Rainfall has an attenuation of backscatter coefficient of the sea surface and a change in the sea surface roughness, and these effects give rise to some errors in retrieving the sea surface wind speed, the significant wave height, and wave slope. It is meaningful to make considerable efforts to study the attenuation of radio waves caused by rainfall. In this article, a new model of analyzing the attenuation characteristics of satellite radar altimeter pulse signals because of rainfall is presented. First, the model of the equivalent permittivity of rainfall is calculated and presented. The imaginary part of the equivalent permittivity is studied when radio frequency and rainfall rate vary, respectively. Second, a new theoretical model and method of analyzing the effect of rainfall on satellite radar altimeter pulses is presented based on a multilayer‐medium model with the equivalent permittivity of rainfall. On the other hand, some existing models of computing rainfall attenuation characteristics of radar signals are studied and improved to some extent. Finally, some attenuation characteristics of radar signals due to rainfall are calculated by those models. The calculated results show that the attenuation characteristics of radar altimeter pulse signals are all in good agreement with those by other models. The results computed by the multilayer‐medium model can provide a good theoretical explanation and understanding for these attenuation characteristics of radar pulse signals and can also give some data support and corrections for the measured oceanic parameters by the satellite radar altimeter.

中文翻译：

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基于多层介质模型的卫星雷达高度计信号衰减特性分析新方法

降雨减弱了海面的后向散射系数并改变了海面的粗糙度，这些影响在获取海面风速，有效波高和波坡度时会引起一些误差。作出巨大的努力来研究降雨引起的无线电波衰减是有意义的。本文提出了一种新的分析降雨引起的卫星雷达高度计脉冲信号衰减特性的模型。首先，计算并给出了降雨等效介电常数的模型。当射频和降雨率分别变化时，研究等效电容率的虚部。第二，提出了一种基于降雨等效介电常数的多层介质模型，分析了降雨对卫星雷达高度计脉冲影响的理论模型和方法。另一方面，对现有的一些雷达信号降雨衰减特性计算模型进行了研究和改进。最后，利用这些模型计算了由于降雨引起的雷达信号衰减特性。计算结果表明，雷达高度计脉冲信号的衰减特性与其他模型的衰减特性吻合良好。