运动目标环境下的调频步进信号目标抽取算法

Target's Redundancy Removed Algorithm for Modulated Frequency Stepped Pulse Radar Signal Echoed by Moving Target

为了减少采样损失,调频步进信号的采样率通常高于chirp子脉冲的带宽。在这种过采样冗余情况下, 需要对IFFT合成高分辨结果进行目标抽取去冗余方能得到高分辨一维距离像。然而当目标运动时,目标抽取的结果会产生目标丢失或伪峰等现象。该文提出了一种基于幅度最强像偏移量的动目标抽取算法,该方法利用幅度最强像的偏移量修正各采样点的目标抽取范围,从而解决了速度估计误差引起的速度-距离耦合对目标抽取算法的影响。计算机实验结果验证了理论分析的正确性。

To reduce the loss of sampling, higher sampling frequency than bandwidth of chirp must be adopted for Modulated Frequency Stepped Pulse（MFSP） radar signal, which will bring on over-sampling result of pulse compression for chirp. So the pick-up algorithm for the MFSP radar signal must be adopted to eliminate target＇s redundancy in order to obtain fine HRRP（High-Resolution Range Profile）. However, because of inaccuracy of the velocity compensation method, the velocity error of the moving target will produce velocity-range coupling error, even bring the influence of losing target or producing spurious peaks on the HRRP. This paper proposes a target＇s redundancy removed algorithm based on the offset of the most powerful scatterer, which can solve the velocity-range coupling problem effectively by modifying the pick-up scopes of all sampled points. Finally, the processing results of both simulated data and real radar data validate the correctness of theoretical analysis.