Definition
Equipment installed on the ground that detects, tracks, and identifies aircraft in flight, providing position and identification data to air traffic controllers. Primary and secondary radar are the traditional examples, with newer systems using ADS-B ground stations to receive position reports broadcast by aircraft.
Plain English
Equipment on the ground that watches aircraft in the sky and tells controllers where each one is.
Context Anchor
Seen in discussions of NextGen improvements, radar coverage, and how controllers track aircraft during instrument flight.
Derivation
Surveillance' comes from the French 'surveiller', meaning 'to watch over.' In aviation, it means watching aircraft to know where they are. 'Ground-based' clarifies that the watching equipment sits on the ground, as opposed to systems based on satellites or onboard the aircraft.
Why Pilots Care
Provides controllers with accurate aircraft positions, supporting safe separation and efficient routing in controlled airspace.
Intuition Check
Do not read “surveillance” here as personal monitoring or spying. Here it means tracking aircraft position and movement for air traffic safety.
Example Sentence 1
In remote regions, ground-based surveillance technology may not provide full radar coverage, so controllers rely on pilot position reports.
Example Sentence 2
NextGen upgrades combine ground-based surveillance technology with satellite data to fill gaps in radar coverage.