Progress in radioclimatological modeling for Southern Africa

This paper presents the work in radioclimatological modeling that has been developed over the last two decades for Southern Africa. The work covers microwave and millimetric wave propagation in clear-air and under precipitation. The paper presents models for the effective earth radius factor (k-factor) for of the determination of diffraction fading over a link. In addition, it presents seasonal variation of the Geoclimatic factor, which is used for the estimation of multipath fading over a link. Under precipitation conditions, the paper covers the average year and worst-month rainfall rate for mainland South Africa and the neighbouring islands of Marion and Gough. Also covered are the rainfall integration time conversion parameters, rain attenuation prediction on terrestrial paths, rain attenuation using forward scattering, and, finally, the raindrop size distribution estimates.