Definition

(U.S.A.). In PHOTOGRAMMETRY, an empirical value which expresses the vertical measuring capability of a given stereoscopic system; generally defined as the ratio of the flight height to the smallest CONTOUR INTERVAL accurately plottable. The C-factor is not a fixed constant but varies over a considerable RANGE, according to the elements and conditions of the photogrammetric system. In planning for AERIAL PHOTOGRAPHY, the C-factor is used to determine the flight height required for a specified CONTOUR INTERVAL, CAMERA, and instrument system.