利用多普勒分辨率的FMCW SAR成像算法

A FMCW SAR Imaging Algorithm Capable of Exploiting Doppler Resolution

调频连续波合成孔径雷达(FMCW SAR)具有低成本、低功耗的优势,小型或微小型SAR普遍采用FMCW工作体制。目前已有的FMCW SAR成像方法均是依靠发射宽带信号获取距离向高分辨,本文给出一种新的FMCW SAR成像算法。该算法除了利用距离分辨外,还可通过利用脉内多普勒频率,有效利用连续波较好的多普勒分辨率,使FMCW SAR在近距离成像时,距离向的分辨率可以不仅受带宽限制,在FMCW带宽较窄时也能够提供良好的距离向分辨率。在算法流程、成像视线方向和分辨率三方面,与基于距离分辨率的传统FMCW SAR成像算法进行对比,分析给出的成像算法的性能,并通过仿真实验进行验证。

Synthetic Aperture Radar using Frequency modulated continuous waveforms （FMCW SAR） has the advantages of low cost and low power consumption, which facilitates the development of small or micro SAR systems. The existing FM- CW SAR imaging algorithms rely on wideband transmitted waveforms to achieve high range resolution. In this paper, we presented a new imaging algorithm for FMCW SAR. Besides the range resolution, this algorithm can exploit the good Doppler resolution provided by CWs by using the temporal/intrapulse Doppler in the imaging, which lead to a range resolu- tion not dependent only on the bandwidth of the transmitted waveform and can provide good range resolution for narrowband cases. The performance of the presented algorithm was analyzed from the perspectives of algorithm flowchart, imaging look- direction and image resolution. Simulations verified the presented algorithm and the theoretical findings.