Glossary for Geospatial Science

azimuthal projections:  (also known as Planar Projections) A class of map projections that are constructed by placing a flat planar surface tangent to a single point on the globe, or by placing the globe to an intersecting (secant) plane.  With azimuthal (or planar) projections, lines of equal distortion are concentric around the point of tangency or the center of the circle of intersection.  Most azimuthal maps do not have standard parallels or standard meridians.  Each map has only one standard point: the center.  Thus, the azimuthal projections are suitable for minimizing distortion in a somewhat circular region, such as Antarctica, but not for an area with predominant length in one direction.  Azimuthal projections include Orthographic, Stereographic, Gnomonic, Lambert Azimuthal Equal-Area, and Azimuthal Equidistant.