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Universal Transverse Mercator (UTM), the Military Grid Reference System (MGRS), and the Universal Polar Stereographic (UPS)


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OVERVIEW | DESIGN | UTM | UTM DOWNLOADS | MGRS | MGRS DOWNLOADS | UPS | LETTERING/NUMBERING | UTM/UPS/MGRS DOCUMENTATION


  • OVERVIEW---- UTM coordinates are based on a family of 120 Transverse Mercator map projections (two for each UTM zone, with one for each N/S hemisphere). The earth is divided into 60 zones, each 6° wide in longitude (with the exception of a few non-standard-width zones for Svalbard and southwest of Norway). See (Figure 1).

  • Figure 1.   60 UTM Zones divided North and South.   Top↑



  • DESIGN---- UTM divides the earth into 60 zones, each 6° wide in longitude (with the exception of a few non-standard-width zones for Svalbard and southwest Norway).
    • UTM is limited to the area between 84°N and 80°S. Beyond that, Universal Polar Stereographic (UPS) coordinates are used. See section on UPS.
      • The X value, called the Easting, has a value of 500,000m at the central meridian of each zone. See (Figure 2).
      • The Y value, called the Northing, has a value of 0m at the equator for the northern hemisphere and 10,000,000m at the equator for the southern hemisphere. See (Figure 3).

    Figure 2.   Easting Values.   Top↑
    Figure 3.   Northing Values.   Top↑



  • POSITIONING IN UTM---- Read below to know how to reference or express a position in Universal Transverse Mercator (UTM) coordinates. See (Figure 4).
    • In the UTM system, positions are expressed as Easting / Northing, e.g. “580817mE, 4251205mN”. In some cases, the letters are left off, e.g. “580817 4251205”.
    • If positions occur near UTM zone junctions, the UTM zone may also be specified, e.g. “580817mE, 4251205mN, Zone 15”.
    • Since the above expresses two possible positions on the earth, the hemisphere may also be specified, e.g. “580817mE, 4251205mN, Zone 15, Northern Hemisphere” (Figure 4).
    • Many systems abbreviate the above, representing the hemisphere as a single letter, “N” for northern hemisphere, and “S” for southern hemisphere, e.g. “15N 580817 4251205”.
    • CAUTION: IN MANY SYSTEMS, THE LETTER AFTER THE ZONE NUMBER DESIGNATES A LATITUDINAL BAND, NOT A HEMISPHERE.

    How to read UTM coordinates
    Figure 4.   Example of position expressed in both Lat/Long and UTM coordinates.   Top↑

  • UTM DOWNLOADS

  • Click the Link To Download UTM Zone Boundaries Shapefile (.shp)
    UTM Zone Boundaries

    Click the Link To Download UTM 1km Polyline Grid Shapefiles (.shp)
    UTM 1km Zones 1-60




  • POSITIONING IN MGRS---- The Military Grid Reference Systems (MGRS) is an alpha-numeric system for expressing UTM/UPS coordinates. A single alpha-numeric value references a position that is unique for the entire earth.MGRS PDF READ ME
    • The components of MGRS values are as follows:
      • (Example: 15SWC8081751205)


    • The first two characters represent the 6° wide UTM zone.
      • Leading zeros are included so that Zone 9 is “09”.
      • For polar areas outside the UTM area, these characters are omitted.


    • The third character is a letter designating a band of latitude.
      • Beginning at 80°S and preceding northward, the 20 bands are lettered C through X, omitting I and O.
      • The bands are all 8° high except band X, which is 12° high.
      • Outside the UTM are, A and B are used near the South Pole, Y and Z near the North Pole.


    • Please See (Figure 5) to the right.
    Figure 5.   Military Grid Reference System (MGRS)   Top↑

    Figure 6.   Military Grid Reference System (MGRS).   Top↑
    • The vertical UTM boundaries are horizontal latitude band boundaries form (generally) 6° X 8° Grid Zones. Hence, the first three letters of the MGRS value, e.g. “15S”, are referred to as the Grid Zone Designator (GZD).




    • The fourth and fifth characters are a pair of letters identifying one of the 100,000-meter grid squares within the grid zone (or UPS area). See (Figure 6) to the left.



      • In the Figure 6 sample area, the Grid Zone Designators are shown in brown. The smaller gray letters are the 100,000-meter grid square identifiers. The example point “15SWC8081751205” is located in the square “WC” near the center of the figure.

    • The remaining characters consist of the numeric Easting and Northing values within the 100,000-meter grid square. See (Figure 7) below.

