双基星载HRWS-SAR系统方位向信号重构的矩阵求逆算法  

Matrix Inversion Method for Azimuth Reconstruction in Bistatic Spaceborne High-Resolution Wide-Swath SAR System

作　　者：林玉川[1] 张剑云[1] 武拥军[1] 周青松[1] 

机构地区：[1]电子工程学院,合肥230037

出　　处：《雷达学报（中英文）》2017年第4期388-396,共9页Journal of Radars

基　　金：安徽省自然科学基金(1508085MF119)~~

摘　　要：双基星载高分辨率宽测绘带SAR系统(HRWS-SAR)的方位向信号普遍为非均匀采样,重构其均匀采样信号或多普勒频谱是成像处理的关键步骤。该文将方位照射时间内时变的发射接收距离比近似为常数,利用双基系统与单基系统方位向通道间传递函数的等效关系,建立了一般双基构型星载HRWS-SAR系统的方位向信号模型,进而给出了方位向信号重构的矩阵求逆算法及重构性能指标信噪比缩放因子和方位模糊比的计算公式。该文对几种典型双基构型的星载HRWS-SAR系统进行方位向信号重构仿真,结果表明在非重叠采样条件下矩阵求逆算法能较好地重构出方位向信号的多普勒频谱。In bistatic spaceborne High-Resolution Wide-Swath SAR systems（HRWS-SAR）, the azimuth reconstruction to obtain a uniform sampling signal or Doppler spectrum is a crucial step in image processing because azimuth signals are generally of non-uniform sampling type. In this study, the variant transmitting distance to receiving distance radio is approximated to be a constant, the equivalence between the bistatic and monostatic SAR azimuth interchannel transfer functions is deduced, and the azimuth signal model in spaceborne HRWS-SAR with general bistatic configuration is established. Furthermore, the matrix inversion algorithm to reconstruct the azimuth signal is proposed; in addition, to measure the reconstruction performance, the formulae for the signal noise ratio scaling factor and the azimuth ambiguity signal ratio are provided. The azimuth reconstruction is simulated in several spaceborne HRWS-SAR systems with typical bistatic configuration, and the results show that the azimuth Doppler spectrum can be correctly reconstructed via the matrix inversion algorithm when the azimuth sampling is conducted without coinciding samples.

关 键 词：双基SAR 高分辨宽测绘带 方位向信号重构 矩阵求逆算法 

分 类 号：TN959.74[电子电信—信号与信息处理]