1.前言在10GHz 以上频段的卫星通信中,有两种情况会造成严重的问题,对低仰角地一空路径尤为严重,那就是雨衰减和闪烁衰落,后者是由于对流层中不均匀体的无线电折射率起伏所造成的。因此,在设计卫星通信系统时,必须要准确地估算由这些效应所造成的信号质量下降。为此,许多研究人员将注意力集中到预测各种传播损耗方面。到目前为止,对雨衰减和闪烁的传播预测一直是分别进行的,因为这些效应的产生机理完全不同,然而,这两种效应有时会同时出现,因此,从实用的角度考虑,需要一种能准确地估算整个信号质量下降的方法。 1. Introduction In satellite communications in the frequency bands 10 GHz and above, there are two serious problems that can be posed. The path to the sky at low elevation angles is particularly severe, namely rain attenuation and flickering decline, the latter due to inhomogeneous radio in the troposphere Refractive index caused by fluctuations. Therefore, in the design of satellite communications systems, the signal quality degradation caused by these effects must be accurately estimated. For this reason, many researchers have focused their attention on predicting various propagation losses. Until now, predictions of the propagation of rain attenuation and flicker have been performed separately, since the mechanisms by which these effects occur are quite different, however, both of these effects sometimes occur simultaneously, and therefore, from a practical point of view, Accurately estimate the overall signal quality degradation.