| ⑶ SURVEILLANCE |
ASDE |
| ASDE (Airport Surface Detection Equipment) is installed at the airport to support ATC controllers detecting the aircraft and vehicle on the ground under the low visibility. ASDE was used only under the low visibility in the past, it is now used all day long as the important information source for the surface detection system. |
| ASR/SSR |
| ASR/SSR (Airport Surveillance Radar/ Secondary Surveillance Radar) is installed at the airport to support ATC controllers detecting the aircraft flying around the airport. The coverage range is about 70NM radius. ASR is called primary radar and SSR is secondary radar with the response of transponder on the aircraft. |
| ARSR/SSR |
| ARSR (Air Route Surveillance Radar) is installed at the top of high mountains with good view to support ATS controllers detecting the aircraft flying en-route with high altitude. The coverage range is about 230NM radius. ARSR is primary radar and SSR is secondary radar. |
| ORSR |
| ORSR (Oceanic Route Surveillance Radar) is installed near the coast line to support ATC controllers detecting the aircraft flying in the oceanic area. The coverage range is about 290NM radius. ORSR is secondary radar only. |
