Natural Earth projection

The Natural Earth projection is a pseudocylindrical map projection designed by Tom Patterson. It is neither conformal nor equal-area.

The Natural Earth is defined by the following formulas:

where

l(φ) and d(φ) are given as polynomials, initially from interpolation of the following values in Flex Projector:

The values for the southern hemisphere are calculated by changing the sign of the corresponding values for the northern hemisphere.