Investigation of the transmission loss in sea fog environment based on Longley-Rice model

Abstract:
Fog is a common meteorological condition on the sea, which has a significant influence on the radio transmission. The existing models for calculating the transmission loss and the formulas for calculating the fog characteristic attenuation cannot quickly and accurately calculate the transmission loss in sea fog environment. Based on the Longley-Rice model, we established a transmission loss model suitable for the sea fog environment, which takes into account the atmospheric refractivity correction and the fog characteristic attenuation. The effects of the electromagnetic parameters of the sea fog environment on transmission loss are investigated in detail. It is found that for low-frequency radio, the increase in the scale of the fog environment causes a widening range with increased refractivity, thereby reducing the transmission loss of radio in the diffraction region. As for high-frequency radio, the increase in the scale of the fog environment enhances the fog characteristic attenuation in the area, resulting in a rapid increase in the transmission loss. For the same scale of the fog environment, the closer the fog environment is to the transmitting antenna, the greater the transmission loss becomes. Moreover, it shows that the fog environment temperature, fog visibility, sea surface roughness, the height of the transceiver antenna and the radio frequency also have important influences on the radio transmission in the sea fog environment. The research results obtained have a reference significance for improving the quality of maritime radio communication.