DocumentCode :
983735
Title :
Asymptotic and hybrid techniques for electromagnetic scattering
Author :
Bouche, Daniel P. ; Molinet, Frederic A. ; Mittra, Raj
Author_Institution :
CEA/CESTA, Atomic Energy Comm., Bordeaux, France
Volume :
81
Issue :
12
fYear :
1993
fDate :
12/1/1993 12:00:00 AM
Firstpage :
1658
Lastpage :
1684
Abstract :
Asymptotic and hybrid methods are widely used to compute the Radar Cross Section (RCS) of objects that are large compared to the wavelength of the incident wave, and the objective of this paper is to present an overview of a number of these methods. The cornerstone of the asymptotic methods is the Geometrical Theory of Diffraction (GTD), which was originally introduced by J. B. Keller, and which represents a generalization of the classical Geometrical Optics (GO) by virtue of the inclusion of diffraction phenomena. After a presentation of the physical principles of GTD, we provide a description of its mathematical foundations. In the process of doing this we point out that GTD gives inaccurate results at caustics and light-shadow boundaries, and subsequently present a number of alternate approaches to dealing with these problems, viz., Uniform theories; Methods for caustics curves; Physical Theory of Diffraction; and Spectral Theory of Diffraction. The effect of coating perfectly conducting bodies with dielectric materials is discussed and hybrid methods, that combine the Method of Moments (MoM) with asymptotic techniques, are briefly reviewed. Finally, the application of GTD and related techniques is illustrated by considering some representative radar targets of practical interest
Keywords :
electromagnetic wave diffraction; electromagnetic wave scattering; geometrical optics; physical optics; radar cross-sections; radar theory; asymptotic techniques; caustics; classical geometrical optics; dielectric material coating; electromagnetic scattering; geometrical theory of diffraction; hybrid techniques; light-shadow boundaries; mathematical foundations; method of moments; perfectly conducting bodies; physical theory of diffraction; radar cross section; radar targets; spectral theory of diffraction; uniform theories; Coatings; Conductors; Dielectric materials; Electromagnetic scattering; Geometrical optics; Moment methods; Optical diffraction; Physical theory of diffraction; Radar applications; Radar cross section;
fLanguage :
English
Journal_Title :
Proceedings of the IEEE
Publisher :
ieee
ISSN :
0018-9219
Type :
jour
DOI :
10.1109/5.248956
Filename :
248956
Link To Document :
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