The Military Grid Reference System (MGRS) is a two-dimensional grid that uniquely identifies a square meter anywhere on the earth. The MGRS attempts to represent the entire surface of the Earth on a worldwide grid. The grid is based on the UTM (between 80°S and 84°N latitudes) and UPS (Universal Polar Stereographic) systems.
Currently, the Geographic Calculator only supports MGRS points in the UTM-based latitude range (between 80°S and 84°N ).
MGRS coordinates are comprised of 7 parts, 3 of which correspond to the UTM/UPS zone that contains the coordinate. In addition to the Datum (which is not explicitly expressed in the MGRS coordinate), the UTM/UPS zone and latitude band (described below) are part of the MGRS point.
The UTM area is divided into 60 longitudinal strips, each 6° wide. The strips are numbered 1-60 beginning at the 180°-174° W (Zone 1) and increase to the East (i.e. 174°-168° W = Zone 2, etc.).
Each strip (i.e. Zone) is then divided (horizontally) into 8° latitude bands. The bands are lettered “C” (80° S) through “X” (80° N) omitting the letters “I” and “O”.
MGRS Coordinates
The MGRS coordinate consists of seven parameters:
Zone Number
Equivalent to corresponding UTM/UPS
zone number.
Example:
19TDJ3858897366
“19”
is equivalent to the corresponding
UTM zone.
Band Letter
Equivalent to UTM/UPS latitude band letter.
Example:
19TDJ3858897366
“T” is the corresponding UTM
latitude band letter.
MGRS Column Letter
This is the first of 2 letters used to define the 100 kilometer square
within the UTM/UPS block. The columns A-Z (excluding "I"
and "O"), like UTM, start at 180° and increase toward the
East. Every 3 columns, the pattern repeats.
Example:
19TDJ3858897366
“D” is the MGRS column letter
MGRS
Row Letters
This is the second of 2 letters used to define the 100 kilometer square
within the UTM/UPS block. Row letters increase to the North. The letters
cycle backwards through the alphabet in the southern hemisphere (J,
H, G, ... going south).Zone 1, A-H; Rows
MGRS Easting
MGRS Easting value consists of 5
digits. Represents the number of meters east of the origin (i.e.
southwest corner) of the 100 kilometer square in which it is contained.
Example:
19TDJ3858897366
“38588”
is the MGRS Easting value
MGRS
Northing
MGRS Northing value consists of 5-digits. Represents the number of
meters north of the origin (i.e. southwest corner) of the 100
kilometer square in which it is contained.
Example:
19TDJ3858897366
“97366” is the MGRS Easting value
Example MGRS Coordinate Conversion
44° 13’ 36.96” N, 069° 46’ 08.11” W (Geodetic/WGS84) is equivalent to 19TDJ3858897366MGRS(WGS84).
UTM Zone 19
Latitude Band T
MGRS column D
MGRS row J
MGRS Easting 38588
MGRS Northing 97366
Note the DATUM is not explicitly stated in the MGRS coordinate.
Conversions between geodetic and MGRS are ellipsoid dependent.
Parker, W. and Bartholomew, R., Issues in Automating the Military Grid Reference System, IN: The Fifth International Geodetic Symposium on Satellite Positioning, Vol. II, 903-913.
Parker, W.S., and Bartholomew, R.G., 1988, Mapping, Charting, and Geodesy in the DoD Standard GPS Receivers, IEEE Plans Record, 145-152.
NOTE: This coordinate system is not supported for vector data conversions