stereographic projections

Noun

stereographic projection (plural stereographic projections)

1. (projective geometry) A function that maps a sphere onto a plane; especially, the map generated by projecting each point of the sphere from the sphere's (designated) north pole to a point on the plane tangent to the south pole.
   • 1974 [Prentice-Hall], Richard A. Silverman, Complex Analysis with Applications, Dover, 1984, Unaltered republication, page 19,
     Thus we see that stereographic projection establishes a one-to-one correspondence between the extended complex plane and the Riemann sphere.