The Eckert II projection is an equal-area pseudocylindrical map projection with rectilinear meridians and an odd appearance. It has no practical use other than making a thematic world map with an unusual shape.
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.
The subsections below describe the Eckert II projection properties.
Eckert II is a pseudocylindric projection. The meridians are regularly distributed straight lines interrupted at the equator. The central meridian is a straight line, half the length of the projected equator. The parallels are unequally distributed straight lines, perpendicular to the central meridian. Their spacing decreases toward the poles. The poles are straight lines, half the length of the equator. The graticule is symmetric across the equator and the central meridian.
Eckert II is an equal-area (equivalent) projection. It distorts shapes, directions, angles, and distances. Scale is correct along the 55°10' North and South parallels and constant along any given parallel. Points at 55°10' North and South at the central meridian have zero distortion. Due to the discontinuity, distortion cannot be determined at the equator. Distortion values are symmetric across the equator and the central meridian.
The Eckert II projection has no practical use other than designing a thematic world map with an unusual shape.
Eckert II is supported on spheres only. For an ellipsoid, the semimajor axis is used for the radius. The equal-area property and some other distortion properties are not maintained when an ellipsoid is used.
Eckert II parameters are as follows:
- False Easting
- False Northing
- Central Meridian
Snyder, J. P. (1993). Flattening the Earth. Two Thousand Years of Map Projections. Chicago and London: University of Chicago Press.
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.