多帧相参积累检测前跟踪方法

Track-before-detect Method Based on Coherent Integration during Multi-scan

为了提高雷达对微弱目标的检测能力,提出了一种多帧相参积累的检测前跟踪(TBD)方法。通过对多帧时间内运动目标回波的分析,建立了相参积累的回波信号模型,其中目标回波出现距离单元走动和多普勒单元走动。利用目标回波的空-时相关性,采用速度匹配法和离散Chirp-Fourier变换(DCFT)联合估计目标径向速度、多普勒频率和调频斜率,补偿距离单元走动和多普勒单元走动,实现多帧时间内目标能量的相参积累。最后,采用仿真实验验证了信号模型的正确性和算法的有效性。

A coherent integration track- before - detect（TBD） method is proposed to enhance the ability of detecting low signal - to - noise ratio（SNR） targets. Based on the analysis of the moving targets＇ echoes during several successive scans, the signal model for the coherent TBD is established, in which the targets echoes exhibit range cell migration and Doppler cell shift. By exploiting the space - time correlation of the received echoes, a lowcomplexity power - efficient algorithm is proposed. By using velocity matching method and discrete Chirp - Fourier transform（DCFT）, the targets parameters such as target radial velocity, Doppler frequency and chirp rate are jointly estimated to compensate range cell migration and Doppler cell shift and realize coherent integration. Finaliv, simulation results show the validity of the signal model and the efficiency of the proposed algorithm.