Research On Error In Parabolic Equation Method

Currently,Parabolic equation method is the most widely used research method of radio wave propagation in the troposphere.Split-step fourier transform method is the most commonly used parabolic equation solving method.Due to the built of parabolic equation and the solving of it,unavoidably produce approximation error and separation error.The paper,take standard parabolic equation as an exanple,researched on the method to increase error produced by parabolic equation in troposphere,and also made experiment.The main contents are as follows:1.In this paper,the influence of the calculation parameters(calculation step),antenna parameters(frequency,elevation angle)and environmental parameters(standard atmosphere,the troposphere duct)and other parameters in approximation error and separation error produced by parabolic equation method are researched.2.The currently definition of separation error ignore the accumulation characteristic of split-step fourier transform method.Based on the currently definition of separation error,the paper defined the accumulated separation error and derived it.With accumulated separation error,we can despribe error cause by interation of operator during the solving of parabolic equation method.3.The paper resaerched the influence of the calculation parameters,antenna parameters and environmental parameters by using Markov process and K-L transform.The horizontal homogeneous standard atmosphere and horizontal inhomogeneous evaporation ductcases are both studied.the result provide a useful reference to improve calculate accuracy of parabolic equation method.Experiment is taken with sea clutter data.The correction method can4.Based on research result,the paper present a correction method amid to correct accumulated separation error in parabolic equation method.The correction method can correct accumulated separation error in parabolic equation method with a great probability.The condition used is an ideal mode,take underlying surface as smooth sea surface,ignore the influence of grazing angle.The result getten by the research and the correction method presented is still have important theoretical significance and practical value for improving the accuracy of parabolic equation method using in radio wave field.