Description
The Behrmann projection is a case of the cylindrical equal-area map projection with standard parallels set at 30° north and south. Due to its equal-area property, it highly compresses polar regions.
The projection was introduced by Walter Behrmann in 1910. 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 Behrmann projection properties.
Graticule
Behrmann is a cylindric projection. The meridians are equally spaced straight lines. The parallels and both poles are straight lines, perpendicular to meridians and the same length as the equator. The spacing between the parallels decreases away from equator. The graticule is symmetric across the equator and the central meridian. The height-to-width ratio of the map is 0.42.
Distortion
Behrmann is an equal-area (equivalent) projection. The scale is true along the latitudes 30° north and 30° south. Shape, direction, angle, and distance distortions increase with the distance from the standard parallels. Shapes are distorted north-south between the standard parallels and distorted east-west above 30° north and below 30° south. Distortion values are symmetric across the equator and the central meridian.
Usage
This projection is appropriate for thematic world maps that require accurate areas, and its phenomena change with longitude.
Parameters
Behrmann parameters are as follows:
- False Easting
- False Northing
- Central Meridian
Sources
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.