Simulation Study Of Rainfall Dynamic Characteristics On Earth Space Link At Ka-band

The physics characteristics of rainfall and cumulative distributions of rain intensity are introduced in detail, and the log-normal law parameters m andσare calculated. The parameter Mc, Ms, Pr6 of weather station are respectively calculated through the bi-linear interpolation law, and the rain probability P0 of taking account of station position is calculated. The method of Ka-band time series synthesis and power spectral densities estimate are given, on the basis of the synthesizer, rainfall series of Beijing, Hainan and Madrid are simulated, Base on the measured data of rain attenuation time series, simulated data of rain attenuation time series are tested. The result show that simulated data of rain attenuation time series are relatively reasonable and approximate to the measured values. On the basis of the ITU-R prediction model, Crane prediction model and ITU-R measured rain attenuation data model, simulated and measured values of cumulative distribution of rain attenuation time series are also discussed and analyzed, and the result show that for Madrid, simulated values of rain attenuation are similar to measured when the rain percentage of time is at 0.03%~0.1%. On the basis of rain cell model, characteristics of rain attenuation values varying with elevation are calculated when moving target through the rain cell series. Based on simulated data of rain attenuation time series, rain attenuation dynamic characteristics of rapid changes of elevation of the rain field communication paths are studied, and the influences of rapid changes of elevation effects on earth-space paths rain attenuation values are analyzed when rainfall randomly varies with space-time. Based on measured rainfall data, rain attenuation values are calculated when elevation rapidly changes, and also compared simulated data with measured data. The result show that simulation and measure of rain attenuation values change trend are consistent, so rationality of synthesizing rain attenuation time series are proven again. The final calculation program of the simulation software is done, so that it is easy for more research calculations. These results have an important practical meaning performance of wireless satellite communications system and wave propagation characteristics of rain area moving target in high frequency during rain.