Study on Electromagnetic Scattering Characteristic of Hypervelocity Model with SBR Method

Author(s):  
Qidi Yu ◽  
Zhou Cong ◽  
Zi He ◽  
Dazhi Ding ◽  
Rushan Chen
Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5802
Author(s):  
Zeyang Zhou ◽  
Jun Huang

With the continuous advancement of rotor dynamic electromagnetic scattering research, the radar cross-section (RCS) of turbofan engines has attracted more and more attention. In order to solve the electromagnetic scattering characteristics of a biaxial multirotor turbofan engine, a dynamic scattering method (DSM) based on dynamic simulation and grid transformation is presented, where the static RCS of the engine and its components is calculated by physical optics and physical theory of diffraction. The results show that the electromagnetic scattering of the engine is periodic when the engine is working stably, while the rotors such as fans and turbines are the main factors affecting the dynamic electromagnetic scattering and the ducts greatly increase the overall RCS level of the engine. The proposed DSM is effective and efficient for studying the dynamic electromagnetic scattering characteristic of the turbofan engine.


Background: Reducing the detection probability by radar stations for military or civil complex shape objects is very important problem of modern radar theory. The solution to this problem is impossible without numerous estimates of the effective scattering surface (RCS) of the investigated object. Objectives: The purpose of the work was to analyze and improve the efficiency of methods for modeling electromagnetic scattering on objects of complex shape. The process of constructing a facet model of an complex shape object for modeling electromagnetic scattering and an algorithm to simplify the geometric model of an object to reduce the time required for modeling is considered. Materials and methods: As the main method for calculating the RCS, we chose the method of rays that fall and reflect (in the English language literature “Shooting and Bouncing Rays” SBR). Wherein the modeling electromagnetic scattering on an complex shape object is based on the methods of physical and geometric optics. Object is represented in the form of a geometric model which takes into account the shape of the object and its electrodynamic properties (reflection coefficient, dielectric and magnetic permeability of the surface, conductivity, etc.). Results: The general steps of the SBR method are discussed, and the efficient of using the surface mesh method to launch the rays is shown. Effective approaches to simplify the calculation for complex shape objects are proposed, in particular, the use of Raytressing and k-d tree is considered. The using of large facets for modeling surface flat sections of complex shape object is proposed. To assess the effect of the facet size on the accuracy of RCS calculations, we simulated electromagnetic scattering for a triangular plate, the surface of which is represented using different numbers of facets. A comparison with the well-known expressions for a triangular plate RCS is made. Conclusions: The accelerating possibilities of the process of electromagnetic wave diffraction calculation on complex shape objects are offered. The efficiency of the created algorithms is tested numerically.


2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Weijie Xia ◽  
Yuanyuan Qi ◽  
Linlin Huang ◽  
Xue Jin

SAR raw signal simulation under the case of maneuver and high-speed has been a challenging and urgent work recently. In this paper, a new method based on one-dimensional fast Fourier transform (1DFFT) algorithm is presented for raw signal simulation of maneuvering target for missile-borne SAR. Firstly, SAR time-domain raw signal model is given and an effective Range Frequency Azimuth Time (RFAT) algorithm based on 1DFFT is derived. In this algorithm, the “Stop and Go” (SaG) model is adopted and the wide radar scattering characteristic of target is taken into account. Furthermore, the “Inner Pulse Motion” (IPM) model is employed to deal with high-speed case. This new RFAT method can handle the maneuvering cases, high-speed cases, and bistatic radar cases, which are all possible in the missile-borne SAR. Besides, this raw signal simulation adopts the electromagnetic scattering calculation so that we do not need a scattering rate distribution map as the simulation input. Thus, the multiple electromagnetic reflections can be considered. Simulation examples prove the effectiveness of our method.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yuqi Yang ◽  
Wei Luo ◽  
Bo Yin ◽  
Yi Ren

A microwave scattering model is proposed for the ground surface covered with multilayers vegetation. The vegetation leaves are simulated with the discrete elliptical particles in layers, which are randomly distributed above the randomly rough surface. The finite element method is applied to solve the scattering magnetic field equation based on the Dirichlet boundary, and the relationship between the radar cross section and bidirectional reflectance distribution function is deduced with the coherent scattering field. The internal mechanism of microwave scattering of multilayers vegetation is explored with the numerical results, and the relationship of vegetation growing parameter with scattering characteristic is established.


2017 ◽  
Vol 9 (7) ◽  
pp. 1499-1507
Author(s):  
Jiakun Wang ◽  
Min Zhang ◽  
Pengbo Wei ◽  
Panpan Jiang

An efficient algorithm is proposed for the radar cross-section (RCS) prediction of complex target with electronically large size, which is a combination of geometrical optics and physical optics (GO–PO) method. The method taking the multiple reflections into account is applied to the electromagnetic scattering analysis of a satellite model. Then RCS curves of entire satellite model and the model without antenna structure are figured out. Based on the simulated echoes, the traditional inverse synthetic aperture radar (ISAR) images are discussed. Moreover, an application of motion compensation technique based on the joint time-frequency analysis is presented for ISAR imaging of the moving satellite that has both translational and rotational movements. Numerical results show good performance of GO–PO method in accuracy and efficiency and the great influence of the antenna with corner structures on the scattering characteristic of the satellite.


Sign in / Sign up

Export Citation Format

Share Document