Eckert V

Description

Eckert V is a compromise pseudocylindrical map projection for world maps. It is the arithmetic mean of projected coordinates of the Plate CarrĂ©e and sinusoidal projections. The meridians are sinusoidal curves, producing undesirable bulging along the equator on the western and eastern edges of the map.

The projection was introduced by Max Eckert in 1906. It is available in ArcGIS Pro 1.0 and later and in ArcGIS Desktop 8.0 and later.

Projection properties

The subsections below describe the Eckert V projection properties.

Graticule

Eckert V is a pseudocylindric projection. The equator and the central meridian are projected as straight lines. The projected equator is about two times as long as the central meridian. Other meridians are sinusoidal curves, bulging away the central meridian, and equally spaced. The parallels are equally distributed straight lines perpendicular to the central meridian. The poles are straight lines half the length of equator. The graticule is symmetric across the equator and the central meridian.

Distortion

The projection is neither conformal nor equal-area. It generally distorts shapes, areas, distances, directions, and angles. The scale is constant along any given parallel. Distortion patterns are similar to other compromise pseudocylindrical projections. Area distortion grows with latitude and does not change with longitude. High latitude areas are exaggerated. Angular distortion is zero at the equator and increases toward the poles. Distortion values are symmetric across the equator and the central meridian.

Usage

Eckert V projection is appropriate for general world maps although its use is not advisable.

Limitations

Supported on spheres only. For an ellipsoid, the semimajor axis is used for the radius.

Parameters

Eckert V parameters are as follows:

• False Easting
• False Northing
• Central Meridian

Sources

Snyder, J. P. and Voxland, P. M. (1989). An Album of Map Projections. U.S. Geological Survey Professional Paper 1453. Washington, DC: United States Government Printing Office.