Low-flying Aircraft Surface Complex Electromagnetic Environment Analysis And Model Simulation

The current states of the world are that intensive application of electronic devices, expanding the field of wireless communications applications, more and more complex electromagnetic environment on Earth. These phenomena increasing influence on the design and normal operation of electronic equipment. Worldwide, the emphasis continues to deepen about the research on the analysis of complex electromagnetic environment (EME). The research in domestic started soon. There are many problems to be solved.To address this situation, this paper refer to the relevant standards and research findings in domestic and international, depth study of the connotation and extension of the complex EME. Simultaneously, based on the analysis of the ITU recommended model of electromagnetic wave propagation prediction, Combine the characteristics of the EME of the aeronautical mobile service, the paper puts forward that applied the uniform geometrical theory of diffraction (UTD) to the analysis of complex EME, refined analysis of the large target, and in the theoretical framework of the electromagnetic topology, set up the analytical model of the complex electromagnetic environment.Firstly, the aeronautical mobile service for the application of background, the article analyzes the electromagnetic wave transmission loss prediction model, focus on low-altitude conditions of the two-ray propagation loss prediction model, get the theoretical methods of the basic transmission loss in the context. Then discuss the electromagnetic field distribution of the target surface, and in accordance with the characteristics of the method of UTD, determine the solution to the problem.In order to apply the two-ray theory and the UTD theory to the scenario, which is the analysas of the electromagnetic environment on the low-flying targets in the aeronautical mobile service, after thorough and careful study, this article made the following results. Developed and implemented the basic transmission loss prediction algorithm based on the two-ray theory. The processes of the establishment of the algorithm were implemented. Then the paper analyzed the constraints, and made typical comparison tests. These tests can prove that the algorithm validity.After the study, obtained the modeling program about the surface model based on NURBS method. Got the calculation method of the NURBS method provides the model surface coordinates of sampling points, the unit vector tangential to the unit vector. The modeling is implemented in Matlab.Based on the NURBS parametric surface model, the paper analyzed the shadowing method between the source points, field point. In the tracing analysis of NURBS-UTD method, tracing algorithm about reflection, edge diffraction and surface diffraction was implemented, and made the comparison authentication with the example in Reference. These tests can prove that the algorithm validity.Finally, study the theories and methods of calculation of body surface field strength, and provide the method of calculation about the field distribution of body surface.In this paper, the model is applied to the EME analysis of the surface of UAV system in the state of low-flying. In the end, the work made a comparison validation between the simulation results and the calculation results of FEKO which is the internationally renowned space electromagnetic field analysis software. Test results show that the algorithms and models of this study are practicable.