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A Study of Misfit Topography towards Waveform Inversion for Prediction Ahead of Underground Tunnel
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Near Surface Geoscience 2015 - 21st European Meeting of Environmental and Engineering Geophysics, Sep 2015, Volume 2015, p.1 - 5
Abstract
This work presents a synthetic study of misfit topography towards identification of geological structure ahead of the underground tunnel by waveform inversion. Simulation of viscoelastic waves is performed by the spectral element method implemented in SPECFEM2D package. By modeling a simple 2-dimensional underground tunnel model with a dip geological interface ahead of the tunnel face, we construct the misfit error landscapes with respect to geometric parameters defining the dip layer interface. As a result it is found that the misfit topography is very multimodal and therefore finding the true model by waveform inversion is likely to be very challenging. However, the choice of misfit definition, for example by using the envelope misfit, can help ease the toughness of misfit topography and facilitate the inversion task.