由实测小时雨量预报地星通信雨致衰减的方法研究

On Prediction of Rain Attenuation to Earth-Satellite Links from Hourly Rain Gauge Data

利用1991年中国333个地面雨量站的小时雨士数据，进行降雨率累积概率对数正态和伽场分布的计算比较，得出伽玛分布在较大的降雨范围内能更好地反映实际降雨率累积概率分布。又通过半经验的转换系数，得到这333个地面站的满足伽玛分布1min累积时间降雨率概率分布。进一步应用所得结呆预报了不同概率点，不同卫星轨道位置，某一频率、温度时的全国地星通信降雨衰减。文中所用的方法对利用较1min累积时间降雨数据少得多的小时雨量数据来做地星通信降雨表减的预报，有其经济实用价值。

Rain rate accumulative log - normal and Gamma distributions are calculated from 1991's hourly rain gauge data for 333 -gauge stations of China. By comparison, it shows that the Gamma distribution depicts are better than the statistic rain rate distribution. So, 1 -minitue accumulative distribution to every gauge station is derived from the piece-wise regedon results of Gamma distribution through half-empirical conversion coefficients. Prediction of rain attenuation to China earth-satellite links is made for different conditions. The data tmetment procedure and its results presented in the poper may be practical and useful in engineering desgn.