Effect of the Sea Surface Evaporation Duct on the Propagation of Electromagnetic Wave

This paper proposes a numerical model based on parabolic approximation equation for the propagation of the electromagnetic wave and analyzes its marching type with Fourier transform algorithm.Numerical simulation is carried out for electromagnetic wave propagation in the evaporation duct at the altitude of 30 meters above the sea surface.From the results,the effect of evaporation duct in trapping electromagnetic waves is analyzed.As compared with ambient conditions of the standard atmospheric refraction,the feasibility of implementing radar transhorizon detection in the marine evaporation duct environments is clearly confirmed.The propagation loss function of electromagnetic waves under the condition of the ocean boundary layer atmosphere is obtained from the parabolic approximate equation mode.The relationship among the departure angle,therelative location of the evaporation duct with respect to the emission source and the wavelength(frequency) is derived,which determines the establishment of ducting propagation in the environments to capture electromagnetic waves.