some Simple Approaches
The proper calibration of weather radars has been at the heart of the problem of accurate reflectivity measurements for more than five decades. This paper summarizes a number of methods that have been used previously and others that areworthy of ...
David Atlas
Synthetic aperture design for increased SAR image rate
High resolution SAR images of a target scene at near video rates can be produced by using overlapped, but nevertheless, full-size synthetic apertures. The SAR images, which respectively correspond to the apertures, can be analyzed in sequence to permit detection of movement in the target scene.
Bielek, Timothy P. (Albuquerque, NM); Thompson, Douglas G. (Albuqerque, NM); Walker, Bruce C. (Albuquerque, NM)
A Bistatic Multiple-Doppler Radar Network
A multiple-Doppler radar network can be constructed using only one, traditional, transmitting pencil-beam radar and one or more passive, low-gain, nontransmitting receivers at remote sites. Radiation scattered from the pencil beam of the ...
Joshua Wurman; Stanley Heckman; Dennis Boccippio
Radar Detection of Turbulence in Precipitation Environments
Imperfect particle tracer response is incorporated into the relations describing the turbulent air motion contribution to Doppler radar spectrum mean and variance. Tracer effects on radar estimates of the eddy dissipation rate (?) increase with ...
Alan R. Bohne
Understanding Radar Refractivity: Sources of Uncertainty
This study presents a 2-yr-long comparison of Weather Surveillance Radar-1988 Doppler (WSR-88D) refractivity retrievals with Oklahoma Mesonetwork (�Mesonet�) and sounding measurements and discusses some challenges to implementing radar ...
David Bodine; Dan Michaud; Robert D. Palmer; Pamela L. Heinselman; Jerry Brotzge; Nick Gasperoni; Boon Leng Cheong; Ming Xue; Jidong Gao
Airborne Doppler Radar Data Analysis Workshop
The Airborne Doppler Radar Data Analysis Workshop, sponsored by the Atmospheric Technology Division (ATD) of the National Center for Atmospheric Research (NCAR), was the first to focus on analyzing airborne Doppler radar data. The workshop (held ...
Wen-Chau Lee; Frank D. Marks; Craig Walther
Doppler Radar Sampling Limitations in Convective Storms
Vertical air motion data from a T-28 aircraft were filtered and sampled to simulate Doppler radar measurements. The results suggest that multiple Doppler radar analyses are subject to potentially large spatial aliasing errors in deep convection ...
R. E. Carbone; M. J. Carpenter; C. D. Burghart
Obstacle penetrating dynamic radar imaging system
An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.
Romero, Carlos E. (Livermore, CA); Zumstein, James E. (Livermore, CA); Chang, John T. (Danville, CA); Leach, Jr.. Richard R. (Castro Valley, CA)
Optimal Planning of a Weather Radar Network
An approach to the optimal planning of a weather radar network is presented. In the approach, several aspects affecting the planning decision, including terrain blockage, the need to measure with two Doppler weather radars in some regions, and ...
R. Minciardi; R. Sacile; F. Siccardi
Operational Application of Meteorological Doppler Radar
Single Doppler weather radar velocity and reflectivity fields have been obtained with the National Center for Atmospheric Research (NCAR) 5 cm radars for a wide variety of weather situations. Among those weather features that can be identified by ...
James Wilson; Richard Carbone; Harold Baynton; Robert Serafin
Scanning ARM Cloud Radar Handbook
The scanning ARM cloud radar (SACR) is a polarimetric Doppler radar consisting of three different radar designs based on operating frequency. These are designated as follows: (1) X-band SACR (X-SACR); (2) Ka-band SACR (Ka-SACR); and (3) W-band SACR (W-SACR). There are two SACRs on a single pedestal at each site where SACRs are deployed. The selection of the operating frequencies at each deployed site is predominantly determined by atmospheric attenuation at the site. Because RF attenuation increases with atmospheric water vapor content, ARM's Tropical Western Pacific (TWP) sites use the X-/Ka-band frequency pair. The Southern Great Plains (SGP) and North Slope of Alaska (NSA) sites field the Ka-/W-band frequency pair. One ARM Mobile Facility (AMF1) has a Ka/W-SACR and the other (AMF2) has a X/Ka-SACR.
Widener, K; Bharadwaj, N; Johnson, K
Estimating fracture apertures from hydraulic data and comparison with theory
Estimates of fracture openings, or apertures, were made for massive hydraulic fracture experiments at the Hot Dry Rock geothermal reservoir at Fenton Hill, New Mexico. The basis of these estimates is that if the injection rate is suddenly increased during fracturing, and the subsequent pressure increase to sustain this additional flow is measured, then the pressure increase must be related to the fracture aperture. More detailed considerations indicate that the fracture aperture estimated in this manner is affected by the nature of the fracture geometry, its propagation distance, and its viscous characteristics, but these effects are surprisingly unimportant. The result is a reasonably accurate aperture estimate, which considering the elusive nature of this measurement by other means, is quite satisfactory. These estimates are in good agreement with the fracturing theory of Geertsma and de Klerk. 10 refs., 6 figs.
Dash, Z.V.; Murphy, H.D.
Multiple Instrument Distributed Aperture Sensor (MIDAS) For Planetary Remote Sensing
Multiple Instrument Distributed Aperture Sensor (MIDAS) For Planetary Remote Sensing Joe Pitman An innovative approach that enables greatly increased return from planetary science remote sensing missions as the primary remote sensing science payload, thereby reducing the cost, resources, complexity, integration
Marcus, Philip S.
Crosswinds from a Single-Aperture Scintillometer Using Spectral Techniques
In this study, spectral techniques to obtain crosswinds from a single large-aperture scintillometer (SLAS) time series are investigated. The crosswind is defined as the wind component perpendicular to a path. A scintillometer obtains a path-...
Dani�lle van Dinther; Oscar K. Hartogensis; Arnold F. Moene
The Dynamic Aperture of an Electrostatic Quadrupole Lattice
OF AN ELECTROSTATIC QUADRUPOLE LATTICE* C.M. Celata, F.M.The dynamic aperture of such a lattice has been investigatednegligible in this short lattice), but the fact that it was
Celata, C.M.; Bieniosek, F.M.; Prost, L.; Seidl, P.A.; Friedman, A.; Grote, D.P.
ARMAR: An Airborne Rain-Mapping Radar
A new airborne rain-mapping radar (ARMAR) has been developed by NASA and the Jet Propulsion Laboratory for operation on the NASA Ames DC-8 aircraft. The radar operates at 13.8 GHz, the frequency to be used by the radar on the Tropical Rainfall ...
S. L. Durden; E. Im; F. K. Li; W. Ricketts; A. Tanner; W. Wilson
Microwave emissions from police radar
The purpose of this study was to evaluate police officers exposures to microwaves emitted by traffic radar units at the ocular and testicular level. Additionally, comparisons were made of the radar manufacturers published maximum power density specifications and actual measured power densities taken at the antenna face of those units. Four different speed enforcement agencies and one transportation research institute provided fifty four different radar units for evaluation. Of those units, nine dash mounted. five rear mounted, and three hand held models were included. During this study, only four of the 986 measurements taken exceeded the American National Standards Institute(ANSI) limit of 5 MW/CM2 , and none exceeded the American Conference of Governmental Industrial Hygienists(ACGIH), Institute of Electrical and Electronic Engineers(IEEE), or Occupational Safety and Health Administration(OSHA) standard of 10 MW/CM2 . None of the 812 measurements taken at the officers seated ocular and testicular positions exceeded .04 MW/CM2. In fact, the highest reading observed in the drivers' position was .034 MW/CM2 taken at the 5th percentile testicular level, less than 1% of the lowest current safety standard. Because of the confusion that exists in the medical and scientific communities concerning non-ionizing radiation, the extent of health risks associated with long term exposure to police radar is not yet known. Until science has indisputably proven that long term, low power exposure is not harmful, it is recommended that police departments take steps to limit officer exposure. There are several ways that police departments can limit exposure cheaply and with minimal effort. The purchasing department should first consider radar units with the lowest published maximum power densities. New hand held radar units should not be purchased because they leave open the opportunity for operators to place their bodies in the radar beam path. Purchasing units whose antennae mount outside the patrol vehicle will also lower exposure to microwaves. Finally, training that stresses the importance of using the radar units' stand-by mode when not actually monitoring traffic will further limit exposure.
Fink, John Michael
Receiver for solar-energy collector having improved aperture aspect
A secondary concentrator for use in receiver systems for linear focusing primary concentrators is provided with reflector wings at each end. The wings increase the capture of light rays reflected from areas adjacent the rim of a primary concentrator, increasing the apparent aperture size of the receiver as viewed from the rim of the primary concentrator. The length, tilt, and curvature of the wing reflectors can be adjusted to provide a receiver having a desired aperture aspect.
McIntire, W.R.
Receiver for solar energy collector having improved aperture aspect
A secondary concentrator for use in receiver systems for linear focusing primary concentrators is provided with reflector wings at each end. The wings increase the capture of light rays reflected from areas adjacent the rim of a primary concentrator, increasing the apparent aperture size of the absorber as viewed from the rim of the primary concentrator. The length, tilt, and curvature of the wing reflectors can be adjusted to provide an absorber having a desired aperture aspect.
McIntire, William R. (Downers Grove, IL)
Sidelobe Contamination in Bistatic Radars
The problem of sidelobe contamination in a bistatic network is explored. The McGill bistatic network consists of one S-band Doppler radar and two low-gain passive receivers at remote sites. Operational experience with the bistatic network ...
Ram�n de El�a; Isztar Zawadzki
Field Training in Radar Meteorology
The NSF Division of Mesoscale Meteorology and the University of Nevada�Reno (UNR) provided support for a two-week field course at the CSU�CHILL radar during 12�24 May 1991. Ten atmospheric science graduate students and two faculty from the Desert ...
John Hallett; Melanie Wetzel; Steven Rutledge
Fluorescence and Hybrid Detection Aperture of the Pierre Auger Observatory
The aperture of the Fluorescence Detector (FD) of the Pierre Auger Observatory is evaluated from simulated events using different detector configurations: mono, stereo, 3-FD and 4-FD. The trigger efficiency has been modeled using shower profiles with ground impacts in the field of view of a single telescope and studying the trigger response (at the different levels) by that telescope and by its neighbours. In addition, analysis cuts imposed by event reconstruction have been applied. The hybrid aperture is then derived for the Auger final extension. Taking into account the actual Surface Detector (SD) array configuration and its trigger response, the aperture is also calculated for a typical configuration of the present phase.
J. A. Bellido; D. D'Urso; H. Geenen; F. Guarino; L. Perrone; S. Petrera; L. Prado Jr.; F. Salamida
Two terminal micropower radar sensor
A simple, low power ultra-wideband radar motion sensor/switch configuration connects a power source and load to ground. The switch is connected to and controlled by the signal output of a radar motion sensor. The power input of the motion sensor is connected to the load through a diode which conducts power to the motion sensor when the switch is open. A storage capacitor or rechargeable battery is connected to the power input of the motion sensor. The storage capacitor or battery is charged when the switch is open and powers the motion sensor when the switch is closed. The motion sensor and switch are connected between the same two terminals between the source/load and ground. 3 figs.
McEwan, T.E.
A simple, low power ultra-wideband radar motion sensor/switch configuration connects a power source and load to ground. The switch is connected to and controlled by the signal output of a radar motion sensor. The power input of the motion sensor is connected to the load through a diode which conducts power to the motion sensor when the switch is open. A storage capacitor or rechargeable battery is connected to the power input of the motion sensor. The storage capacitor or battery is charged when the switch is open and powers the motion sensor when the switch is closed. The motion sensor and switch are connected between the same two terminals between the source/load and ground.
McEwan, Thomas E. (Livermore, CA)
High-Temporal-Resolution Capabilities of the National Weather Radar Testbed Phased-Array Radar
Since 2007 the advancement of the National Weather Radar Testbed Phased-Array Radar (NWRT PAR) hardware and software capabilities has been supporting the implementation of high-temporal-resolution (1 min) sampling. To achieve the increase in ...
Pamela L. Heinselman; Sebasti�n M. Torres
Measurement of Atmospheric Aspect Sensitivity Using Coherent Radar Imaging after Mitigation of Radar Beam Weighting Effect
The aspect angle, a measurement of the aspect sensitivity of atmospheric refractivity irregularities, was estimated with multiple-receiver coherent radar imaging (CRI) of very high frequency (VHF) atmospheric radar. Two CRI parameters retrieved by ...
Jenn-Shyong Chen; Jun-ichi Furumoto
The Use of TRMM Precipitation Radar Observations in Determining Ground Radar Calibration Biases
Since the successful launch of the Tropical Rainfall Measuring Mission (TRMM) satellite, measurements of a wide variety of precipitating systems have been obtained with unprecedented detail from the first space-based radar [precipitation radar (...
Emmanouil N. Anagnostou; Carlos A. Morales; Tufa Dinku
Monitoring the Reflectivity Calibration of a Scanning Radar Using a Profiling Radar and a Disdrometer
This paper describes a method of absolutely calibrating and routinely monitoring the reflectivity calibration from a scanning weather radar using a vertically profiling radar that has been absolutely calibrated using a collocated surface ...
Christopher R. Williams; Kenneth S. Gage; Wallace Clark; Paul Kucera
Rapid Sampling of Severe Storms by the National Weather Radar Testbed Phased Array Radar
A key advantage of the National Weather Radar Testbed Phased Array Radar (PAR) is the capability to adaptively scan storms at higher temporal resolution than is possible with the Weather Surveillance Radar-1988 Doppler (WSR-88D): 1 min or less ...
Pamela L. Heinselman; David L. Priegnitz; Kevin L. Manross; Travis M. Smith; Richard W. Adams
The 30th International Conference on Radar Meteorology
The 30th International Conference on Radar Meteorology, held in Munich, Germany, 19�24 July 2001, highlighted recent progress in the field of radar meteorology and demonstrated how radar is used in many integrated ways to better understand and ...
Matthias Steiner; Peter F. Meischner
Ultra-wideband radar motion sensor
A motion sensor is based on ultra-wideband (UWB) radar. UWB radar range is determined by a pulse-echo interval. For motion detection, the sensors operate by staring at a fixed range and then sensing any change in the averaged radar reflectivity at that range. A sampling gate is opened at a fixed delay after the emission of a transmit pulse. The resultant sampling gate output is averaged over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion. 15 figs.
Multiple Instrument Distributed Aperture Sensor (MIDAS) For Remote Sensing
Multiple Instrument Distributed Aperture Sensor (MIDAS) For Remote Sensing Joe Pitman,a , Alan that enables greatly increased return from earth and planetary science remote sensing missions is described are integrated into MIDAS as the primary remote sensing science payload, thereby reducing the cost, resources
Fienup, James R.
Retrieval of Precipitation Profiles from Airborne Radar and Passive Radiometer Measurements: Comparison with Dual-Frequency Radar Measurements
This study compares precipitation rate profiles derived from a single frequency radar and radiometer with such profiles derived from a dual-frequency radar.
J. A. Weinman; R. Meneghini; K. Nakamura
Radar Determination of Snowfall Rate and Accumulation
A unique method that provides for relating radar-measured reflectivity factors to snowfall rates at the ground is presented. Data were provided by a CPS-9, 3.2 cm radar from six 1978 Massachusetts snowstorms A best-fit power-law relationship ...
Roland J. Boucher; James G. Wieler
Helicopter discrimination apparatus for the murine radar
A helicopter discrimination apparatus for a radar utilizing doppler filtering to discriminate between a missile and ground clutter. The short duration of the doppler filter pulses which are emitted by helicopter rotor blades are processed to prevent false alarms, thus allowing the radar-protected helicopter to operate in formation with other helicopters while maintaining protection against infra-red-seeking missiles.
Webb, Jr., John G. (Sandia Park, NM); Gray, Roger M. (Dallas, TX)
Ultra-wideband radar sensors and networks
Ultra wideband radar motion sensors strategically placed in an area of interest communicate with a wireless ad hoc network to provide remote area surveillance. Swept range impulse radar and a heart and respiration monitor combined with the motion sensor further improves discrimination.
Leach, Jr., Richard R; Nekoogar, Faranak; Haugen, Peter C
Utilizing Spaceborne Radars to Retrieve Dry Snowfall
A dataset consisting of one year of CloudSat Cloud Profiling Radar (CPR) near-surface radar reflectivity Z associated with dry snowfall is examined in this study. The CPR observations are converted to snowfall rates S using derived Ze�S ...
Mark S. Kulie; Ralf Bennartz
A Synthetic Aperture Radar�Based Climatology of Open-Cell Convection over the Northeast Pacific Ocean
This paper presents an 8-yr (1999�2006) climatology of the frequency of open-cell convection over the northeastern Pacific Ocean and the thermodynamic and kinematic environment associated with its development. The climatology is based on ...
Todd D. Sikora; George S. Young; Caren M. Fisher; Matthew D. Stepp
Coseismic and Postseismic Deformations Associated With the 1992 Landers, California, Earthquake Measured by Synthetic Aperture Radar Interferometry
iv "Not everything that I do with my roast chicken is necessarily scientific. Many aspects of my method are based on my feeling and experience. For instance, I always give my bird a generous butter massage before I put it in the oven. Why?
Yehuda Bock; J. Bernard Minster; Hubert Staudigel; Evelyn J. Price; Dr. Albert; M. Price; Virginia L. Price; Julia Child
Reservoir monitoring and characterization using satellite geodetic data: Interferometric Synthetic Aperture Radar observations from the Krechba field, Algeria
production and oil-related subsidence: in Tison, L. J. , (Ed. ), Land subsidence, 1 , International Association ofand T. F. Yen, 1994, Subsidence due to ?uid withdrawal:
Vasco, D.W.
Inversion of synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field
Monitoring and modeling land subsidence at the Cerro PrietoH. Vadon (1997), �Land subsidence caused by the East MesaA third potential source of subsidence that we are presently
site and the Okuaizu geothermal field, Japan", Geothermics,at the Cerro Prieto geothermal field, Baja California,and seismicity in the Coso geothermal area, Inyo County,
of a tracer test at Dixie Valley, Nevada�, Proc. 22 ndand footwall faulting at Dixie Valley, Nevada�, Geothermalthe shallow thermal regime at Dixie Valley geothermal field,
Transmission of Megawatt Relativistic Electron Beams Through Millimeter Apertures
High power, relativistic electron beams from energy recovery linacs have great potential to realize new experimental paradigms for pioneering innovation in fundamental and applied research. A major design consideration for this new generation of experimental capabilities is the understanding of the halo associated with these bright, intense beams. In this Letter, we report on measurements performed using the 100 MeV, 430 kWatt CW electron beam from the energy recovery linac at the Jefferson Laboratory's Free Electron Laser facility as it traversed a set of small apertures in a 127 mm long aluminum block. Thermal measurements of the block together with neutron measurements near the beam-target interaction point yielded a consistent understanding of the beam losses. These were determined to be 3 ppm through a 2 mm diameter aperture and were maintained during a 7 hour continuous run.
R. Alarcon; S. Balascuta; S. V. Benson; W. Bertozzi; J. R. Boyce; R. Cowan; D. Douglas; P. Evtushenko; P. Fisher; E. Ihloff; N. Kalantarians; A. Kelleher; R. Legg; R. G. Milner; G. R. Neil; L. Ou; B. Schmookler; C. Tennant; C. Tschalaer; G. P. Williams; S. Zhang
Penning discharge ion source with self-cleaning aperture
An ion source of the Penning discharge type having a self-cleaning aperture is provided by a second dynode with an exit aperture in a position opposite a first dynode, from which the ions are sputtered, two opposing cathodes, each with an anode for accelerating electrons emitted from the cathodes into a cylindrical space defined by the first and second dynode. A support gas maintained in this space is ionized by the electrons. While the cathodes are supplied with a negative pulse to emit electrons, the first dynode is supplied with a negative pulse (e.g., -300 V) to attract atoms of the ionized gas (plasma). At the same time, the second dynode may also be supplied with a small voltage that is negative with respect to the plasma (e.g., -5 V) for tuning the position of the plasma miniscus for optimum extraction geometry. When the negative pulse to the first dynode is terminated, the second dynode is driven strongly negative (e.g., -600 V) thereby allowing heavy sputtering to take place for a short period to remove virtually all of the atoms deposited on the second dynode from material sputtered off the first dynode. An extractor immediately outside the exit aperture of the second dynode is maintained at ground potential while the anode, dynode, and cathode reference voltage is driven strongly positive (about +20 kV to +30 kV) so that ions accelerated through the aperture will be at ground potential. Material from the first dynode deposited on the second dynode will be sputtered, in time, to add to the ion beam.
Gavin, B.F.; MacGill, R.A.; Thatcher, R.K.
An ion source of the Penning discharge type having a self-cleaning aperture is provided by a second dynode (24) with an exit aperture (12) in a position opposite a first dynode 10a, from which the ions are sputtered, two opposing cathodes (14, 16), each with an anode (18, 20) for accelerating electrons emitted from the cathodes into a cylindrical space defined by the first and second dynode. A support gas maintained in this space is ionized by the electrons. While the cathodes are supplied with a negative pulse to emit electrons, the first dynode is supplied with a negative pulse (e.g., -300 V) to attract atoms of the ionized gas (plasma). At the same time, the second dynode may also be supplied with a small voltage that is negative with respect to the plasma (e.g., -5 V) for tuning the position of the plasma miniscus for optimum extraction geometry. When the negative pulse to the first dynode is terminated, the second dynode is driven strongly negative (e.g., -600 V) thereby allowing heavy sputtering to take place for a short period to remove virtually all of the atoms deposited on the second dynode from material sputtered off the first dynode. An extractor (22) immediately outside the exit aperture of the second dynode is maintained at ground potential during this entire period of sputtering while the anode, dynode and cathode reference voltage is driven strongly positive (about +20 kV to +30 kV) so that ions accelerated through the aperture will be at ground potential. In that manner, material from the first dynode deposited on the second dynode will be sputtered, in time, to add to the ion beam. Atoms sputtered from the second dynode which do not become ionized and exit through the slit will be redeposited on the first dynode, and hence recycled for further ion beam generation during subsequent operating cycles.
