分形大地土壤表面与部分埋藏目标复合散射特性

采用土水混合物介电常数的Topp方程模型表示大地土壤的介电特性，应用带限Weierstrass-Mandelbrot分形粗糙面模型和Monte Carlo方法模拟大地土壤表面，运用矩量法研究了带限分形大地土壤表面与部分埋藏矩形截面柱复合模型的电磁散射，得出了复合散射系数的角分布曲线；计算了复合散射系数随带限分形大地土壤表面分维、空间基频、高度起伏均方根、土壤含水率、矩形截面柱几何参数、埋藏深度、倾角、入射波频率等的变化情况，并做了详细分析与讨论；结果表明，土壤表面分维等参数对复合散射系数的影响是非常复杂的，镜像附近的角分布曲线具有明显的分形特征。

Characteristics of composite electromagnetic scattering from fractal earth soil surface and target buried partially

The dielectric property of the earth soil is expressed using the TOPP equation model of dielectric constant of soil-water mixture, the earth soil surface is simulated with model of band-limited fractal rough surface and Monte Carlo Method. The composite electromagnetic scattering from the earth soil surface based on band-limited fractal and the column with rectangular cross-section buried partially is studied using Method of Moment. The angle distribution curves of composite bistatic scattering coefficient is obtained. The composite bistatic scattering coefficient varying with the fractal dimension, the space fundamental frequency and the root mean square of the earth soil surface, the moisture capacity of earth soil, the geometric parameter, buried depth and tilt angle of the column with rectangular cross-section, and incident frequency of electromagnetic wave are calculated in detail. The results show that the influences of the fractal dimension of soil surface and other parameters on the composite scattering coefficient are very complex, and the angular distribution curves near the mirror have obvious fractal characteristics.