Research On Typical Targets Electromagnetic Simulation Based On Mixed Calculation Of MRTD And IPO

Modern remote sensing technology is developing rapidly,and synthetic aperture radar remote sensing images are more widely used.Due to the different imaging principles,SAR images are very different from optical images.In order to solve the difficulty of manually reading SAR images,it is necessary to analyze and study the electromagnetic scattering characteristics of typical targets under different conditions.In computational electromagnetics,the commonly used electromagnetic calculation methods are numerical methods and high-frequency approximation methods.Numerical calculation methods can obtain accurate calculation results through strict modeling iterations,but require a large amount of computational resources,so when targeting large-scale targets There will be problems of low efficiency and long time.The high-frequency approximation method quickly obtains the target's scatter data by high-frequency approximation conditions,consuming less computational resources,but at the expense of the accuracy of the calculation results.In order to solve the problem of efficiency and precision,this paper proposes an electromagnetic simulation method combining numerical calculation method and high frequency approximation method,making full use of their respective advantages,and aiming at the mixed target of electric large size.Time Domain Multi-resolution(MRTD)is a combination of moment method and multi-resolution technique.It has second-order precision,theoretical sampling interval can reach Nyquist limit,and can provide intuitive results in time domain.Iterative physical optics(IPO)It is an improved algorithm of physical optics,which is a high-frequency approximation method by solving the small-surface electromagnetic flow of the target surface to obtain the overall scattering characteristics.The high-low frequency hybrid method firstly divides into two high and low frequency calculation areas according to the complexity of the target,and then uses the MRTD method and the IPO method to perform electromagnetic simulation in different areas,and uses the near-far field extrapolation technique to obtain the target far-field data.According to the Kirchhoff equation and the near-near field extrapolation technique,the equivalent electromagnetic flow between the high and low frequency regions is used as the secondary excitation source,and the coupled field of the two regions is calculated.Finally,the target electromagnetic scattering characteristics are obtained by superposition.The simulation results are analyzed.The quantitative comparison of the scattering results verifies the accuracy of the high-low frequency hybrid electromagnetic simulation method studied in this paper,and compares the simulation time to achieve a fast calculation of the typical target electromagnetic scattering characteristics.Therefore,the method studied in this paper has certain practical significance and value in the electromagnetic simulation of fast electric large size target.