Effects of rain area motions on site diversity techniques in Ku band satellite signal attenuation

The effects of site diversity techniques on Ku-band rain attenuation are investigated using two sets of simultaneous satellite signal observations, which have been conducted among Osaka Electro-Communication University (OECU) in Neyagawa, Kyoto University in Uji, and Shigaraki MU Observatory in Koga for about past nine years, and among the headquarters of OECU in Neyagawa and their other facilities in Shijonawate and Moriguchi for about past six years. The site diversity effects are found to be largely affected by the passing direction of rain areas. The diversity effects primarily depends on the distance between the sites projected to the rain area motions, and the time percentages of rain attenuation can be reduced down to about 60 % of the ITU-R predictions between the fixed two sites, by choosing a pair of the two sites out of the three, which is aligned nearest to the rain area motion in each rainfall event.