Bj?rck-Schmidt正交化微波凝视成像方法的研究  

The Research on Bj?rck-Schmidt Orthogonalization for Microwave Staring Imaging

作　　者：邵鹏[1] 许然[1] 李浩林[1] 李亚超[1] 邢孟道[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,西安710071

出　　处：《信号处理》2014年第4期450-456,共7页Journal of Signal Processing

基　　金：航空基金项目(20110181004);中央高校基本科研业务费(K5051202016)

摘　　要：微波凝视成像作为一种新的成像模式,依靠多个相互独立的天线阵元发射随机信号,在空间形成时空两维随机辐射场,将回波信号形成的辐射场与预存的随机辐射场进行关联处理,从而实现成像。由于电磁信号在空间形成的辐射场具有很强的相关性,因此在进行直接关联处理后,得到图像的副瓣很高。本文针对上述问题提出对预存辐射场分别进行Schmidt及Bj?rck-Schmidt正交化处理,减小了邻近单元散射电磁信号的相关性,从而抑制了目标的副瓣,图像的信噪比得到提高,最终获得良好聚焦的图像。文中给出了直接关联处理及Schmidt和Bj?rck-Schmidt两种正交化方法性能的对比,同时对预存辐射场正交化处理后的信号特性进行了分析。仿真实验证明了Bj?rck-Schmidt正交化方法可以明显降低目标的副瓣,进而说明了该方法的有效性。Microwave staring imaging as a new radar imaging mode,depends on antenna sensor radiating random signal respectively and spatial-temporal two-dimension random radiation field is formed.The received echo signal and pre-stored random radiation field are processed and the image is obtained.Due to the problem of strong correlation for electromagnetic signal,the scatterer point sidelobe is very high after directly correlated processing.To solve the proposed problem,this paper proposes a new method,which is based on Schmidt and Bjorck-Schmidt orthogonalization of the pre-stored random radiation field.The correlation of random radiation field between different scatterers is reduced by these two methods and the sidelobe of scatterer is suppressed.The ratio of signal-to-noise for processed image is enhanced.Finally,the fine focused image is obtained.The comparison between signals orthogonlized by Schmidt and Bjorck-Schmidt is shown in this paper and the characteristic of the pre-stored random radiation field is analyzed.Simulation experiments show that the proposed approach is feasible.

关 键 词：凝视成像 时空两维随机辐射场 Bj(o)rck-Schmidt正交化 关联处理 

分 类 号：TN957[电子电信—信号与信息处理]