去调频FM-CW SAR距离维成像研究

调频连续波(FM-CW)合成孔径雷达因其体积小、重量轻、成本低及分辨率高等特点越来越受到关注。详细分析了去调频FM-CW SAR距离维成像过程,得到了FM-CW SAR残留视频相位在距离维傅立叶变换过程中被消除的有用结论;分析了影响距离维分辨率的因素,提出了改善FM-CW SAR距离分辨率,同时降低距离维采样率的方法。理论分析表明,去调频连续波SAR同样存在斜置现象,因此,还详细分析了FM-CW SAR斜置的产生以及去斜的方法,提出了包含去斜的距离维成像算法,为方位向更好的聚焦提供了条件。

Study on Range Imaging of De-chirped FM-CW SAR

There is a growing interest in the frequency modulated continuous wave(FM-CW) SAR for its advantages such as small cubage,light weight,cost-effective and high resolution.In this paper,imaging process in range direction was analyzed in detail,and a useful conclusion was drawn that the RVP is removed in the course of performing Fourier transform in range direction;Then,the factors affecting range resolution for the de-chirped FM-CW SAR was discussed,and the method improving the range resolution as well as decreasing the range sample frequency was put forward.The deduction of the process shows that the slope factor exists in FM-CW SAR.Therefore,the generation of the slope factor and the method of de-sloping were analyzed,and the corresponding range imaging algorithm was also presented,creating better focus conditions for the azimuth direction.