降雨率的最坏月分区转换模式研究

最坏月分布特性是无线电系统设计和研制过程中需要考虑的重要指标，大多数无线电气象数据和传播数据只能提供年平均分布概率，这就要求提供最坏月分布和年平均分布之间的转换模式. 本文首先给出了包含累积分布和互补累积分布完整的最坏月概念. 然后分析了对流层散射传输损耗、降雨率和雨衰减、地面视距链路多径衰落等多种电波环境和传播特性的年平均和最坏月概率转换关系，并通过对比分析给出了最优的模型参数，其对应的均方根误差最小，其中对流层散射和雨衰减的均方根误差小于10%，同时论证了雨衰减的转换关系可以由降雨率的转换关系得到. 本文的研究将有力支撑无线电系统的最坏月设计.

Worst month statistics

The distribution characteristics for the worst month period are important technical requirement for the design of radio communication systems. The reference statistics for many radio meteorological data and propagation prediction methods is the long-term average annual distribution, consequently there is a need for a method that provides for the conversion of the annual to the worst month statistics. The complete concept of the worst-month is proposed including cumulative distribution and complementary cumulative distribution. The conversion models of annual statistics to worst month statistics is analyzed for troposcatter transmission loss, rain rate, rain attenuation, and multipath propagation loss at line-of-sight links, and the parameters. The optimal model parameters are given through comparative analysis, and the root mean square (RMS) error corresponding to the optimal model parameters is the smallest, among which the RMS errors of tropospheric scattering and rain attenuation are less than 10%. Meanwhile, it is demonstrated that the conversion relationship of rain attenuation can be obtained from the conversion relationship of rain rate. The research herein will strongly support the worst month design of radio systems.