Gavin, Basil F. (Berkeley, CA); MacGill, Robert A. (Richmond, CA); Thatcher, Raymond K. (El Cerrito, CA)
Alignment and Aperture Scan at the Fermilab Booster
The Fermilab Booster is currently in the process of an intensity upgrade referred to as the Proton Improvement Plan (PIP). The goal of PIP is to have the Booster provide a proton beam flux of 2 x 10{sup 17} protons/hour. This is almost double the current operation of 1.1 x 10{sup 17} protons/hour. Beam losses in the machine due to the increased flux will create larger integrated doses on aperture limiting components that will need to be mitigated. The Booster accelerates beam from 400 MeV to 8 GeV at a rep rate of 15hz and then extracts beam to the Main Injector. Several percent of the beam is lost within 3 msec after injection in the early part of acceleration. The aperture at injection energy was recently measured using corrector scans. Along with magnet survey data and aperture scan data a plan to realign the magnets in the Booster was developed and implemented in May 2012. The beam studies, analysis of the scan and alignment data, and the result of the magnet moves are presented.
Seiya, K.; Lackey, J.; Marsh, W.; Pellico, W.; Still, D.; Triplet, K.; Waller, A.; /Fermilab
Using doppler radar images to estimate aircraft navigational heading error
A yaw angle error of a motion measurement system carried on an aircraft for navigation is estimated from Doppler radar images captured using the aircraft. At least two radar pulses aimed at respectively different physical locations in a targeted area are transmitted from a radar antenna carried on the aircraft. At least two Doppler radar images that respectively correspond to the at least two transmitted radar pulses are produced. These images are used to produce an estimate of the yaw angle error.
Doerry, Armin W. (Albuquerque, NM); Jordan, Jay D. (Albuquerque, NM); Kim, Theodore J. (Albuquerque, NM)
DOE/SC-ARM-12-009 ARM Radar Organization JW Voyles
Bharadwaj Radar Calibration Plan, controlled document Nitin Bharadwaj Instrument Handbooks, controlled documents Kevin Widener Radar status and information: www.radar.arm.gov...
Virtual CSU-CHILL Radar: The VCHILL
The Virtual CHILL (VCHILL) system makes it possible to transfer the educational and research experience of the Colorado State University dual polarization radar to remote locations over the Internet. The VCHILL operation includes remote control ...
V. Chandrasekar; Yoong-Goog Cho; D. Brunkow; A. Jayasumana
Mean Radar Echo Characteristics during Project GALE
The mean radar echo characteristics during the Genesis of Atlantic Lows Experiment (GALE) are presented for the southeastern United States during the 15 January�15 March 1986 field phase of the program. The echo characteristics were derived from ...
Thomas J. Trunk; Lance F. Bosart
Multiple-Doppler Radar Network Design
Observing programs utilizing Doppler radar must have them deployed in optimum locations to best satisfy experimental objectives and maximize economies. One wishes to determine the coordinate triples (xi, yi, zi), where i equals the number of ...
Peter S. Ray; Karen L. Sangren
On the Sensitivity of Weather Radars
This paper discusses the subject of weather radar system sensitivity from a general point of view, with emphasis an the influence of wavelength. Expressions for the echo signal-to-noise ratio are examined using a detection theory approach to ...
Paul L. Smith
Radar Backscattering by Inhomogeneous Precipitation Particles
Calculations of radar backscattering by inhomogeneous precipitation particles require values of the dielectric function of two-component mixtures. Four such dielectric functions are critically examined and their relative merits are weighed. ...
Craig F. Bohren; Louis J. Battan
Radar and Radiation Properties of Ice Clouds
The authors derive relations of the equivalent radar reflectivity Ze and extinction coefficient ? of ice clouds and confirm the theory by in situ aircraft observations during the First International Satellite Cloud Climatology Project Regional ...
David Atlas; Sergey Y. Matrosov; Andrew J. Heymsfield; Ming-Dah Chou; David B. Wolff
Radar Observations of a Major Industrial Fire
On 23 May 1996, a Montreal suburban paint factory containing several hundred thousand gallons of paints, solvents, and other chemicals burned to the ground in a spectacular fire. The smoke plume from the fire was readily detected by three radars ...
R. R. Rogers; W. O. J. Brown
Geostationary Doppler Radar and Tropical Cyclone Surveillance
The potential usefulness of spaceborne Doppler radar as a tropical cyclone observing tool is assessed by conducting a high-resolution simulation of an intense hurricane and generating synthetic observations of reflectivity and radial velocity. The ...
William E. Lewis; Eastwood Im; Simone Tanelli; Ziad Haddad; Gregory J. Tripoli; Eric A. Smith
Optimization of Multiparameter Radar Estimates of Rainfall
The estimates of rainfall rate derived from a multiparameter radar based on reflectivity factor (RZH), differential reflectivity (RDR), and specific differential propagation phase (RDP) have widely varying accuracies over the dynamic range of the ...
V. Chandrasekar; Eugenio Gorgucci; Gianfranco Scarchilli
Mapping of Airborne Doppler Radar Data
Two sets of equations are derived to 1) map airborne Doppler radar data from an aircraft-relative coordinate system to an earth-relative coordinate system, and 2) remove the platform motion from the observed Doppler velocities. These equations ...
Wen-Chau Lee; Peter Dodge; Frank D. Marks Jr.; Peter H. Hildebrand
Radar System Errors in Polarization Diversity Measurements
The measurement capability of a polarization diversity radar is limited by several characteristics of the system and particularly by the performance of the antenna, which is characterized by the integrated cancellation ratio or integrated cross-...
James I. Metcalf; James S. Ussailis
Ground Penetrating Imaging Radar Phase II
EPRI project "Ground Penetrating Imaging Radar Phase II," also called the "GPiR Project," started in August 1998 at Schlumberger-Doll Research, a division of Schlumberger Technology Corporation. Its goal was to determine if modern ground-penetrating radar (GPR) could make three-dimensional (3D) images of buried utility lines accurate and detailed enough to help utility companies better manage their underground infrastructure. Work began with a comparison of commercial and prototype GPR systems in the lab...
Use of the CSU�CHILL Radar in Radar Meteorology Education at Colorado State University
A recent example illustrating the use of the CSU�CHILL Doppler radar in a graduate-level course in radar meteorology at Colorado State University (CSU) is described. In addition to providing students in the Department of Atmospheric Science with �...
Steven A. Rutledge; Patrick C. Kennedy; David A. Brunkow
Nonuniform Beamfilling Correction for Spaceborne Radar Rainfall Measurement: Implications from TOGA COARE Radar Data Analysis
A method is studied to make a nonuniform beamfilling (NUBF) correction for the path-integrated attenuation (PIA) derived from spaceborne radar measurement. The key of this method is to estimate rain-rate variability within a radar field of view ...
Toshiaki Kozu; Toshio Iguchi
Integration of InSAR and GIS in the Study of Surface Faults Caused by Subsidence-Creep-Fault Processes in Celaya, Guanajuato, Mexico
In Celaya city, Subsidence-Creep-Fault Processes (SCFP) began to become visible at the beginning of the 1980s with the sprouting of the crackings that gave rise to the surface faults 'Oriente' and 'Poniente'. At the present time, the city is being affected by five surface faults that display a preferential NNW-SSE direction, parallel to the regional faulting system 'Taxco-San Miguel de Allende'. In order to study the SCFP in the city, the first step was to obtain a map of surface faults, by integrating in a GIS field survey and an urban city plan. The following step was to create a map of the current phreatic level decline in city with the information of deep wells and using the 'kriging' method in order to obtain a continuous surface. Finally the interferograms maps resulted of an InSAR analysis of 9 SAR images covering the time interval between July 12 of 2003 and May 27 of 2006 were integrated to a GIS. All the maps generated, show how the surface faults divide the city from North to South, in two zones that behave in a different way. The difference of the phreatic level decline between these two zones is 60 m; and the InSAR study revealed that the Western zone practically remains stable, while sinkings between the surface faults 'Oriente' and 'Universidad Pedagogica' are present, as well as in portions NE and SE of the city, all of these sinkings between 7 and 10 cm/year.
Avila-Olivera, Jorge A. [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, C.U., 04510 Mexico D.F. (Mexico); Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, C.U., 58030 Morelia, Michoacan (Mexico); Farina, Paolo [Dipartimento di Scienze della Terra, Universita degli Studi di Firenze, Via G. La Pira 4, 50121 Firenze (Italy); Garduno-Monroy, Victor H. [Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, C.U., 58030 Morelia, Michoacan (Mexico)
Strengths and Limitations of Current Radar Systems for Two Stakeholder Groups in the Southern Plains
Advancements in radar technology since the deployment of the Weather Surveillance Radar-1988 Doppler (WSR-88D) network have prompted consideration of radar replacement technologies. In order for the outcomes of advanced radar research and ...
Daphne S. LaDue; Pamela L. Heinselman; Jennifer F. Newman
A Comparison of Tornado Warning Lead Times with and without NEXRAD Doppler Radar
The installation of the network of NEXRAD (Next Generation Weather Radar) WSR-88D (Weather Surveillance Radar�1988 Doppler) radars has been an ongoing process for more than three years. An assessment is made on how these radars and related ...
Paul Bieringer; Peter S. Ray
Spurious Velocities in Doppler Radar Data Caused by a Moving Antenna Feedhorn
Modern Doppler weather radars use clutter filtering to reduce the strength of ground targets and enhance the detection of meteorological echoes. WSR-88D [NEXRAD (Next Generation Radar) and TDWR (Terminal Doppler Weather Radar)] radars, for ...
Ronald E. Rinehart
AUGUST 2008 VOLUME 46 NUMBER 8 IGRSD2 (ISSN 0196-2892) C-band Radarsat-1 InSAR image shows water-level changes over the swamp forest in southeastern Louisiana between May 22 and June 15, 2003.
-level changes of coastal wetlands over southeastern Louisiana. The InSAR image suggests that water-level changes, and other species combine to place the coastal wetlands of Louisiana among the nation's most productive-level changes over the swamp forest in southeastern Louisiana between May 22 and June 15, 2003. In
The purpose of this paper is to present the results of a theoretical study pertaining to the feasibility of Phase Induced Amplitude Apodization (PIAA) units using deformable mirrors (DMs). We begin by reviewing the general derivation of the design equations driving PIAA. We then show how to solve these equations for square apertures and show the performance of pure PIAA systems in the ray optics regime. We tie these design equations into the study of edge diffraction effects and provide a general expression for the field after a full propagation through a PIAA coronagraph. Third, we illustrate how a combination of pre- and post-apodizers yields a contrast of 10{sup -10} even in the presence of diffractive effects, for configuration with neither wavefront errors or wavefront control. Finally, we present novel PIAA configurations over square apertures which circumvent the constraints on the manufacturing of PIAA optics by inducing the apodization with two square DMs. Such solutions rely on pupil size smaller than currently envisioned static PIAA solutions and thus require aggressive pre- and post-apodizing screens in order to mitigate for diffractive effect between the two mirrors. As a result they are associated with significant loss in performance, throughput in particular.
Pueyo, Laurent [Department of Physics and Astronomy, Johns Hopkins University, 366 Bloomberg Center, 3400 N. Charles Street, Baltimore, MD 21218 (United States); Jeremy Kasdin, N.; Carlotti, Alexis [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Vanderbei, Robert, E-mail: email@example.com [Department of Operations Research and Financial Engineering, Princeton University, Princeton, NJ 08544 (United States)
Definition: PSInSAR | Open Energy Information
PSInSAR PSInSAR Jump to: navigation, search Dictionary.png PSInSAR Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) is a remote sensing technique that uses radar signals from a satellite to accurately measure ground displacement. PSInSAR is an improved and more accurate analysis algorithm compared to the InSAR method.[1] Related Terms InSAR References ↑ http://parviztarikhi.files.wordpress.com/2010/05/3psinsar-i-parviz_tarikhi.pdf Ret LikeLike UnlikeLike You like this.Sign Up to see what your friends like. rieved from "http://en.openei.org/w/index.php?title=Definition:PSInSAR&oldid=682952" Category: Definitions What links here Related changes Special pages Printable version Permanent link Browse properties 429 Throttled (bot load) Error 429 Throttled (bot load)
An Integrated Display and Analysis Methodology for Multivariable Radar Data
Polarimetric Doppler radars provide valuable information about the kinematic and microphysical structure of storms. However, in-depth analysis using radar products, such as Doppler-derived wind vectors and hydrometeor identification, has been ...
Brenda A. Dolan; Steven A. Rutledge
An 11-cm Coherent Polarimetric Radar for Meteorological Research
The Geophysics Directorate of the U.S. Air Force developed a unique 11-cm (S-band) coherent polarimetric radar. The radar can transmit signals of alternating orthogonal polarizations, with either circular or linear basis, and receive signals of ...
James I. Metcalf; Alexander W. Bishop; Richard C. Chanley; Timothy C. Hiett; Pio J. Petrocchi
A 94-GHz Doppler Radar for Cloud Observations
A Doppler radar operating at 3.2 mm wavelength was designed and assembled primarily for observation of clouds and precipitation. Phase detection of the radar signals which is required for Doppler operation is implemented through the use of a ...
Roger Lhermitte
Inversion of Marine Radar Images for Surface Wave Analysis
A method to estimate sea surface elevation maps from marine radar image sequences is presented. This method is the extension of an existing inverse modeling technique to derive wave spectra from marine radar images, which assumes linear wave ...
Jos�C. Nieto Borge; Germ�n Rodr�guez Rodr�guez; Katrin Hessner; Paloma Izquierdo Gonz�lez
Simulating Range Oversampled Doppler Radar Profiles of Inhomogeneous Targets
A new technique for generating range oversampled profiles of Doppler radar signals that have been backscattered by distributed targets is presented in this paper. The technique was developed for spaceborne cloud radars, but it can just as well be ...
N. A. J. Schutgens
Dual-Polarization Radar Characteristics of an Apartment Fire
Dual-polarimetric microwave wavelength radar observations of an apartment fire in Huntsville, Alabama, on 3 March 2008 are examined to determine the radar-observable properties of ash and fire debris lofted into the atmosphere. Dual-polarimetric ...
Thomas A. Jones; Sundar A. Christopher; Walt Petersen
Retrieval of Reflectivity in a Networked Radar Environment
A system for reflectivity and attenuation retrieval for rain medium in a networked radar environment is described. Electromagnetic waves backscattered from a common volume in networked radar systems are attenuated differently along the different ...
V. Chandrasekar; S. Lim
Evaluation of a 35 GHz Radar for Cloud Physics Research
A 1960 35 GHz radar has been modernized through the use of solid state electronics, Dopplerization and improved data-display capabilities. Radars of this frequency are particularly useful for observing the internal structures of clouds and for ...
Peter V. Hobbs; Nathan T. Funk; Richard R. Weiss Sr.; John D. Locatelli; Kumud R. Biswas
On the Use of Radars for Operational Wind Profiling
The application of clear-air radars to operational wind profiling is considered. Several alternative techniques for determining atmospheric winds from radars are surveyed and, in light of the current interest in operational applications, the ...
B. B. Balsley; K. S. Gage
95-GHz Polarimetric Radar Measurements of Orographic Cap Clouds
The use of millimeter-wavelength radars for cloud microphysical research was investigated in experiments at the Elk Mountain Observatory near Laramie, Wyoming, between April 1990 and March 1992. The 95-GHz polarimetric radar used in these ...
Andrew Pazmany; James Mead; Robert McIntosh; Mark Hervig; Robert Kelly; Gabor Vali
Factors Affecting the Accuracy of SHOWEX HF Radar Wave Measurements
Ocean Surface Current Radar (OSCR) HF radar measurements of ocean waves and currents were made during the Shoaling Waves Experiment (SHOWEX) in the fall of 1999. During some periods, at some locations, good quality wave measurements were ...
Lucy R. Wyatt; Guennadi Liakhovetski; Hans C. Graber; Brian K. Haus
A Dual-Wavelength Radar Method to Measure Snowfall Rate
A dual-wavelength radar method to estimate snowfall rate has been developed. The method suggests taking simultaneous and collocated reflectivity measurements at two radar wavelengths. Snowfall backscattering at one of these wavelengths should be ...
Sergey Y. Matrosov
International Weather-Radar Networking in Western Europe
During the last few years there has been considerable activity in Western Europe aimed at establishing national radar networks. Concurrent with this work, several bilateral agreements to exchange weather-radar data across national boundaries have ...
C. G. Collier; C. A. Fair; D. H. Newsome
The Effect of Radar Pulse Length on Cloud Reflectivity Statistics
When observing clouds with radars, there are a number of design parameters, such as transmitted power, antenna size, and wavelength, that can affect the detection threshold. In making calculations of radar thresholds, also known as minimum ...
Taneil Uttal; Robert A. Kropfli
A Radar Study of the Plasma and Geometry of Lightning
Radar measurements and model studies are combined to investigate the plasma condition and the physical structure of lightning in thunderclouds. The lightning radar target is inferred to be an arclike plasma whose temperature exceeds 5000 K, ...
Earle R. Williams; Spiros G. Geotis; A. B. Bhattacharya
Heating Profiles Derived From Cm-wavelength Radar During TWP...
Heating Profiles Derived From Cm-wavelength Radar During TWP-ICE Heating Profiles Derived From Cm-wavelength Radar During TWP-ICE Courtney Schumacher and Kaycee Frederick Courtney...
Auxiliary Signal Processing System for a Multiparameter Radar
The design of an auxiliary signal processor for a multiparameter radar is described with emphasis on low cost, quick development, and minimum disruption of radar operations. The processor is based around a low-cost digital signal processor card ...
V. Chandrasekar; G. R. Gray; I. J. Caylor
A radar antenna intercepts thermal radiation from various sources including the ground, the sun, the sky, precipitation and man-made radiators. In the radar receiver, this external radiation produces noise that constructively adds to the receiver ...
Igor R. Ivi?; Christopher Curtis; Sebasti�n M. Torres
Procedures to Improve the Accuracy of Airborne Doppler Radar Data
The navigation correction method proposed in Testud et al. (referred to as the THL method) systematically identifies uncertainties in the aircraft Inertial Navigation System and errors in the radar-pointing angles by analyzing the radar returns ...
Brian L. Bosart; Wen-Chau Lee; Roger M. Wakimoto
Tracking system for photon-counting laser radar
The purpose of this thesis is to build the tracking system for a photon-counting laser radar specifically a laser radar that has the ability to perform direct and coherent detection measurement at low signal levels with ...
Chang, Joshua TsuKang
VHF and UHF Doppler Radars as Tools for Synoptic Research
Applications of VHF and UHF Doppler radars to research in synoptic meteorology are reviewed. We find that these radars show great potential for studies of large scales, but the area of research where the instruments really excel is in studying ...
M. F. Larsen; J. R�ttger
Mean Vertical Motions Seen by Radar Wind Profilers
Radar wind profilers have been used to measure directly the vertical motion above the radar site. Mean values of vertical motions in the troposphere and lower stratosphere reported at sites in and near mountains are often several centimeters per ...
G. D. Nastrom; T. E. VanZandt
A Statistical Approach to Ground Radar-Rainfall Estimation
This paper presents development of a statistical procedure for estimation of ensemble rainfall fields from a combination of ground radar observations and in situ rain gauge measurements. The uncertainty framework characterizes radar-rainfall ...
Alemu Tadesse; Emmanouil N. Anagnostou
Estimation of Atmospheric Duct Structure Using Radar Sea Clutter
Retrieving atmospheric refractivity profiles from the sea surface backscattered radar clutter is known as the refractivity-from-clutter (RFC) technique. Because the relationship between refractivity and radar sea clutter is clearly nonlinear and ...
Zhao Xiaofeng; Huang Sixun
The New French Operational Radar Rainfall Product. Part II: Validation
A new operational radar-based rainfall product has been developed at M�t�o-France and is currently being deployed within the French operational network. The new quantitative precipitation estimation (QPE) product is based entirely on radar data ...
P. Tabary; J. Desplats; K. Do Khac; F. Eideliman; C. Gueguen; J-C. Heinrich
Operational Monitoring of Radar Differential Reflectivity Using the Sun
A method for the daily monitoring of the differential reflectivity bias for polarimetric weather radars is presented. Sun signals detected in polar volume data produced during operational scanning of the radar are used. This method is an ...
Iwan Holleman; Asko Huuskonen; Rashpal Gill; Pierre Tabary
The Rain Profiling Algorithm Applied to Polarimetric Weather Radar
The algorithm developed in this paper for ground-based polarimetric radars is derived from those used for the spaceborne rain radar of TRMM (Tropical Rainfall Measurement Mission)�the so-called rain profiling algorithms. The characteristic of ...
Jacques Testud; Erwan Le Bouar; Estelle Obligis; Mustapha Ali-Mehenni
Beam Multiplexing Using the Phased-Array Weather Radar
The recently installed S-band phased-array radar (PAR) at the National Weather Radar Testbed (NWRT) offers fast and flexible beam steering through electronic beam forming. This capability allows the implementation of a novel scanning strategy ...
Tian-You Yu; Marko B. Orescanin; Christopher D. Curtis; Dusan S. Zrni?; Douglas E. Forsyth
Dual-wavelength polarimetric radar analyses of tornadic debris signatures
Statistical properties of tornado debris signatures (TDSs) are investigated using S- and C-band polarimetric radar data with comparisons to damage surveys and satellite imagery. Close proximity of the radars to the 10 May 2010 Moore-Oklahoma City ...
David J. Bodine; Robert D. Palmer; Guifu Zhang
Weather Radar Polarimetry-Trends Toward Operational Applications
This is a version of a speech presented at the 27th Conference on Radar Meteorology. Relative advantages of polarimetry are contrasted with the advantages accrued by the introduction of radar into meteorology and by the addition of Doppler ...
