Conventional radio beacon VOR (RMA-90) is the ground equipment of azimuth aircraft navigation system of VHF radio range with VOR format of signals, and is recommended by ICAO as major short-range navigation facility at air route or as supplementary facility for civil aircraft approach and landing. Radio beacon DME/N (RMD-90) represents ground equipment of distance measuring aircraft navigation system with DME/N format of signals, which is defined by ICAO documents as major short-range navigation facility at air route and airdrome area.
VOR/DME is intended for generating in airspace navigation signals, that contain information of azimuth of any coverage zone point relatively radio beacon installation site, and for generating of the radio beacon identification signals. Distance measuring radio beacon can be installed jointly with VOR or can be used independently in DME-DME network. In this case data of aircraft position relatively radio beacon installation site are provided onboard in two distances measurement system, that allows solving problems of enroute air navigation as well as at aerodrome area.