Study On Composite Electromagnetic Scattering Of Nearshore Environment And Target

The research on the composite electromagnetic scattering characteristics of nearshore environment and target is of great significance to marine remote sensing and target detection and identification in the terrestrial environment,and is also the research hotspot of scholars all over the world.The coupling between environment and target is an important factor that cannot be ignored in the study of composite scattering,and it is also an important and difficult point in the calculation of composite electromagnetic scattering.This article mainly aims at the offshore environment and target compound electromagnetic scattering characteristics of related research,focus on the electromagnetic scattering characteristics of complex target analysis,nearshore environmental geometric modeling and the electromagnetic scattering characteristics analysis and nearshore environmental and composite target scattering characteristics calculation and analysis of three aspects of research,thesis main research work is as follows:1.Geometrical modeling of complex targets was carried out based on modeling software.In view of the high-frequency approximation method of electromagnetic scattering of targets,the physical mechanism differences between the physical-optical method and the geometrical-physical-optical method were analyzed and compared through numerical examples.For the Radar Cross Section(RCS)calculation of the coated target,the far field approximation method is used to obtain the calculation formula of backscattering,which improves the calculation efficiency while ensuring the accuracy.The absorbing performance of radar absorbing materials at different thicknesses and different frequencies is analyzed.Finally,the electromagnetic scattering characteristics of the complex coated target are calculated and the calculated results are analyzed.2.Different from the deep sea area,the fluctuation above the nearshore sea is more varied.Based on the oceanographic theory and the shallowness coefficient,the geometric modeling of the nearshore sea is carried out,and the geometric modeling of the nearshore cement ground and nearshore sand is carried out by linear filtering method based on the exponential spectrum and Gaussian spectrum.Using the small slope approximation method and analyses the nearshore sea inshore electromagnetic scattering characteristics of ground,mainly analyses the water depth,wind speed,wind direction Angle and frequency on the electromagnetic scattering characteristics,the influence of the nearshore sea and dielectric constant,root mean square height,relative factors such as length and sand humidity effects on offshore ground electromagnetic scattering characteristics.3.Using four path correction model for offshore environment and composite electromagnetic scattering characteristics of target,in view of the coastal environment and target the calculation of coupling field,using the geometrical and physical optics method in calculation of thought to solve multiple reflections,the tablet cube model numerical example to verify the correctness of the modified four path model,then uses the simple combination target for different composite scenario(land/sea),Nearshore ground root mean square of the height,correlation length and different Angle of incidence and nearshore sea target height,different wind speed,above the surface of the target with different size and different types of eight kinds of the main factors influencing the composite scattering characteristics of a particular compound scene modeling,and in view of the above various factors under the influence of the offshore environment and target to analyze specific composite scattering,finally respectively conducted missile battery,ships and other complex target and nearshore sea environment composite electromagnetic scattering model,and the calculation results are reasonably analyzed.