The orthographic projection is a projection from infinity that preserves neither area nor angle. It is given by

			(1)
			(2)

where is the latitude, is the longitude, and and are reference longitudes and latitudes, respectively.

The inverse transformations are

			(3)
			(4)

where

			(5)
			(6)

and the two-argument form of the inverse tangent function is best used for this computation.

Snyder, J. P. Map Projections--A Working Manual. U. S. Geological Survey Professional Paper 1395. Washington, DC: U. S. Government Printing Office, pp. 145-153, 1987.

CITE THIS AS:

Weisstein, Eric W. "Orthographic Projection." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/OrthographicProjection.html