Two-Dimensional Polarization Scattering Center Extraction Of Radar Target And Stealth Performance Analysis

The modern military aircraft types are becoming more and more complicated.The traditional RCS information,which regards equipment as a target,can not describe the structural characteristics of complex targets.The high resolution radar imaging method can better describe the geometric structure of the target,reflecting the strong scattering structure of complex targets.Stealth military targets often use coating materials,placement materials,geometric structure adjustment of the electromagnetic stealth optimization to achieve the purpose of radar stealth.This paper focuses on the application of high resolution radar imaging algorithm and the application of such algorithms in stealth performance evaluation,and the predictive analysis method of aircraft stealth based on radar RCS and ISAR imaging.Finally,the three-dimensional modeling and electromagnetic simulation methods in practical engineering are introduced,which provide the nesearch data for the research of this paper.The article from the following aspects of research:(1)This paper analyzes the limitations of radar target RCS can only be used to analyze point targets,and leads to high resolution radar imaging based on matrix theory that can exvtract multi-scatter centers.This paper introduces three methods of calculation of moments,time domain finite difference method and high frequency algorithm,which provides data source for high resolution radar imaging.The predictive method of radar echo signal is described,including a variety of smoothing preprocessing methods and covariance matrix decorrelation method of airspace filtering.(2)Based on the radar echo signal model,the MUSIC and ESPRIT high resolution Lei imaging algorithms are analyzed and deduced,and the theoretical basis of the correlation matrix theory is described.Orthogonal projection theory,subspace rotation invariant theory,generalized Eigenvalue decomposition,singular value decomposition and so on The ESPRIT algorithm is used to improve the ESPRIT algorithm.and the ESPRIT algorithm based on the coherent polarization scattering model is used to deal with the fully polarized signal vector.The algorithm can accurately complete the polarization matching and longitudinal resolution polarization matching problem,the imaging efficiency is higher,the obtained strong scattering center is more comprehensive and accurate.(3)In this paper,the radar echo signal model of the coherent polarization ideal point scattering model is processed and the mathematical expression of the scattering center position and the scattering center strength is obtained.The imaging performance of MUSIC,ESPRIT,2D-TLS-ESPRIT imaging algorithm is programmed and tested to verify the accuracy of imaging algorithm.Radial radiation targets with different bandwidths and polarizations are used to assess the imaging differences caused by this change.(4)In this paper,we study the physical meaning of radar echo data file of several electromagnetic simulation software,and develop the corresponding far field data reading code to provide simulation data input interface for high resolution imaging.This paper studies the relevant electromagnetic numerical calculation method and geometric modeling method,and provides the research data for the algorithm research of this thesis.(5)In this paper,the stealth related technology of aircraft material is studied,and the stealth principle of total reflection and diffraction of new artificial electromagnetic materials is analyzed.Based on geometric modeling and electromagnetic simulation,the new type of artificial electromagnetic material is mounted on the surface of the aircraft,and its backscattering echo is calculated.Then,the high resolution radar image of the new type of artificial electromagnetic material is used to obtain the scattering center distribution of the aircraft,and the stealth effect of the new type of artificial electromagnetic material is analyzed by using the optimized high resolution imaging algorithmThis paper realizes the far-field data interface and two-dimensional MUSIC and ESPRIT algorithms of various electromagnetic simulation software,and uses the electromagnetic simulation and the code realized in this paper to analyze and evaluate the stealth performance of the new artificial electromagnetic material.In this paper,we use the-imaging method which is different from traditional ISAR imaging radar target characteristic and stealth performance analysis,which is of great significance to the basic research of radar stealth technology.