Two-dimension visualization of rain cell structures

A methodology is described for the simulation of two-dimensional rain rate fields based on a formulation derived from radar measurements of other investigators and modeled point rain rate distributions. This simulation enables a determination of typical radar clutter maps of rain backscatter and estimates of terrestrial path attenuation as a function of distance and azimuth. Rain rate fields are derived for three diverse climatological regions, and a step-by-step methodology is presented for determining them. Parameters are tabulated, enabling the determination of rain rate fields for any of the 15 International Telecommunication Union–Radio Communication rain rate zones. Examples giving typical path attenuation at 10 GHz versus distance profiles and 3-GHz radar backscatter profiles are calculated. A modified formulation that predicts cumulative slant path fade distributions for Earth-satellite scenarios using many of the elements of the simulation technique is reviewed. As a partial validation of the described rain rate field simulation technique, the cumulative fade distribution was calculated at 28.56 GHz and compared to the derived distribution from a previous 3-year measurement program involving the COMSTAR satellite. The calculated and measured levels were observed to give close agreement over the attenuation range from 3 to 25 dB, resulting in a root-mean-square deviation smaller than 1 dB and a standard error of approximately 10%.