Influence of the rain cell structure on attenuation predictions on earth-space paths

This paper examined the influence of modeled rain cell horizontal structure, size, and statistics on the prediction of rain induced attenuation of radiowaves along an earth-space slant path. Circularly symmetric uniform, exponential, and Gaussian shapes were compared. It was shown that the modeled rain cell horizontal shape has little influence on the long term slant path attenuation predictions. However, the rain cell size model can have a significant impact on the attenuation predictions. The magnitude and shape of this effect depends upon the manner in which the rain cell model is implemented into the attenuation model. The characteristics differ for commonly used models that assume a well defined relation between the cell size parameter and the rain rate than for approaches in which the statistics of the cell size parameter are applied.