中文摘要：

首先建立大尺度分层介质粗糙面散射的物理模型，基于Stratton．Chu积分方程和Kirchhoff近似导出了粗糙面散射场的计算公式．采用高斯随机粗糙面来模拟实际的分层介质粗糙面，通过数值计算得到了正下视单站雷达接收到的后向散射回波．理论推导了散射场强度与表面粗糙度之间的定量关系，并从数值仿真的角度分析了表面和次表面的粗糙度对散射回波的影响，给出了散射场随粗糙度变化的曲线．最后考察了分层介质的电特性参数（介电常数和电导率）对分层粗糙面散射场的影响，并对计算结果做出了分析．

英文摘要：

A physical model for the electromagnetic scattering from large-scale rough surface of layered medium is established. Stratton- Chu integral equation and Kirchhoff approximation are adopted to calculate the electromagnetic scattering field. The Gaussian random rough surface is selected to simulate the actual rough surface of layered medium. The scattering echo is detected with a single-station nadir-looking radar sounder. The effects of surface and subsurface＇s roughness on the scattering filed are examined both theoretically and numerically. The effect of upper layer＇s electric properties （permittivity and conductivity） on the scattering field is also investigated and some analysis for the numerical results is presented.