雪层覆盖地面电磁散射的矩量法

为实现分层介质粗糙面电磁散射的矩量法研究，给出一种分层介质粗糙面电磁积分方程的区域分解方法.将格林定理应用于粗糙面所分的各子空间，结合波动方程和格林函数推导分层粗糙面的电磁积分方程，利用矩量法对其进行离散，数值计算得到雪层覆盖地面散射系数的角分布曲线，其中，粗糙表面由一维带限Weierstrass分形谱和Monte Carlo方法模拟.通过与时域有限差分法数值结果的比对，验证该方法的准确性，并分析散射系数随雪和地面参数、介质参数以及入射波参数的变化，获得了较完整的散射特征.

Method of Moment for Electromagnetic Scattering from Ground Covered with Snow

To investigate electromagnetic scattering from layered rough surface by method of moment, a direct domain decomposition method is used to derive electromagnetic integral equation of layered rough surface. Combining with wave equation and Green's function, electromagnetic integral equations of layered rough surface are obtained by applying Green's theorem to each space divided by rough surface. Then integral equation is discretized using method of moment. Angular distributions of electromagnetic scattering coefficient from ground covered with snow are obtained with numerical calculation, in which snow surface and ground are described with 1D band-limited Weierstrass fractal spectrum and Monte Carlo method. Accuracy of the domain decomposition is demonstrated by finite difference time domain results. Through analyzing scattering coefficient that varies with parameters of snow and ground, medium parameters of snow and soil, parameters of incident wave, the complete scattering characteristics are obtained.