Statistical modeling of atmospheric refractivity for ducting channel from meteorological observation data in marine environments [RF interference prediction]

Ray paths in the atmosphere depend on the variation of atmosphere. In some cases, like a duct, the rays can be enhanced and this can cause unexpected interference between neighboring nations along oceanic paths. To predict such interference levels accurately, we modeled the refractive index profiles around the Korean peninsula statistically using meteorological data. The upper-air observation data were measured by radio sonde at Pohang and Baengnyeongdo Meteorological Observatory, located in the south coastal area and west sea of Korea, respectively. We classified the refractive index profiles into three classes and fitted each duct parameters to suitable probability distribution functions. The ducting channels are generated numerically, and the pass losses were calculated using the split-step discrete mixed Fourier transform (DMFT) algorithm. Simulation results were compared with the experiment data measured in 1999 for a Korea-Japan channel, and an excellent agreement was found.