conic projection |
A map projection in which the surface features of a globe are depicted as if projected onto a cone typically positioned so as to rest on the globe along a parallel (a line of equal latitude). In flattened form a conic projection produces a roughly semicircular map with the area below the apex of the cone at its center. When the central point is either of Earth's poles, parallels appear as concentric arcs and meridians as straight lines radiating from the center. Distances along the meridians remain true to scale, while the distortion along the parallels is progressively greater moving away from the parallel on which the cone is assumed to rest. Conic projections centered over a pole are often used in regional or national maps of temperate zones, where the distortion in the middle latitudes (the resting point of the cone) is minimal. Compare azimuthal projection, cylindrical projection.