同航线双基调频连续波SAR改进距离徙动算法  

Modified RMA for the tandem bistatic FMCW SAR with frequency non-linearity correction

作　　者：梁毅[1] 王虹现[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

出　　处：《西安电子科技大学学报》2011年第1期71-79,84,共10页Journal of Xidian University

基　　金：国家自然科学基金资助项目(60890072);中央高校基本科研业务费专项资金资助项目(JY10000902031)

摘　　要：考虑到调频连续波合成孔径雷达具有较长的扫频周期,要达到频率的线性化非常困难,针对现有非线性校正方法的不足,提出了改进的频率非线性校正方法.另外,分析了平台连续运动带来的多普勒频移的影响.对于频率非线性校正后的信号,利用瞬时频率的概念,通过引入双基角,推导出基于调频连续波的同航线双基合成孔径雷达回波信号的二维波数域表达式,在此基础上提出了包含频率非线性校正的同航线双基调频连续波合成孔径雷达的改进距离徙动成像算法.仿真数据的处理验证了频率非线性校正方法以及成像处理算法的有效性.Considering the long sweep period of the Frequency Modulated Continuous Wave （FMCW） SAR, it becomes difficult to maintain the linearity of frequency. For lack of the satisfactory correction methods, a modified frequency non-liuearity correction algorithm is presented. Furthermore, the Doppler frequency shift introduced by the platform＇s continuous motion is analyzed in detail. For the signals after frequency non-linearity correction, the concept of instantaneous frequency is used by introducing the parameter, i.e., bistatic angle, to deduce the signal analytical expression in the two dimensional wave-number domain. Based on this, a modified Range Migration Algorithm（RMA） with frequency non-linearity correction is proposed which is aimed at the Tandem Bistatic FMCW SAR. Simulation data processing verifies the correctness of the analysis and the effectiveness of the algorithms, including frequency non linearity correction and imaging processing.

关 键 词：调频连续波 同航线双基合成孔径雷达 频率非线性校正 多普勒频移 瞬时频率 改进距离徙动算法 

分 类 号：TN957.52[电子电信—信号与信息处理]