Included within each zipfile is a FGDB (Esri 9.3) containing the following:
Military Grid Reference System (MGRS) 10km Square Identifier polygons for the specific Grid Zone Designator (GZD), for each 100,000-meter square identifier’s(100km) Grid Square.
Abstract: This is a Military Grid Reference System (MGRS) 10km Square Identifier polygon shapefile. The polygons are defined by UTM zone MGRS regions, with subdivisions into MGRS 10km Square Identifiers. The MGRS is the geocoordinate standard used by US Armed Forces and NATO militaries for locating points on the earth. The MGRS is derived from the UTM (Universal Transverse Mercator) grid system and the UPS (Universal Polar Stereographic) grid system, but uses a different labeling convention. A single alpha-numeric value references an area that is unique for the entire earth. The MGRS is used for the entire earth.
Military Grid Reference System (MGRS) 1km Square Identifier polygons for the specific Grid Zone Designator (GZD), for each 100,000-meter square identifier’s(100km) Grid Square.
Abstract: This is a Military Grid Reference System (MGRS) 1km Square Identifier polygon shapefile. The polygons are defined by UTM zone MGRS regions, with subdivisions into MGRS 1km Square Identifiers. The MGRS is the geocoordinate standard used by US Armed Forces and NATO militaries for locating points on the earth. The MGRS is derived from the UTM (Universal Transverse Mercator) grid system and the UPS (Universal Polar Stereographic) grid system, but uses a different labeling convention. A single alpha-numeric value references an area that is unique for the entire earth. The MGRS is used for the entire earth.
Military Grid Reference System (MGRS) 100m Square Identifier polygons for the specific Grid Zone Designator (GZD), for each 100,000-meter square identifier’s(100km) Grid Square.
Abstract: This is a Military Grid Reference System (MGRS) 100m Square Identifier polygon Shapefile. The polygons are defined by UTM zone and MGRS band letters into mostly 100km MGRS regions, with subdivisions into MGRS 100m Square Identifiers. The MGRS is the geocoordinate standard used by US Armed Forces and NATO militaries for locating points on the earth. The MGRS is derived from the UTM (Universal Transverse Mercator) grid system and the UPS (Universal Polar Stereographic) grid system, but uses a different labeling convention. A single alpha-numeric value references an area that is unique for the entire earth. The MGRS is used for the entire earth.
Additionally each FGDB comes with a MGRS 100km Square Identifier polygon created by the NGA.
MGRS 100km Square Identifier polygon
Abstract: This is a MGRS 100km Square Identifier polygon shapefile. The polygons are defined by UTM zone and MGRS band letters into mostly 6ºx8º polygons, with subdivisions into MGRS 100km Square Identifiers. There are no classification restrictions on this information. This information was created by the National Geospatial-Intelligence Agency (NGA) Coordinate Systems Analysis Team (SNAC). This information was created in 2009. Acronyms used in the attribute table and file name include: CM = central meridian, GZD = grid zone designator, n = northern hemisphere, s = southern hemisphere, LAT = latitude, LONG = longitude.
Each Zipfile contains Military Grid Reference System (MGRS) Data.
The 100m MGRS data layers have been derived by the GeoPlan Center from the National Geospatial-Intelligence Agency (NGA) 100KM MGRS data layers for each UTM Zone’s MGRS Grid Zone Designator (GZD). Each MGRS GZD File Geodatabase (ArcGIS 9.3) has been placed in its own folder. Each folder contains the metadata for each data type (100km, 10km, 1km, 100m) found in the File Geodatabase:
Example: mgrs_17s_100m
- MGRS_17S_100m_esri93.gdb
- MGRS_100kmSQ_ID_17S [This is a MGRS 100km Square Identifier polygon layer]
- MGRS_17S_10km [This is a MGRS 10km Square Identifier polygon layer]
- MGRS_17S_1km [This is a MGRS 1km Square Identifier polygon layer]
- MGRS_17SKA_100m [This is a MGRS 100m Square Identifier polygon layer]
To view the NGA Worldwide MGRS GZD layer (mgrs_gzd_worldwide_wgs84) please see the mgrs_supplemental_data directory (MGRS_Supplemental_Data.gdb)
When converting from MGRS to USNG use the following projection transformation:
NAD_1983_To_WGS_1984_5
Transformation parameters calculated by the U. S. National Geodetic Survey (NGS) using CORS stations, and ties WGS 1984 to ITRF96. This transformation method should be used for the 48 contiguous states and for the state of Alaska, as well, effective with version 9.3 of ArcGIS Desktop.
The Universal Transverse Mercator (UTM) projection is a planer projection used to project the curved surface of the earth on a two-dimensional plane. In the U.S, excluding Alaska, there are approximately 12 UTM zones. Irregular grid cells with areas less than 1-kilometer square occur along the edges of each zone junction. These Zipper Cells occur because mapping the three-dimensional spherical earth on a two-dimensional plane creates distortions which may appear as sliver polygons.
Source: U.S. Fish and Wildlife Service
Additionally there is also a small North and South MGRS zipper effect where seams with slivers are also a by-product of the transformation of the earth from a round object to a flat one, however, this by-product is more easily observed in the East and West MGRS seams.