Geocart Projections

What is a projection?

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Orthoapsidal (term coined by originator)
Neither conformal nor equal area


Meridians: Central meridian (10° or 15° E.) is straight. Other meridians are elliptical arcs, concave toward the central meridian.
Parallels: Elliptical arcs of the same eccentricity, concave toward the North Pole
Poles: North Pole is semiellipse. South Pole cannot be shown.
Symmetry: About the central meridian


Gradually decreases with distance from the center


Distortion is moderate in central portions.

Other features

An oblique orthographic projection of the world plotted with equidistant meridians and parallels onto a portion of a torus ring (similar to a doughnut). Antarctic region cannot be shown, but the projection was claimed to have “more land in proportion to sea than any other world map”. Often plotted with New Zealand, normally hidden from view, appended to Australia as a “pigtail”.


Whole-world maps


Presented by Erwin J. Raisz (1893-1968) of Harvard University in 1943


Oblique is the basic aspect.

Other names


Similar projections

Other “orthoapsidal” projections proposed by Raisz in 1943. Raisz coined this term from “orthographic” and “apsidal.”.

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.