Collision avoidance for future operation

For the future of aviation it is prudent to explore collision avoidance methods that can deliver maximum performance without requiring scientific breakthroughs, exotic methods, or yet-to-be-invented equipment. Automatic Dependent Surveillance - Broadcast (ADS-B) is envisioned to be an essential component of future aviation collision avoidance. This paper addresses an alternative ADS-B implementation that uses available provisions (Mode-S and GPS receivers) and existing algorithms and techniques (modern estimation in combination with GPS double differencing). This alternative has many advantages over the current ADS-B implementation, and can be pursued in a low-cost pilot program that will not interfere with ongoing ADS-B efforts.