Definition
The geographic area and altitude range within which an air traffic control radar can reliably detect and display aircraft. Coverage is limited by the radar's range, the curvature of the earth, terrain, and the aircraft's altitude, since radar signals travel in essentially straight lines and cannot see through hills or below the horizon.
Plain English
The space around a radar station where it can actually 'see' aircraft. Outside that space, the controller cannot track you on radar.
Context Anchor
Seen in tower en route control discussions, where routes depend on whether controllers can maintain radar contact along the route.
Derivation
Radar comes from “radio detection and ranging,” meaning finding something and measuring its distance using radio energy. Coverage means the area reached by a system. Together, radar coverage means the part of the sky where radar can detect aircraft.
Why Pilots Care
Determines whether a pilot can receive radar vectors, traffic advisories, or separation services during flight.
Intuition Check
Coverage does not mean radio reception, chart coverage, or permission to fly. Here it means whether radar can detect the aircraft in a specific area and altitude range.
Example Sentence 1
The controller advised that radar coverage ended below 4,000 feet in that area, so we would lose flight following on the descent.
Example Sentence 2
Due to mountainous terrain, radar coverage does not extend below 5,000 feet in this sector.