Winkel Tripel Projection

sc_projections_winkel.png

 

A modified azimuthal projection that is neither conformal nor equal area. This is a low precision projection as normally used since it is calculated for a sphere and not an ellipsoid. However, when presenting whole world maps the difference between a spherical and ellipsoidal Earth is invisible.

 

Scale

 

True along the central meridian. Constant along the Equator.

 

Distortion

 

Moderate except near outer meridians in polar regions.

 

Usage

 

Whole world maps. After languishing for many years, the Winkel Tripel is becoming fashionable once more as a result of usage by the National Geographic Society.

 

Origin

 

Presented by Oswald Winkel (1873-1953) of Germany in 1921. The Winkel Tripel is obtained by averaging coordinates of Cylindrical Equidistant and the Aitoff projections. Winkel coined the name "tripel" (meaning "triple" in English) to reflect the three step process: project into Cylindrical Equidistant, project into Aitoff and then average the two projections.