    • MGRS coordinates may be rounded to reflect lesser refinement. For example:
      • 15SWC8081751205 is at 1-meter refinement.
      • 15SWC80825121 is at 10-meter refinement.
      • 15SWC808512 is at 100-meter refinement.
      • 15SWC8151 is at 1000-meter refinement.

    • There are two lettering schemes for the 100,000-meter grid square identifiers. Generally, one scheme is used for WGS-84, and the other is used for older ellipsoids associated with the local datums.
      • Example: 15SWC8081751205 is on WGS-84. When converted to NAD-27 datum, Clarke 1866 ellipsoid, its value is: 15SWN8083350993
      • The 100,000-meter grid square “WC” for WGS-84 generally coincides with the grid square “WN” for Clarke 1866. See the section on USNG for further guidance.

    • The magenta arrows show how MGRS Easting and Northing values are determined from within the 100,000-meter grid square. The MGRS value of this position is 15SWC8081751205. See (Figure 7) to the right.


    • CAUTION: IN MANY SYSTEMS, THE LETTER AFTER THE ZONE NUMBER DESIGNATES A LATITUDINAL BAND, NOT A HEMISPHERE.
    Figure 7.   Military Grid Reference System (MGRS).   Top↑

  • MGRS DOWNLOADS

  • Click the Link To Download MGRS Grid Zone Designator Shapefile (.shp)
    MGRS GZD WorldWide

    Click the Link To Download MGRS 1km Grid Shapefiles (.shp)
    MGRS 1km Zones 1-60

    Click the Link To Download MGRS 100km Grid Shapefiles (.shp)
    MGRS 100km Zones 1-60 | MGRS 100km UPS North | MGRS 100km UPS South




  • POSITIONING IN UPS---- The Universal Polar Stereographic (UPS) Systems coordinates are based on a family of two Polar Stereographic map projections, one for each pole.
    • The origin of the UPS coordinate system is at the poles, where X=2,000,000m and Y=2,000,000m. For UPS North see (Figure 8); or for UPS South see (Figure 9).
    • The X-axis lies along the meridians 90°E and 90°W.
      • Moving from the pole (north or south), X-values (Eastings) increase along the 90°E meridian.
    • The Y-axis lies along the meridians 0° and 180°.
      • Moving from the North Pole, Y-values (Northings) increase along the 180° meridian.
      • Moving from the South Pole, Y-values (Northings) increase along the 0° meridian.
    • CAUTION: IN MANY SYSTEMS, THE LETTER AFTER THE ZONE NUMBER DESIGNATES A LATITUDINAL BAND, NOT A HEMISPHERE.

    Figure 8.  Universal Polar Stereographic (UPS) North, 100km MGRS Letters   Top↑
    Figure 9.  Universal Polar Stereographic (UPS) South, 100km MGRS Letters   Top↑



  • LETTERING/NUMBERING IN UTM & UPS---- The letter after the UTM zone number: is that a hemisphere or a latitudinal band? Since the creation of UTM, developers have interpreted the rules for expressing an earth-wide unique UTM position in one of two ways:
    • By including an “N” or “S” after the zone number to specify a hemisphere.
    • By including the 8° latitudinal band designator (see the section on MGRS) after the zone number.

      • Example: The position at 92°W, 38°N, expressed in UTM coordinates, is:
        • 587798m E, 4206287m N, Zone 15.
    • This reference is valid for two positions on the earth. In order to make it unique for only one position worldwide, i.e. 92°W, 38°N:
      • Developer #1 includes an “N” to specify northern hemisphere:
        • 15N 587798 4206287
      • Developer #2 includes the 8° latitudinal band designator:
        • 15S 587798 4206287
    • This situation is causing confusion among users and developers. The two 8° latitudinal bands, from 0° to 8°N and from 32°N to 40°N, are assigned the designations “N” and “S”, respectively. These designations are often mistaken for hemisphere designations. NGA updated version of NGA.SIG.0012_2.0.0_UTMUPS contains the authoritative definition of UTM.


       UTM / UPS / MGRS DOCUMENTATION   
    FAQ:
    Documents:
    File Size:
    How do I use the Universal Grid System? Reference Guide to the Universal Grid System (1.19 MB)
    What are MGRS Grid Zone Designators (GZD)? MGRS Grid Zone Designators (GZD) Graphic (4.72 MB)




    Point of Contact: Coordinate Systems Analysis Team
    Phone (314) 676-9124, DSN 846-9124
    coordsys@nga.mil

    Document last modified July 02, 2014


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