TCAS surveillance algorithm modifications for reduced channel utilization

The Traffic Alert and Collision Avoidance System (TCAS) is a collision avoidance system mandated on board all large transport aircraft world-wide. The system uses beacon interrogations to determine the relative positions of nearby aircraft. TCAS shares communications channels with several other air traffic control surveillance systems such as ground-based secondary surveillance radars and Automatic Dependent Surveillance-Broadcast (ADS-B). As a result of several systems operating on the same frequencies, restrictions are imposed on TCAS to limit interference with the other surveillance systems. Potential improvements to the surveillance algorithms that limit channel interference are investigated.