What is a VOR and how does a VOR receiver determine course?

• A. A VOR is a satellite-based navigation aid providing azimuth; the receiver displays the radial relative to the station and can guide you to or from the station.
• B. A VOR is a ground-based weather radar system that provides wind information.
• C. A VOR is an autopilot feature that maintains cruise altitude.
• D. A VOR is a flight management system function used only for IFR approaches.

Answer: (B)

A VOR provides azimuth information from a ground-based station so you can determine your bearing relative to that station. The station transmits two signals: a reference signal that is the same in every direction and a rotating signal that creates a pattern of directional cues. The VOR receiver compares the phase of these signals, which tells you the radial you are on from the station. You then set the desired radial with the course selector, and the CDI shows how far off you are from that line as well as whether you are flying toward or away from the station (TO/FROM). This delivers directional guidance (azimuth) rather than distance, and it’s not satellite-based like GPS, nor is it weather radar or an autopilot feature.