Rain attenuation characteristics of Ku-band satellite signals in relation to the wind velocities observed on the ground

The recent satellite communications tend to use high frequency bands of more than 10 GHz, in addition to the traditional C band of 6/4 GHz. In these higher frequency bands, however, the rain attenuation of radio waves becomes one of the severe problems of satellite communications. Thus, detailed observations and statistical analyses of rain attenuation characteristics are necessary for reliable operations of satellite communication links [1]. In this study, Ku-band satellite signal levels have been simultaneously observed at Osaka Electro-Communication University (OECU, Neyagawa, Osaka), the Research Institute for Sustainable Humanosphere (Uji, Kyoto) and the Shigaraki MU radar observatory (Koga, Shiga) of Kyoto University since September 2002 [2]. The direction and speed of rain area motions are estimated from the time differences in the attenuation detected at these three locations, and compared with the wind direction and speed measured by the AMeDAS located at a nearby station (Hirakata, Osaka) on the ground.