VOR (VHF Omnidirectional Radio Range) is the ICAO standard short and medium range navigation aid that is installed at airports and en-route locations. VOR is a ground-based radio navigation aid transmitting an omnidirectional signal that enables an aircraft to determine its bearing in relation to the location of the beacon.
There are two types of VOR aids: CVOR (Conventional VOR) and DVOR (Doppler VOR).
DVOR is the further development of the CVOR, providing improved signal quality and accuracy compared to CVOR at demanding locations, where the geographical conditions are difficult, using the Doppler effect.
There are more than 570 systems in operation worldwide, as it is an ideal system for aerodromes and airports.