Research On The Influence Of The Simplification Of Terrain On The Prediction Accuracy Of Complex Electromagnetic Environment

In the simulation of complex electromagnetic environment based on ray tracing technology,a large number of triangular surfaces are needed to divide the terrain of the scene,and the calculation of time consumption in ray tracing model is to determine the intersection between ray and triangular surfaces,which leads to a long simulation time.Therefore,this paper simplifies the terrain,reduces the number of triangular surfaces,and shortens the simulation time.The change of terrain will affect the effective path obtained by ray-tracing model,which will affect the simulation result.This paper will research the influence of terrain simplification on the simulation accuracy.This paper carries out research based on these two points.In the research of terrain simplification,Douglas-Poker algorithm is used to simplify the terrain.In consideration of the shortcoming that this algorithm lacks the influence of adjacent nodes in a certain direction when applied directly to three-dimensional terrain simplification.In this paper,the terrain is first divided into blocks,and then the column and diagonal elevation information are considered comprehensively when simplifying each terrain.Finally,each terrain is pieced into a complete terrain according to the original order for simulation.Through experimental research and analysis,it is found that under the condition of acceptable power error,applying the simplified terrain to electromagnetic simulation can significantly shorten the simulation time and improve the simulation efficiency.In order to research the influence of terrain simplification on the prediction accuracy of electromagnetic simulation,a visibility algorithm based on the relationship between triangle plane and space plane and a power propagation model based on probability are proposed in this paper.The spatial visibility algorithm is to calculate the set of visible triangular surfaces by using the relationship between triangular surfaces and triangular surfaces.The probability-based power propagation model uses the visibility algorithm based on the relationship between the triangles and the space plane to obtain the relationship between the triangles,and then calculates the radio wave propagation probability.Combined with the radio wave propagation characteristics,the variation of the simulation results caused by the simplification of the terrain is calculated.Comparing the experimental results of the probability model with the simulation results of the wireless electromagnetic simulation software Wireless InSite,the experimental simulation analysis shows that the error is 1.47 dB,and the power change curve obtained by the probability propagation model is consistent with the trend of the Wireless InSite simulation result curve.