基于方位向预处理和后处理的TOPSAR成像方法  

An Imaging Approach for TOPSAR Data Based on Azimuth Pre-processing and Post-processing

作　　者：徐伟[1,2] 邓云凯[1] 

机构地区：[1]中国科学院电子学研究所,北京100190 [2]中国科学院研究生院,北京100039

出　　处：《电子与信息学报》2011年第4期798-804,共7页Journal of Electronics & Information Technology

摘　　要：Burst工作模式和方位波束主动扫描使得TOPSAR(Terrain Observation by Progressive scans SAR)回波信号同时具备ScanSAR和聚束模式回波信号特点,即方位输出时间混叠和多普勒频谱混叠。虽然时域和频域同时升采样操作能够解决混叠问题,但同时带来成像运算量明显提高和内存消耗显著增大的问题。针对TOPSAR回波信号特殊的方位时频关系,该文提出一种结合方位向预处理和后处理的TOPSAR成像方法。该方法利用复制拼接和去斜的方法来解决混叠问题,利用信号截取操作剔除干扰信号,同时还可以减少采样点数,提高算法运算效率。点目标和分布目标的仿真结果验证了这种成像方法的有效性。Burst mode and azimuth beam steering lead to echoes of TOPSAR mode obtain echo characteristics of both ScanSAR and spotlight mode,such as azimuth data folding in the output time domain and Doppler spectrum aliasing.Up-sampling both in the slow time and Doppler frequency domain can resolve the aliasing problem but with the unwanted result of seriously increased computational complexity and memory consumption.According to the TOPSAR raw data support in the slow Time/Frequency Domain（TFD）,a new TOPSAR imaging approach combined with azimuth pre-processing and post-processing operations is proposed.The mosaiking with deramping operation approach is adopted to resolve the data aliasing problem.Furthermore,azimuth data interception is used to eliminate the disturbance signals and reduce azimuth total samples to improve the computational efficiency.Simulation results of point targets and distributed target validate the effectiveness of the presented imaging approach.

关 键 词：TOPSAR Burst模式 波束扫描 混叠 CS算法 

分 类 号：TN958[电子电信—信号与信息处理]