FIXED-GAIN 2-STAGE ESTIMATORS FOR TRACKING MANEUVERING TARGETS

The two-stage alpha-beta-gamma estimator is proposed as an alternative to adaptive gain versions of the alpha, beta and alpha, beta, gamma f ilters for tracking maneuvering targets. The purpose of this work is t o accomplish fixed-gain, variable dimension filtering with a two-stage alpha-beta-gamma estimator. The two-stage alpha-beta-gamma estimator is derived from the two-stage Kalman estimator, and the noise variance reduction matrix and steady-state error covariance matrix are given a s a function of the steady-state gains. A procedure for filter paramet er selection is also given along with a technique for maneuver respons e and a gain scheduling technique for initialization. The kinematic co nstraint for constant speed targets is also incorporated into the two- stage estimator to form the two-stage alpha-beta-gamma-lambda estimato r. Simulation results are given for a comparison of the performances o f estimators with that of the alpha-beta-gamma filter.