Sunday, April 10, 2011


If you use maps and charts a lot in your work like I do - whether for navigation or survey purposes - you will find this information useful.

The U.S. Military Grid Reference System (MGRS) conveniently flattens the world out into 6° by 8° geographic areas, each of which is given a unique identification, called the Grid Zone Designation - essentially, 100,000-meter square "chessboards".

Latitude & Longitude vs UTM grids.

Each square is identified by two letters called tie 100,000-meter square identification. This identification is unique within the area covered by the Grid Zone Designation.

100,000 meter MGRS Square Designators

If you've spent more than a day in uniform, you already know this, and you've probably relied upon land navigation skills at least once in your life. For everybody else - to include the military guys - you must be aware that the world is becoming smaller, but yet at the same time increasingly more complex.

Back in the good old days a soldier could navigate and operate happily with a lensatic compass and a 1:50,000 mapsheet, nowadays navigational tools may include civilian GPS devices and 1:250,000 Joint Operational Graphic (JOG) charts - which give Lat / Long but no MGRS.

This tool allows you to convert a coordinate from latitude longitude, into MGRS (Military Grid Reference System) coordinates using the WGS 84 standard. Enter the LAT / LONG coordinates in decimal degrees (convert degree minutes seconds to decimal degrees).

Enough for one day? Today's Bird HERE



  1. Never did get used to that newfangled GPS. I always trust a good compass. Lensatic is good, but I prefer a Brunton. good for measuring strikes & dips.

  2. I find when locating my destination face east and north is in the left.
    Face west and the north is in the right.
    The earth rotates from the West to the East.
    On a cloudy day you look for the trees that will give you the south direction because the leaves point always to the South.
    For me I use the map 24 Zones lettered A to Z (Omitting I and O).
    12 Bands lettered A to M (Omitting I).
    15 degrees Intervals (15 degrees 1 hour) (4 minutes per 1 degree).
    15X15 minute grids lettered from A to Q from bottom South west corner.
    (Omitting I).
    sub divide to seconds.