Directory of Map Projections

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ellipsoidal transverse Mercator


Gauss conformal

Gauss Hannover

transverse cylindric orthomorphic

Aspects of: Mercator

Parameters: Scale factor along central meridian




The preferred transverse aspect development for the ellipsoidal transverse Mercator.


Meridians and parallels: Central meridian, each meridian 90° from central meridian, and the equator are straight lines. Other meridians and parallels are complex curves, concave toward the central meridian and the nearest pole, respectively.
Poles: Points along the central meridian.
Symmetry: About any straight meridian or the equator.


True along the central meridian or along two straight lines on the map equidistant from and parallel to the central meridian.
Constant along any straight line on the map parallel to the central meridian. (These lines are only approximately straight for the projection of the ellipsoid.) Increases with distance from the central meridian Becomes infinite 90° from the central meridian.

Other features

Conceptually projected onto a cylinder wrapped around the globe tangent to the central meridian or secant along two small circles equidistant from the central meridian.
Cannot be geometrically (or perspectively) projected.
Rhumb lines generally are not straight lines.


Many of the topographic and planimetric map quadrangles throughout the world at scales of 1:24,000 to 1:250,000.
Basis for Universal transverse Mercator (UTM) grid and projection.
Basis for State Plane Coordinate System in U.S. States having predominantly north-south extent.
Recommended for conformal mapping of regions having predominantly north-south extent.


Presented by Johann Heinrich Lambert (1728–1777) of Alsace in 1772. Formulas for ellipsoidal use developed by Carl Friedrich Gauss of Germany in 1822 and by L. Krüger of Germany, L.P. Lee of New Zealand, and others in the 20th century.

Description adapted from J.P. Snyder and P.M. Voxland, An Album of Map Projections, U.S. Geological Survey Professional Paper 1453. United States Government Printing Office: 1989.