maps after data has been corrected. Surveying software There are a large number of surveying packages available on various computer platforms, most of which have been developed by cavers with a basis in computer programming. Many of the packages perform particularly well for specific tasks, and as such many cave surveyors will not solely choose one product over another for all cartographic tasks. A popular program for producing a centerline survey is Survex, which was originally developed by members of the Cambridge University Caving Club for processing survey data from club expeditions to Austria. It was released to the public in 1992. The centerline data can then be exported in various formats and the cave detail drawn in with various other programmes such as AutoCAD, Adobe Illustrator and Inkscape. Other programmes such as 'Tunnel' and Therion have full centerline and map editing capabilities. Therion notably, when it closes survey loops, warps the passages to fit over their length, meaning that entire passages do not have to be redrawn. Unlike Therion's 2D warping capabilities, CaveWhere warps passages in 3D. This includes warping plan and profile sketches. CaveWhere also supports loop closure (using Survex) and provides a user friendly interface for entering and visualizing cave survey data. Terrestrial LiDAR units are increasing significantly in accuracy and decreasing in price. Several Caves have been "scanned" using both "time of flight" and "phase shift" LiDAR units. The differences are in the relative accuracies available to each. The Oregon Caves National Park, was LiDAR scanned in August 2011, as were the Paisley Caves Archaeological dig site in SE Oregon. Both were scanned with a FARO Focus Phase shift scanner with +/-2mm accuracy. The Oregon Caves were scanned from the main public entrance to the 110 exit and were loop surveyed to the point of beginning. The data is not yet available for public use, but copies are retained by both the US Park Service and i-TEN Associates in Portland, Oregon. Automated methods In recent years an underground geographic positioning technology called HORTA has been utilized in the mining industry. The inertial navigation system technology utilizes a gyroscope and an accelerometer to aid in 3D-position determination. Such automated methods have provided a more than fifty-fold increase in underground surveying productivity with more accurate and finer detail maps as well. See also References External links Laser Scanning History: Paisley Caves Compass Points, the official journal of the