Definition
The long-range surveillance radars used by Air Route Traffic Control Centers (ARTCCs) to track aircraft flying en route through controlled airspace, typically above 18,000 feet and across large geographic regions between terminal areas.
Plain English
The radars that ARTCC controllers use to watch aircraft as they cruise across the country between airports, rather than the shorter-range radars used near airports.
Context Anchor
Seen in instrument flying discussions of Air Route Traffic Control Centers, especially when describing how Center controllers monitor aircraft over large regions.
Derivation
‘Center’ here is short for Air Route Traffic Control Center. ‘Radar’ comes from RAdio Detection And Ranging — a system that sends out radio waves and uses the returning echoes to locate aircraft. So ‘Center radars’ simply means the radars belonging to and operated by a Center.
Why Pilots Care
On an IFR flight, you spend most of your en route time being watched by Center radars. Knowing that Center radars cover wide areas at higher altitudes — and that coverage may be limited at low altitudes or in mountainous terrain — helps you understand why radar contact can be lost and why position reports may still be required.
Intuition Check
Do not read “Center” as meaning the radar is located in the physical center of an area. Here, “Center” means the FAA facility responsible for controlling aircraft over a large en route region.
Example Sentence 1
Once clear of the Class B airspace, the controller handed us off to Center radars for the cruise portion of the flight.
Example Sentence 2
Center radars allow controllers to maintain separation between aircraft across large areas of airspace.