Measurements on UHF radio propagation over the Seto Inland Sea

This paper investigates the characteristics of UHF band radio propagation over the Seto Inland Sea in order to obtain primary data to estimate interferences of the terrestrial digital TV system that will be operated in UHF band. The authors have measured UHF band TV broadcasting waves from the Matsuyama station at two observatories in Hiroshima prefecture since June in 2005. From the measurement data, it was clarified that short-term fading with a duration time less than 1 hour frequently occurred in summer season and that long-term fading related to sea level fluctuations occurred in winter season. It was also found that the received level became stable when the typhoon with strong winds hit the propagation paths.