VHF Omni-Directional Range. An aircraft navigation system giving a position line which radiates from the station. VOR stations transmit two signals, the phase difference of which changes with your bearing to the station. For simplicity, they are said to have 360 'spokes' or 'radials' emanating from their centers. The difference in the signals is converted by (once analogue now digital) equipment to a cockpit display showing deviation from a selected radial. They can be used for inbound or outbound on-track homing, or to provide a position line for further calculation.

VOR stations only provide a position line and not a triangulation. To get an exact position, one of the following references must also be present:
  • Another position line (from a VOR, sighting, land feature such as a river or NDB station)
  • a DME station