Du�an S. Zrni?
Coastal Oceanography Applications of Digital Image Data from Marine Radar
A marine radar attached to a digital image capture system has been adapted for deployment from shore sites. Optimum operating parameters have been identified in relation to the resolution and sampling capabilities of both the radar and the ...
I. S. Robinson; N. P. Ward; C. P. Gommenginger; M. A. Tenorio-Gonzales
Gust Front Characteristics as Detected by Doppler Radar
Gust fronts produce low altitude wind shear that can be hazardous to aircraft operations, especially during takeoff and landing. Radar meteorologists have long been able to identify gust front signatures in Doppler radar data, but in order to use ...
Diana L. Klingle; David R. Smith; Marilyn M. Wolfson
Comparison of Dual-Polarization Radar Estimators of Rain
Several polarimetric radar estimators of rain rate R and rainwater content M are examined. The accuracy of the estimators is analyzed using a gamma drop size distribution (DSD) simulation and a radar wavelength of 11 cm. The estimators that use ...
A. V. Ryzhkov; D. S. Zrni?
Radar Observations of the 3 May 1999 Oklahoma City Tornado
The 3 May 1999 Oklahoma City storm is unique from a weather radar perspective because a long-track violent tornado passed within close range of several Doppler radars, because a detailed damage survey was conducted immediately after the event, ...
Donald W. Burgess; Michael A. Magsig; Joshua Wurman; David C. Dowell; Yvette Richardson
Adaptive Range Oversampling to Achieve Faster Scanning on the National Weather Radar Testbed Phased-Array Radar
This paper describes a real-time implementation of adaptive range oversampling processing on the National Weather Radar Testbed phased-array radar. It is demonstrated that, compared to conventional matched-filter processing, range oversampling can ...
Christopher D. Curtis; Sebasti�n M. Torres
Can a VHF Doppler Radar Provide Synoptic Wind Data? A Comparison of 30 Days of Radar and Radiosonde Data
A number of experiments have shown that UHF and VHF Doppler radars can make �clear air� wind measurements in the troposphere and lower stratosphere, even in the presence of clouds and precipitation. Past comparisons of radar and rawinsonde ...
Miguel Folkmar Larsen
Polarization Radar Measurements in Rain at 5 and 9 GHz
There is increased interest in dual-polarization radar measurements at 9 and 5 GHz not only for scientific reasons but also because such radars are less expensive to build and are easier to transport than 3-GHz S-band radars. Unfortunately, ...
A. R. Jameson
The New French Operational Polarimetric Radar Rainfall Rate Product
In 2012 the M�t�o France metropolitan operational radar network consists of 24 radars operating at C and S bands. In addition, a network of four X-band gap-filler radars is being deployed in the French Alps. The network combines polarimetric and ...
Jordi Figueras i Ventura; Pierre Tabary
Quality Assessment of Weather Radar Wind Profiles during Bird Migration
Wind profiles from an operational C-band Doppler radar have been combined with data from a bird tracking radar to assess the wind profile quality during bird migration. The weather radar wind profiles (WRWPs) are retrieved using the well-known ...
Iwan Holleman; Hans van Gasteren; Willem Bouten
Dual-transponder Precision Navigation System for Synthetic Aperture Sonar
The technical details of a dual-transponder, long-baseline positioning system to measure the sway of a free towed Synthetic Aperture Sonar (SAS) are presented. The sway is measured with respect to freely deployed, battery powered, transponders which sit stationary on the seabed connected via cables to floating buoys housing high-accuracy GPS timing receivers. A T/R switch allows a single hydrophone on each transponder to alternately receive and transmit linear FM chirp signals. The time of flight of the signals is determined by matched-filtering using a DSP and transmitted to the towboat for storage in real time using RF modems. The sway information is completely independent for each sonar ping and allows the deblurring of the SAS images by post processing. A Matlab simulation predicts a worst case sway accuracy of cm.
E N Pilbrow; M P Hayes; P T Gough
Trapped Ion Imaging with a High Numerical Aperture Spherical Mirror
Efficient collection and analysis of trapped ion qubit fluorescence is essential for robust qubit state detection in trapped ion quantum computing schemes. We discuss simple techniques of improving photon collection efficiency using high numerical aperture (N.A.) reflective optics. To test these techniques we placed a spherical mirror with an effective N.A. of about 0.9 inside a vacuum chamber in the vicinity of a linear Paul trap. We demonstrate stable and reliable trapping of single barium ions, in excellent agreement with our simulations of the electric field in this setup. While a large N.A. spherical mirror introduces significant spherical aberration, the ion image quality can be greatly improved by a specially designed aspheric corrector lens located outside the vacuum system. Our simulations show that the spherical mirror/corrector design is an easy and cost-effective way to achieve high photon collection rates when compared to a more sophisticated parabolic mirror setup.
G Shu; M R Dietrich; N Kurz; B B Blinov
Shu, G; Kurz, N; Blinov, B B
Design of large aperture, low mass vacuum windows
Large vacuum vessels are employed downstream of fixed targets in High Energy Physics experiments to provide a long path for particles to traverse without interacting with air molecules. These vessels generally have a large aperture opening known as a vacuum window which employs a thin membrane to preserve the vacuum environment yet allows the particles to pass through with a minimal effect on them. Several large windows have been built using a composite of Kevlar/Mylar including circular windows to a diameter of 96.5 cm and rectangular windows up to 193 cm x 86 cm. This paper describes the design, fabrication, testing and operating experience with these windows and relates the actual performance to theoretical predictions.
Leonhardt, W.J.; Mapes, M.
Batch fabrication of cantilever array aperture probes for scanning near-field optical microscopy
We have developed a novel batch fabrication process for cantilever array aperture probes used in scanning near-field optical microscopy (SNOM). The array probes, consisting of 16 parallel cantilevers with each tip having an identical aperture, are proposed ... Keywords: Cantilever probes, Nanofabrication, Scanning near-field optical microscopy (SNOM)
Y. Zhang; K. E. Docherty; J. M. R. Weaver
Effects of Raindrop-Size Distribution Variation within the Radar Scattering Volume on Radar Observables
Dual linear polarization weather radars measure as primary observables the mean power P?H, and P?V, corresponding to returns at horizontal and vertical polarizations, respectively. Differential reflectivity ZDR is defined as the ratio between ...
G. Scarchilli; E. Gorgucci; T. A. Seliga; K. Aydin
Hydraulic transmissivity and heat exchange efficiency of open fractures: a model based on lowpass filtered apertures
Natural open joints in rocks commonly present multi-scale self-affine apertures. This geometrical complexity affects fluid transport and heat exchange between the flow- ing fluid and the surrounding rock. In particular, long range correlations of self-affine apertures induce strong channeling of the flow which influences both mass and heat advection. A key question is to find a geometrical model of the complex aperture that describes at best the macroscopic properties (hydraulic conductivity, heat exchange) with the smallest number of parameters. Solving numerically the Stokes and heat equa- tions with a lubrication approximation, we show that a low pass filtering of the aperture geometry provides efficient estimates of the effective hydraulic and thermal properties (apertures). A detailed study of the influence of the bandwidth of the lowpass filtering on these transport properties is also performed. For instance, keeping the information of amplitude only of the largest Fourier length scales allows us to rea...
Neuville, Am�lie; Schmittbuhl, Jean; 10.1111/j.1365-246X.2011.05126.x
Insects Observed Using Dual-Polarization Radar
Two radars of different characteristics were used on a clear night in early summer to investigate the nature of the clear air echoes. It is deduced that most of the echoes on this evening were due to insects rather than atmospheric turbulence or ...
Eugene A. Mueller; Ronald P. Larkin
A Typhoon Observed with the MU Radar
During the passage of Typhoon 8719 a 60-h continuous observation was made of the troposphere and the lower stratosphere with the MU (middle and upper atmosphere) radar. Height profiles of the wind velocity vector were measured every 2.5 min with ...
Toru Sato; Naoki Ao; Mamoru Yamamoto; Shoichiro Fukao; Toshitaka Tsuda; Susumu Kato
Acoustic Radar Studies of Rain Microphysics
Raindrop size distributions are obtained from the Doppler frequency spectrum of an acoustic radar. Number concentrations of 12 drop diameters with a minimum diameter 0.14 cm are obtained and averaged over 3�15 min at 20-m range gates from 20 to ...
S. G. Bradley
Radar Measurement of Cooling Tower Drift
A method of radar measurement of drift, generated by the wet cooling towers of power plants, is proposed. The water given off by the evaporative towers consists of two kinds of droplets: the recondensation droplets�generally less than 20 ?m in ...
Henri Sauvageot
DOW Radar Observations of Wind Farms
The growth of the wind industry in recent years has motivated investigation into wind farm interference with the operation of the nationwide Weather Surveillance Radar-1988 Doppler (WSR-88D) network. Observations of a wind farm were taken with a Doppler ...
Mallie Toth; Erin Jones; Dustin Pittman; David Solomon
Generating nonlinear FM chirp waveforms for radar.
Nonlinear FM waveforms offer a radar matched filter output with inherently low range sidelobes. This yields a 1-2 dB advantage in Signal-to-Noise Ratio over the output of a Linear FM waveform with equivalent sidelobe filtering. This report presents design and implementation techniques for Nonlinear FM waveforms.
Transmitter passband requirements for imaging radar.
In high-power microwave power amplifiers for radar, distortion in both amplitude and phase should generally be expected. Phase distortions can be readily equalized. Some amplitude distortions are more problematic than others. In general, especially for SAR using LFM chirps, low frequency modulations such as gain slopes can be tolerated much better than multiple cycles of ripple across the passband of the waveform.
Discover the Benefits of Radar Imaging | Open Energy Information
Discover the Benefits of Radar Imaging Discover the Benefits of Radar Imaging Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Discover the Benefits of Radar Imaging Author William V. Parker Published EIJ Earth Imaging Journal, 2012 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Discover the Benefits of Radar Imaging Citation William V. Parker. Discover the Benefits of Radar Imaging [Internet]. 2012. N/A. EIJ Earth Imaging Journal. [updated 2013/09/20;cited 2013/09/20]. Available from: http://eijournal.com/2012/discover-the-benefits-of-radar-imaging GEOTHERMAL ENERGYGeothermal Home Web Site: Discover the Benefits of Radar imaging Details Abstract: Unavailable Author(s): William V. Parker Published: EIJ Earth Imaging Journal, 2012
Radar interferometry for monitoring land subsidence and coastal change in the Nile Delta, Egypt
Land subsidence and coastal erosion are worldwide problems, particularly in densely populated deltas. The Nile Delta is no exception. Currently, it is undergoing land subsidence and is simultaneously experiencing retreat of its coastline. The impacts of these long-term interrelated geomorphic problems are heightened by the economic, social and historical importance of the delta to Egypt. Unfortunately, the current measures of the rates of subsidence and coastal erosion in the delta are rough estimates at best. Sustainable development of the delta requires accurate and detailed spatial and temporal measures of subsidence and coastal retreat rates. Radar interferometry is a unique remote sensing approach that can be used to map topography with 1 m vertical accuracy and measure surface deformation with 1 mm level accuracy. Radar interferometry has been employed in this dissertation to measure urban subsidence and coastal change in the Nile Delta. Synthetic Aperture Radar (SAR) data of 5.66 cm wavelength acquired by the European Radar Satellites (ERS-1 and ERS- 2) spanning eight years (1993-2000) have been used in this investigation. The ERS data have been selected because the spatial and temporal coverage, as well as the short wavelength, are appropriate to measure the slow rate of subsidence in the delta. The ERS tandem coherence images are also appropriate for coastal change detection. The magnitude and pattern of subsidence are detected and measured using Permanent Scatterer interferometry. The measured rates of subsidence in greater Cairo, Mansura, and Mahala are 7, 9, and 5 mm yr-1, respectively. Areas of erosion and accretion in the eastern side of the delta are detected using the ERS tandem coherence and the ERS amplitude images. The average measured rates of erosion and accretion are -9.57 and +5.44 m yr-1, respectively. These measured rates pose an urgent need of regular monitoring of subsidence and coastline retreat in the delta. This study highlighted the feasibility of applying Permanent Scatterer interferometry in inappropriate environment for conventional SAR interferometry. The study addressed possibilities and limitations for successful use of SAR interferometry within the densely vegetated delta and introduced alternative strategies for further improvement of SAR interferometric measurements in the delta.
Aly, Mohamed Hassan
Aperture-Tolerant, Chemical-Based Methods to Reduce Channeling
This final technical progress report describes work performed from October 1, 2004, through May 16, 2007, for the project, 'Aperture-Tolerant, Chemical-Based Methods to Reduce Channeling'. We explored the potential of pore-filling gels for reducing excess water production from both fractured and unfractured production wells. Several gel formulations were identified that met the requirements--i.e., providing water residual resistance factors greater than 2,000 and ultimate oil residual resistance factors (F{sub rro}) of 2 or less. Significant oil throughput was required to achieve low F{sub rro} values, suggesting that gelant penetration into porous rock must be small (a few feet or less) for existing pore-filling gels to provide effective disproportionate permeability reduction. Compared with adsorbed polymers and weak gels, strong pore-filling gels can provide greater reliability and behavior that is insensitive to the initial rock permeability. Guidance is provided on where relative-permeability-modification/disproportionate-permeability-reduction treatments can be successfully applied for use in either oil or gas production wells. When properly designed and executed, these treatments can be successfully applied to a limited range of oilfield excessive-water-production problems. We examined whether gel rheology can explain behavior during extrusion through fractures. The rheology behavior of the gels tested showed a strong parallel to the results obtained from previous gel extrusion experiments. However, for a given aperture (fracture width or plate-plate separation), the pressure gradients measured during the gel extrusion experiments were much higher than anticipated from rheology measurements. Extensive experiments established that wall slip and first normal stress difference were not responsible for the pressure gradient discrepancy. To explain the discrepancy, we noted that the aperture for gel flow (for mobile gel wormholing through concentrated immobile gel within the fracture) was much narrower than the width of the fracture. The potential of various approaches were investigated for improving sweep in parts of the Daqing Oil Field that have been EOR targets. Possibilities included (1) gel treatments that are directed at channeling through fractures, (2) colloidal dispersion gels, (3) reduced polymer degradation, (4) more viscous polymer solutions, and (5) foams and other methods. Fractures were present in a number of Daqing wells (both injectors and producers). Because the fractures were narrow far from the wellbore, severe channeling did not occur. On the contrary, fractures near the wellbore aided reservoir sweep. In the February 2006 issue of the Journal of Petroleum Technology, a 'Distinguished-Author-Series' paper claimed that a process using aqueous colloidal dispersion gels (CDG gels) performed superior to polymer flooding. Unfortunately, this claim is misleading and generally incorrect. Colloidal dispersion gels, in their present state of technological development, should not be advocated as an improvement to, or substitute for, polymer flooding.
Randall S. Seright
LAGOVirtual: A Collaborative Environment for the Large Aperture GRB Observatory
We present the LAGOVirtual Project: an ongoing project to develop platform to collaborate in the Large Aperture GRB Observatory (LAGO). This continental-wide observatory is devised to detect high energy (around 100 GeV) component of Gamma Ray Bursts, by using the single particle technique in arrays of Water Cherenkov Detectors (WCD) at high mountain sites (Chacaltaya, Bolivia, 5300 m a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m a.s.l). This platform will allow LAGO collaboration to share data, and computer resources through its different sites. This environment has the possibility to generate synthetic data by simulating the showers through AIRES application and to store/preserve distributed data files collected by the WCD at the LAGO sites. The present article concerns the implementation of a prototype of LAGO-DR adapting DSpace, with a hierarchical structure (i.e. country, institution, followed by collections that contain the metadata and data files), for the captured/simulated data. This structure was generated by using the community, sub-community, collection, item model; available at the DSpace software. Each member institution-country of the project has the appropriate permissions on the system to publish information (descriptive metadata and associated data files). The platform can also associate multiple files to each item of data (data from the instruments, graphics, postprocessed-data, etc.).
R. Camacho; R. Chacon; G. Diaz; C. Guada; V. Hamar; H. Hoeger; A. Melfo; L. A. Nunez; Y. Perez; C. Quintero; M. Rosales; R. Torrens; the LAGO Collaboration
We present the LAGOVirtual Project: an ongoing project to develop platform to collaborate in the Large Aperture GRB Observatory (LAGO). This continental-wide observatory is devised to detect high energy (around 100 GeV) component of Gamma Ray Bursts, by using the single particle technique in arrays of Water Cherenkov Detectors (WCD) at high mountain sites (Chacaltaya, Bolivia, 5300 m a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m a.s.l). This platform will allow LAGO collaboration to share data, and computer resources through its different sites. This environment has the possibility to generate synthetic data by simulating the showers through AIRES application and to store/preserve distributed data files collected by the WCD at the LAGO sites. The present article concerns the implementation of a prototype of LAGO-DR adapting DSpace, with a hierarchical structure (i.e. country, institution, followed by collections that contain the metadata and data files), for the captured/simulate...
Camacho, R; Diaz, G; Guada, C; Hamar, V; Hoeger, H; Melfo, A; Nunez, L A; Perez, Y; Quintero, C; Rosales, M; Torrens, R
Comments on momentum aperture of 100 GeV/n Au runs in RHIC
In RHIC 2010 100 GeV/n Au run, the momentum aperture has been an issue in the re-bucketing and the beam intensity lifetime in store. Both Blue and Yellow beams with comparable storage RF voltage and peak current have suffered more beam loss than in Run 2007. In this note, some comments are made for the momentum aperture of the lattices used from the Au runs in 2007, 2008 and 2010. From the wigglings and the beam decays of each lattice, information regarding the machine momentum aperture is presented. Several directions in further improvement are discussed.
Zhang, S.Y.
Development of a Drillrod/Telemetry Radar
Efficient extraction of deeply buried natural resources is dependent upon accurate geologic models. The model becomes the basis for developing plans for extraction of the resource. Geoscientists working in geothermal and hydrocarbon recovery have a great deal in common with fellow geoscientists working in the mining industry. They appreciate the intractable problem of increasing the depth of investigation to tens of meters from the wellbore. The goal of this project was to develop a borehole radar tool to acquire data within tens of meters from the wellbore. For geothermal and hydrocarbon applications, the tool was to acquire data for mapping fractures surrounding the wellbore. In mining of coal, the radar acquires data for determining coal seam thickness and detecting geologic anomalies ahead of mining.
Raton Technology Research, Inc.
ARM - Field Campaign - 2001 Multi-Frequency Radar IOP
govCampaigns2001 Multi-Frequency Radar IOP govCampaigns2001 Multi-Frequency Radar IOP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : 2001 Multi-Frequency Radar IOP 2001.03.01 - 2001.09.30 Lead Scientist : Stephen Sekelsky Data Availability http://abyss.ecs.umass.edu For data sets, see below. Summary Install UMass and NOAA Aeronomy Laboratory "guest instrument" radars at the SGP CART site adjacent to the MMCR system. Both the UMass and NOAA Aeronomy Laboratory systems will run autonomously for approximately a six month period. Description Scientific hypothesis: A. Measurements from the University of Massachusetts (UMass) Cloud Profiling Radar System (CPRS) - 95/33 GHz Radar indicate that the 95 GHz channel is much less sensitive to insect clutter than the 35 GHz channel by
Iterative aperture mask design in phase space using a rank constraint
We present an iterative camera aperture design procedure, which determines an optimal mask pattern based on a sparse set of desired intensity distributions at different focal depths. This iterative method uses the ambiguity ...
Horstmeyer, Roarke William
Design of a neutron penumbral-aperture microscope with 10-. mu. m resolution
We are currently designing a 10-{mu}m resolution neutron penumbral-aperture microscope to diagnose high-convergence targets at the Nova laser facility. To achieve such high resolution, the new microscope will require substantial improvements in three areas. First, we have designed thick penumbral apertures with extremely sharp cutoffs over a useful ({approx}100 {mu}m) field of view; fabrication of such apertures appears feasible using gold electroplating techniques. Second, the limited field of view and required close proximity of the aperture to the target (2 cm) necessitates a durable mounting and alignment system with {plus}25 {mu}m accuracy. Finally, a neutron detector containing 160,000 scintillator elements is required; readout and optimization of this large array are outstanding issues. 5 refs., 3 figs.
Ress, D.; Lerche, R.A.; Ellis, R.J.; Lane, S.M.
Vertical Velocity and Buoyancy Characteristics of Coherent Echo Plumes in the Convective Boundary Layer, Detected by a Profiling Airborne Radar
Aircraft and airborne millimeter-wave radar observations are used to interpret the dynamics of radar echoes and radar-inferred updrafts within the well-developed, weakly sheared continental convective boundary layer. Vertically pointing radar ...
Qun Miao; Bart Geerts; Margaret LeMone
Scale Dependence of Radar Rainfall Uncertainty: Initial Evaluation of NEXRAD�s New Super-Resolution Data for Hydrologic Applications
This study explores the scale effects of radar rainfall accumulation fields generated using the new super-resolution level II radar reflectivity data acquired by the Next Generation Weather Radar (NEXRAD) network of the Weather Surveillance Radar-...
Bong-Chul Seo; Witold F. Krajewski
An Evaluation of a 94-GHz Radar for Remote Sensing of Cloud Properties
The performance of a 94-GHz radar is evaluated for a variety of cloud conditions. Descriptions of the radar hardware, signal processing, and calibration provide an overview of the radar's capabilities. An important component of the signal ...
E. E. Clothiaux; M. A. Miller; B. A. Albrecht; T. P. Ackerman; J. Verlinde; D. M. Babb; R. M. Peters; W. J. Syrett
Relationship between Radar-Estimated Precipitation and Synoptic Weather Patterns in the European Alps
A 9-yr (2000�08) analysis of precipitation characteristics for the central and western European Alps has been generated from ground-based operational weather radar data provided by the Swiss radar network. The radar-based precipitation analysis ...
