Adaptive alpha-beta tracking filters for ATC applications

Adaptive, alpha-beta tracking filters are proposed as a convenient solution for air traffic control systems' conflicting requirement for (1) adaptive filters that will implement the tracking function of a track-while-scan (TWS) system, for aircraft motion, and (2) low computation algorithms, to meet system processing constraints. Four alpha-beta tracking filter implementation alternatives are presented, on the basis of appropriate filter coefficient values and of a strategy for switching among values, depending on the results of comparisons between radar measurements and filter outputs. Computational loading is much lower in these cases than for adaptive Kalman filters. The performance results of the four adaptive strategies are given for two typical, computer-simulated civil aircraft flight paths, and are then compared with alpha-beta nonadaptive tracking algorithm performance results.