基于级数反演的斜视FMCW SAR成像算法研究  

Frequency Modulated Continuous Wave Squint Synthetic Aperture Radar Imaging Algorithm Based on Series Reversion

作　　者：张双喜[1] 李军[2] 张磊[1] 邢孟道[1] 保铮[1] 

机构地区：[1]西安电子科技大学雷达信号处理国家重点实验室,陕西西安710071 [2]北京无线电测量研究所,北京100854

出　　处：《电子学报》2013年第3期532-538,共7页Acta Electronica Sinica

基　　金：国家自然科学基金优秀青年基金(No.61222108)

摘　　要：在斜视调频连续波(FMCW)合成孔径雷达(SAR)成像中,斜距的三次项不仅会对相位产生影响,同时对包络也会有影响.如果不进行有效校正,将会影响到SAR图像的聚焦效果.针对这个问题,本文利用级数反演的方法推导出斜距展开到三次项时回波信号的距离多普勒频谱表达式,并在距离多普勒域上对三次项进行包络和相位滤波处理.此外,考虑到时域走动校正带来方位空变性问题,本文利用方位非线性变标算法(NCS)解决其沿方位空变性问题并给出结合运动补偿的实测数据处理的算法流程图.最后通过对多个点目标的场景进行仿真实验以及实测数据处理来验证本文成像算法的可行性和有效性.In the frequency modulated continuous wave（FMCW）squint synthetic aperture radar（SAR）imaging,not only the phases but also the envelopes of the echoes will be affected by the third term in range.If it isn＇t well-corrected,the performance of focusing for the SAR image will be deteriorated.Thus,the echo expression in the range-Doppler domain is presented by the series Reversion algorithm when the range expression comes to the third item.After that,a correction is implemented in the range-Doppler domain.In addition,considering the azimuth-variance in phase brought by the linear rang migration correction in azimuth time domain,the non-linear chirp scaling algorithm is utilized to solve the azimuth-variance problem.And a flowchart of the proposed FMCW imaging algorithm with motion compensation for processing the real measured data is given in this paper.Finally,the simulated experiment with multiple point targets scenario and the imaging result of real measured data are utilized to validate the feasibility and effectiveness of the proposed imaging algorithm.

关 键 词：合成孔径雷达 调频连续波 解线性调频 非线性变标 级数反演 

分 类 号：TN958[电子电信—信号与信息处理]