Geodetic network

A geodetic network (also: reference or controlnetwork) is a network of triangles which are measured exactly by techniques of terrestrial surveying or by satellite geodesy.

In "classical geodesy" (up to the sixties) this is done by triangulation, based on measurements of angles and of some spare distances; the precise orientation to the geographic north is achieved through methods of geodetic astronomy. The principal instruments used are theodolites and tacheometers, which nowadays are equipped with infrared distance measuring, data bases, communication systems and partly by satellite links.