Effects of small-scale stochastic heterogeneity on the tomographic inversion of crosshole georadar data

Détails

ID Serval
serval:BIB_469A5070C6C7
Type
Actes de conférence (partie): contribution originale à la littérature scientifique, publiée à l'occasion de conférences scientifiques, dans un ouvrage de compte-rendu (proceedings), ou dans l'édition spéciale d'un journal reconnu (conference proceedings).
Collection
Publications
Titre
Effects of small-scale stochastic heterogeneity on the tomographic inversion of crosshole georadar data
Titre de la conférence
Proceedings of the Ninth International Conference on Ground Penetrating Radar, Santa Barbara, California
Auteur(s)
Holliger K., Maurer H.R.
Editeur
Society of Photo-Optical Instrumentation Engineers
ISBN
0-8194-4522-3
Statut éditorial
Publié
Date de publication
2002
Volume
4758
Pages
388-391
Langue
anglais
Résumé
Analyses of traveltimes and amplitudes of crosshole georadar data
provide estimates of the electromagnetic velocity and attenuation
of the probed media. In contrast to inversions of traveltimes, which
are well established and robust, ray-based inversions of amplitudes
depend critically on a priori assumptions about the directive properties
of the antennas. In particular, the influence of electric material
property fluctuations on antenna performance may lead to serious
distortions of the radiation pattern. Such distortions cannot be
accounted for by currently employed ray-based amplitude inversion
algorithms. To explore the problem of antenna coupling to local heterogeneities,
we generate synthetic crosshole georadar data for a suite of stochastic
models using a finite-difference time-domain (FDTD) solution of Maxwell's
equations in cylindrical coordinates. Analyses of the radiation patterns
extracted from the synthetic data indicate that distortions of the
radiation patterns are primarily due to propagation effects and not
to dipole-coupling effects. We do, however, find that the quality
of the amplitude tomograms diminishes rapidly with increasing heterogeneity,
probably because of inherent inadequacies in ray-based inversion
methods. In contrast, the quality of ray-based traveltime tomograms
is surprisingly high, even in the presence of strong heterogeneity.
Création de la notice
25/11/2013 19:28
Dernière modification de la notice
03/03/2018 16:48
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