ABSTRACT

ABSTRACT: The two-scale Model (TSM) is broadly employed for studying EM scattering from rough sea surface due to its advantage of simple and practical. However, it suffers from a drawback in the prediction of microwave scattering from sea surface. That is the TSM cannot provide accurate predictions for hh polarized scattering coefficients. To overcome this problem, a modified TSM (MTSM) is proposed in this paper. Through analysing the validity conditions of the KA (Kirchhoff approximation) and SPM (small perturbation method), the concept of ‘transition spectral region’ is proposed for the first time. In this region, both the validity conditions of the KA and SPM are satisfied, indicating both the specular scattering and Bragg scattering contributed to the scattered energy in this region. Therefore, in the MTSM, two cut-off parameters are used to divide sea surface roughness into ‘specular scattering region’ and ‘Bragg scattering region’. Additionally, in the MTSM, the KA-SP rather than the commonly used KA-GO is employed for simulating the specular scattering component. Numerical simulations confirm that the MTSM performs better than the TSM and the SSA-1, especially in the prediction of hh polarized scattering coefficient.

摘要

摘要：两尺度模型（TSM）由于其简单实用的优势而广泛用于研究EM从粗糙海面的散射。但是，在预测海面微波散射方面存在缺点。那就是TSM无法为hh提供准确的预测极化散射系数。为了克服这个问题，本文提出了一种改进的TSM（MTSM）。通过分析KA（基尔霍夫近似）和SPM（小扰动方法）的有效性条件，首次提出了“跃迁谱区”的概念。在该区域，KA和SPM的有效性条件均得到满足，这表明镜面散射和布拉格散射均对该区域的散射能量有贡献。因此，在MTSM中，使用两个截止参数将海面粗糙度分为“镜面散射区”和“布拉格散射区”。另外，在MTSM中，采用KA-SP而非常用的KA-GO来模拟镜面散射分量。hh极化散射系数。