Filter Design for Steady-State Tracking of Maneuvering Targets with LFM Waveforms

Modern radars employ linear frequency modulated (LFM) waveforms for target tracking as the range-Doppler coupling enables better track accuracy in range. This paper derives expressions for the sensor-noise only (SNO) covariance matrix and the position and velocity lags during maneuvers for an alphabeta-filter processing measurements from LFM waveforms. These expressions were confirmed through computer simulations. An analysis of the maximum root-mean-square error (RMSE) in position and velocity estimates is performed, and the gains that minimize the maximum RMSE in either position or velocity are plotted versus the tracking index. For deterministic maneuvers, the paper introduces the concept of the deterministic tracking index and shows its relation to the typical tracking index generally used for random maneuvers. Using these relations, the paper also proposes a method to calculate the optimal process noise variance to be used in the tracking filter for a deterministic tracking index.