Taming the non-linearity problem in GPR full-waveform inversion for high contrast media
Taming the non-linearity problem in GPR full-waveform inversion for high contrast media
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 in...
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Personal Name(s): | Meles, Giovanni (Corresponding Author) |
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Greenhalgh, Stewart / der Kruk, Jan van / Green, Alan / Maurer, Hansruedi | |
Contributing Institute: |
Agrosphäre; IBG-3 |
Published in: | Journal of applied geophysics, 78 (2012) S. 31 - 43 |
Imprint: |
Amsterdam [u.a.]
Elsevier Science
2012
|
DOI: |
10.1016/j.jappgeo.2011.12.001 |
Document Type: |
Journal Article |
Research Program: |
Terrestrial Systems: From Observation to Prediction Modelling and Monitoring Terrestrial Systems: Methods and Technologies |
Publikationsportal JuSER |
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). |