Research On The Parabolic Equation Method Of Electromagnetic Scattering And Propagation Of Lossy Media

The parabolic equation method is an approximate numerical method derived from the wave equation.The parabolic equation method is not only widely used in the problem of wave propagation,but also used in the analysis of electromagnetic scattering characteristics of electrically large targets.The parabolic equation method bridges the rigorous method and the high frequency methods.It can give encouraging accuracy with limited computational resources.This dissertation focuses on the parabolic equation method for analyzing EM scattering from dielectric body and EM wave propagation in lossy medium.At first,the vector parabolic equation method is described and the modeling of the target is introduced.Then the boundary condition for PEC body is shown.Moreover,the impedance boundary condition(IBC)for dielectric body is given.Secondly,the vector parabolic equation method with impedance boundary conditions(IBC-PE)is used to analyze the EM scattering from lossy dielectric targets.The proper form of impedance boundary condition is derived for the vector parabolic equation.Both the Crank-Nicolson(CN)and alternating direction implicit(ADI)schemes are used for the vector parabolic equation method with impedance boundary condition.Then the vector Claerbout parabolic equation is used to obtain a wider angle IBC-PE.After that,the IBC-PE in frequency domain is further extended to the time domain,so the broadband electromagnetic scattering characteristics of dielectric targets can be analyzed.At last,the EM wave propagation in lossy media is analyzed,such as the atmospheric and wind sand.Through constructing the complex refractive index model of atmosphere and wind sand,the electromagnetic propagation properties of the media can be obtained.Then the EM wave propagation characteristics can be analyzed by taking advantage of the complex refractive index model.