Geocart Projections

What is a projection?

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Parameters: Parallel shown straight, Circular longitude pair


Geocart menu class: Miscellaneous


Meridians: Central meridian is straight. Other meridians are circular arcs, concave toward the central meridian.
Parallels: One parallel, often the Equator, is straight. Other parallels are circular arcs, concave toward the pole which is on the same side of the straight parallel.
Poles: Points
Symmetry: About the central meridian. Also about the Equator, if the Equator is straight.


Increases rapidly with distance from the center


Great distortion of area and scale when the center is compared with poles or other outer limits. Conformality fails at the poles.

Other features

The general formula can be used to create a variety of conformal maps.


Whole-world maps and conformal maps within a circle of smaller portions of the world


Johann Heinrich Lambert (1728–1777) of Alsace presented the world conformally in a circle in 1772. This projection is usually called the Lagrange projection, however, after Joseph Louis Lagrange (1736–1813) of France, who generalized Lambert’s concept in 1779.

Similar projections

Van der Grinten I is not conformal.

Special forms

Equatorial or oblique Stereographic projection Littrow projection

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.