James V. Rudolph; Katja Friedrich; Urs Germann
An Early Performance Evaluation of the NEXRAD Dual Polarization Radar Rainfall Estimates for Urban Flood Applications
Dual polarization radars are expected to provide better rainfall estimates than single polarization radars due to their ability to characterize hydrometeor type. The goal of this study is to evaluate single and dual polarization radar rainfall ...
Luciana K. Cunha; James A. Smith; Mary Lynn Baeck; Witold F. Krajewski
Estimating Rainfall Intensities from Weather Radar Data: The Scale-Dependency Problem
Meteorological radar is a remote sensing system that provides rainfall estimations at high spatial and temporal resolutions. The radar-based rainfall intensities (R) are calculated from the observed radar reflectivities (Z). Often, rain gauge ...
Efrat Morin; Witold F. Krajewski; David C. Goodrich; Xiaogang Gao; Soroosh Sorooshian
Hail Detection Using S- and C-Band Radar Reflectivity Difference
In reflectivity fields observed with conventional radar networks, hailstorm identification is not easy. In the present paper, a hailstorm detection method using two single-wavelength radars located far from each other is discussed. The two radars,...
Laurent F�ral; Henri Sauvageot; Serge Soula
Eddy Dissipation Rates in Thunderstorms Estimated by Doppler Radar in Relation to Aircraft In Situ Measurements
High-resolution aircraft turbulence measurements, well coordinated with radar Doppler spectral width measurements, have been used to verify radar-estimated energy dissipation rates within thunderstorms anvils. The radar-estimated eddy dissipation ...
Peter Meischner; Robert Baumann; Hartmut H�ller; Thomas Jank
A Solo-based automated quality control algorithm for airborne tail Doppler radar data
An automated quality control pre-processing algorithm for removing non-weather radar echoes in airborne Doppler radar data has been developed. This algorithm can significantly reduce the time and experience level required for interactive radar ...
Michael M. Bell; Wen-Chau Lee; Cory A. Wolff; Huaqing Cai
An Experimental Study of Small-Scale Variability of Radar Reflectivity Using Disdrometer Observations
Analysis of data collected by four disdrometers deployed in a 1-km2 area is presented with the intent of quantifying the spatial variability of radar reflectivity at small spatial scales. Spatial variability of radar reflectivity within the radar ...
Benjamin J. Miriovsky; A. Allen Bradley; William E. Eichinger; Witold F. Krajewski; Anton Kruger; Brian R. Nelson; Jean-Dominique Creutin; Jean-Marc Lapetite; Gyu Won Lee; Isztar Zawadzki; Fred L. Ogden
Effects of Radar Sampling on Single-Doppler Velocity Signatures of Mesocyclones and Tornadoes
Simulated WSR-88D (Weather Surveillance Radar-1988 Doppler) radar data were used to investigate the effects of discrete azimuthal sampling on Doppler velocity signatures of modeled mesocyclones and tornadoes at various ranges from the radar and ...
Vincent T. Wood; Rodger A. Brown
Boll�ne-2002 Experiment: Radar Quantitative Precipitation Estimation in the C�vennes�Vivarais Region, France
The Boll�ne-2002 Experiment was aimed at developing the use of a radar volume-scanning strategy for conducting radar rainfall estimations in the mountainous regions of France. A developmental radar processing system, called Traitements ...
Guy Delrieu; Brice Boudevillain; John Nicol; Beno�t Chapon; Pierre-Emmanuel Kirstetter; Herv� Andrieu; D. Faure
The Kinetic Energy of Hailfalls. Part IV: Patterns of Hailpad and Radar Data
Ground-and radar-measured patterns of hail kinetic energy from eight hailstorms have been compared. The radar patterns were shifted horizontally in such a way that the correlation coefficient between the ground and radar data reaches a maximum. ...
W. Schmid; H. H. Schiesser; A. Waldvogel
Ka-Band ARM Zenith Radar (KAZR) Instrument Handbook
The Ka-band ARM zenith radar (KAZR) is a zenith-pointing Doppler cloud radar operating at approximately 35 GHz. The KAZR is an evolutionary follow-on radar to ARM's widely successful millimeter-wavelength cloud radar (MMCR). The main purpose of the KAZR is to provide vertical profiles of clouds by measuring the first three Doppler moments: reflectivity, radial Doppler velocity, and spectra width. At the sites where the dual-polarization measurements are made, the Doppler moments for the cross-polarization channel are also available. In addition to the moments, velocity spectra are also continuously recorded for each range gate.
Argonne radar meteorologist Scott Collis named one of Popular...
Physical Sciences from the Australian National University in 2007. Click to enlarge. Argonne radar meteorologist Scott Collis named one of Popular Science's 'Brilliant 10' By...
Forthcoming Upgrades to the ARM MMCRs: Improved Radar Processor...
Improved Radar Processor and Dual-Polarization K. P. Moran, B. E. Martner, and K. A. Clark National Oceanic and Atmospheric Administration Environmental Technology Laboratory...
LCLS X-ray mirror measurements using a large aperture visible light interferometer
Synchrotron or FEL X-ray mirrors are required to deliver an X-ray beam from its source to an experiment location, without contributing significantly to wave front distortion. Accurate mirror figure measurements are required prior to installation to meet this intent. This paper describes how a 300 mm aperture phasing interferometer was calibrated to LCLS) at Stanford Linear Accelerator Center. Measuring focus mirrors with an interferometer requires additional calibration, because high fringe density introduces systematic errors from the interferometer's imaging optics. This paper describes how these errors can be measured and corrected. The calibration approaches described here apply equally well to interferometers larger than 300 mm aperture, which are becoming more common in optics laboratories. The objective of this effort was to install LCLS flats with < 10 nm of spherical curvature, and < 2 nm rms a-sphere. The objective was met by measuring the mirrors after fabrication, coating and mounting, using a 300 mm aperture phasing interferometer calibrated to an accuracy < 1 nm. The key to calibrating the interferometer accurately was to sample the error using independent geometries that are available. The results of those measurements helped identify and reduce calibration error sources. The approach used to measure flats applies equally well to focus mirrors, provided an additional calibration is performed to measure the error introduced by fringe density. This calibration has been performed on the 300 mm aperture interferometer, and the measurement correction was evaluated for a typical focus mirror. The 300 mm aperture limitation requires stitching figure measurements together for many X-ray mirrors of interest, introducing another possible error source. Stitching is eliminated by applying the calibrations described above to larger aperture instruments. The authors are presently extending this work to a 600 mm instrument. Instruments with 900 mm aperture are now becoming available, which would accommodate the largest mirrors of interest.
McCarville, T; Soufli, R; Pivovaroff, M
Wideband Waveform Design Principles for Solid-State Weather Radars
The use of solid-state transmitters is becoming increasingly viable for atmospheric radars and is a key part of the strategy to realize any dense network of low-powered radars. However, solid-state transmitters have low peak powers and this ...
Nitin Bharadwaj; V. Chandrasekar
Detailed Observations of Wind Turbine Clutter with Scanning Weather Radars
The wind power industry has seen tremendous growth over the past decade and with it has come the need for clutter mitigation techniques for nearby radar systems. Wind turbines can impart upon these radars a unique type of interference that is not ...
B. M. Isom; R. D. Palmer; G. S. Secrest; R. D. Rhoton; D. Saxion; T. L. Allmon; J. Reed; T. Crum; R. Vogt
The Distribution of Rainfall over Oceans from Spaceborne Radars
A combination of rainfall estimates from the 13.8-GHz Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and the 94-GHz CloudSat Cloud Profiling Radar (CPR) is used to assess the distribution of rainfall intensity over tropical ...
Wesley Berg; Tristan L�Ecuyer; John M. Haynes
A 35-GHz Scanning Doppler Radar for Fog Observations
To observe fog, a 35-GHz scanning Doppler radar was designed, assembled, and tested. The radar, mounted on a flatbed vehicle for portability, transmits peak powers of 100 kW in a pulse of 0.5-�s width and a beamwidth of 0.3�. Thus, a reflectivity ...
Kyosuke Hamazu; Hiroyuki Hashiguchi; Toshio Wakayama; Tomoya Matsuda; Richard J. Doviak; Shoichiro Fukao
Radar Nowcasting of Total Lightning over the Kennedy Space Center
A long-term radar dataset over Melbourne, Florida, was matched with three-dimensional lightning data to optimize radar-derived predictors of total lightning over the Kennedy Space Center (KSC). Four years (2006�09) of summer (June�August) daytime (...
Gregory N. Seroka; Richard E. Orville; Courtney Schumacher
Subglacial water presence classification from polar radar data
Ground and airborne radar depth-sounding of the Greenland and Antarctic ice sheets have been used for many years to remotely determine characteristics such as ice thickness, subglacial topography, and mass balance of large bodies of ice. Ice coring efforts ... Keywords: Ensemble classification, Machine learning, Pattern recognition, Radar remote sensing, Subglacial water
Christopher M. Gifford; Arvin Agah
A Description of the CSU�CHILL National Radar Facility
The subject of this paper is the Colorado State University�University of Chicago�Illinois State Water Survey (CSU�CHILL) National Radar Facility�s S-band polarimetric research radar. Key features of this system include polarization agility (...
David Brunkow; V. N. Bringi; Patrick C. Kennedy; Steven A. Rutledge; V. Chandrasekar; E. A. Mueller; Robert K. Bowie
Climatology of Anomalous Propagation Radar Echoes in a Coastal Area
Anomalous propagation (AP) of ground-based radar beam results in the detection of ground echoes beyond the horizon. One year of data gathered with an S-band meteorological radar located on the coast in southwest France is used to analyze the ...
Fr�d�ric Mesnard; Henri Sauvageot
A Robust Dual-Frequency Radar Profiling Algorithm
In this study, an algorithm to retrieve precipitation from spaceborne dual-frequency (13.8 and 35.6 GHz, or Ku/Ka band) radar observations is formulated and investigated. Such algorithms will be of paramount importance in deriving radar-based and ...
Mircea Grecu; Lin Tian; William S. Olson; Simone Tanelli
Radio Acoustic Sounding with a UHF Volume Imaging Radar
An implementation of a radio acoustic sounding system (RASS) using a UHF volume imaging radar is presented. The volume-imaging ability of the radar permits the study the spatial structure of the RASS echo observing both the diffraction pattern on ...
Paco L�pez Dekker; Stephen J. Frasier
Ultrawideband radar clutter measurements of forested terrain, 1991--1992
The ultrawideband (UWB) radar clutter measurements project was conducted to provide radar clutter data for new ultrawideband radar systems which are currently under development. A particular goal of this project is to determine if conventional narrow band clutter data may be extrapolated to the UWB case. This report documents measurements conducted in 1991 and additional measurements conducted in 1992. The original project consisted of clutter measurements of forested terrain in the Olympic National Forest near Sequim, WA. The impulse radar system used a 30 kW peak impulse source with a 2 Gigasample/second digitizer to form a UHF (300--1000 MHz) ultrawideband impulse radar system. Additional measurements were conducted in parallel using a Systems Planning Corporation (SPC) step-chirp radar system. This system utilized pulse widths of 1330 nanoseconds over a bandwidth of 300--1000 MHz to obtain similar resolution to the impulse system. Due to the slow digitizer data throughput in the impulse radar system, data collection rates were significantly higher using the step-chirp system. Additional forest clutter measurements were undertaken in 1992 to increase the amount of data available, and especially to increase the amount of data from the impulse radar system.
Sheen, D.M.; Severtsen, R.H.; Prince, J.M.; Davis, K.C.; Collins, H.D.
Radar-cross-section reduction of wind turbines. part 1.
In recent years, increasing deployment of large wind-turbine farms has become an issue of growing concern for the radar community. The large radar cross section (RCS) presented by wind turbines interferes with radar operation, and the Doppler shift caused by blade rotation causes problems identifying and tracking moving targets. Each new wind-turbine farm installation must be carefully evaluated for potential disruption of radar operation for air defense, air traffic control, weather sensing, and other applications. Several approaches currently exist to minimize conflict between wind-turbine farms and radar installations, including procedural adjustments, radar upgrades, and proper choice of low-impact wind-farm sites, but each has problems with limited effectiveness or prohibitive cost. An alternative approach, heretofore not technically feasible, is to reduce the RCS of wind turbines to the extent that they can be installed near existing radar installations. This report summarizes efforts to reduce wind-turbine RCS, with a particular emphasis on the blades. The report begins with a survey of the wind-turbine RCS-reduction literature to establish a baseline for comparison. The following topics are then addressed: electromagnetic model development and validation, novel material development, integration into wind-turbine fabrication processes, integrated-absorber design, and wind-turbine RCS modeling. Related topics of interest, including alternative mitigation techniques (procedural, at-the-radar, etc.), an introduction to RCS and electromagnetic scattering, and RCS-reduction modeling techniques, can be found in a previous report.
Brock, Billy C.; Loui, Hung; McDonald, Jacob J.; Paquette, Joshua A.; Calkins, David A.; Miller, William K.; Allen, Steven E.; Clem, Paul Gilbert; Patitz, Ward E.
Properties of tropical convection observed by ARM millimeter-radars
Properties of tropical convection observed by ARM millimeter-radars Properties of tropical convection observed by ARM millimeter-radars Haynes, John Colorado State University Stephens, Graeme Colorado State University Category: Cloud Properties The results of an analysis of tropical cloud systems observed from a variety of vertically pointing radar systems are described. In particular, observations taken during five years of operation of the ARM millimeter wavelength radar system (MMCR) at Manus Island in the Tropical West Pacific region are characterized into cloud classes according to the radar reflectivity structures of these cloud systems, associated rainfall, and surface radiative properties. These observations of cloud properties are composited with respect to various phases of the Madden Julian Oscillation, which is a dominant mode of variability at Manus Island. A method of better
Title: Radar-observed convective characteristics during TWP-ICE
Title: Radar-observed convective characteristics during TWP-ICE Title: Radar-observed convective characteristics during TWP-ICE Schumacher, Courtney Texas A&M University Houze, Robert University of Washington May, Peter Bureau or Meteorology Research Centre Frederick, Kaycee Cetrone, Jasmine Vallgren, Andreas Category: Field Campaigns This poster will describe the radar dataset obtained in the Tropical Warm Pool International Cloud Experiment (TWP-ICE), which is to take place 20 January - 14 February 2006 in the vicinity of Darwin, Australia. We will describe the convective systems observed during the project by two scanning C-band Doppler radars, one of which will provide dual-polarization measurements, and ARM's vertically pointing cloud radar and lidar installations. In addition, we will discuss the potential for combining
W-Band ARM Cloud Radar - Specifications and Design
W-Band ARM Cloud Radar - Specifications and Design W-Band ARM Cloud Radar - Specifications and Design K. B. Widener Pacific Northwest National Laboratory Richland, Washington J. B. Mead ProSensing, Inc. Amherst, Massachusetts Abstract The Atmospheric Radiation Measurement (ARM) Program and ProSensing, Inc. have teamed to develop and deploy the W-band ARM Cloud Radar (WACR) at the SGP central facility. The WACR will be co- located with the ARM millimeter wave cloud radar (MMCR) with planned operation to begin in early 2005. This radar will complement the measurements of the MMCR and will aid in filtering out insect contamination in the data. In this poster we present the design goals, expected performance characteristics, and the detailed design for the WACR. Introduction The MMCR has been operating at the Southern Great Plains (SGP) site since 1998. It has proven to be
PATTERN: Advantages of High Resolution Weather Radar Networks [EVS Event]
PATTERN: Advantages of High Resolution Weather Radar Networks PATTERN: Advantages of High Resolution Weather Radar Networks September 30, 2013 Speaker: Dr. Katharina Lengfeld Meteorological Institute, University of Hamburg, Germany Date: Monday, September 30, 2013 Time: 11 am - 12 noon Location: Argonne National Laboratory TCS Building 240 Room 4301 Precipitation observations with radars operating in the X-band frequency range are essential for meeting present and future requirements for flood forecasting, water management, and other hydro-meteorological applications. Besides having higher resolution, these systems are cost-effective compared to S- or C-band radars because of smaller antenna size. Disadvantages of single X-band radars are the large influence of attenuation by liquid water and a relatively short range.
Assembly flow simulation of a radar
A discrete event simulation model has been developed to predict the assembly flow time of a new radar product. The simulation was the key tool employed to identify flow constraints. The radar, production facility, and equipment complement were designed, arranged, and selected to provide the most manufacturable assembly possible. A goal was to reduce the assembly and testing cycle time from twenty-six weeks to six weeks. A computer software simulation package (SLAM II) was utilized as the foundation a for simulating the assembly flow time. FORTRAN subroutines were incorporated into the software to deal with unique flow circumstances that were not accommodated by the software. Detailed information relating to the assembly operations was provided by a team selected from the engineering, manufacturing management, inspection, and production assembly staff. The simulation verified that it would be possible to achieve the cycle time goal of six weeks. Equipment and manpower constraints were identified during the simulation process and adjusted as required to achieve the flow with a given monthly production requirement. The simulation is being maintained as a planning tool to be used to identify constraints in the event that monthly output is increased. ``What-if`` studies have been conducted to identify the cost of reducing constraints caused by increases in output requirement.
Rutherford, W.C.; Biggs, P.M.
Off-momentum dynamic aperture for lattices in the RHIC heavy ion runs
To reduce transverse emittance growth rates from intrabeam scattering in the RHIC heavy ion runs, a lattice with an increased phase advance in the arc FODO cells was adopted in 2008-2011. During these runs, a large beam loss due to limited off-momentum dynamic aperture was observed during longitudinal RF re-bucketing and with transverse cooling. Based on the beam loss observations in the previous ion runs and the calculated off-momentum apertures, we decided to adopt the lattice used before 2008 for the 2012 U-U and Cu-Au runs. The observed beam decay and the measured momentum aperture in the 2012 U-U run are presented.
Luo Y.; Bai, M.; Blaskiewicz, M.; Gu, X.; Fischer, W.; Marusic, A.; Roser, T.; Tepikian, S.; Zhang, S.
Studies of Precipitation Processes in the Troposphere Using an FM-CW Radar
In the field of FM-CW tropospheric radar, new breakthroughs have become possible due to progress in FM-CW radar hardware, in FM-CW radar signal processing and in the availability of the Doppler polarimetric FM-CW radar DARR. DARR has a high ...
L. P. Ligthart; L. R. Nieuwkerk
Experimental study of natural convection heat transfer through an aperture in passive solar heated buildings
The objective of this study is to obtain correlations between natural convection heat transfer through an aperture and temperature difference between the two rooms. A one-fifth similitude model of a two-room building is used. The model is filled with Freon gas to satisfy similarity of the experiment to full-scale conditions in air. The experimental apparatus and experimental techniques are explained. Experimental results are presented in terms of Grashof, Nusselt, and Prandtl numbers. The effects of the height, the width, and the vertical position of the apertures are investigated, as is the effect of the room volume.
Yamaguchi, Kenjiro
Preliminary Report on the Feasibility of Using Synthetic Aperture Radar Interferometry to Image Localized Strain as a Discriminator of Geothermal Resources
Most producing geothermal fields and known geothermal resources in the Basin and Range province are associated with Quaternary active fault systems, within which hydrothermal fluids are presumed to circulate from depth to relatively shallow production levels through high permeability fractures. Research at the Dixie Valley field by Barton et al. (1997) indicates that hydraulically conductive fractures within the Stillwater fault zone are those that have orientations such that the fractures are critically stressed for normal shear failure under the regional tectonic stress field. In general, therefore, we might expect geothermal resources to occur in areas of high inter-seismic strain accumulation, and where faults are favorably oriented with respect to the regional strain tensor; in the case of Basin and Range normal faults, these would generally be faults striking normal to the direction of maximum extension. Expanding this hypothesis, Blewitt et al. (2003), based on preliminary, broad-scale analysis of regional strain and average fault strike in the northwestern Basin and Range, have proposed that geothermal resources occur in areas where fault-normal extension associated with shear strain is the greatest. Caskey and Wesnousky (2000) presented evidence that the Dixie Valley field occupies a 10 km-long gap between prehistoric Holocene ruptures of the fault segments on either side. Modeled maximum shear and Coulomb failure stress are high within the gap owing to the stress concentrations at the ends of the ruptures. These results suggest that a major contributing factor to the enhanced permeability at fault-hosted geothermal systems may be localized stress and strain concentrations within fault zone segments. This notion is generally consistent with the common occurrence of geothermal fields within fault offsets (pull-aparts) along strike-slip fault systems, where the local strain field has a large extensional component (e.g., Salton Sea and Coso). Blewitt et al. (2003) suggested that resources correlate with abrupt changes in fault orientation and with changes in the direction of extensional strain.
Foxall, W
History of Operational Use of Weather Radar by U.S. Weather Services. Part II: Development of Operational Doppler Weather Radars
The second part of a history of the use of storm surveillance radars by operational military and civil weather services in the United States is presented. This part describes the genesis and evolution of two operational Doppler weather radars, ...
Roger C. Whiton; Paul L. Smith; Stuart G. Bigler; Kenneth E. Wilk; Albert C. Harbuck
Comparison of Radar Reflectivity and Vertical Velocity Observed with a Scannable C-Band Radar and Two UHF Profilers in the Lower Troposphere
A C-band meteorological Doppler radar has been used to investigate the dynamic processes and the coherent organizations within a clear air atmospheric boundary layer (ABL). Depending on the atmospheric conditions, this moderate sensitive radar ...
