Eckert-Greifendorff projection
The Eckert-Greifendorff projection is an equal-area map projection described by Max Eckert-Greifendorff in 1935. Unlike his previous six projections, It is not pseudocylindrical.Development
Directly inspired by the Hammer projection, Eckert-Greifendorff suggested the use of the equatorial form of the Lambert azimuthal equal-area projection instead of Aitoff's use of the azimuthal equidistant projection:
where laea and laea are the x and y components of the equatorial Lambert azimuthal equal-area projection. Written out explicitly:
The inverse is calculated with the intermediate variable
The longitude and latitudes can then be calculated by
where λ is the longitude from the central meridian and φ is the latitude.
