The Craster Parabolic projection is a pseudocylindrical, equal area projection used for thematic world maps in textbooks. It was originally presented by John Evelyn Edmund Craster in 1929. It was further developed by Charles H. Deetz and O.S. Adams in 1934. The central meridian is a straight line half as long as the Equator. Other meridians are equally spaced parabolas intersecting at the poles and concave toward the central meridian. The parallels are unequally spaced, farthest apart near the Equator. They run perpendicular to the central meridian. This projection is symmetrical about the central meridian or the equator. Scale is true along latitudes 36°46' N and S, and constant along any given latitude. This projection is supported on spheres only.
This projection is also known as Putniņš P4, which was independently presented in Latvia in 1934.
The "CrasterParabolic" Projection has the following Parameters:
|
Parameter Name |
Parameter String |
Units |
|
Longitude of the Central Meridian |
central_meridian |
|
|
False Easting |
false_easting |
|
|
False Northing |
false_northing |
NOTE: Only a spherical form of this projection is used. The semi-major axis of the ellipsoid (sphere) is used for forward and inverse projection from grid to geodetic coordinates within the system wherein this projection is incorporated.