IMPROVEMENTS TO AIRCRAFT COLLISION AVOIDANCE

摘要

A collision avoidance arrangement where aircraft transmits and receives radio signals modulated by a digital pulse sequence (34), if a potential collision is detected (35) the arrangement is adapted to transmit and receive interrogation radio signals and from these signals each aircraft estimates the closing speed of the aircraft (36) and then determines the range between the aircraft (37), and the arrangement also being adapted such that each aircraft transmits to the other the estimate of the closing speed calculated aboard the aircraft and then averages the estimates of the closing speed from each aircraft to obtain a more accurate value for the closing speed of the aircraft.