基于方位向相位编码技术的方位向多通道SAR距离模糊抑制方法

Range Ambiguity Suppression for Multi-channel SAR System Using Azimuth Phase Coding Technique

距离模糊一直是影响合成孔径雷达(SAR)成像质量的重要因素之一。方位向相位编码(APC)技术是一种有效抑制距离模糊的方法,但是由于APC技术高度依赖于高过采样率,对于多通道SAR系统,APC技术的距离模糊抑制效果很有限。该文提出一种新的基于APC技术的多通道系统距离模糊抑制方法。该方法首先通过APC技术将部分距离模糊信号产生方位平移,通过额外增加接收通道数提供的额外信号自由度,能够在方位向上通过合适的数字波束形成(DBF)技术同时滤去距离模糊和重建方位向信号,因此距离模糊信号可以被很好地抑制。该文最后给出仿真结果,证明该方法的有效性。

For Synthetic Aperture Radar （SAR）, the range ambiguity is one of the important factors causing significant deterioration of the imaging performance. Azimuth Phase Coding （APC） technique is an effective method to suppress the range ambiguity. However, since the suppression performance heavily depends on the system over-sampling rate, the APC technique could not have the same suppression performance for a multi-channel SAR system compared with a single-channel SAR system. This paper presents a novel method to suppress the range ambiguity for multi-channel SAR system based on the APC technique. First, the range ambiguity can be shifted in the azimuth frequency domain by using the APC technique, then by taking advantages of more phase centers of multiple channels, the Digital BeamForming （DBF） method can be used to filter out the range ambiguity and reconstruct the useful signal, thus most of the ambiguity components can be suppressed significantly. Finally, the simulation results validate the effectiveness of the proposed method.