Diversity- and single-site radiometric measurements of 12-GHz rain attenuation in different climates

The results from three dual-site radiometric measurements of 12 GHz rain attenuation and space-diversity effects are presented in order to characterize the rain attenuation on slant paths. The analyses utilized data collected for approximately one-year periods in three regions with different rainfall conditions. It was found that both rain climate and path geometry strongly affect the path fading for single-path statistics. The attenuation distributions for the paths of two sites were dominated by the convective rain climate, while the statistics for the paths of the third site were strongly influenced by the low (6 degrees) elevation angle. However, the cumulative statistics of rain attenuation for the diversity configurations appear to be controlled primarily by path configuration, although the performance for the paths of two sites with diversity switching was better than expected, probably as a result of the local rain climate. In addition, the relation between diversity gain and single-site fading was determined to be independent of rain climate.