Natural Earth projection - Alchetron, the free social encyclopedia

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

Definition

The Natural Earth is defined by the following formulas:

x = 0.8707 × l ( φ ) × λ , y = 0.8707 × 0.52 × d ( φ ) × π , ,

where

x, y are the Cartesian coordinates;

λ is the longitude from the central meridian;

φ is the latitude;

l(φ) is the length of the parallel at latitude φ;

d(φ) is the distance of the parallel from the equator at latitude φ.

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.

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