Geocart Projections

What is a projection?

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armadillo

Classifications

Geocart menu class: Miscellaneous
Orthoapsidal (term coined by originator)
Neither conformal nor equal area

Graticule

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

Scale

Gradually decreases with distance from the center

Distortion

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”.

Usage

Whole-world maps

Origin

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

Aspects

Oblique is the basic aspect.

Other names

Raisz

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.