Definition
An air traffic service in which controllers use an ATS surveillance system — such as primary radar, secondary surveillance radar (SSR), ADS-B, or multilateration — to identify aircraft and provide separation, sequencing, navigation assistance, and other services based on the surveillance picture they see on their display.
Plain English
It is the kind of air traffic service where the controller can see your aircraft on a screen and uses that picture to give you instructions, keep you separated from other traffic, and help you navigate.
Context Anchor
Seen in ICAO and international air traffic control procedures, especially where services are described as being provided by radar or other position-tracking systems.
Derivation
ATS stands for Air Traffic Services. 'Surveillance' comes from the French surveiller, meaning 'to watch over.' The phrase literally means 'an air traffic service where the controller is watching over the aircraft' using electronic means.
Why Pilots Care
Provides reliable separation assurance and navigation assistance, especially when visual references are limited.
Intuition Check
Surveillance does not mean spying on the pilot. In this context, it means ATC is observing aircraft position so it can provide an air traffic service.
Example Sentence 1
Once established in radar coverage, the crew was provided an ATS surveillance service for the remainder of the oceanic crossing.
Example Sentence 2
Request ATS Surveillance Service for traffic advisories in the terminal area.