Eckert IV

The Eckert IV and Eckert VI were created by Max Eckert in 1906, and are used for world maps. Both are Pseudocylindrical projections whose central meridian is a straight line. 180th meridians of the Eckert IV projection are semicircle, and all other meridians are equally spaced elliptical Arcs. The parallels are unequally spaced straight lines parallel to one another, and the Poles are straight lines half as long as the equator. Scale is true along latitude 40º30' for the Eckert IV.

The "EckertIV" Projection has the following Parameters:

Longitude of the Central Meridian
Latitude of Origin
Radius of the Sphere
False Northing
False Easting

NOTE: If the spherical_radius parameter is set to a value greater than zero, then it will be used as the radius of the sphere. If this parameter is set to a value less than or equal to zero, then the Semi-Major radius of the Ellipsoid will be used as the radius of the sphere.