Effect of compensation for rain attenuation on earth‐satellite links by onboard resource sharing using AMeDAS data

Onboard resource sharing (ORS) is a method wherein, for increasing effective isotropically radiated power, surplus satellite resources (radiated power or time slots in TDMA) are used to maintain communications quality in areas affected by rain attenuation. This paper analyzes simultaneous occurrence rates of rain over a wide area using Automated Meteorological Data Acquisition System (AMeDAS) data (1 hr rain rate data at approximately 1300 locations in Japan provided by the Japan Meteorological Agency). An ORS system is proposed using AMeDAS data as dynamic information for controlling satellite transmission power. Then a control simulation is performed by using actual reception intensities of satellite signals and rain rate information derived from AMeDAS data at corresponding times. The effect of the proposed ORS system is demonstrated in compensating for rain attenuation. From these results it was confirmed that the forementioned compensation provides a saving of about one-third compared to the case where unavailable time is not compensated.