Directory of Map Projections

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Universal Transverse Mercator

Parameters: UTM Zone


The Universal transverse Mercator (UTM) is a system that uses the ellipsoidal transverse Mercator as the foundation for each of 60 zones that cover most of the Earth. The projection changes only the central meridian per zone. The zones are 6° in east-west extent. Polar regions south of 80°S and north of 84°N are excluded from the system. When using UTM, coordinates are given on the plane, alone with the zone designation.




Transverse aspect of the ellipsoidal transverse Mercator applied to a system for worldwide mapping.


Meridians: Central meridian is straight; others are complex curves.
Parallels: Complex curves.


Scale is a fixed 0.9996 along the central meridian, is correct along two vertical lines about 181 km east and west of the central meridian, and rises to 1/0.9996 = 1.0004 at about 256 km east and west.


Low near the central meridian, increasing away from it.

Similar projections

The ellipsoidal transverse Mercator is the basis for the UTM.
At the scale that the UTM is used, many projections are similar.
Many national grid systems use variants of the ellipsoidal transverse Mercator via efficient, but truncated, series developments.


The basic system appears to have originated in the 1942–1943 timeframe by the German military and subsequently adopted and extended by the United States Army Corps in 1947, using the 0.9996 central meridian scale that is now standard.

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