基于多普勒重采样的恒加速度大斜视SAR成像算法  

A Doppler Resampling Based Imaging Algorithm for High Squint SAR with Constant Acceleration

作　　者：李宁[1,2] 别博文[1,2] 邢孟道 孙光才[1,2] LI Ning;BIE Bowen;XING Mengdao;SUN Guangcai(National Key Laboratory of Radar Signal Processing,Xidian University,Xi’an 710071,China;Collaborative Innovation Center of Information Sensing and Understanding,Xidian University,Xi’an 710071,China)

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,西安710071 [2]西安电子科技大学信息感知技术协同创新中心,西安710071

出　　处：《电子与信息学报》2019年第12期2873-2880,共8页Journal of Electronics & Information Technology

基　　金：国家重点研发计划(2017YFC1405600);国家自然科学基金创新群体基金(61621005);中央高校基本业务费(JB180213)~~

摘　　要：针对机动平台大斜视(HS)SAR存在的方位相位系数空变特性,该文提出一种基于多普勒重采样的改进谱分析(SPECAN)成像方法。首先,对于恒加速度HS SAR,给出了一种正交坐标斜距模型,可以处理传统方法中距离走动校正(RWC)引起的坐标旋转,解决了斜距模型与信号之间的失配问题。在此基础上通过方位多普勒重采样校正相位系数的空变性,并且结合SPECAN技术实现方位向聚焦。最后,通过仿真数据验证了该文算法的有效性,与参考算法相比该文方法聚焦质量有明显提升。A modified SPECtral ANalysis(SPECAN)algorithm based on Doppler resampling is proposed to deal with the azimuth Space-Variant(SV)phase coefficients of the High Squint(HS)SAR data acquired from maneuvering platform.Firstly,for HS SAR with constant acceleration,an orthogonal coordinate slant range model is presented,which can handle the coordinate rotation caused by the traditional method of Range Walk Correction(RWC),and solve the mismatch between the range model and the signal after RWC.Then azimuth Doppler resampling is used to correct the SV phase coefficients.The focused image is achieved by SPECAN technique.Finally,the proposed algorithm is validated by processing of simulated SAR data,and has significant improvement on focusing quality over the reference one.

关 键 词：SAR成像 恒加速 正交坐标斜距模型 相位空变 多普勒重采样 谱分析 

分 类 号：TN957.5[电子电信—信号与信息处理]