DEVELOPMENT OF EXPERIMENTAL AUTOMATIC DEPENDENT SURVEILLANCE SYSTEM AND INFLIGHT PERFORMANCES

The automatic dependent surveillance (ADS) system has been developed a nd tested through flight trials using INMARSAT satellites. ADS is a ne w surveillance system that uses a satellite datalink for aircraft in o ceanic areas; Test results showed that the ADS transmission protocol i s-reliable and message losses are very few, the transmission delay for the R channel is about 3.4 s and that for the T channel is 15.6 s und er fair link conditions. The latter should be reduced for additional i mprovement in surveillance capability in the future. It map increase d ue to degradation of link condition by aircraft attitude change.