A map projection which is a conformal mapping, i.e., one for which local (infinitesimal) angles on a sphere are mapped
to the same angles in the projection. On maps of an entire sphere, however, there
are usually singular points at which local angles are distorted.
The term conformal was applied to map projections by Gauss in 1825, and eventually supplanted the alternative terms "orthomorphic" (Lee 1944; Snyder 1987, p. 4) and "autogonal" (Tissot 1881, Lee 1944).
No projection can be both equal-area and conform, and projections which are neither equal-area
nor conformal are sometimes called aphylactic
(Lee 1944; Snyder 1987, p. 4).
Lee, L. P. "The Nomenclature and Classification of Map Projections." Empire Survey Rev.7, 190-200, 1944.Snyder,
J. P. Map
Projections--A Working Manual. U. S. Geological Survey Professional
Paper 1395. Washington, DC: U. S. Government Printing Office, 1987.Thomas,
P. S. Conformal
Projections in Geodesy and Cartography. Washington, DC: U. S. Coast
and Geodetic Survey Spec. Pub. 251, 1952.Tissot, A. Mémoir
sur la représentation des surfaces et les projections des cartes géographiques.
Paris: Gauthier-Villars, 1881.
