United States National Grid (USNG)

USNG is functionally equivalent to MGRS. The difference between the two systems is in the method for specifying the datum. In MGRS, an alternate lettering scheme is used for the 100,000-meter grid square designator when the position is referenced to an older datum (see section on MGRS). The USNG does not use the alternate lettering scheme, but simply specifies the datum after the position reference. For example, a position on the NAD 27 datum is reported in the two systems as follows:

MGRS: “15SWN8083350993”

USNG: “15SWC8083350993 (NAD 27)”

Click here for an Instruction guide on how to read the USNG

Document last modified April 29, 2013