a network or system of points selected in a definite manner and marked on the ground, serving as control points for topographical surveying and geodetic measurements on the ground. A distinction is made between the plane geodetic control network and the altitudinal geodetic control network. The plane network is constructed primarily by the method of triangulation, and the relative position of its points is determined by geodetic coordinates or, more frequently, rectangular coordinates. The altitudinal geodetic control network (leveling network) is constructed by the method of geometric leveling, which is used to determine the altitude of points above sea level. The geodetic control network is of great practical importance in compiling topographical maps and determining the shape and size of the earth.