指数型粗糙地面与上方矩形截面柱宽带电磁散射的时域有限差分法研究

Study on wide-band scattering from rectangular cross-section above rough land surface with exponential type distribution using FDTD

采用土壤介电常数的四成分模型表示实际地面的介电特性,应用指数型分布粗糙面模型和Monte Carlo方法模拟实际的粗糙地面,运用时域有限差分方法研究了微分高斯脉冲波照射时粗糙地面与上方目标的宽带电磁散射问题,得出了后向复合散射系数的频率响应曲线,计算了后向复合散射系数随粗糙地面高度起伏均方根、相关长度、土壤湿度、目标尺寸、高度、倾角等几何参数及介电参数等的变化情况,并做了详细分析与讨论,得到了指数型粗糙地面与上方目标宽带电磁散射特性.

The dielectric property of the actual land surface is expressed using the four-component model of dielectric constant of soil, the actual rough land surface is simulated with model of exponential type distribution rough surface and Monte Carlo method, the wide-band electromagnetic scattering from column with rectangular cross-section above rough land surface under Gaussian difierential pulse irradiation is studied using FDTD, the curves of frequency distribution of back composite scattering coeficient is obtained, the back composite scattering coeficient varying with the root-mean-square of height fiuctuation, the correlation length of rough land surface, the moisture capacity of soil, the geometric parameter of the target, such as height, size, tilt and dielectric parameter of the target is calculated in details, the characteristics of the wide-band composite scattering from object above rough land surface with exponential type distribution are obtained.