土壤表面散射特性对大地遥感等问题有着重要应用,地面对雷达波束的镜面反射是造成镜像干扰的主要原因,利用粗糙地面的布儒斯特效应将有效削弱镜面反射。采用四成分土壤介电模型计算不同类型土壤的介电常数,以二维高斯粗糙面模拟实际地面,引入锥形入射波来克服粗糙面的边缘衍射;应用基于物理意义的双网格法(PBTG)结合稀疏矩阵规范网格法(SMCG)计算分析土壤类型和湿度对地面散射特性的影响,进一步探究了粗糙地面布儒斯特效应随土壤类型、湿度及入射波频率等的变化关系。分析表明:土壤类型和湿度等因素对地面散射特性及布儒斯特效应均会产生不同程度的影响。研究成果对于不同土壤类型的地面环境遥感探测以及削弱镜像干扰提供了理论支撑。

The scattering characteristics of soil surface have important applications in earth environment remote sensing and other issues. The bistatic specular scattering of earth surface plays a major role in the mirror interference. The specular scatter can be weakened effectively by using the Brewster effect of earth surface. The permittivity of different types soil is calculated by using four component model. The 2D Gaussian rough surface model is generated to simulate the real earth surface. The tapered incident wave is applied to eliminate the edge diffraction. The effects of soil components and moisture on the earth surface scattering characteristics are analyzed by using PBTG/SMCG algorithm, and the impacts of soil components, soil moisture, as well as the frequency of the incident wave on Brewster effect are further studied. The analysis shows that the soil components and moisture have different influences on the scattering characteristics and Brewster effect of earth surface. The results of this paper have a theoretical support for earth environment remote sensing and mirror interference weakening.

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国家自然科学基金资助项目