Journal Article

PreJuSER-17301

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Taming the non-linearity problem in GPR full-waveform inversion for high contrast media

Meles, G. A. ; Greenhalgh, S. ; van der Kruk, J.FZJ* ; Green, A. G. ; Maurer, H.FZJ*

2011
Elsevier Science Amsterdam [u.a.]

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Please use a persistent id in citations: doi:10.1016/j.jappgeo.2011.01.001

Abstract: We present a new algorithm for the inversion of full-waveform ground-penetrating radar (GPR) data. It is designed to tame the non-linearity issue that afflicts inverse scattering problems, especially in high contrast media. We first investigate the limitations of current full-waveform time-domain inversion schemes for GPR data and then introduce a much-improved approach based on a combined frequency-time-domain analysis. We show by means of several synthetic tests and theoretical considerations that local minima trapping (common in full bandwidth time-domain inversion) can be avoided by starting the inversion with only the low frequency content of the data. Resolution associated with the high frequencies can then be achieved by progressively expanding to wider bandwidths as the iterations proceed. Although based on a frequency analysis of the data, the new method is entirely implemented by means of a time-domain forward solver, thus combining the benefits of both frequency-domain (low frequency inversion conveys stability and avoids convergence to a local minimum; whereas high frequency inversion conveys resolution) and time-domain methods (simplicity of interpretation and recognition of events; ready availability of FDTD simulation tools). (C) 2011 Elsevier B.V. All rights reserved.

Keyword(s): J ; GPR (auto) ; FDTD (auto) ; Inversion (auto) ; Time-domain (auto) ; Frequency-domain (auto) ; Bandwidth expansion (auto) ; Stability (auto)

Note: This work was supported by grants from ETH Zurich and the Swiss National Science Foundation. We benefited from stimulating discussions with Dr Jacques Ernst and are indebted to Anja Klotzsche for providing the traveltime tomography starting models for some waveform inversions. We thank Dr Thomas Hansen and an anonymous reviewer for their helpful and insightful reviews of the paper.

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Contributing Institute(s):

1. Agrosphäre (IBG-3)

Research Program(s):

1. Terrestrische Umwelt (P24)

Appears in the scientific report 2011

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