Definition
A ground-based service in which a controller or specialist uses direction finding equipment to determine the bearing of an aircraft's radio transmissions and provides that information to the pilot, typically to assist a lost or disoriented aircraft in navigating to a known point such as an airport.
Plain English
A ground station listens to your radio transmissions and works out which direction you are calling from. They then tell you which way to fly to reach them or another known location.
Context Anchor
Seen in radio navigation and air traffic control discussions when a station is using an aircraft’s transmission to help determine where the aircraft is relative to that station.
Derivation
From 'direction finding' — the technique of locating the source of a radio signal by measuring the direction it arrives from. The ground station does the finding; the aircraft simply transmits.
Why Pilots Care
Provides a means to obtain a bearing for navigation or to help search-and-rescue locate the aircraft when other navigation is unavailable.
Grounding Statement
The key idea is that the station is not just hearing the radio call; it is using the call to determine the direction it came from.
Intuition Check
Do not read reception here as simply hearing a radio clearly. In this context, reception means receiving the signal in a way that allows its direction to be determined.
Example Sentence 1
The pilot, unsure of position in deteriorating weather, requested DF reception from the nearest facility and was given headings to the airport.
Example Sentence 2
Terrain between the aircraft and the station reduced DF reception and made the bearing unreliable.