一种基于改进压缩感知的低信噪比ISAR高分辨成像方法  

A New Method of High Resolution ISAR Imaging under Low SNR Based on Improved Compressive Sensing

作　　者：张龙[1,2] 张磊[1] 邢孟道[1] 

机构地区：[1]西安电子科技大学雷达信号处理重点实验室,西安710071 [2]西安工程大学电子信息学院,西安710048

出　　处：《电子与信息学报》2010年第9期2263-2267,共5页Journal of Electronics & Information Technology

基　　金：国家自然科学基金重大项目(60890072);陕西省自然科学基础研究基金(2009JQ8022);陕西省教育厅自然科学专项基金(09JK468);西安工程大学校校基础研究基金项目(09XG06)资助课题

摘　　要：针对低信噪比下基于压缩感知(CS)的ISAR成像方法性能下降甚至失效的问题,该文提出了一种改进CS的成像方法,即用能量门限分离含目标的距离单元和噪声单元,同时在方位向上用相干投影来提高观测数据的信噪比,利用迭代加权的1-范数优化以增强真实散射点能量并且压制噪声。改进CS算法适用于强噪声的环境下的ISAR成像,并可利用很少脉冲数获得高分辨的目标像。实测数据处理验证了该方法可以有效克服强噪声与杂波。同时,仅用16个回波脉冲就可得到高分辨ISAR图像,验证了该方法在非常有限脉冲条件下的稳健性。In consideration of the the issue of the weakness performance of Compressive Sensing （CS） ISAR imaging under low SNR condition,an improved CS method is proposed in this paper. Energy based threshold is proposed to identify range cells containing only noise,a coherent projection in cross-range to improve the SNR of measurements then a iterative re-weighting l1 norm optimization is applied to enhance the signal recovery while reject noise. Moreover,an advantage of this robustness is the ability to produce a high quality image and is suitable for ISAR imaging by using very limited echoes under strong noise and clutter. Experimental result of real data processing verifies the proposed method＇s capability of depressing noise or clutter and extracting strong scatterers to construct high resolution image. In the experiment,high quality image can be generated by using only 16 pulses and its robustness is confirmed too.

关 键 词：逆合成孔径雷达 雷达成像 压缩感知(CS) 有限脉冲 超分辨 

分 类 号：TN957.52[电子电信—信号与信息处理]