Tackling the non-linearity problem in GPR waveform inversion

Crosshole radar tomography is a non-invasive tool used in diverse geological, hydrogeological and engineering investigations. Conventional tomograms provided by standard ray-based techniques have limited resolution. Higher resolution radar tomograms can be derived by using full-waveform inversion sc...

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Bibliographic Details
Published inProceedings of the XIII Internarional Conference on Ground Penetrating Radar pp. 1 - 6
Main Authors Meles, G A, Greenhalgh, S A, Green, A G, van der Kruk, J
Format Conference Proceeding
LanguageEnglish
Published IEEE 01.06.2010
Subjects
Bandwidth
component
Convergence
FDTD
Frequency
Geology
Ground penetrating radar
Inverse problems
Inversion
Low pass filters
Radar scattering
Scattering parameters
Tomography
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Summary:Crosshole radar tomography is a non-invasive tool used in diverse geological, hydrogeological and engineering investigations. Conventional tomograms provided by standard ray-based techniques have limited resolution. Higher resolution radar tomograms can be derived by using full-waveform inversion schemes. However, despite the theoretical improvement in resolution, convergence problems can arise in the application of full-waveform schemes due to the ill-posed nature of the inverse problem and the high non-linearity of the relationship between the model parameters and the scattered fields (i.e. the forward problem). We present here a new inversion scheme that starts with a low-pass filtered version of the radargrams and progressively expands the frequency bandwidth as the iterations proceed, thus reducing the likelihood of the inversion getting trapped in a local minimum. The benefits over standard full-waveform time- domain inversion are demonstrated by means of three synthetic examples.
ISBN:142444604X
9781424446049
DOI:10.1109/ICGPR.2010.5550233