M. Lothon; B. Campistron; S. Jacoby-Koaly; B. B�nech; F. Lohou; F. Girard-Ardhuin
Deformation and seismicity in the Coso geothermal area, Inyo County,
source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Deformation and seismicity in the Coso geothermal area, Inyo County, California, observations and modeling using satellite radar interferometry Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Deformation and seismicity in the Coso geothermal area, Inyo County, California, observations and modeling using satellite radar interferometry Details Activities (2) Areas (1) Regions (0) Abstract: Interferometric synthetic aperture radar (InSAR) data collected in the Coso geothermal area, eastern California, during 1993-1999 indicate ground subsidence over a approximately 50 km 2 region that approximately
Aperture Test for Internal Target Operation in the JLAB High-current ERL
A high current beam transmission test has been successfully completed at the JLAB FEL Facility, culminating in very low-loss transmission of a high current CW beam through a small aperture. The purpose of this test was to determine if an ERL is capable of meeting the stringent requirements imposed by the use of a 1018/cm3 internal gas target proposed for the DarkLight experiment*. Minimal beamline modifications were made to create a machine configuration that is substantially different from those used in routine UV or IR FEL operation. A sustained (8 hour) high power beam run was performed, with clean transmission through a 2 mm transverse aperture of 127 mm length simulating the target configuration. A beam size of 50 um (rms) was measured near the center of the aperture. Experimental data from a week-long test run consistently exhibited beam loss of only a few ppm on the aperture while running 4.5 mA current at 100 MeV -- or nearly 0.5 MW beam power. This surpassed the users? expectation and demonstrated a unique capability of an ERL for this type of experiments. This report presents a summary of the experiment, a brief overview of our activities, and outlines future plans.
Zhang, Shukui
Detection optimization using linear systems analysis of a coded aperture laser sensor system
Minimum detectable irradiance levels for a diffraction grating based laser sensor were calculated to be governed by clutter noise resulting from reflected earth albedo. Features on the earth surface caused pseudo-imaging effects on the sensor`s detector arras that resulted in the limiting noise in the detection domain. It was theorized that a custom aperture transmission function existed that would optimize the detection of laser sources against this clutter background. Amplitude and phase aperture functions were investigated. Compared to the diffraction grating technique, a classical Young`s double-slit aperture technique was investigated as a possible optimized solution but was not shown to produce a system that had better clutter-noise limited minimum detectable irradiance. Even though the double-slit concept was not found to have a detection advantage over the slit-grating concept, one interesting concept grew out of the double-slit design that deserved mention in this report, namely the Barker-coded double-slit. This diffractive aperture design possessed properties that significantly improved the wavelength accuracy of the double-slit design. While a concept was not found to beat the slit-grating concept, the methodology used for the analysis and optimization is an example of the application of optoelectronic system-level linear analysis. The techniques outlined here can be used as a template for analysis of a wide range of optoelectronic systems where the entire system, both optical and electronic, contribute to the detection of complex spatial and temporal signals.
Gentry, S.M. [Sandia National Labs., Albuquerque, NM (United States). Optoelectronic Design Dept.
Modeling Of Surface Deformation From Satellite Radar Interferometry In The
Modeling Of Surface Deformation From Satellite Radar Interferometry In The Modeling Of Surface Deformation From Satellite Radar Interferometry In The Salton Sea Geothermal Field, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Modeling Of Surface Deformation From Satellite Radar Interferometry In The Salton Sea Geothermal Field, California Details Activities (1) Areas (1) Regions (0) Abstract: Surface deformation in the Salton Sea geothermal field is modeled using results from satellite radar interferometry, data from leveling surveys, and observations from the regional GPS network. The field is located in the Salton Trough, an active spreading center in southern California, which is traversed by the Brawley seismic zone. Deformation time series at thousands of points in the study area are obtained from a
The �Owl Horn� Radar Signature in Developing Southern Plains Supercells
During spring 2001 in the Southern Plains, a recurring, hitherto undocumented reflectivity signature that the authors have called the �Owl Horn� signature (because the radar reflectivity pattern resembles the profile of the Great Horned Owl) was ...
Matthew R. Kramar; Howard B. Bluestein; Andrew L. Pazmany; John D. Tuttle
Radar Observations and Simulation of the Melting Layer of Precipitation
The melting layer in precipitation is physically modeled and compared with high resolution Doppler radar data. The model includes a new formulation of the dielectric properties and can handle all ice particles with densities ranging from pure ...
Wim Klaassen
Mesocyclone and Microburst Signature Distortion with Dual PRT Radars
A simple model is used to illustrate the limitations of dual pulse repetition time (PRT) radars for measurements of wind fields with strong horizontal wind gradients. In such conditions, errors may occur even if the radial velocity measurements ...
Peter T. May
An Interactive System for Compositing Digital Radar and Satellite Data
This paper describes an approach for compositing digital radar data and GOES satellite data for meteorological analysis. The processing is performed on a user-oriented image processing system, and is designed to be used in the research mode. It ...
Gerald M. Heymsfield; Koushik K. Ghosh; Lily C. Chen
Estimation of Cloud Content by W-Band Radar
W-band (3.2-mm) radars are seeing increasing utilization as a result of improving microwave technologies and the increased research emphasis being given to nonprecipitating clouds. This niche is exemplified by the study of the radiatively ...
Kenneth Sassen; Liang Liao
Radar Observations of the Early Evolution of Bow Echoes
The evolution of 273 bow echoes that occurred over the United States from 1996 to 2002 was examined, especially with regard to the radar reflectivity characteristics during the prebowing stage. It was found that bow echoes develop from the ...
Brian A. Klimowski; Mark R. Hjelmfelt; Matthew J. Bunkers
The CASA Integrated Project 1 Networked Radar System
This paper describes the Collaborative Adaptive Sensing of the Atmosphere (CASA) Integrated Project 1 (IP1) weather radar network, the first distributed collaborative adaptive sensing test bed of the Engineering Research Center for Collaborative ...
Francesc Junyent; V. Chandrasekar; D. McLaughlin; E. Insanic; N. Bharadwaj
Prospects of the WSR-88D Radar for Cloud Studies
Sounding of nonprecipitating clouds with the 10-cm wavelength Weather Surveillance Radar-1988 Doppler (WSR-88D) is discussed. Readily available enhancements to signal processing and volume coverage patterns of the WSR-88D allow observations of a ...
Valery M. Melnikov; Dusan S. Zrni?; Richard J. Doviak; Phillip B. Chilson; David B. Mechem; Yefim L. Kogan
Assessing Snowfall Rates from X-Band Radar Reflectivity Measurements
Realistic aggregate snowflake models and experimental snowflake size distribution parameters are used to derive X-band power-law relations between the equivalent radar reflectivity factor Ze and the liquid equivalent snowfall precipitation rate S ...
Sergey Y. Matrosov; Carroll Campbell; David Kingsmill; Ellen Sukovich
Spatial Averaging of HF Radar Data for Wave Measurement Applications
HF radar data are often collected for time periods that are optimised for current measurement applications where, in many cases, very high temporal resolution is needed. Previous work has demonstrated that this does not provide sufficient ...
Lucy R. Wyatt; Jasmine B. D. Jaffr�s; Mal L. Heron
Observations of Strong Surface Radar Ducts over the Persian Gulf
Ducting of microwave radiation is a common phenomenon over the oceans. The height and strength of the duct are controlling factors for radar propagation and must be determined accurately to assess propagation ranges. A surface evaporation duct ...
Ian M. Brooks; Andreas K. Goroch; David P. Rogers
Objective Tropical Cyclone Center Tracking Using Single-Doppler Radar
This study presents an extension of the ground-based velocity track display (GBVTD)-simplex tropical cyclone (TC) circulation center�finding algorithm to further improve the accuracy and consistency of TC center estimates from single-Doppler radar ...
Michael M. Bell; Wen-Chau Lee
Influence of Ground Clutter Contamination on Polarimetric Radar Parameters
The influence of ground clutter contamination on the estimation of polarimetric radar parameters, horizontal reflectivity (Zh), differential reflectivity (Zdr), correlation coefficient (?h?), and differential propagation phase (dp) was examined. ...
Katja Friedrich; Urs Germann; Pierre Tabary
The Assimilation of Radar Data for Weather Prediction
Assimilation of radar data is one of the key scientific challenges for numerical weather prediction of convective systems. Considerable progress has been made in recent years including retrieval of boundary layer winds from single-Doppler ...
Juanzhen Sun; James W. Wilson
TRMM Radar Observations of Shallow Precipitation over the Tropical Oceans
Observations from the precipitation radar aboard the Tropical Rainfall Measuring Mission satellite provide the first opportunity to map vertical structure properties of rain over the entire Tropics and subtropics. Storm height histograms reveal a ...
David A. Short; Kenji Nakamura
A Microphysical Interpretation of Radar Reflectivity�Rain Rate Relationships
The microphysical aspects of the relationship between radar reflectivity Z and rainfall rate R are examined. Various concepts discussed in the literature are integrated into a coherent analytical framework and discussed with a focus on the ...
Matthias Steiner; James A. Smith; Remko Uijlenhoet
A Rain-Rate Retrieval Algorithm for Attenuated Radar Measurements
A dynamic regularization scheme for rain-rate retrievals from attenuated radar measurements is presented. Most regularization techniques, including the optimal estimation method, use the state-space parameters to regularize the problem, which ...
Prabhat K. Koner; Alessandro Battaglia; Clemens Simmer
The Spaced Antenna Technique for Radar Wind Profiling
The Doppler method for radar wind profiling of the troposphere and stratosphere has been the standard technique used for operational and most research applications of the instrumentation. An alternative approach for measuring winds, by making use ...
Quality Control and Verification of Weather Radar Wind Profiles
Weather radar wind profiles (WRWPs) have been retrieved from Doppler volume scans using different implementations of the velocity�azimuth display (VAD) and volume velocity processing (VVP) methods. An extensive quality control of the radial ...
Iwan Holleman
Cloud Model-Based Simulation of Spaceborne Radar Observations
Simulations of observations from potential spaceborne radars are made based on storm structure generated from the three-dimensional (3D) Goddard cumulus ensemble model simulation of an intense overland convective system. Five frequencies of 3, 10,...
H-Y. M. Yeh; N. Prasad; R. Meneghini; W-K. Tao; J. A. Jones; R. F. Adler
Direct Observations of Coherent Backscatter of Radar Waves in Precipitation
In previous work, it was argued that a source of radar coherent scatter occurs in the direction perpendicular to the direction of wave propagation because of the presence of grids of enhanced particle concentrations with spatial periodicities in ...
A. R. Jameson; A. B. Kostinski
The Atmospheric Radiation Measurement Program Cloud Radars: Operational Modes
During the past decade, the U.S. Department of Energy (DOE), through the Atmospheric Radiation Measurement (ARM) Program, has supported the development of several millimeter-wavelength radars for the study of clouds. This effort has culminated in ...
Eugene E. Clothiaux; Kenneth P. Moran; Brooks E. Martner; Thomas P. Ackerman; Gerald G. Mace; Taneil Uttal; James H. Mather; Kevin B. Widener; Mark A. Miller; Daniel J. Rodriguez
Radar and Profiler Analysis of Colliding Boundaries: A Case Study
The kinematics of a head-on collision between two gust fronts, followed by a secondary collision between a third gust front and a bore generated by the initial collision, are described using analyses of Weather Surveillance Radar-1988 Doppler (...
Haldun Karan; Kevin Knupp
Cloud Liquid Water and Ice Content Retrieval by Multiwavelength Radar
Cloud liquid water and ice content retrieval in precipitating clouds by the differential attenuation method using a dual-wavelength radar, as a function of the wavelength pair, is first discussed. In the presence of non-Rayleigh scatterers, ...
Nicolas Gaussiat; Henri Sauvageot; Anthony J. Illingworth
Polarimetric Radar at Attenuated Wavelength as a Hydrological Sensor
A new method for the estimation of the rain rate using a polarimetric radar at attenuated wavelengths is proposed. At attenuated wavelengths, the differential reflectivity for horizontal and vertical polarization, ZDR, is the addition of a term ...
The Clear-Air Coastal Vespertine Radar Bands
It is known that the insects observed in the lower layers of the atmosphere produce radar echos and that their spatiotemporal distribution is strongly influenced by the meteorological conditions and the thermodynamic structure of the atmosphere. ...
Henri Sauvageot; Gilbert Despaux
The Effects of Rain on ERS-1 Radar Altimeter Data
An investigation into a potentially important, but little-studied effect on altimeter data�rain contamination�has been carried out using ERS-1. The method involves identifying large changes in the radar backscatter coefficient and relating these ...
Trevor H. Guymer; Graham D. Quartly; Meric A. Srokosz
Ocean Wave Slope Observations Using Radar Backscatter and Laser Altimeters
Combination of laser and radar aboard an aircraft is used to directly measure long gravity wave surface tilting simultaneously with nadir-viewing microwave backscatter from the sea surface. The presented dataset is extensive, encompassing varied ...
D. Vandemark; B. Chapron; J. Sun; G. H. Crescenti; H. C. Graber
Sensitivity Studies of the Models of Radar-Rainfall Uncertainties
It is well acknowledged that there are large uncertainties associated with the operational quantitative precipitation estimates produced by the U.S. national network of the Weather Surveillance Radar-1988 Doppler (WSR-88D). These errors result ...
Gabriele Villarini; Witold F. Krajewski
Stratocumulus Liquid Water Content from Dual-Wavelength Radar
A technique is described to retrieve stratocumulus liquid water content (LWC) using the differential attenuation measured by vertically pointing radars at 35 and 94 GHz. Millimeter-wave attenuation is proportional to LWC and increases with ...
Robin J. Hogan; Nicolas Gaussiat; Anthony J. Illingworth
On Deriving Vertical Air Motions from Cloud Radar Doppler Spectra
A method for deriving vertical air motions from cloud radar Doppler spectrum measurements is introduced. The method is applicable to cloud volumes containing small particles, in this case liquid droplets, which are assumed to trace vertical air ...
Matthew D. Shupe; Pavlos Kollias; Michael Poellot; Edwin Eloranta
Two Examples of Operational Tornado Warnings Using Doppler Radar Data
The National Weather Service Forecast Office in Denver, Colorado; has access to a variety of new observational datasets via an advanced, interactive workstation. This paper describes the impact of one of these datasets�Doppler radar�on the real-...
Lawrence B. Dunn
Using Radar Wind Observations to Improve Mesoscale Numerical Weather Prediction
A high-resolution radar data assimilation system is presented for high-resolution numerical weather prediction models. The system is under development at the Naval Research Laboratory for the Navy�s Coupled Ocean�Atmosphere Mesoscale Prediction ...
Qingyun Zhao; John Cook; Qin Xu; Paul R. Harasti
Advanced Weather Radar Systems in Europe: The COST 75 Action
The European Union COST (Cooperation in Science and Technology) action on advanced weather radar systems is described. The associated five-year research project, which began in early 1993, has the objective to develop guideline specifications for ...
P. Meischner; C. Collier; A. Illingworth; J. Joss; W. Randeu
Use of Dual-Wavelength Radar for Snow Parameter Estimates
Use of dual-wavelength radar, with properly chosen wavelengths, will significantly lessen the ambiguities in the retrieval of microphysical properties of hydrometeors. In this paper, a dual-wavelength algorithm is described to estimate the ...
Liang Liao; Robert Meneghini; Toshio Iguchi; Andrew Detwiler
Radar Reflectivity�Based Estimates of Mixed Layer Depth
This study investigates the potential for estimating mixed layer depth by taking advantage of the radial gradients in the radar reflectivity field produced by the large vertical gradients in water vapor mixing ratio that are characteristic of the ...
P. L. Heinselman; P. L. Spencer; K. L. Elmore; D. J. Stensrud; R. M. Hluchan; P. C. Burke
An Evaluation of Radar Rainfall Estimates from Specific Differential Phase
Specific differential propagation phase (KDP) is examined for estimating convective rainfall in Colorado and Kansas. Estimates are made at S band with KDP alone and in combination with radar reflectivity (ZH). Results are compared to gauge ...
Edward A. Brandes; Alexander V. Ryzhkov; Dus?an S. Zrni?
Radar Signatures of Tropical Cyclone Tornadoes in Central North Carolina
During the tropical cyclone season of 2004, there were four tropical cyclones that spawned tornadoes in central North Carolina: Frances, Gaston, Ivan, and Jeanne. This study examines the environmental characteristics and radar signatures from ...
Douglas Schneider; Scott Sharp
Radar Wind Profiler Radial Velocity: A Comparison with Doppler Lidar
The accuracy of the radial wind velocity measured with a radar wind profiler will depend on turbulent variability and instrumental noise. Radial velocity estimates of a boundary layer wind profiler are compared with those estimated by a Doppler ...
Stephen A. Cohn; R. Kent Goodrich
Signal Processing System for the CASA Integrated Project I Radars
This paper describes the waveform design space and signal processing system for dual-polarization Doppler weather radar operating at X band. The performance of the waveforms is presented with ground clutter suppression capability and mitigation ...
Nitin Bharadwaj; V. Chandrasekar; Francesc Junyent
Assessment of Vertically Integrated Liquid (VIL) Water Content Radar Measurement
Vertically integrated liquid (VIL) water content is a parameter obtained from a radar performing voluminal scanning. This parameter has proven useful in the detection of severe storms and may be a worthwhile indicator for very short-term rainfall ...
Brice Boudevillain; Herv� Andrieu
Raindrop Size Distributions and the Radar Bright Band
The relationship between raindrop size distribution, measured with a disdrometer, and a radar parameter of the melting-layer bright band is investigated. The data, obtained in July 1993 in Switzerland, cover 120 h of precipitation. A good ...
A. Huggel; W. Schmid; A. Waldvogel
Dealiasing of Doppler Radar Velocities Using a Torus Mapping
A novel dealiasing algorithm for Doppler radar velocity data has been developed at the Swedish Meteorological and Hydrological Institute (SMHI). Unlike most other methods, it does not need independent wind information from other instruments (e.g.,...
G�nther Haase; Tomas Landelius
Feasibility Test of an Airborne Pulse-Doppler Meteorological Radar
A vertically scanning, airborne, pulse-Doppler radar is described. Data processing methods to yield pseudo-dual-Doppler horizontal winds are presented. Results of an intercomparison with a ground-based dual-Doppler network are presented and ...
David P. Jorgensen; Peter H. Hildebrand; Charles L. Frush
An Automated Radar Technique for the Identification of Tropical Precipitation
A radar-based automated technique for the identification of tropical precipitation was developed to improve quantitative precipitation estimation during extreme rainfall events. The technique uses vertical profiles of reflectivity to identify the ...
Xiaoyong Xu; Kenneth Howard; Jian Zhang
Finescale Radar Observations of Tornado and Mesocyclone Structures
A variety of vortex configurations observed at finescale with Doppler On Wheels (DOW) radars in and near the hook echoes of supercell thunderstorms are described. These include marginal/weak tornadoes, often with no documented condensation funnels,...
Joshua Wurman; Karen Kosiba
Use of Ground Clutter to Monitor Polarimetric Radar Calibration
It is suggested that urban ground clutter can have a role in monitoring calibration of reflectivity factor ZH and differential reflectivity ZDR on polarimetric radars. The median and average values of these variables are considered. Analysis of ...
L. Borowska; D. Zrnic
Impacts of Polarimetric Radar Observations on Hydrologic Simulation
Rainfall estimated from the polarimetric prototype of the Weather Surveillance Radar-1988 Doppler [WSR-88D (KOUN)] was evaluated using a dense Micronet rain gauge network for nine events on the Ft. Cobb research watershed in Oklahoma. The ...
Jonathan J. Gourley; Scott E. Giangrande; Yang Hong; Zachary L. Flamig; Terry Schuur; Jasper A. Vrugt
CloudSat as a Global Radar Calibrator
The calibration of the CloudSat spaceborne cloud radar has been thoroughly assessed using very accurate internal link budgets before launch, comparisons with predicted ocean surface backscatter at 94 GHz, direct comparisons with airborne cloud ...
A. Protat; D. Bouniol; E. J. O�Connor; H. Klein Baltink; J. Verlinde; K. Widener
Upscale Evolution of MCSs: Doppler Radar Analysis and Analytical Investigation
The development of two small mesoscale convective systems (MCSs) in northeastern Colorado is investigated via dual-Doppler radar analysis. The first system developed from several initially isolated cumulonimbi, which gradually coalesced into a ...
Ray L. McAnelly; Jason E. Nachamkin; William R. Cotton; Melville E. Nicholls
Remote Sensing of Hail with a Dual Linear Polarization Radar
A technique for the remote sensing of hail with an S-band dual linear polarization radar is described. The method employs a new hail signal HDR, which is derived from disdrometer measurements of raindrop size distributions. Experimental ...
K. Aydin; T. A. Seliga; V. Balaji
VHF Doppler Radar Observations of Buoyancy Waves Associated with Thunderstorms
The Platteville VHF Doppler radar, located on the Colorado piedmont near Platteville, Colorado, continuously measured the vertical wind velocity during a 12-day period in late July and early August 1981. Measurements were made every 2.5 min on ...
Daren Lu; T. E. VanZandt; W. L. Clark
Operational Weather Radar in the United States: Progress and Opportunity
The NEXRAD operational system consisting of a network of WSR�88D radars is now operational within the 50 states, as well as Puerto Rico and Guam. This technology has been enthusiastically received by weather forecasters in all regions and ...
Robert J. Serafin; James W. Wilson
Automatic Detection of Wind Turbine Clutter for Weather Radars
Wind turbines cause contamination of weather radar signals that is often detrimental and difficult to distinguish from cloud returns. Because the turbines are always at the same location, it would seem simple to identify where wind turbine ...
Kenta Hood; Sebasti�n Torres; Robert Palmer
Antenna Pattern Analysis and Measurements for Multiparameter Radars
Measuring the full polarization matrix using a research radar requires knowledge of the complex (i.e., amplitude and phase) antenna pattern to properly correct for bias errors in the measurements. However, generally only power patterns are ...
V. Chandrasekar; R. Jeffrey Keeler
Operational Monitoring of Weather Radar Receiving Chain Using the Sun
A method for operational monitoring of a weather radar receiving chain, including the antenna gain and the receiver, is presented. The �online� method is entirely based on the analysis of sun signals in the polar volume data produced during ...
