Modeling And Simulation For The Electromagnetic Situation Of Ground Environment

More and more communication base stations have been established in order to meet the increasing demands of people because of the popularization of smart devices.For regional construction,the regional electromagnetic state has a certain reference value for the location of antenna base station,among which the influence of ground environment can not be ignored.Assessing the electromagnetic situation of the ground environment not only needs to consider the impact of the topography,but also the impact of buildings and trees in different areas of the ground.The electrical size of the ground environment is huge,and the undulations of the terrain and the complex and diverse surface coverings have brought great challenges to the study of the electromagnetic situation distribution of the ground environment.To understand the electromagnetic radiation characteristics of the terrain surface,it is necessary to grasp the distribution characteristics of ground clutter under various conditions,and effectively reduce the impact of ground clutter.This has important theoretical significance and application value for ground high-resolution observation and target recognition.For the undulations of the terrain,the surface fitting method can be used to process the DEM to generate a surface terrain model,combined with buildings,trees and other models to obtain the ground model that needs to predict the electromagnetic situation.The ray tracing technology is used to simulate the ground model,so that the electromagnetic field situation change can be described by the change of the ray field,so as to accurately calculate the characteristics of the electric wave transmission in the ground environment.In this thesis,the hybrid algorithm of high and low frequency combining HOMo M and UTD is used to carry out ray tracing on the established ground model,and the final electromagnetic state prediction results are obtained.This thesis first introduces the basic concepts of Mo M and flat UTD,and the HOMo M-UTD hybrid algorithm of high and low frequency.Next,a method for generating surface terrain is proposed.The surface is fitted to DEM data.The terrain is generated using bicubic Bezier surface and cubic surface.The comparison with the original DEM data shows that the surface terrain has a higher Accuracy.Aiming at the generated surface terrain,a method for surface UTD ray tracing is given,combined with the ray field formula,and compared with Mo M,which shows the method is correct and achievable.The method is applied to the actual mountainous terrain,and the simulation results are compared with the actual measurement data,which shows the method can calculate the radio wave propagation characteristics of the curved terrain quickly and accurately.Finally,the method is applied to the ground environment to realize the prediction of the electromagnetic situation of the ground environment,which can meet the needs of engineering projects.