Track-Before-Detect for Bistatic Radar Based on Velocity Filtering

Conventional track-before-detect methods for bistatic radar usually detect weak target according to an approximate target motion model. The inaccuracy of this approximation motion model tends to cause degradation of detection performance. To remedy this issue, a weak target detection algorithm for bistatic radar with velocity filtering based on the accurate target motion model is addressed in this paper. First, the evolutions of bistatic range and incident angle are obtained by the constant velocity motion model in Cartesian coordinate system (CCS). Then, the cells in the bistatic polar coordinate system (PCS) are transformed into the CCS and their positions in the CCS are predicted with the help of the supposed velocity. Further, the predicted positions are transformed inversely into the bistatic PCS and the measurement of each cell is added to that of the cell nearest its predicted position to realize multiframe accumulation. The process of energy integration and the output envelope of bistatic PCS are deduced elaborately. Finally, the effectiveness and superiority of the proposed method is demonstrated by several simulation results.