Rain Attenuation Characteristics due to Typhoon Wind Velocities in Satellite Communications Links

Rain attenuation characteristics due to typhoon passage are discussed using the satellite signal observations conducted in Osaka, from 1988 to 2019. The ratio of hourly rain attenuation to rainfall rate is largely enhanced as the typhoon passes the east side of the station, while it becomes smaller in the case of west side passage. Compared with the ground wind velocities of nearby AMeDAS, the equivalent path lengths of rain attenuation become larger as the wind directions approach the opposite of the satellite azimuth angle, while they become smaller as the wind directions near the satellite azimuth angle.