Stereographic projection

From Wikinfo

In cartography and geometry, the stereographic projection is a mapping that projects each point on a sphere onto a tangent plane along a straight line from the antipode of point of tangency, with one exception: the center of projection, antipodal to the point of tangency, is not projected to any point. Two remarkable properties of this projection were demonstrated mathematically by Hipparchus:

• This mapping is conformal, i.e. it preserves angles at which curves cross each other, and
• This mapping transforms circles on the surface of the sphere that do not pass through the center of projection, to circles in the plane.

See also

• map projection
• projective geometry

References

• Adapted from the Wikipedia article, "Stereographic_projection" http://en.wikipedia.org/wiki/Stereographic_projection, used under the GNU Free Documentation License