conical projections


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Related to conical projections: polyconic projection, Polyconic map projection

conical projections

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A map projection produced by projecting the geographic meridians and parallels onto a cone that is tangent to (or intersects with) the surface of a sphere and then developing the cone into a plane. Conic map projections include cylindrical map projections when the apex of the cone is at an infinite distance from the sphere, and projections on a tangent plane when that distance is zero. Conic map projections may be illustrated with a single cone that is tangent to the sphere or cuts the sphere along two parallels, or they may be a series of tangent cones, all with apexes on an extension of the axis of the sphere, at constantly increasing (or decreasing) distances from the sphere. It is best used to show areas of large longitudinal rather than latitudinal distances. Also called tangent conical map projection.