VOR VOR/DME VORTAC
VHF omnidirectional radio range (VOR), is a type of short-range radio navigation system for aircraft, enabling aircraft to determine their position and stay on course by receiving radio signals transmitted by a network of fixed ground radio beacons, with a receiver unit. It uses radio frequencies in the very high frequency (VHF) band from 108 to 117.95 MHz.
A VOR ground station sends out a master signal, and a highly directional second signal that varies in phase 30 times a second compared to the master. This signal is timed so that the phase varies as the secondary antenna spins, such that when the antenna is 90 degrees from north, the signal is 90 degrees out of phase of the master. By comparing the phase of the secondary signal to the master, the angle (bearing) to the station can be determined.
This line of position is called the "radial" from the VOR. The intersection of two radials from different VOR stations on a chart provides the position of the aircraft. VOR stations are fairly short range, the signals have a range of about 200 miles.
VOR stations broadcast a VHF radio composite signal including the station's identifier, voice (if equipped), and navigation signal. The identifier is typically a two- or three-letter string in Morse code. The voice signal, if used, is usually the station name, in-flight recorded advisories, or live flight service broadcasts.
In many cases, VOR stations have co-located Distance measuring equipment (DME) or military Tactical Air Navigation (TACAN) — the latter includes both the DME distance feature and a separate TACAN azimuth feature that provides military pilots data similar to the civilian VOR. A co-located VOR and TACAN beacon is called a VORTAC. A VOR co-located only with DME is called a VOR-DME. A VOR radial with a DME distance allows a one-station position fix. Both VOR-DMEs and TACANs share the same DME system.
VHF omnidirectional radio range (VOR), is a type of short-range radio navigation system for aircraft, enabling aircraft to determine their position and stay on course by receiving radio signals transmitted by a network of fixed ground radio beacons, with a receiver unit. It uses radio frequencies in the very high frequency (VHF) band from 108 to 117.95 MHz.
A VOR ground station sends out a master signal, and a highly directional second signal that varies in phase 30 times a second compared to the master. This signal is timed so that the phase varies as the secondary antenna spins, such that when the antenna is 90 degrees from north, the signal is 90 degrees out of phase of the master. By comparing the phase of the secondary signal to the master, the angle (bearing) to the station can be determined.
This line of position is called the "radial" from the VOR. The intersection of two radials from different VOR stations on a chart provides the position of the aircraft. VOR stations are fairly short range, the signals have a range of about 200 miles.
VOR stations broadcast a VHF radio composite signal including the station's identifier, voice (if equipped), and navigation signal. The identifier is typically a two- or three-letter string in Morse code. The voice signal, if used, is usually the station name, in-flight recorded advisories, or live flight service broadcasts.
In many cases, VOR stations have co-located Distance measuring equipment (DME) or military Tactical Air Navigation (TACAN) — the latter includes both the DME distance feature and a separate TACAN azimuth feature that provides military pilots data similar to the civilian VOR. A co-located VOR and TACAN beacon is called a VORTAC. A VOR co-located only with DME is called a VOR-DME. A VOR radial with a DME distance allows a one-station position fix. Both VOR-DMEs and TACANs share the same DME system.