Title: United States National Grid - Wikipedia
Headings: United States National Grid
United States National Grid
Contents
Overview
Description: How the USNG works
History
Advantages over latitude/longitude
Limitations and tradeoffs
Adoption and current applications
Standards
Gridded maps
Software applications
Search and rescue (SAR)
Emergency Location Marker (ELM)
First responders
Emergency Management
Asset Identification and Mapping
Recreation and other uses
Future direction and initiatives
See also
References
Further reading
External links

Content: In the first half of the 20th Century, State Plane Coordinate Systems (SPCS) brought the simplicity and convenience of Cartesian coordinates to state-level areas, providing high accuracy (low distortion) survey-grade coordinates for use primarily by state and local governments. ( Both of these planar systems remain in use today for specialized purposes.) Internationally, during the period between World Wars I and II, several European nations mapped their territory with national-scale grid systems optimized for the geography of each country, such as the Ordnance Survey National Grid (British National Grid). Near the end of World War II, the Universal Transverse Mercator (UTM) coordinate system extended this grid concept around the globe, dividing it into 60 zones of 6 degrees longitude each. Circa 1949, the US further refined UTM for ease of use (and combined it with the Universal Polar Stereographic system covering polar areas) to create the Military Grid Reference System (MGRS), which remains the geocoordinate standard used across the militaries of NATO counties. In the 1990s, a US grass-roots citizen effort led to the Public X-Y Mapping Project, a not-for-profit organization created specifically to promote the acceptance of a national grid for the United States. The Public XY Mapping Project developed the idea, conducting informal tests and surveys to determine which coordinate reference system best met the requirements of national consistency and ease of human use. Based on its findings, a standard based on the MGRS was adopted and brought to the Federal Geographic Data Committee (FGDC) in 1998. After an iterative review process and public comment period, the USNG was adopted by the FGDC as standard FGDC-STD-011-2001 in December 2001. Since then, the USNG has seen gradual but steadily increasing adoption both in formal standards and in practical use and applications, in public safety and in oth