一种基于Deramp处理的空时自适应处理方法

摘要

In multichannel Synthetic Aperture Radar-Ground Moving Targets Indication (SAR-GMTI) systems, three problems are led by utilizing the conventional Post Doppler-Space-Time Adaptive Processing (PD-STAP) technique. Firstly, the target Doppler spectrum is wrapped because of the Doppler shift caused by the cross-track velocity of the moving target. The ambiguities are appeared if directly using the matched filtering. Secondly, in the case of the signal undersampling, a Pulse Repeating Frequency (PRF) shifting is caused in the azimuth direction for a moving target in the focused image. This makes the moving target detection much more complicated and challenging. Thirdly, the traditional PD-STAP technique also has a high computational complexity. To overcome these problems, a novel space-time adaptive processing method based on Deramp processing is proposed. Simulation results validate the effectiveness of the proposed algorithm.%在多通道合成孔径雷达动目标检测(SAR-GMTI)系统中，直接利用传统的后多普勒空时自适应处理(PD-STAP)技术进行杂波抑制会导致3个问题。第一，由于动目标径向速度引起的多普勒偏移会导致动目标出现谱卷绕，直接利用匹配滤波的方法对动目标聚焦会出现虚假目标。第二，在信号下采样的情况下，动目标聚焦位置会出现脉冲重复频率(PRF)的偏差，从而导致一个动目标可能出现在多个位置，使得动目标检测变得复杂。第三，利用传统的PD-STAP技术进行杂波抑制会导致很大的计算复杂性。基于此，该文提出一种基于Deramp处理的空时自适应处理方法进行杂波抑制处理，可以有效解决上述问题。该文最后通过仿真实验验证了该方法的有效性。