In radio navigation, a VOR/DME is a radio beacon that combines a VHF omnidirectional range (VOR) with a distance measuring equipment (DME). The VOR allows the receiver to measure its bearing to or from the beacon, while the DME provides the slant distance between the receiver and the station. Together, the two measurements allow the receiver to compute a position fix.
The VOR system was first introduced in the 1950s, but became much more practical with the introduction of low-cost solid state receivers in the 1960s. DME was a modification of World War II-era navigation systems like Gee-H, and began development in 1946. Like VOR, it only became practical with the introduction of solid state receivers during the 1960s.