Research On Propagation Characteristic Of Electromagnetic Wave In Atmospheric Duct And Reversion Based On Genetic Algorithm

In this paper this dissertation gives a thorough research in depth on the subject including the parameter description and the propagation characteristic of electromagnetic wave in atmospheric duct, and the reversion to the evaporation duct height from radar sea clutter used the genetic algorithm. Firstly, the formal condition and the parameter characteristics of the atmospheric duct and the impact on the EM-wave propagation are studied. Secondly, the EM-wave propagation paths are modeled with ray-tracing method. The propagation are analyzed when transmitting antenna are lay in the trapping layer and outside the trapping layer. Thirdly, the solutions of the parabolic equation and its Discrete Mixed Fourier Transform method are systematically analyzed under the boundary conditions of the smooth and rough sea surface, and the Discrete Mixed Fourier Transform method over the rough sea surface are improved. The focus on the EM-wave propagation over the rough sea surface, as the grazing angle,'big V'problem, boundary conditions and antenna source, are analyzed in detail. The influence of the wind speed and the incident frequency on the propagation loss is discussed in detail. Lastly, evaporation duct height is respectively reversed from radar sea clutter and GPS clutter based on genetic algorithm.