Iwan Holleman; Asko Huuskonen; Mikko Kurri; Hans Beekhuis
Measurement of Mean Raindrop Shape from Polarimetric Radar Observations
Interpretation of polarimetric radar measurements in rainfall such as differential reflectivity and specific differential phase shifts depends on the mean raindrop shape�size relationship. Currently, semiempirical relations between the oblateness ...
Eugenio Gorgucci; Gianfranco Scarchilli; V. Chandrasekar; V. N. Bringi
Comparison of Polarimetric Radar Drop Size Distribution Retrieval Algorithms
Recently, two physically based algorithms, the �beta� (?) method and the �constrained-gamma� method, have been proposed for retrieving the governing parameters of the gamma drop size distribution (DSD) from polarimetric radar measurements. The ? ...
Edward A. Brandes; Guifu Zhang; J. Vivekanandan
Polarization Radar Estimates of Raindrop Size Spectra and Rainfall Rates
The differential reflectivity (ZDR) measures the mean shape of hydrometeors and provides an estimate of the mean size of raindrops Observations of ZDR for rain may be combined with the conventional radar reflectivity factor (Z) and fitted to any ...
A. J. Illingworth; I. J. Caylor
Partially Coherent Backscatter in Radar Observations of Precipitation
Classical radar theory only considers incoherent backscatter from precipitation. Can precipitation generate coherent scatter as well? Until now, the accepted answer has been no, because hydrometeors are distributed sparsely in space (relative to ...
Processing and Interpretation of Coherent Dual-Polarized Radar Measurements
Dual-polarized coherent radar measurements are used to estimate the differential propagation phase or DP between horizontal and vertical polarization states. The slope of DP is an estimate of the specific differential phase KDP. This process is ...
J. Hubbert; V. Chandrasekar; V. N. Bringi; P. Meischner
Cloud Ice Crystal Classification Using a 95-GHz Polarimetric Radar
Two algorithms are presented for ice crystal classification using 95-GHz polarimetric radar observables and air temperature (T). Both are based on a fuzzy logic scheme. Ice crystals are classified as columnar crystals (CC), planar crystals (PC), ...
K. Aydin; J. Singh
The Window Probability Matching Method for Rainfall Measurements with Radar
A simplified probability matching method is introduced that relies on matching the unconditional probabilities of R and Ze, using data from a C-band radar and raingage network near Darwin, Australia. This is achieved by matching raingage ...
Daniel Rosenfeld; David B. Wolff; Eyal Amitai
Enclosing Shapes for Single-Doppler Radar Features
The primary function of the Terminal Doppler Weather Radar (TDWR) system is to issue microburst alerts when a microburst hazard endangers aircraft. The steps of the algorithm process include 1) determining that a microburst hazard is present, and ...
F. W. Wilson Jr.; R. K. Goodrich; K. Brislawn
Least Squares Reconstruction of Doppler Radar Spectra for Irregular PRT
A least squares method for the reconstruction of Doppler spectra of weather radars with irregular pulse repetition time used to increase the range of unambiguous velocity is presented and evaluated. This method is a robust spectral method that is ...
John Kalogiros
A Model for Probability Nowcasts of Accumulated Precipitation Using Radar
A new model for making probability forecasts of accumulated spot precipitation from weather radar data is presented. The model selects a source region upwind of the forecast spot. All pixels (horizontal size 2 � 2 km2) within the source region ...
Tage Andersson; Karl-Ivar Ivarsson
Measurement of Raindrop Size Distributions Using a Small Doppler Radar
A small X-band bistatic Doppler radar originally developed for use in automated weather stations as a Precipitation Occurrence Sensor System (POSS) can also measure real time raindrop size distributions. In contrast to large-scale pulsed Doppler ...
Brian E. Sheppard
A Radar and Electrical Study of Tropical �Hot Towers�
Radar and electrical measurements for deep tropical convection are examined for both �break period� and �monsoonal� regimes in the vicinity of Darwin, Australia. Break period convection consists primarily of deep continental convection, whereas ...
E. R. Williams; S. G. Geotis; N. Renno; S. A. Rutledge; E. Rasmussen; T. Rickenbach
Earth curvature and atmospheric refraction effects on radar signal propagation.
The earth isn't flat, and radar beams don't travel straight. This becomes more noticeable as range increases, particularly at shallow depression/grazing angles. This report explores models for characterizing this behavior.
A Proposed Technique for Diagnosis by Radar of Hurricane Structure
A Doppler radar technique is proposed for remote estimation of hurricane structure by sampling the kinematic properties of the hurricane wind field in a relatively small circular area outside the radius of maximum winds. This technique uses ...
Ralph J. Donaldson Jr.
A Radar Simulator for High-Resolution Nonhydrostatic Models
A full radar simulator for high-resolution (1�5 km) nonhydrostatic models has been developed within the research nonhydrostatic mesoscale atmospheric (Meso-NH) model. This simulator is made up of building blocks, each of which describes a ...
Olivier Caumont; V�ronique Ducrocq; Guy Delrieu; Marielle Gosset; Jean-Pierre Pinty; Jacques Parent du Ch�telet; Herv� Andrieu; Yvon Lema�tre; Georges Scialom
Statistical Quality of Spectral Polarimetric Variables for Weather Radar
Spectral polarimetry for weather radar capitalizes on both Doppler and polarimetric measurements to reveal polarimetric variables as a function of radial velocity through spectral analysis. For example, spectral differential reflectivity at a ...
Tian-You Yu; Xiao Xiao; Yadong Wang
Raindrop Size Distribution and Radar Parameters at Cape Verde
Precipitation measurement using passive or active microwaves from space- or ground-based radar involves hypotheses about the raindrop size distribution (DSD). A universal knowledge of DSD characteristics is needed. A 4-yr dataset collected with a ...
Armand Nzeukou; Henri Sauvageot; Abe Delfin Ochou; Cheikh Mouhamed Fadel Kebe
Agile-Beam Phased Array Radar for Weather Observations
Weather radars with conventional antenna cannot provide desired volume scan updates at intervals of one minute or less, which is essential for significant improvement in warning lead time of impending storm hazards. The agile-beam multimission ...
D. S. Zrnic; J. F. Kimpel; D. E. Forsyth; A. Shapiro; G. Crain; R. Ferek; J. Heimmer; W. Benner; T. J. McNellis; R. J. Vogt
Rock Joint Surfaces Measurement and Analysis of Aperture Distribution under Different Normal and Shear Loading Using GIS
Geometry of the rock joint is a governing factor for joint mechanical and hydraulic behavior. A new method of evaluating aperture distribution based on measurement of joint surfaces and three dimensional characteristics of each surface is developed. Artificial joint of granite surfaces are measured,processed, analyzed and three dimensional approaches are carried out for surface characterization. Parameters such as asperity's heights, slope angles, and aspects distribution at micro scale,local concentration of elements and their spatial localization at local scale are determined by Geographic Information System (GIS). Changes of aperture distribution at different normal stresses and various shear displacements are visualized and interpreted. Increasing normal load causes negative changes in aperture frequency distribution which indicates high joint matching. However, increasing shear displacement causes a rapid increase in the aperture and positive changes in the aperture frequency distribution which could be ...
Sharifzadeh, Mostafa; Esaki, Tetsuro
Guard Rail Detection Using Radar and Vision Data Fusion
This paper describes a method for detecting guard rails fusing radar and vision data in order to improve and speed-up vehicle detection algorithms. The method is based on the search for uninterrupted oblique lines that cross an interest area. The interest area is dinamically indicated by a radar sensor. A method to manage overlapping areas is also described. The method's efficiency, both in terms of time saving and correct detection rate, is numerically shown.
For Vehicle Detection; Alberto Broggi; Pietro Cerri; Fabio Oleari; Marco Paterlini
During the year 2008, the United States National Weather Service (NWS) completed an eight fold increase in sampling capability for weather radars to 250 m resolution. This increase is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current NWS operational model domains utilize grid spacing an order of magnitude larger than the radar data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of radar reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution was investigated under a Laboratory Directed Research and Development (LDRD) 'quick hit' grant to determine the impact of improved data resolution on model predictions with specific initial proof of concept application to daily Savannah River Site operations and emergency response. Development of software to process NWS radar reflectivity and radial velocity data was undertaken for assimilation of observations into numerical models. Data values within the radar data volume undergo automated quality control (QC) analysis routines developed in support of this project to eliminate empty/missing data points, decrease anomalous propagation values, and determine error thresholds by utilizing the calculated variances among data values. The Weather Research and Forecasting model (WRF) three dimensional variational data assimilation package (WRF-3DVAR) was used to incorporate the QC'ed radar data into input and boundary conditions. The lack of observational data in the vicinity of SRS available to NWS operational models signifies an important data void where radar observations can provide significant input. These observations greatly enhance the knowledge of storm structures and the environmental conditions which influence their development. As the increase in computational power and availability has made higher resolution real-time model simulations possible, the need to obtain observations to both initialize numerical models and verify their output has become increasingly important. The assimilation of high resolution radar observations therefore provides a vital component in the development and utility of numerical model forecasts for both weather forecasting and contaminant transport, including future opportunities to improve wet deposition computations explicitly.
Chiswell, S.; Buckley, R.
Absolute Calibration of Radar Reflectivity Using Redundancy of the Polarization Observations and Implied Constraints on Drop Shapes
A major limitation of improved radar-based rainfall estimation is accurate calibration of radar reflectivity. In this paper, the authors fully automate a polarimetric method that uses the consistency between radar reflectivity, differential ...
Jonathan J. Gourley; Anthony J. Illingworth; Pierre Tabary
Constructing Three-Dimensional Multiple-Radar Reflectivity Mosaics: Examples of Convective Storms and Stratiform Rain Echoes
The advent of Internet-2 and effective data compression techniques facilitates the economic transmission of base-level radar data from the Weather Surveillance Radar-1988 Doppler (WSR-88D) network to users in real time. The native radar spherical ...
Jian Zhang; Kenneth Howard; J. J. Gourley
Impact of CASA Radar and Oklahoma Mesonet Data Assimilation on the Analysis and Prediction of Tornadic Mesovortices in an MCS
The impact of radar and Oklahoma Mesonet data assimilation on the prediction of mesovortices in a tornadic mesoscale convective system (MCS) is examined. The radar data come from the operational Weather Surveillance Radar-1988 Doppler (WSR-88D) ...
Alexander D. Schenkman; Ming Xue; Alan Shapiro; Keith Brewster; Jidong Gao
An Innovative Transponder-Based Interferometric Radar for Vibration Measurements
Ground-based radar interferometry has recently emerged as an innovative technology of remote sensing, able to accurately measure the static or dynamic displacement of several points of a structure. This technique in the last couple of years has been applied to different types of structures, such as bridges, towers and chimneys. This paper presents a prototype system developed by IDS, originally aimed at measuring the structural vibrations of helicopter rotor blades, based on an interferometric technique and constituted by combination of a radar sensor and a series of transponders installed on the target structure. The main advantages of this solution with respect to conventional interferometric radars, are related to the increased spatial resolution of the system, provided by the possibility to discriminate different transponders installed within the same resolution cell of the radar sensor, and to the reduction of the ambient noise (e.g. multi-path) on the radar measurement. The first feature allows the use of the microwave technology even on target areas with limited dimensions, such as industrial facilities, while the second aspect may extend the use of radar interferometric systems to complex scenarios, where multi-reflections are expected due to the presence of natural targets with high reflectivity to the radar signal. In the paper, the system and its major characteristics are first described; subsequently, application to the measurement of ambient vibration response of a lab set-up is summarized. Then the data acquired on a rotating mock-up are reported and analyzed to identify natural frequencies and mode shapes of the investigated structure.
Coppi, F.; Cerutti, A.; Farina, P.; De Pasquale, G.; Novembrini, G. [IDS Ingegneria dei Sistemi S.p.A., Via Livornese 1019, Pisa (Italy)
A new aperture for neutron and x-ray imaging of inertial confinement fusion experiments
Recent neutron imaging of experiments at the National Ignition Facility has provided useful information about the hotspot shape and cold-fuel distribution and has also given insight into avenues for improvement. Neutron image reconstruction depends on accurate pointing information because the point-spread function of the neutron aperture is not shift invariant. Current pointing techniques are limited in their accuracy and rely upon detailed information about the as-built structure of the array, which is difficult to determine. We present a technique for extracting high-precision pointing information from both neutron and x-ray images, and a new aperture design with features to facilitate this technique, and allow future co-registration of neutron and x-ray images.
Danly, C. R.; Grim, G. P.; Guler, N.; Intrator, M. H.; Merrill, F. E.; Volegov, P.; Wilde, C. H. [Los Alamos National Laboratory, PO Box 1663, Los Alamos, New Mexico 87545 (United States)
Coherent hard x-ray diffractive imaging of nonisolated objects confined by an aperture
Coherent hard x-ray imaging of nonisolated weak phase objects is demonstrated by confining x-ray beam in a region of a few micrometers in cross section using a micrometer-sized aperture. Two major obstacles in the hard x-ray coherent diffraction imaging, isolating samples and obtaining central speckles, are addressed by using the aperture. The usefulness of the proposed method is illustrated by reconstructing the exit wave field of a nanoscale trench structure fabricated on silicon which serves as a weak phase object. The quantitative phase information of the exit wave field was used to reconstruct the depth profile of the trench structure. The scanning capability of this method was also briefly discussed.
Kim, Sunam; Kim, Chan; Lee, Suyong; Marathe, Shashidhara; Noh, D. Y.; Kang, H. C.; Kim, S. S.; Sandy, A.; Narayanan, S. [Department of Materials Science and Engineering and Nanobio Materials and Electronics, Graduate Program of Photonics and Applied Physics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Department of Advanced Materials Engineering and BK21 Education Center of Mould Technology for Advanced Materials and Parts, Chosun University, Gwangju 501-759 (Korea, Republic of); Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
Rainfall Estimation from Polarimetric Radar Measurements: Composite Algorithms Immune to Variability in Raindrop Shape�Size Relation
Polarization diversity radar measurements such as reflectivity factor, differential reflectivity, and differential propagation phase are extensively used in rainfall estimation. Algorithms to estimate rainfall from polarimetric radar measurements ...
Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures
We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-off, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that need to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, multipactoring inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation when the machine is tuned for 130 MeV operation.
Alarcon, Ricardo [Arizona State University, Glendale, AZ (United States); Balascuta, S. [Arizona State University, Glendale, AZ (United States); Benson, Stephen V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Bertozzi, William [Massachusetts Institute of Technology, Cambridge, MA (United States); Boyce, James R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Cowan, Ray [Massachusetts Institute of Technology, Cambridge, MA (United States); Douglas, David R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Evtushenko, Pavel [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Fisher, P. [Massachusetts Institute of Technology, Cambridge, MA (United States); Ihloff, Ernest E. [Hampton University, Hampton, VA (United States); Kalantarians, Narbe [Hampton University, Hampton, VA (United States); Kelleher, Aidan Michael [Massachusetts Institute of Technology, Cambridge, MA (United States); Krossler, W. J. [William and Mary College, Williamsburg, VA (United States); Legg, Robert A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Long, Elena [University of New Hampshire, Durham, NH (United States); Milner, Richard [Massachusetts Institute of Technology, Cambridge, MA (United States); Neil, George R. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Ou, Longwu [Massachusetts Institute of Technology, Cambridge, MA (United States); Schmookler, Barack Abraham [Massachusetts Institute of Technology, Cambridge, MA (United States); Tennant, Christopher D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Tschalar, C. [Massachusetts Institute of Technology, Cambridge, MA (United States); Williams, Gwyn P. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhang, Shukui [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
A VAD-Based Dealiasing Method for Radar Velocity Data Quality Control
This paper describes a new velocity�azimuth display (VAD)-based dealiasing method developed for automated radar radial velocity data quality control to satisfy the high-quality standard and efficiency required by operational radar data ...
Qin Xu; Kang Nai; Li Wei; Pengfei Zhang; Shun Liu; David Parrish
Effects of Nonuniform Beam Filling on Rainfall Retrieval for the TRMM Precipitation Radar
The Tropical Rainfall Measuring Mission (TRMM) will carry the first spaceborne radar for rainfall observation. Because the TRMM Precipitation Radar (PR) footprint size of 4.3 km is greater than the scale of some convective rainfall events, there ...
S. L. Durden; Z. S. Haddad; A. Kitiyakara; F. K. Li
The Influence of Airborne Doppler Radar Data Quality on Numerical Simulations of a Tropical Cyclone
The impact of airborne Doppler radar data assimilation on improving numerical simulations of tropical cyclones (TCs) has been well recognized. However, the influence of radar data quality on the numerical simulation of tropical cyclones has not ...
Lei Zhang; Zhaoxia Pu; Wen-Chau Lee; Qingyun Zhao
An Application of Linear Programming to Polarimetric Radar Differential Phase Processing
Differential phase and its range derivative KDP are of interest to several hydrological applications from weather radar systems. Despite the attractive qualities of polarimetric differential phase measurements, the usefulness of these radar ...
Scott E. Giangrande; Robert McGraw; Lei Lei
Combination of Manually Digitized Radar and GOES IR for Real-Time Display of Rainfall Intensity
Manually Digitized Radar (MDR) and Geostationary Operational Environmental Satellite (GOES) thermal infrared (IR) data were merged to form a higher-resolution radar/IR product than that represented by the MDR. The combination MDR/IR maps were ...
Paul H. Heinemann; J. David Martsolf; John F. Gerber; Daniel L. Smith
Radar Echo Structure, Air Motion and Hail Formation in a Large Stationary Multicellular Thunderstorm
Observations from aircraft, Doppler radars, surface mesonetwork, upper air network and surveillance radar are used to describe the structure and evolution of a large rain and hailstorm that occurred on 22 June 1976 in northeastern Colorado. In ...
L. J. Miller; J. C. Fankhauser
Visual Cloud Histories Related to First Radar Echo Formation in Northeast Colorado Cumulus
Using quantitative analysis of time-lapse motion pictures from aircraft and a sensitive meteorological radar, the cloud top history is related to the early radar echo development in 12 vigorous, summer, convective cloud turrets in northeastern ...
Charles A. Knight; William D. Hall; Philip M. Roskowski
Experiments in Rainfall Estimation with a Polarimetric Radar in a Subtropical Environment
A unique dataset consisting of high-resolution polarimetric radar measurements and dense rain gauge and disdrometer observations collected in east-central Florida during the summer of 1998 was examined. Comparison of the radar measurements and ...
Enhanced Radar Backscattering due to Oriented Ice Particles at 95 GHz during StormVEx
Nonspherical atmospheric ice particles can enhance radar backscattering and attenuation above that expected from spheres of the same mass. An analysis of scanning 95 GHz radar data collected during the Storm Peak Laboratory cloud property ...
Roger Marchand; Gerald G. Mace; A. Gannet Hallar; Ian B. McCubbin; Sergey Y. Matrosov; Matthew D. Shupe
Detection of Ice Hydrometeor Alignment Using an Airborne W-band Polarimetric Radar
This paper presents airborne W-band polarimetric radar measurements at horizontal and vertical incidence on ice clouds using a 95-GHz radar on the University of Wyoming King Air research aircraft. Coincident, in situ measurements from probes on ...
J. Galloway; A. Pazmany; J. Mead; R. E. McIntosh; D. Leon; J. French; R. Kelly; G. Vali
Evaluating Radial Current Measurements from CODAR High-Frequency Radars with Moored Current Meters
The performance of a network of five CODAR (Coastal Ocean Dynamics Application Radar) SeaSonde high-frequency (HF) radars, broadcasting near 13 MHz and using the Multiple Signal Classification (MUSIC) algorithm for direction finding, is described ...
Brian M. Emery; Libe Washburn; Jack A. Harlan
Observations of a Colorado Tornado. Part II: Combined Photogrammetric and Doppler Radar Analysis
An integrated analysis of photographic and Doppler radar observations of a tornadic storm during the Convection Initiation and Downburst Experiment (CINDE) is presented. High-resolution single-Doppler radar measurements are combined with cloud ...
Roger M. Wakimoto; Brooks E. Martner
Analysis and Interpretation of Dual-Polarized Radar Measurements at +45� and ?45� Linear Polarization States
Equations are derived for transforming radar data obtained with �45� linear polarization states to conventional radar parameters measured at horizontal and vertical polarization states. The derivation is based on the covariance matrix and assumes ...
V. Chandrasekar; J. Hubbert; V. N. Bringi; P. F. Meischner
Continuous Humidity Monitoring in a Tropical Region with the Equatorial Atmosphere Radar
A radar remote sensing technique that estimates humidity profiles using a wind profiler is applied to the equatorial atmosphere radar (EAR) to monitor detailed humidity variations in tropical regions. Turbulence echo power intensity is related to ...
Jun-ichi Furumoto; Toshitaka Tsuda; Satoshi Iwai; Toshiaki Kozu
Dealiasing Doppler Velocities Measured by a Bistatic Radar Network during a Downburst-Producing Thunderstorm
The object of this paper was to develop an automated dealiasing scheme that dealiases Doppler velocities measured by a bistatic Doppler radar network. The particular network consists of the C-band polarimetric diversity Doppler radar, POLDIRAD, ...
Katja Friedrich; Olivier Caumont
Incoherent scatter radar detection of enhanced plasma line in ionospheric E-region over Arecibo
A series of incoherent scatter radar (ISR) observation were conducted at the Arecibo Observatory from December 27, 2005 until January 3, 2006. From plasma line measurements that were taken during this radar campaign, we ...
Pradipta, Rezy
Radar Reflectivity-Ice Water Content Relationships for Use above the Melting Level in Hurricanes
Regression equations linking radar reflectivity (Ze) and ice water content (IWC) were calculated from airborne radar and particle image data that were collected above the melting level in two hurricanes. The Ze ? IWC equation from the stratiform ...
