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 cemicircle, and all other meridians are equally spaced
elliptical Arcs. Meridians on the Eckert VI projection are equally spaced
sinusoidal curves. In both projections, 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 latitudes 40º30' for
the Eckert IV projection, and 49º16' for Eckert VI.
The "EckertIV" Projection has
the following Parameters:
|
Parameter Name |
Parameter String |
Units |
|
Longitude of the Center of the Projection |
central_meridian |
|
|
Radius of the Sphere |
spherical_radius |
|
|
False Easting |
false_easting |
|
|
False Northing |
false_northing |
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 SemiMajor radius of the Ellipsoid will be used as the radius of the sphere.