摘要
本文在分析平面板元上Ｇｏｒｄｏｎ算法（Ｇ－ＰＰＭ）与傅里叶交换算法（ＦＴ─ＰＰＭ）数值稳定性的基础上指出：板块元边缘的任意分割会导致ＦＴ－ＰＰＭ的坏条件计算问题；而板块元边缘的任意分割对于Ｇ─ＰＰＭ而言都是好条件计算问题。因此Ｇ－ＰＰＭ是数值稳定性更好的算法。本文进一步推证了简化Ｇｏｒｄｏｎ板块元算法（ＳＧ─ＰＰＭ），并给出了ＳＧ－ＰＰＭ的具体算例。算例表明ＳＧ－ＰＰＭ快速、有效、稳定性好。
Electromagnetic scattering computation from electrically large bodies arises in many physical contexts. The fast, effective, precise and stable computational methods are the goal to be sought out. Traditionally, the scattering computation of electrically large bodies often adopt the approzimating analogous computations by regular plates. ellipses, spheres, cylinders etc. Though the analogous computations seem simple, they can not precisely, effectively show the influence of shape's variation. in scattering bodies.Today, the polygon patch methods are more and more applied in the computation of electrically large bodies.Among them, one is foe Fourier Transform of polygonal Shape Function, the other is the Gordon's line integral representation of Polygon patch. Both methods find wide applications in many works and computational programs. Both methods reduce the costs of numerical calculations by order of magnitude. The reason for these are that if N sample points are required to evaluate the integral of a function over the boundary of a domain, the N squared points would be required to evaluate the corresponding (double) integral over the domain with the same degree of precision.Which one is better (fast, effective, precise and arable), the Fourier Transform Polygon Patch Method (FTPPM), or the Gordon's Polygon Patch Method (G-PPM). The purpose of this paper is to compare the computingstability of the former with the latter. Based on the numerical analysis, it is found that the boundary of a polygon Patch directly influences the accuracy of FT-PPM, the dividing of the whole integral surface into a union of polygon patches always seriously affacts the computing-stability of FT-PPM. i. e., the ill dividing Of the aides in a patch would lead to in conditioned computing problem for FT-PPM. Nevertheless, to the G-PPM, arbitrary dividing of a patch's aides is all well-conditioned computing problem. G-PPM has strong computational stability and continuity.Furthermore, from out deduction, a Simplified Gordon's Polygon Patch (SG-PPA) can be directly added to the scattering of each patch. omitting the complicate process of transforming global coordinates into local coordinates and moving local phase center into global plase center. SG-PPA greatly reduces the numerical computing time.
出处
《电波科学学报》
EI
CSCD
1996年第1期33-41,共9页
Chinese Journal of Radio Science
关键词
电磁计算
GORDON
板块元算法
电磁散射
Ekectromagnetil computation. Gordon's polygon patch method ((G - FPM ),Simplified Gordon's polygon patch methad (SG-PPM), Fourier transform polygon patch method(FT-PPM). Radar cross section
