Velocity Filtering Based Track-Before-Detect With Range And Doppler Ambiguities in Doppler Radars

Velocity filtering based track-before-detect has the strength of high energy integration efficiency and parameter estimation accuracy. However, conventional velocity filtering based approach may suffer from performance degradation due to the possible range and Doppler ambiguities in Doppler radars. In this paper, a new velocity filtering based track-before-detect method is proposed for multiframe weak target detection with ambiguous range and Doppler measurements. To deal with motion model mismatch in ambiguous range-Doppler plane, the accurate range-Doppler evolution with range and Doppler ambiguities is derived. It can be determined by the constant velocity, range and Doppler ambiguity factors of the target. Then, a complex pseudo-spectrum based velocity filtering track-before-detect method is proposed for weak target detection in ambiguous range-Doppler plane of Doppler radars. The constant target velocity, range and Doppler factors are matched, and the complex pseudo-spectrum is constructed to use additional phase information of raw data for efficient energy integration. Finally, simulation results are conducted to demonstrate the effectiveness of the proposed method in raw ambiguous range-Doppler plane of Doppler radars.