Benefits of the horizontal component in quantitative imaging of near-surface interfaces with lateral variations: synthetic model inversion and reduced scale modeling
Résumé
In near-surface quantitative seismic imaging, the mechanical properties of an heterogeneous medium are usually inferred from the measure of the normal velocity component at different locations. In this study, it is proposed to investigate the benefits of measuring also the tangential velocity component. For that purpose, a realistic synthetic model is defined and the benefits of each component are analyzed in the framework of seismic imaging by Full Waveform inversion. The model is a two-layer medium including lateral variations close to the surface and the synthetic data are generated using a visco-elastic finite elements code. An analysis of the information contained for the different components is carried out and the behavior of the inversion algorithm is studied for each component. To conclude this part, inversion results from inversion strategies integrating the two components are presented. The last part concerns the experimental modeling facility developed in order to experimentally validate the imaging methods. This measurement bench reproduces seismic measurement configurations at a reduced scale using an ultrasonic source and a laser interferometer. This facility has already been validated for the case of the measurement of the vertical component, and first experimental results of the horizontal component are presented.
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