Aircraft collision avoidance based on GPS position broadcasts

The current airborne collision avoidance system provides pilots with approximate information on the relative location of nearby traffic, and with recommended escape maneuvers in the vertical plane. It relies on range measurements, and suffers from high false alarm rate. This paper studies a new collision avoidance system, which is based on periodic broadcasts of aircraft position as derived by an on-board GPS receiver. Several collision detection algorithms were evaluated by using a Monte Carlo simulation of random encounters in a free-flight environment. The algorithm selected uses the miss distance vector for both detection and avoidance. This approach can significantly improve the effectiveness of the current collision avoidance system, while lowering both the probability of false alarm and the probability of late alarm.