Studies on radio duct occurrence and properties

It is necessary to clarify radio duct properties in order to estimate propagation characteristics for radio system design. In this paper, radio duct properties are statistically analyzed using aerological data observed at six typical stations in Japan over seven years, and meteorological data observed near the ground by a balloon or tower. Radio refractivity gradient statistics are then compared with duct occurrence probability and fading occurrence probability. Consequently, it was possible to evaluate quantitatively a probability of duct occurrence using refractivity statistics. Certain properties of the radio duct were also quantitatively obtained.