地空路径统计雨衰减建模的几个问题

地空路径雨衰减统计特性是卫星通信等地空无线电系统设计和运行评估的关键参数.针对地空路径统计雨衰减的建模研究, 分析了影响模型准确度的几个关键因素, 它们包括雨滴谱分布、雨顶高度、降雨率在水平和垂直路径的不均匀性等.同时比较分析了现有主要模型计算的路径调整因子随仰角的变化、与频率的关系等, 讨论了现有模型的局限性和可能的改进途径.通过上述对比研究, 提出了地空路径雨衰减统计建模向确定性模型方向发展的观点.

Issues on modelling rain attenuation statistics on Earth-Space links

The rain attenuation statistics are key parameters for the proper planning and evaluating of earth-space radio systems such as satellite communication systems. The key factors affecting the accuracy of the rain attenuation prediction model on slant path are analyzed herein, which include rain drop size distribution(DSD), rain height, the non-uniformity of rain rate in horizontal and vertical direction, etc. Meanwhile, the dependencies of main rain attenuation models on elevation and frequency are compared and analyzed, and the limitations of the existing models and the approaches of improving the models potentially are discussed. Through the investigation of the above comparison, an opinion is put forward that the tendency of rain attenuation statistics modeling on earth-space path is to the path-specific model.