Robert A. Black
Rainfall Parameter Estimation from Dual-Radar Measurements Combining Reflectivity Profile and Path-integrated Attenuation
Rain rate estimation properties of multiparameter radar measurements combining radar reflectivity and microwave attenuations are studied through simulations using a two-year disdrometer dataset. In the first simulation, properties of �complete� ...
Toshiaki Kozu; Kenji Nakamura
Biases of Rain Retrieval Algorithms for Spaceborne Radar Caused by Nonuniformity of Rain
The biases of various rain retrieval algorithms for a spaceborne rain radar due to nonuniformity of rain are studied using simple models and an actual time sequence of rainfall rate. A conventional rain retrieval algorithm in which measured radar ...
Kenji Nakamura
Study of Polarization Differences in Ku-Band Ocean Radar Imagery
Radar returns from the sea surface can be represented as the sum of two contributions from Bragg scattering and from individual breaking events. This representation is used to analyze polarimetric radar images of ocean areas obtained at grazing ...
Andre V. Smirnov; Valery U. Zavorotny
Three Methods to Determine Profiles of Reflectivity from Volumetric Radar Data to Correct Precipitation Estimates
The vertical variability of radar reflectivity reduces the reliability of precipitation estimation by radar, especially in complex orography. This important source of error can, at least partially, be corrected for, if the vertical profile of ...
Bertrand Vignal; Gianmario Galli; J�rg Joss; Urs Germann
Predictability of Precipitation from Continental Radar Images. Part IV: Limits to Prediction
Predictability of precipitation is examined from storm to synoptic scales through an experimental approach using continent-scale radar composite images. The lifetime of radar reflectivity patterns in Eulerian and Lagrangian coordinates is taken ...
Urs Germann; Isztar Zawadzki; Barry Turner
Objective Identification of Echoes Due to Anomalous Propagation in Weather Radar Data
Serious contamination of weather radar data can occur in atmospheric conditions that cause anomalous propagation of the radar beam. Excessive downward refraction of the beam may be sufficient to cause ground returns (�anaprop�), which may be ...
J. A. Pamment; B. J. Conway
Design and Deployment of a Portable, Pencil-Beam, Pulsed, 3-cm Doppler Radar
A portable, pencil-beam, pulsed, Doppler, 3-cm wavelength radar has been constructed to study a wide variety of meteorological phenomena including tornadoes, severe storms, and boundary layer processes. The new radar, the Doppler on Wheels (DOW), ...
Joshua Wurman; Jerry Straka; Erik Rasmussen; Mitch Randall; Allen Zahrai
CSU-CHILL Polarimetric Radar Measurements from a Severe Hail Storm in Eastern Colorado
Polarimetric radar measurements made by the recently upgraded CSU-CHILL radar system in a severe hailstorm are analyzed permitting for the first time the combined use of Zh, ZDR, linear depolarization ratio (LDR), KDP, and ?h? to infer ...
J. Hubbert; V. N. Bringi; L. D. Carey; S. Bolen
First Radar Echoes and the Early ZDR History of Florida Cumulus
The early histories of radar echo and polarization differential reflectivity (ZDR) from growing cumulus clouds observed in Florida with a 10-cm-wavelength radar are reported in detail. Raindrops 1 to several millimeters in diameter are present at ...
Charles A. Knight; Jothiram Vivekanandan; Sonia G. Lasher-Trapp
A Radar-Based Climatology of Thunderstorm Days across New York State
Archived radar reports, derived from the National Weather Service radar network, were used to estimate the average annual frequencies of thunderstorm days across New York State for the period 1978�81. The archival records consist of manually-...
Phillip D. Falconer
Lightning Activity in a Hail-Producing Storm Observed with Phased-Array Radar
This study examined lightning activity relative to the rapidly evolving kinematics of a hail-producing storm on 15 August 2006. Data were provided by the National Weather Radar Testbed Phased-Array Radar, the Oklahoma Lightning Mapping Array, and ...
C. Emersic; P. L. Heinselman; D. R. MacGorman; E. C. Bruning
The Vertical Structure of TOGA COARE Convection. Part I: Radar Echo Distributions
Radar data collected by the 5-cm MIT radar, which was deployed aboard the R/V Vickers during the intensive observing period of the Tropical Ocean Global Atmosphere Coupled Ocean�Atmosphere Response Experiment, are partitioned into convective and ...
Charlotte A. DeMott; Steven A. Rutledge
Derivation of a 10-Year Radar-Based Climatology of Rainfall
Weather radars give quantitative precipitation estimates over large areas with high spatial and temporal resolutions not achieved by conventional rain gauge networks. Therefore, the derivation and analysis of a radar-based precipitation �...
Aart Overeem; Iwan Holleman; Adri Buishand
Preliminary Results from Multiparameter Airborne Rain Radar Measurement in the Western Pacific
Preliminary results are presented from multiparameter airborne radar measurements of tropical storms. The experiment was conducted in the western Pacific in September 1990 with the NASA DC-8 aircraft that was equipped with a dual-wavelength radar ...
Hiroshi Kumagai; Robert Meneghini; Toshiaki Kozu
Observations of the Small-Scale Variability of Precipitation Using an Imaging Radar
For many years, spatial and temporal inhomogeneities in precipitation fields have been studied using scanning radars, cloud radars, and disdrometers, for example. Each measurement technique has its own advantages and disadvantages. Conventional ...
Robert D. Palmer; Boon Leng Cheong; Michael W. Hoffman; Stephen J. Frasier; F. J. L�pez-Dekker
Vertical Structure of Hurricane Eyewalls as Seen by the TRMM Precipitation Radar
Statistical analysis of the vertical structure of radar echoes in the eyewalls of tropical cyclones, shown by the Tropical Rainfall Measurement Mission (TRMM) Precipitation Radar (PR), shows that the eyewall contains high reflectivities and high ...
Deanna A. Hence; Robert A. Houze Jr.
Vertical Structure of Tropical Cyclone Rainbands as Seen by the TRMM Precipitation Radar
Ten years of data from the Tropical Rainfall Measurement Mission satellite�s Precipitation Radar (TRMM PR) show the vertical structure of tropical cyclone rainbands. Radar-echo statistics show that rainbands have a two-layered structure, with ...
A Study of Thunderstorm Microphysics with Multiparameter Radar and Aircraft Observations
Excellent agreement was found between multiparameter radar signatures of hail, raindrops, and mixed-phase precipitation and in situ precipitation particle measurements made by aircraft in a northeastern Colorado hail-storm. Radar reflectivity ...
E. A. Brandes; J. Vivekanandan; J. D. Tuttle; C. J. Kessinger
A Variational Scheme for Retrieving Rainfall Rate and Hail Reflectivity Fraction from Polarization Radar
Polarization radar offers the promise of much more accurate rainfall-rate R estimates than are possible from radar reflectivity factor Z alone, not only by better characterization of the drop size distribution, but also by more reliable ...
Robin J. Hogan
The Measurement of Doppler Wind Fields with Fast Scanning Radars: Signal Processing Techniques
This paper discusses signal processing techniques being developed for making Doppler wind velocity measurements using airport surveillance radars. Techniques are presented and evaluated for velocity estimation using fast-rotating radars. In ...
John R. Anderson
Gaussian Model Adaptive Processing in Time Domain (GMAP-TD) for Weather Radars
The Gaussian model adaptive processing in the time domain (GMAP-TD) method for ground clutter suppression and signal spectral moment estimation for weather radars is presented. The technique transforms the clutter component of a weather radar ...
Cuong M. Nguyen; V. Chandrasekar
Meteorological and Astronomical Influences on Radar Reflectivity in the Convective Boundary Layer
Observations are presented of time-varying radar reflectivity during a partial solar eclipse in Oklahoma. The measurements from a radar of 10-cm wavelength, were obtained in the clear-air boundary layer. The reflectivity changes closely follow ...
Robert M. Rabin; Richard J. Doviak
Multifunction Phased-Array Radar: Time Balance Scheduler for Adaptive Weather Sensing
Phased-array radars (PARs) have the capability of instantaneously and dynamically controlling beam position on a pulse-by-pulse basis, which allows a single radar to perform multiple functions, such as tracking multiple storms or weather and ...
Ricardo Reinoso-Rondinel; Tian-You Yu; Sebasti�n Torres
Polarimetric Radar Analysis of Raindrop Size Variability in Maritime and Continental Clouds
During the Queensland Cloud Seeding Research Program, the �CP2� polarimetric radar parameter differential radar reflectivity Zdr was used to examine the raindrop size evolution in both maritime and continental clouds. The focus of this paper is to ...
James W. Wilson; Charles A. Knight; Sarah A. Tessendorf; Courtney Weeks
The ELDORA/ASTRAIA Airborne Doppler Weather Radar: High-Resolution Observations from TOGA COARE
The ELDORA/ASTRAIA (Electra Doppler Radar/Analyese Stereoscopic par Impulsions Aeroporte) airborne Doppler weather radar was recently placed in service by the National Center for Atmospheric Research and the Centre d'�tude des Environnements ...
Peter H. Hildebrand; Wen-Chau Lee; Craig A. Walther; Charles Frush; Mitchell Randall; Eric Loew; Richard Neitzel; Richard Parsons; Jacques Testud; Fran�ois Baudin; Alain LeCornec
A Doppler Radar Emulator with an Application to the Detectability of Tornadic Signatures
A Doppler radar emulator was developed to simulate the expected mean returns from scanning radar, including pulse-to-pulse variability associated with changes in viewing angle and atmospheric structure. Based on the user�s configuration, the ...
Ryan M. May; Michael I. Biggerstaff; Ming Xue
Uncertainties in Oceanic Radar Rain Maps at Kwajalein and Implications for Satellite Validation
The Kwajalein, Marshall Islands, Tropical Rainfall Measuring Mission (TRMM) ground validation radar has provided a multiyear three-dimensional radar dataset at an oceanic site. Extensive rain gauge networks are not feasible over the ocean and, ...
Robert A. Houze Jr; Stacy Brodzik; Courtney Schumacher; Sandra E. Yuter; Christopher R. Williams
Weather Radar Ground Clutter. Part II: Real-Time Identification and Filtering
The identification and mitigation of anomalous propagation (AP) and normal propagation (NP) ground clutter is an ongoing problem in radar meteorology. Scatter from ground-clutter targets routinely contaminates radar data and masks weather returns ...
J. C. Hubbert; M. Dixon; S. M. Ellis
Doppler-Radar Measurements of Clear Air Atmospheric Turbulence at 1290 MHz
We present Doppler-radar observations for the refractivity turbulence structure constant CN2 obtained with the Chatanika Radar Facility, near Fairbanks, Alaska, during a 7-day observing period in October 1976.
Ben Balsley; Vern L. Peterson
Objective Optimization of Weather Radar Networks for Low-Level Coverage Using a Genetic Algorithm
The current Weather Surveillance Radar-1988 Doppler (WSR-88D) radar network is approaching 20 years of age, leading researchers to begin exploring new opportunities for a next-generation network in the United States. With a vast list of ...
James M. Kurdzo; Robert D. Palmer
The Joint Polarization Experiment: Polarimetric Radar in Forecasting and Warning Decision Making
To test the utility and added value of polarimetric radar products in an operational environment, data from the Norman, Oklahoma (KOUN), polarimetric Weather Surveillance Radar-1988 Doppler (WSR-88D) were delivered to the National Weather Service ...
Kevin A. Scharfenberg; Daniel J. Miller; Terry J. Schuur; Paul T. Schlatter; Scott E. Giangrande; Valery M. Melnikov; Donald W. Burgess; David L. Andra Jr.; Michael P. Foster; John M. Krause
Characteristics of Radar-Identified Big Drop Zones in Swiss Hailstorms
The characteristics of the so-called �radar-identified big drop zones� (rBDZ) have been investigated. The study employs radar observations of several thunderstorms and simultaneous microphysical and vertical wind measurements with a penetrating T-...
Albert Waldvogel; Laszlo Klein; Dennis J. Musil; Paul L. Smith
An Evaluation of a Drop Distribution�Based Polarimetric Radar Rainfall Estimator
A method for estimating the governing parameters of gamma drop size distributions (DSDs) and associated rainfall rates from polarimetric radar measurements at the S band is examined. The technique uses radar reflectivity at horizontal ...
Simulation and Interpretation of the Phase Data Used by the Radar Refractivity Retrieval Algorithm
The radar refractivity retrieval algorithm applied to radar phase measurements from ground targets can provide high-resolution, near-surface moisture estimates in time and space. The reliability of the retrieval depends on the quality of the ...
Shinju Park; Fr�d�ric Fabry
Radar and Surface Measurement of Rainfall during CaPE: 26 July 1991 Case Study
Conventional usage of multiparameter radar measurements for rainfall estimation has been associated with tracking the variability of the raindrop size distribution. The use of multiparameter radar measurements in a statistical framework to ...
Eugenio Gorgucci; V. Chandrasekar; Gianfranco Scarchilli
A Wintertime Gulf Coast Squall Line Observed by EDOP Airborne Doppler Radar
An extensive wintertime squall line on 13 January 1995 occurring along the U.S. Gulf of Mexico coastline is examined using airborne radar observations combined with conventional data analysis. Flight tracks with the ER-2 Doppler radar (EDOP) ...
G. M. Heymsfield; J. B. Halverson; I. J. Caylor
Spatially Variable Advection Correction of Radar Data. Part II: Test Results
The spatially variable advection-correction/analysis procedure introduced in Part I is tested using analytical reflectivity blobs embedded in a solid-body vortex, and Terminal Doppler Weather Radar (TDWR) and Weather Surveillance Radar-1988 ...
Alan Shapiro; Katherine M. Willingham; Corey K. Potvin
Hurricane Structure and Wind Fields from Stereoscopic and Infrared Satellite Observations and Radar Data
Infrared and stereoscopic visible satellite data from synchronized scanning of GOES-East and -West are combined with ground-based radar data for Hurricane Frederic (1979) and time-composited airborne radar for Hurricane Alien (1980) to ...
A. Frederick Hasler; K. Robert Morris
The Influence of Antenna Radome on Weather Radar Calibration and Its Real-Time Assessment
Operational weather radars are usually equipped with a radome to reduce the wind load on the antenna and to allow continuous operation under bad weather conditions. The study is focused on quantifying the impact on radar polarimetric measurements ...
E. Gorgucci; R. Bechini; L. Baldini; R. Cremonini; V. Chandrasekar
The Turbulence Structure in a Continental Stratocumulus Cloud from Millimeter-Wavelength Radar Observations
The turbulent-scale vertical velocity structure in a continental stratocumulus cloud is studied using a 3-mm wavelength Doppler radar operating in a vertically pointing mode. The radar observations provided 30-m sampling in the vertical with 2-s ...
Pavlos Kollias; Bruce Albrecht
Attenuation Calibration of an X-Band Weather Radar Using a Microwave Link
The attenuation of a radar signal is a serious problem facing meteorologists and hydrologists. In heavy rain, reflectivity information can be completely lost from large portions of a radar scan. The problem is particularly acute for X-band ...
A. R. Rahimi; A. R. Holt; G. J. G. Upton; S. Kr�mer; A. Redder; H-R. Verworn
Prognostic Equation for Radar Radial Velocity Derived by Considering Atmospheric Refraction and Earth Curvature
The prognostic equation for the radial velocity field observed with a Doppler radar is derived to include the effects of atmospheric refraction and earth curvature on radar-beam height and slope angle. The derived equation, called the radial ...
Qin Xu; Li Wei
Doppler Cloud Radar Derived Drop Size Distributions in Liquid Water Stratus Clouds
A cloud particle size retrieval algorithm that uses radar reflectivity factor and Doppler velocity obtained by a 35-GHz Doppler radar and liquid water path estimated from microwave radiometer radiance measurements is developed to infer the size ...
Seiji Kato; Gerald G. Mace; Eugene E. Clothiaux; James C. Liljegren; Richard T. Austin
Systematic Variation of Observed Radar Reflectivity�Rainfall Rate Relations in the Tropics
The Tropical Rainfall Measuring Mission Global Validation Program provides a unique opportunity to compare radar datasets from different sites, because they are analyzed in a relatively uniform procedure. Monthly observed radar reflectivity�...
Eyal Amitai
Attenuation-Based Estimates of Rainfall Rates Aloft with Vertically Pointing Ka-Band Radars
An approach is suggested to retrieve low-resolution rainfall rate profiles and layer-averaged rainfall rates, Ra, from radar reflectivity measurements made by vertically pointing Ka-band radars. This approach is based on the effects of ...
Observations of Two Colorado Thunderstorms by Means of a Zenith-Pointing Doppler Radar
A description is given of the distributions of radar reflectivity, mean Doppler velocity, vertical air velocity and Doppler-velocity variance in two thunderstorms over eastern Colorado. A zenith-pointing Doppler radar was used to obtain data at ...
Louis J. Battan
The Transition from the Present Radar Dissemination System to the NEXRAD Information Dissemination Service (NIDS)
The National Weather Service (NWS) will begin replacing its current system of weather radars with Next Generation Weather Radars (NEXRAD) in late 1990. Presented is an overview of previous and current systems, and the replacement NEXRAD ...
Vico E. Baer
Potential Role Of Dual- Polarization Radar In The Validation Of Satellite Precipitation Measurements: Rationale and Opportunities
Dual-polarization weather radars have evolved significantly in the last three decades culminating in operational deployment by the National Weather Service. In addition to operational applications in the weather service, dual-polarization radars ...
V. Chandrasekar; V. N. Bringi; S. A. Rutledge; Arthur Hou; Eric Smith; Gail Skofronick Jackson; E. Gorgucci; W. A. Petersen
Mesobeta Profiles to Extrapolate Radar Precipitation Measurements above the Alps to the Ground Level
In the Alps, the volume visible by a radar is reduced because of ground clutter, elevated horizon, and earth curvature. This often inhibits a direct view on precipitation close to the ground. When using radar measurements from aloft to estimate ...
Urs Germann; J�rg Joss
Case Studies of the Vertical Velocity Seen by the Flatland Radar Compared with Indirectly Computed Values
The hypothesis that temporal averages of vertical motions over a single radar station are representative of weather systems large enough to be resolved by the radiosonde network is tested using data from the Flatland VHF radar, located in the ...
G. D. Nastrom; W. L. Clark; K. S. Gage; T. E. VanZandt; J. M. Warnock; R. Creasey; P. M. Pauley
Tropopause Folding and the Variability of the Tropopause Height as Seen by the Flatland VHF Radar
The Flatland radar, a VHF wind profiler located near Urbana, Illinois, has been used to study the variability of the tropopause over the period March 1987�April 1988. The vertically directed radar beam provides an indicator of tropopause height ...
G. D. Nastrom; J. L. Green; K. S. Gage; M. R. Peterson
Multilag Correlation Estimators for Polarimetric Radar Measurements in the Presence of Noise
The quality of polarimetric radar data degrades as the signal-to-noise ratio (SNR) decreases. This substantially limits the usage of collected polarimetric radar data to high SNR regions. To improve data quality at low SNRs, multilag correlation ...
Lei Lei; Guifu Zhang; Richard J. Doviak; Robert Palmer; Boon Leng Cheong; Ming Xue; Qing Cao; Yinguang Li
Characteristics of Rainbands, Radar Echoes, and Lightning near the North Carolina Coast during GALE
Characteristics of mesoscale rainbands and echoes in radar reflectivity data recorded during the field phase of the Genesis of Atlantic Lows Experiment (GALE) are presented. The primary sources of data were radar microfilm and manually digitized ...
Peter P. Dodge; Robert W. Burpee
Determining Weather Radar Antenna Pointing Using Signals Detected from the Sun at Low Antenna Elevations
A method to determine the elevation and azimuth biases of the radar antenna using solar signals observed by a scanning radar is presented. Data recorded at low elevation angles where the atmospheric refraction has a significant effect on the ...
Asko Huuskonen; Iwan Holleman
Comparison of Dual-Polarization Radar Measurements of Rain with Ground-Based Disdrometer Measurements
Dual-polarization radar measurements of ZH and ZDR, where ZDR = 10 logZH/ZV and ZH, ZV are the radar reflectivity factors for horizontal and vertical polarizations, respectively, are compared with values derived from raindrop-size distributions ...
J. W. F. Goddard; S. M. Cherry; V. N. Bringi
Oscillations in Mesocyclone Signatures with Range Owing to Azimuthal Radar Sampling
When a thunderstorm mesocyclone changes range relative to a Doppler radar, the deduced core diameter and mean rotational velocity of the Doppler velocity mesocyclone signature oscillate back and forth, even though the radar beam�s physical width ...
Properties of Tropical Convection Observed by Millimeter-Wave Radar Systems
This paper describes the results of analysis of over 825 000 profiles of millimeter-wave radar (MWR) reflectivities primarily collected by zenith-pointing surface radars observing tropical convection associated with various phases of activity of ...
Graeme L. Stephens; Norman B. Wood
The Impact of Beam Broadening on the Quality of Radar Polarimetric Data
The impact of beam broadening on the quality of radar polarimetric data in the presence of nonuniform beam filling (NBF) is examined both theoretically and experimentally. Cross-beam gradients of radar reflectivity Z, differential reflectivity Z...
Alexander V. Ryzhkov
Radar Observations of Transport and Diffusion in Clouds and Precipitation Using TRACIR
A remote-sensing technique called TRACIR (tracking air with circular-polarization radar) was developed recently for studying air-parcel trajectories in clouds. The technique uses a dual-circular-polarization radar to detect microwave chaff fibers ...
Brooks E. Martner; Robert A. Kropfli; John D. Marwitz
The Refractive Index Spectra within Clouds from Forward-Scatter Radar Observations
When long-wavelength radars are used to observe the atmosphere, there are occasions when radar return from a volume of cloud is unexpectedly large relative to that predicted by the classical incoherent scatter from individual cloud droplets. The ...
Earl E. Gossard; Richard G. Strauch
The Kinetic Energy of Hailfalls. Part III: Sampling Errors Inferred, from Radar Data
The representativeness of hailfall kinetic energies derived from point measurements of networks is studied by means of radar data of hail cells. The 202 cells were observed within a radius of 60 km from the 10 cm radar. Different Cartesian ...
