论文部分内容阅读
建立二维粗糙面模型研究了大地土壤表面对高频超视距雷达电磁波的散射特性。采用半经验公式计算了HF频段给定频率下土壤媒质在不同温度、湿度时的有效相对介电常数,并与微波频段下情形进行对比。采用Monte Carlo法结合高斯谱函数生成二维粗糙面模拟真实大地土壤表面,建立了土壤表面积分方程,采用锥形波入射消除人为截断粗糙面带来的边缘衍射,采用基于物理意义的双网格法(Physics Based Two Grid,PBTG)结合稀疏网格迭代法(Sparse Matrix Canonical Grid,SMCG)求解土壤表面的双站散射系数。研究了不同温度和湿度条件下,大地土壤表面对高频超视距雷达电磁波的散射特性。研究结果为高频超视距雷达遥感探测提供了理论参考。
The two-dimensional rough surface model was established to study the scattering characteristics of the earth’s surface to the electromagnetic waves of high-frequency over-the-horizon radar. The semi-empirical formula was used to calculate the effective relative permittivity of soil media under different temperature and humidity at a given frequency of HF band, and compared with the microwave frequency band. Monte Carlo method combined with Gaussian spectral function to generate two-dimensional rough surface to simulate the real earth surface soil surface integral equation was established, the use of conical waves to eliminate edge artifacts caused by truncated rough edge diffraction, the use of physics-based dual-grid (Physics Based Two Grid, PBTG) and the Sparse Matrix Canonical Grid (SMCG) were used to solve the bistatic scattering coefficient of soil surface. Under different temperature and humidity conditions, the scattering characteristics of the earth’s surface to electromagnetic waves of high-frequency over-the-horizon radar were studied. The results provide a theoretical reference for the detection of high-frequency OTHR remote sensing.