RADAR (Radio Detection and Ranging)
RADAR (Radio Detection And Ranging) is a system that uses radio waves to detect and locate objects. In aviation, radar is used by ATC for surveillance (locating and tracking aircraft), weather observation (detecting precipitation), and for precision approach guidance (PAR).
Types of Aviation Radar
- PSR (Primary Surveillance Radar): Skin-return radar; detects aircraft position; no transponder required
- SSR (Secondary Surveillance Radar): Interrogates transponder; provides position, altitude, identity
- ASR (Airport Surveillance Radar): Terminal-area radar combining PSR and SSR for approach sequencing
- ARSR (Air Route Surveillance Radar): Long-range en route radar
- PAR (Precision Approach Radar): Controller-directed precision approach guidance
- Weather radar: Detects precipitation; used for weather avoidance and cockpit display (Wx radar)
Radar Identification
When ATC has positively identified your aircraft on radar, they will say “radar contact” and may issue radar vectors or advisories. If radar contact is lost, ATC will advise “radar contact lost” and resume position reporting procedures.