My visitation logs show a surprisingly large number of visitors interested in converters for the Military Grid Reference System (MGRS), the standard geocoordinate system used by members of the NATO Alliance. So I thought I’d do a quick roundup of previous links/posts related to MGRS, and then talk about another program that might be useful if you’re working in that coordinate system.
- A link to a KML network file that puts a labeled MGRS grid into Google Earth (original post); zoom in to the desired area, then check the box next to the link to display the grid
- A simple converter program for converting a single point from MGRS to lat/long or UTM (and back again) (original post)
- Using the Inquire tool in the ERDAS Viewfinder program to determine the MGRS coordinate on a georeferenced raster image (original post)
- The GeoTrans program from the NGA can handle single point MGRS conversions, as well as batch processing of coordinates in text files (original post)
The new option is MicroDEM, a versatile terrain analysis GIS program. If you open a raster or vector file in the program, and move the cursor across the data display, the default is for the latitude/longitude of that cursor point to be displayed at the bottom in the status bar. Go to the Options menu, Units tab, select either MGRS or Short MGRS, and the MGRS location corresponding to the current cursor position will now be displayed at the bottom instead of lat/long. Go to the Options menu, Coordinates tab, check the box next to “MGRS and Lat/Long when roaming”, and both coordinates in both systems will display on the bottom status bar:
For a raster image display, select Calculate => Map Window Corners, and get the MGRS coordinates for the corners of the map ,as well as the center, in a text box you can copy and paste from:
HUMPHREYS PEAK 24K Current map window, corners and center:
Size: 13.10×16.41 km
Sat on map: HUMPHREYS PEAK 24K
Finally, while there doesn’t seem to be a direct function to click on a map and get the coordinate position, there is an indirect function that serves the same purpose. Choose Cartography => Datum Shift, select a secondary datum from the list that comes up, then select “No Labels”. Double-click on any point on the map, and you’ll get a text box with the coordinates at that position in lat/long and MGRS, in the program’s native WGS84 datum and the one you selected above:
WGS84: N35.3125633° W111.693389° 12SVE3696807927
NAD27: N35.3125304° W111.692657° 12SVQ3703307724
Lat/long shift: 66.5 m E, 4.1 m N, 66.7 m total
UTM Shift: 65.1 m E, 202.6 m N, 212.8 m total
Use the select/zoom tools at the top of the MicroDEM map display window for finer placement of the cursor position.
If there is enough interest I could post some conversion code for MGRS too. The code is also in GeoTrans. It would be good to mention that MGRS is really UTM with additional grid numbers.
The GEOTRANS software is from the government you can download it here (with source code in C):
Or you can use this website with using a Java Applet: