蒸发波导条件下风速风向对电磁波传播的影响

Influence of Wind Speed and Wind Direction on Electromagnetic Wave Propagation in the Presence of Evaporation Duct

海洋蒸发波导是重要的军事敏感要素,严重影响着海上电磁波的传播。风向、风速是决定蒸发波导强弱的重要因素,为精确模拟蒸发波导条件下的电磁波传播,准确评估预报雷达、通信等电子设备的性能,文中利用抛物线方程模型,结合粗糙度参数和蒸发波导条件下大气修正折射指数廓线模型来求解电磁波波动方程,基于电磁波传播的数值模拟结果,重点研究蒸发波导条件下风速和风向对电磁波传播的影响。并得到如下结论:在同一传播距离处,风速越大,海面粗糙度越大,海面电磁波传播损耗就越大;当电磁波传播方向与风向夹角为0°时,其传播路径损耗远远大于在45°或90°条件下,即顺风条件下电磁波传播损耗大于侧风。

The evaporation duct is an important military sensitive factor at the sea,which affects the propagation of the electromagnetic waves.The wind direction and the wind speed are the important factors that determine the strength of the evaporation duct.In order to accurately simulate the propagation of the electromagnetic wave in the evaporation duct and evaluate the performance of the radar,communication and other electronic equipment,this paper uses the Parabolic Equation Method to solve the wave equation above a generated random sea surface which furthermore takes into account the roughness parameter and the atmospheric modified refraction index model under the evaporation duct conditions.Based on the numerical results of the EM wave propagation,this paper deals with the effects of the wind speed and the wind direction on electromagnetic wave propagation in the presence of evaporation duct.This paper draws the following conclusions:At the same propagation distance,the wind speed is higher;the sea surface roughness is bigger,the electromagnetic wave propagation loss is greater.When the angle between the electromagnetic wave propagation direction and wind direction is 0o,the propagation path loss is much greater than 45°and 90°,namely,the propagation loss of the electromagnetic wave under the downwind condition is greater than the crosswind.