A. Waldvogel; W. Schmid
An Extended Kalman Filter Framework for Polarimetric X-Band Weather Radar Data Processing
The different quantities measured by dual-polarization radar systems are closely linked to each other. An extended Kalman filter framework is proposed in order to make use of constraints on individual radar observables that are induced by these ...
Marc Schneebeli; Alexis Berne
Estimating the Vertical Structure of Intense Mediterranean Precipitation Using Two X-Band Weather Radar Systems
The present study aims at a preliminary approach of multiradar compositing applied to the estimation of the vertical structure of precipitation�an important issue for radar rainfall measurement and prediction. During the HYDROMET Integrated Radar ...
A. Berne; G. Delrieu; H. Andrieu
High-Resolution, Mobile Doppler Radar Observations of Cyclic Mesocyclogenesis in a Supercell
On 15 May 2003, two ground-based, mobile, Doppler radars scanned a supercell that moved through the Texas Panhandle and cyclically produced mesocyclones. The two radars collected data from the storm during a rapid cyclic mesocyclogenesis stage ...
Michael M. French; Howard B. Bluestein; David C. Dowell; Louis J. Wicker; Matthew R. Kramar; Andrew L. Pazmany
The Genesis of Three Nonsupercell Tornadoes Observed with Dual-Doppler Radar
Dual-Doppler radar analyses of three tornadoes associated with a multicellular line of storms are presented. The F2�F3 intensity tornadoes occurred on 15 June 1988 near Denver, Colorado, during the Terminal Doppler Weather Radar (TDWR) Project. ...
Rita D. Roberts; James W. Wilson
Documenting Storm Severity in the Mid-Atlantic Region Using Lightning and Radar Information
Storm severity in the mid-Atlantic region of the United States is examined using lightning, radar, and model-derived information. Automated Warning Decision Support System (WDSS) procedures are developed to create grids of lightning and radar ...
Scott D. Rudlosky; Henry E. Fuelberg
Precipitation Observed in Oklahoma Mesoscale Convective Systems with a Polarimetric Radar
In this paper, the fields of three radar polarimetric variables-differential reflectivity ZDR, specific differential phase KDP, and correlation coefficient between horizontally (H) and vertically (V) polarized echoes ?hv-along with radar ...
Nocturnal Aerosol Optical Depth Measurements with a Small-Aperture Automated Photometer Using the Moon as a Light Source
A method is described that enables the use of lunar irradiance to obtain nighttime aerosol optical depth (AOD) measurements using a small-aperture photometer. In this approach, the U.S. Geological Survey lunar calibration system was utilized to ...
Timothy A. Berkoff; Mikail Sorokin; Tom Stone; Thomas F. Eck; Raymond Hoff; Ellsworth Welton; Brent Holben
Time Correlations in Backscattering Radar Reflectivity Measurements from Cirrus Clouds
Time Correlations in Backscattering Radar Reflectivity Time Correlations in Backscattering Radar Reflectivity Measurements from Cirrus Clouds K. Ivanova, H. N. Shirer, and E. E. Clothiaux Pennsylvania State University University Park, Pennsylvania T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington Introduction The state variables of the atmosphere exhibit correlations at various spatial and temporal scales. These correlations are crucial for understanding short- and long-term trends in climate. Cirrus clouds are important phenomena in the troposphere affecting climate. To improve future parameterization of cirrus clouds in climate models, we must understand the cloud properties and how they change within the cloud. We consider fluctuations of cloud radar signals obtained at isodepths within cirrus clouds
W-band ARM Cloud Radar (WACR) Update and Status
W-band ARM Cloud Radar (WACR) Update and Status W-band ARM Cloud Radar (WACR) Update and Status PopStefanija, Ivan ProSensing, Inc. Mead, James ProSensing Inc. Widener, Kevin Pacific Northwest National Laboratory Category: Instruments Two W-band ARM Cloud Radars (WACR) have been developed for the SGP and the ARM Mobile Facility (AMF) by ProSensing. The SGP WACR was successfully deployed in the same shelter as the MMCR in 2005. It is currently collecting co-polarization and cross-polarization spectral moments (reflectivity, Doppler velocity, and spectral width) along with spectra data. The AMF WACR will be deployed with the AMF in Niamey, Niger early in 2006. We will present ingested WACR data formats available from the ARM Archive, a selected comparisons of WACR and MMCR data at SGP, and data from
Mixed-Phase Cloud Retrievals Using Doppler Radar Spectra
Mixed-Phase Cloud Retrievals Using Mixed-Phase Cloud Retrievals Using Doppler Radar Spectra M. D. Shupe, S. Y. Matrosov, and T. L. Schneider National Oceanic and Atmospheric Administration Environmental Technology Laboratory Boulder, Colorado P. Kollias Rosentiel School of Marine Atmospheric Sciences University of Miami Miami, Florida Introduction The radar Doppler spectrum contains a wealth of information on cloud microphysical properties. Typically, radar-based cloud retrievals use only the zeroth or first moments of the Doppler spectrum - reflectivity and mean Doppler velocity - to derive quantities such as cloud water content and particle characteristic size (e.g., Liou and Sassen 1994; Matrosov et al. 2002). When using only the moments of the Doppler spectrum, important spectral information can be lost, particularly when the spectrum is
Wideband Waveform Design principles for Solid-state Weather Radars
The use of solid-state transmitter is becoming a key part of the strategy to realize a network of low cost electronically steered radars. However, solid-state transmitters have low peak powers and this necessitates the use of pulse compression waveforms. In this paper a frequency diversity wideband waveforms design is proposed to mitigate low sensitivity of solid-state transmitters. In addition, the waveforms mitigate the range eclipsing problem associated with long pulse compression. An analysis of the performance of pulse compression using mismatched compression filters designed to minimize side lobe levels is presented. The impact of range side lobe level on the retrieval of Doppler moments are presented. Realistic simulations are performed based on CSU-CHILL radar data and Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) Integrated Project I (IP1) radar data.
Bharadwaj, Nitin; Chandrasekar, V.
Application of Dual-Polarization Radar Melting-Layer Detection Algorithm
A polarimetric melting-layer detection algorithm developed for an S-band radar has been modified for use by the King City C-band radar in southern Ontario, Canada. The technique ingests radar scan volume data to determine the melting-layer top ...
S. Boodoo; D. Hudak; N. Donaldson; M. Leduc
Scatter and Doppler Effect of Wind Power Plants to Land Radars
Wind power plant installations at different scales are in an increasing pattern starting from year 2000. A curiosity has been raised about 4-5 years ago for if wind turbines interfere with radars. The interference occurs when wind turbines reflect radar ... Keywords: clutter, Doppler, radar, scatter, turbine, wind
Derya Sozen; Mesut Kartal
Exploring Impacts of Rapid-Scan Radar Data on NWS Warning Decisions
Rapid-scan weather radars, such as the S-band phased array radar at the National Weather Radar Testbed in Norman, Oklahoma, improve precision in the depiction of severe storm processes. To explore potential impacts of such data on forecaster ...
Pamela L. Heinselman; Daphne S. LaDue; Heather Lazrus
Proposal for a Spaceborne Dual-Beam Rain Radar with Doppler Capability
The potential characteristics and performances of a spaceborne dual-beam radar (or stereo radar) operating at 24 GHz, and devoted primarily to the retrieval of rain-rate structure by using the stereo-radar analysis, were presented in a previous ...
Paul Amayenc; Jacques Testud; Mongi Marzoug
Elements of a continuous-wave borehole radar. Final report
The theory is developed for the antenna array for a proposed continuous-wave, ground-penetrating radar for use in a borehole, and field measurements are presented. Accomplishments include the underground measurement of the transmitting beam in the azimuth plane, active azimuth-steering of the transmitting beam, and the development of a range-to-target algorithm. The excellent performance of the antenna array supports the concept of a continuous-wave borehole radar. A field-prototype should be developed for use in both geothermal zones and for the exploration and recovery of oil and gas.
Caffey, T.W.H. [Sandia National Labs., Albuquerque, NM (United States). Geophysical Technology Dept.
Science Goals for the ARM Recovery Act Radars
Science Goals for the ARM Recovery Act Radars. In October 2008, an ARM workshop brought together approximately 30 climate research scientists to discuss the Atmospheric Radiation Measurement (ARM) Climate Research Facility's role in solving outstanding climate science issues. Through this discussion it was noted that one of ARM's primary contributions is to provide detailed information about cloud profiles and their impact on radiative fluxes. This work supports cloud parameterization development and improved understanding of cloud processes necessary for that development. A critical part of this work is measuring microphysical properties (cloud ice and liquid water content, cloud particle sizes, shapes, and distribution). ARM measurements and research have long included an emphasis on obtaining the best possible microphysical parameters with the available instrumentation. At the time of the workshop, this research was reaching the point where additional reduction in uncertainties in these critical parameters required new instrumentation for applications such as specifying radiative heating profiles, measuring vertical velocities, and studying the convective triggering and evolution of three-dimensional (3D) cloud fields. ARM was already operating a subset of the necessary instrumentation to make some progress on these problems; each of the ARM sites included (and still includes) a cloud radar (operating at 35 or 94 GHz), a cloud lidar, and balloon-borne temperature and humidity sensors. However, these measurements were inadequate for determining detailed microphysical properties in most cases. Additional instrumentation needed to improve retrievals of microphysical processes includes radars at two additional frequencies for a total of three at a single site (35 GHz, 94 GHz, and a precipitation radar) and a Doppler lidar. Evolving to a multi-frequency scanning radar is a medium-term goal to bridge our understanding of two-dimensional (2D) retrievals to the 3D cloud field. These additional microphysical measurements would allow detailed cloud properties to be derived even in the presence of light precipitation. It is important to couple these detailed measurements of cloud microphysics to vertical motion on the cloud scale to couple microphysics with meteorological processes. Vertically pointing Doppler radars provide the vertical motion of cloud particles but, to separate particle motion from air motion, a wind profiler is required. The American Recovery and Reinvestment Act provided the means to address these needs and implement a multi-frequency suite of radars, including scanning radars, at each of the ARM sites. In addition, Doppler lidars have been deployed at several sites. With these new measurement capabilities, ARM has the measurement capabilities to tackle the problems of improving microphysical profile descriptions and evaluating the relationship between our current narrow-field-of view, zenith perspective on clouds to a description of the full 3D cloud field and its temporal evolution.
JH Mather
Aperture lamp
A discharge lamp includes means for containing a light emitting fill, the fill being capable of absorbing light at one wavelength and re-emitting the light at a different wavelength, the light emitted from the fill having a first spectral power distribution in the absence of reflection of light back into the fill; means for exciting the fill to cause the fill to emit light; and means for reflecting some of the light emitted by the fill back into the fill while allowing some light to exit, the exiting light having a second spectral power distribution with proportionately more light in the visible region as compared to the first spectral power distribution, wherein the light re-emitted by the fill is shifted in wavelength with respect to the absorbed light and the magnitude of the shift is in relation to an effective optical path length. Another discharge lamp includes an envelope; a fill which emits light when excited disposed in the envelope; a source of excitation power coupled to the fill to excite the fill and cause the fill to emit light; and a reflective ceramic structure disposed around the envelope and defining an light emitting opening, wherein the structure comprises a sintered body built up directly on the envelope and made from a combination of alumina and silica.
MacLennan, Donald A. (Gaithersburg, MD); Turner, Brian P. (Damascus, MD)
State of the Science: Radar View of Tropical Cyclones
Radar played an important role in studies of tropical cyclones since it was developed in the 1940s. In the last 15 years, technological improvements such as the U.S. National Oceanic and Atmospheric Administration (NOAA) WP-3D tail airborne ...
Frank D. Marks Jr.
Application of Electromagnetic (EM): Radar Salah M. Al-Ofi
the atomic bomb [2]. III. PRINCIPLE OF WORK The main concept of radar relays on ECHO PRINCIPLE Engineering King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia. Abstract- This report lunched bombs. The British government was the first to gather a team of scien- tists and engineers
Masoudi, Husain M.
Considerations for Polarimetric Upgrades to Operational WSR-88D Radars
This paper reports on the steps taken by the National Severe Storms Laboratory (NSSL) to 1) develop open system hardware to facilitate upgrades to the WSR-88D (NEXRAD) radar and 2) improve identification of the type of precipitation and its ...
R. J. Doviak; V. Bringi; A. Ryzhkov; A. Zahrai; D. Zrni?
Estimation of the Mean Field Bias of Radar Rainfall Estimates
In this paper procedures are developed for estimating the mean field bias of radar rainfall estimates. Mean field bias is modeled as a random process that varies not only from storm to storm but also over the course of a storm. State estimates of ...
James A. Smith; Witold F. Krajewski
High-Frequency Radar Mapping of Surface Currents Using WERA
A dual-station high-frequency Wellen Radar (WERA), transmitting at 16.045 MHz, was deployed along the west Florida shelf in phased array mode during the summer of 2003. A 33-day, continuous time series of radial and vector surface current fields ...
Lynn K. Shay; Jorge Martinez-Pedraja; Thomas M. Cook; Brian K. Haus; Robert H. Weisberg
Radar Backscattering of Microwaves by Spongy Ice Spheres
The radar backscattering cross section of a spongy ice hailstone�a mixture of ice and liquid water�depends on its size, shape and dielectric function. There are two types of theories of the effective dielectric function of two-component mixtures: ...
Hydrological Validation of a Radar-Based Nowcasting Technique
Nowcasting precipitation is a key element in the anticipation of floods in warning systems. In this framework, weather radars are very useful because of the high resolution of their measurements both in time and space. The aim of this study is to ...
Marc Berenguer; Carles Corral; Rafael S�nchez-Diezma; Daniel Sempere-Torres
Assessment Of The Wind Farm Impact On The Radar
This study shows the means to evaluate the wind farm impact on the radar. It proposes the set of tools, which can be used to realise this objective. The big part of report covers the study of complex pattern propagation factor as the critical issue of the Advanced Propagation Model (APM). Finally, the reader can find here the implementation of this algorithm - the real scenario in Inverness airport (the United Kingdom), where the ATC radar STAR 2000, developed by Thales Air Systems, operates in the presence of several wind farms. Basically, the project is based on terms of the department "Strategy Technology & Innovation", where it has been done. Also you can find here how the radar industry can act with the problem engendered by wind farms. The current strategies in this area are presented, such as a wind turbine production, improvements of air traffic handling procedures and the collaboration between developers of radars and wind turbines. The possible strategy for Thales as a main pioneer was given as ...
Norman, Evgeny D
Radar Measurement of Tidal Winds at Stratospheric Heights over Arecibo
Wind oscillations of tidal periods that showed a marked downward phase progression were detected at the lower stratosphere using the Arecibo radar. The amplitudes of 1�5 m s?1 were inferred for both diurnal and semidiurnal components, much larger ...
Shoichiro Fukao; Toru Sato; Norikazu Yamasaki; Robert M. Harper; Susumu Kato
A Wavelet-Based Ammunition Doppler Radar System
Today's state-of-the-art ammunition Doppler radars use the Fourier spectrogram for the joint time-frequency analysis of ammunition Doppler signals. In this paper, we implement the joint time-frequency analysis of ammunition Doppler signals based on the ...
S. H. Ong; Abbas Z. Kouzani
X-Band Polarimetric Weather Radar Observations of a Hailstorm
This paper presents an analysis of a hail event that occurred 27 May 2012 over Brignoles, located in southeastern France. The event was observed by an X-band polarimetric radar located in Mont Maurel, 75 km northeast of the hailstorm. Lightning ...
Jordi Figueras i Ventura; Fran�oise Honor�; Pierre Tabary
Doppler Radar Observations of Dust Devils in Texas
Analyses of a dust-devil dataset collected in northwest Texas are presented. The data were collected just above the ground at close range with a mobile, W-band (3-mm wavelength) Doppler radar having an azimuthal (radial) resolution of 3�5 m (30 m)...
Howard B. Bluestein; Christopher C. Weiss; Andrew L. Pazmany
FODO-Supercell Based Compact Ring Design with Tunable Momentum Compaction and Optimized Dynamic Aperture
A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and predamping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.
Sun, Yipeng; /SLAC
A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and pre-damping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.
Eulerian and Lagrangian Correspondence of High-Frequency Radar and Surface Drifter Data: Effects of Radar Resolution and Flow Components
This study investigated the correspondence between the near-surface drifters from a mass drifter deployment near Martha�s Vineyard, MA and the surface current observations from a network of 3 high-resolution high-frequency radars to understand the ...
I. I. Rypina; A. Kirincich; R. Limeburner; I. A. Udovydchenkov
Polarimetric Radar Observations in the Ice Region of Precipitating Clouds at C-Band and X-Band Radar Frequencies
Data collected by C-band and X-band radars in northwestern Italy are analyzed to study the behavior of the polarimetric variables in the ice region of precipitating clouds, with special emphasis on the specific differential phase Kdp. It is found ...
R. Bechini; L. Baldini; V. Chandrasekar
Geographic Information System At Brady Hot Springs Area (Laney, 2005) |
Geographic Information System At Brady Hot Springs Geographic Information System At Brady Hot Springs Area (Laney, 2005) Exploration Activity Details Location Brady Hot Springs Area Exploration Technique Geographic Information System Activity Date Usefulness not indicated DOE-funding Unknown Notes InSAR Ground Displacement Analysis, Gary Oppliger and Mark Coolbaugh. This project supports increased utilization of geothermal resources in the Western United States by developing basic measurements and interpretations that will assist reservoir management and expansion at Bradys, Desert Peak and the Desert Peak EGS study area (80 km NE of Reno, Nevada) and will serve as a technology template for other geothermal fields. Raw format European Space Agency (ESA) ERS 1/2 satellite synthetic Aperture Radar (SAR) radar scenes acquired from 1992 through 2002 are being processed to
Single fracture aperture patterns: Characterization by slit-island fractal analysis
Single fracture measurements are difficult to obtain, but they are the only means we have to observe and study natural fracture morphology. The character of the fracture openings (apertures) is often one of the primary factors controlling fluid flow in the fracture. In particular, the shape, distribution, and connectivity of contact areas and flow channels can affect the relative permeability of wetting and non-wetting fluid phases in unsaturated systems. In this paper we use three methods of fractal analysis (the slit-island, the divider, and the variogram) as well as statistical and geostatistical analysis to characterize the geometry of measured fracture apertures obtained from two different fractured rock specimens from the field. One of these is a granitic fracture (crack) of homogeneous lithology and no displacement, the other is a fracture (fault) obtained from a highly altered fault zone, containing striations and slickensides. We discuss the fractal and geostatistical analysis of these two fractures in the context of what information is most helpful for making predictions about fluid flow in single fractures.
Cox, B.L.; Wang, J.S.Y.
A Methodology to Derive Radar Reflectivity�Liquid Equivalent Snow Rate Relations Using C-Band Radar and a 2D Video Disdrometer
The objective of this work is to derive equivalent radar reflectivity factor�liquid equivalent snow rate (Ze�SR) power-law relations for snowfall using the C-band King City operational weather radar and a 2D video disdrometer (2DVD). The 2DVD ...
Gwo-Jong Huang; V. N. Bringi; Robert Cifelli; David Hudak; W. A. Petersen
Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments
Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by observing neutron images in two different energy bands for primary (13-17 MeV) and down-scattered (6-12 MeV) neutrons. From this, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. These experiments provide small sources with high yield neutron flux. An aperture design that includes an array of pinholes and penumbral apertures has provided the opportunity to image the same source with two different techniques. This allows for an evaluation of these different aperture designs and reconstruction algorithms.
Guler, N.; Volegov, P.; Danly, C. R.; Grim, G. P.; Merrill, F. E.; Wilde, C. H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States)
Sample Observations from the 2001.Multi-Frequency Radar IOP
Sample Observations from the 2001 Sample Observations from the 2001 Multi-Frequency Radar IOP C. R. Williams Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder, Colorado C. R. Williams and K. S. Gage National Oceanic and Atmospheric Administration Aeronomy Laboratory Boulder, Colorado L. Leon and S. Cruz-Pol University of Puerto Rico Mayaguez Campus S. M. Sekelsky Microwave Remote Sensing Laboratory University of Massachusetts Amherst, Massachusetts Introduction The 2001 Multi-Frequency Radar Intensive Operational Period (IOP) was designed to collect a long dataset of W-band (95 GHz), Ka-band (35 GHz), and S-band (2.8 GHz) vertical profiling observations to investigate insect scattering and precipitating particle scattering above the Southern Great Plains
Feasibility of a borehole VHF radar technique for fracture mapping
Experiments were conducted to establish the feasibility of a downhole high-frequency electromagnetic technique for location of fractures in the vicinity of boreholes. An existing flame-cut slot in granite was filled with salt water to simulate a brine-filled fracture. A transmitter consisting of a phased dual-dipole array arranged to provide a directional signal toward the fracture was installed in a borehole opposite the fracture. A receiver operated at 30 to 300 MHz was also located in the same borehole. The radar returns from the simulated fracture were detectable in boreholes located at distances of up to 12 meters from the fracture. These results indicate for the first time the feasibility of a downhole VHF radar for use in a single borehole for detection of fractures located away from the borehole.
Chang, H.T.
Dictionary for Sparse Representation of Chirp Echo in Broadband Radar
A new dictionary for sparse representation of chirp echo in broadband radar is put forward in this paper. Different with chirplet decomposition which decomposes echo in time-frequency plane, the dictionary transforms the sparsity of target observed by radar in distance range to the sparsity in frequency domain by stretch processing and the sparse representation of echo is realized. Using strict deduction with mathematics, the sparsity of echo in dictionary is proved and the dictionary is orthogonal. In the application property, the construction of dictionary is simple, the parameters that are needed for dictionary can be obtained conveniently and the dictionary is convenient to use. Furthermore, the object of application can be expanded to the echo of multi-component chirps with single freedom degree.
Gao, Lei