高分辨宽测绘带SAR频域NLCS成像算法  

An Improved Frequency NLCS Algorithm for High-resolution and Wide-swath SAR Imaging

作　　者：陈国瑾 刘静 章坚武[1] 钟华[1] CHEN Guojin;LIU Jing;ZHANG Jianwu;ZHONG Hua(School of Communication Engineering,Hangzhou Dianzi University,Hangzhou Zhejiang 310018,China)

机构地区：[1]杭州电子科技大学通信工程学院,浙江杭州310018

出　　处：《杭州电子科技大学学报（自然科学版）》2020年第6期26-31,共6页Journal of Hangzhou Dianzi University：Natural Sciences

基　　金：浙江省公益技术研究计划资助项目(LGG18F010009);声纳技术重点实验室开放基金资助项目(6142109KF201807);浙江省教育厅一般科研资助项目(Y201840789,Y201840739)。

摘　　要：针对高分辨宽测绘带合成孔径雷达(Synthetic Aperture Radar,SAR)由斜视角空变引起的多普勒参数空变进而导致的成像性能下降的问题,提出新的多普勒参数空变解析式并给出改进的频域非线性变标(Frequency Non-Linear Chirp Scaling,FNLCS)算法。算法通过线性距离走动校正(Linear Range Walk Correction,LRWC)和梯形变换(Keystone Transform,KT)降低了回波的距离多普勒耦合,并构建了用于描述多普勒参数空变特性的距离方位频域模型,以此重新求解FNLCS算法的均衡函数和压缩函数。仿真结果表明,所提模型和算法能有效处理SAR回波的多普勒参数空变问题,获得更好的成像效果。The spatial-variant squint angle produces spatial variant Doppler parameters and further degrades the image quality when focusing high-resolution wide-swath synthetic aperture radar(SAR)data.To circumvent this issue,an improved Frequency Non-Linear Chirp Scaling(FNLCS)algorithm based on an innovative analytical expression of Doppler parameters is proposed.Firstly,a linear range walk correction(LRWC)and a Keystone transform(KT)are adopted to mitigate the range-Doppler coupling.Then,a new range-azimuth model in the frequency is derived to depict the spatial-variant properties of Doppler parameters.Finally,the equalization factors of FNLCS algorithm and the compression function are resolved.Simulation results are presented to validate the effectiveness of the proposed algorithm.

关 键 词：合成孔径雷达 梯形变换 距离多普勒耦合 频域非线性变标 

分 类 号：TN958.4[电子电信—信号与信息处理]