复杂目标电磁散射仿真与频率步进雷达对三维目标的重构  

Scattering simulation and reconstruction of a 3D complex target using downward-looking step-frequency radar

作　　者：戴俊文[1] 金亚秋[1] 徐丰[1] 

机构地区：[1]复旦大学波散射与遥感信息教育部重点实验室,上海200433

出　　处：《中国科学：信息科学》2011年第8期912-928,共17页Scientia Sinica(Informationis)

基　　金：国家自然科学基金(批准号:60971091;41071219);复旦大学研究生创新基金资助项目

摘　　要：提出下视频率步进雷达对电大复杂三维体目标电磁散射数值模拟、成像,以及几何特征的重构.采用双向射线解析跟踪BART方法(bidirectional analytic ray tracing method),数值计算随机粗糙面上电大复杂三维目标的极化散射场;基于下视聚束模式的频率步进雷达合成二维圆弧形孔径,获取包含幅度与相位的三维后向散射矩阵;通过波数域的三维插值,获取在XYZ坐标系中的均匀重采样数据;再对重采样数据进行三维快速Fourier变换(3D-FFT)快速获得三维聚焦图像,实现三维目标几何特征的重构.同时,采用基于物理光学(physical optics,PO)的FEKO软件计算简单体目标的散射场及其成像与重构,作为验证与比较.论证了本文对于地面背景上三维复杂体目标散射、成像与重构的可行、准确、高效的良好性能.Numerical simulations of polarized scattering-3D imaging-profile reconstruction of a complex-shaped electric-large target above a rough surface are developed.The bidirectional analytic ray tracing （BART） method is first applied to calculation of polarized scattering from volumetric target and surface.By using the step-frequency （SF） radar working in downward-looking spotlight mode and moving within a two-dimensional circular arc aperture,a 3D matrix of backscattering fields in both the amplitude and phase is obtained.The three-dimensional fast Fourier transform （3D-FFT） algorithm is adopted for uniformly resampling data in X Y Z coordinate system,which are acquired by interpolating the collected uniformly sampling backscattering fields to quickly form a focused image.Automatic reconstruction of the target is well demonstrated.As validation and comparison,the scattering fields are also computed and compared using widely accepted software FEKO based on physical optics.The technique of imaging and reconstruction for a 3D complex-shaped perfect electric conductor （PEC） electric-large target,such as a tank-like object,is presented.

关 键 词：背景中电大目标 电磁散射BART 三维成像 特征重构 

分 类 号：TN957.52[电子电信—信号与信息处理]