VOR (VHF Omnidirectional Range) is a radio navigation technology used by aircraft to determine their position and remain on-course.

VOR (VHF Omnidirectional Range) is a radio navigation technology used by aircraft to determine their position and remain on-course.

The Wikipedia article on VORs contains some of the technical details on how the radio signal actually works, but a very simple conceptual explanation of how a VOR works can be found here, and is paraphrased below:

At its core a VOR station emits two signals - a "sweep" and a "strobe"

  • The sweep signal continually rotates through a 360 degree circle at a known rate.
  • Every time the sweep signal crosses 0 degrees (North) the strobe signal fires.

By timing the difference between when you receive the "strobe" signal and when the "sweep" signal arrives you can determine your bearing to the station, as shown in the animation below.

VOR animation

For an interactive demonstration of how VOR signals correspond to the navigational instruments in an aircraft check out this VOR simulator (requires Flash).

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