| The research of electromagnetic scattering characteristics of radar targets has been an important research field of computational electromagnetics, also a key of the stealth and anti-stealth techniques. Therefore, there is the important theoretical value and military applications to carry out the study of fast and accurate estimation of radar cross section(RCS) of the object. However, RCS is a function of frequency and angel variable, in the given frequency band or angel range, In order to guarantee the computational accuracy often need to process point-by-point computation, which cause computation efficiency decreases. Interpolation method proposed can overcome this problem, realized using a few points'electromagnetic information to obtain the whole frequency band or angle range electromagnetic scattering characteristics.In this paper, the specific work and innovation include the following:1. Follow the research hotspot of electromagnetic scattering characteristics, and study electric field integral equation (EFIE), magnetic filed integral equation (MFIE), physical optics method (PO),shooting and bouncing ray (SBR),and chebyshev approximation to obtain programming ability. Learn the modeling processes of simple or complex object.2. According to the surface electric current characteristics on conducting objects, amplitude-phase detached interpolation method is applied to quickly analyze radar cross section (RCS) of a complex electrically large object over a wind frequency band. The method combine chebyshev approximation with phase extraction, use phase extraction to obtain an amplitude function whose frequency response is smooth. Together with physical optics method (PO) the nodes of Chebyshev within a given frequency range were found firstly, and the function value at these nodes were computed. Then the function is estimated by using chebyshev approximation. Last the electric current distribution, which is used to compute the scattered fields and the wideband radar cross section, can be obtained at any frequency within the given frequency range. The numerical results show that the proposed method is efficient and accurate.3. An interpolation technique which combines Chebeshev approximation and shooting and bouncing ray (SBR) method is proposed to calculate wide angel radar cross section (RCS) of electrically large object with open cavities. The nodes of Chebyshev within a given angel range were found firstly, and the RCS at these nodes were computed by SBR method. Then the wide angels RCS can be obtained at any angel within the given angel range via the Chebeshev approximation. The numerical results show that this method is efficient and accurate,and can save more than 60% computing time. |
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