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Polarization ratios anomalies of 3D rough surface scattering as second order effects

Sei, Alain and Caponi, Maria and Bruno, Oscar (2001) Polarization ratios anomalies of 3D rough surface scattering as second order effects. In: IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting. IEEE , Piscataway, NJ, pp. 726-729. ISBN 0-7803-7070-8. https://resolver.caltech.edu/CaltechAUTHORS:20181105-123901867

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Abstract

A detailed analysis of the behaviour of electromagnetic scattering from various corrugated bidimensional surfaces is presented. We show that rigorous electromagnetic computations on two dimensional surfaces can in fact yield HH/VV polarization ratios greater than one, with values consistent with those observed experimentally. We also show that HH/VV ratios greater than one are ubiquitous in the case of surfaces of the form f(x, y)=f_1/(x)+f_2(y), known as crossed gratings in optics. Theoretically and numerically, these surfaces are shown to produce backscattered returns for which the first order Rice/Valenzuela term vanishes for off axis incidence. The second order term becomes dominant and has the property that HH returns exceed VV returns for a significant range of incident angles. Our approach is based on the methods of O.Bruno and F. Reitich (see J. Opt. Soc. A., vol.10, p.2551-62, 1993) which yield accurate results for a large range of values of the surface height. In particular, these methods can be used well beyond the domain of applicability of the first order theory of S.O. Rice (1951). The error in our calculations is guaranteed to be several orders of magnitude smaller than the computed values. The high order expansions provided by these methods are essential to determining the role played by the second order terms as they show that these terms indeed dominate most of the backscattering returns for the surfaces mentioned. Classically, large HH/VV ratios were sought by means of first order approximations on one dimensional sinusoidal profiles. In that case, we show that the first order terms do not vanish and the first order theories predict the behaviour of the backscattered returns, for small values of the height to period ratio. However, in the case of a two dimensional bisinusoidal surface, strong polarization dependent anomalies appear in the scattering returns as a result of the contributions of second order terms since, in that case, the first order contributions vanish.


Item Type:Book Section
Related URLs:
URLURL TypeDescription
https://doi.org/10.1109/APS.2001.960200DOIArticle
ORCID:
AuthorORCID
Bruno, Oscar0000-0001-8369-3014
Additional Information:© 2001 IEEE. The authors gratefully acknowledge support from TRW internal research fund.
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TRWUNSPECIFIED
Record Number:CaltechAUTHORS:20181105-123901867
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20181105-123901867
Official Citation:A. Sei, M. Caponi and O. Bruno, "Polarization ratios anomalies of 3D rough surface scattering as second order effects," IEEE Antennas and Propagation Society International Symposium. 2001 Digest. Held in conjunction with: USNC/URSI National Radio Science Meeting (Cat. No.01CH37229), Boston, MA, USA, 2001, pp. 726-729 vol.3. doi: 10.1109/APS.2001.960200
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:90645
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:06 Nov 2018 18:38
Last Modified:03 Oct 2019 20:27

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