Directory of Map Projections

What is a projection?

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plate carrée

simple cylindric




Meridians: Equally spaced straight parallel lines half as long as the equator.
Parallels: Equally spaced straight parallel lines, perpendicular to and having same spacing as meridians.
Poles: Straight lines equal in length to the equator.
Symmetry: About any meridian or the equator.


Normal is described here.
Transverse aspect is the Cassini projection, which is also applied to the ellipsoid.
Oblique aspect is rarely used.


True along the equator and along all meridians.
Increases with the distance from the equator along parallels.
Constant along any given parallel; same scale at the parallel of opposite sign.


Infinitesimally small circles of equal size on the globe (indicatrices) are ellipses except along the equator, where they remain circles. Areas of the ellipses also vary. Thus, there is distortion of both shape and area.

Other features

Most simply constructed graticule of any projection.
Conceptually projected onto a cylinder wrapped around the globe tangent to the equator.
Not perspective.


Many maps during the 15th and 16th centuries.
Simple outline maps of regions or of the world or index maps.
Used only for the Earth taken as a sphere.

Similar projections

If meridians are compressed relative to parallels, the equirectangular projection results.


May have been originated by Eratosthenes (275?-195? B.C.) Marinus of Tyre also credited with its invention about A.D. 100.

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.