蒸发波导环境下风浪对电磁波传播影响的数值模拟研究

An evaporation duct is a kind of atmospheric ducts in which electromagnetic wave could be trapped to achieve over-the-horizon propagation. Affected by temperature, humidity, wind speed, and microwave frequency above sea surface, the characteristics of microwave propagation in an ocean evaporation duct are very complicated. Previous works focus on the effects of meteorological factors on the refractive index profile of the evaporation duct, and the simulation results are biased from the observation. Therefore, we analyzed the influence on the propagation path loss and found that the calculated results are quite different from the experimental data using a one-dimensional fractal sea surface model to generate sea surface “topography”. In addition, we input the calculated results to the parabolic equation propagation model, compared the corresponding path loss with that of traditional method, and analyzed the outputs under different evaporation duct heights, frequencies, and receiver heights. When the frequency of microwave propagating in the evaporation duct is less than 4.5 GHz, wind speed has little influence on the propagation path loss. When the microwave frequency is about 6-10 GHz, the path loss difference becomes more obvious. The findings of this study could be applied to the design of ship communication system or radar system.