【作者】 刘天金； 丁北乘； 陈成增； 许小剑；

【Author】 LIU Tianjin;DING Beicheng;CHEN Chengzeng;XU Xiaojian;School of Electronics and Information Engineering,Beihang University;Pinghu Laboratory,Beijing Institute of Radio Measurement;

【机构】 北京航空航天大学电子信息工程学院； 北京无线电测量研究所平湖实验室；

【摘要】 微粗糙表面对高频段雷达目标的电磁散射特性有着不可忽视的影响.本文提出一种微粗糙金属表面目标建模方法,研究了具有高斯随机分布微粗糙表面的雷达目标电磁散射特性.采用二维数字滤波理论与几何模型矢量运算方法建立了高斯分布粗糙表面几何模型,分析了粗糙表面的雷达散射截面(radar crosssection,RCS)随粗糙程度电尺寸和雷达入射擦地角的二维变化关系.针对具有微粗糙表面的典型目标,采用二维逆合成孔径雷达(inverse synthetic aperture radar, ISAR)成像对比分析了不同均方根高度和相关长度对微粗糙表面雷达目标成像特性的影响.理论分析与仿真结果表明,光滑表面仅在尖顶和棱边等不连续处形成散射中心,而粗糙表面会在整个照亮面上均产生散射中心,形成带斑点的轮廓图,能够反映目标更为完整的结构信息.更多还原

【Abstract】 Slightly rough surface makes a significant influence on the electromagnetic(EM) scattering characteristics of radar targets,especially at high frequency bands.In this paper,a modeling technology of slightly rough metal surface target is proposed.The EM scattering characteristics of radar targets with Gaussian distribution-based slightly rough surface are studied.The geometric models of Gaussian slightly rough surface are established according to two-dimensional(2-D) digital filtering theory with geometric vector operation method.The radar cross section(RCS) of rough surface on different rough levels is analyzed versus radar grazing angle and electric size.For typical radar targets with slightly rough surface,the effects of different root mean square(RMS) heights and correlation lengths on radar imagery are compared using 2-D inverse synthetic aperture radar(ISAR) imaging.Theoretical analysis and simulation results demonstrate that the scattering centers on smooth surface are only excited at the discontinuities such as the tips and edges,while those on rough surface are formed on the whole illuminated surface,reflecting more details on the target.更多还原