Li, Yubing, Stereo-wave tomography

Li, Yubing*

Stereo-wave tomography

H. Chauris (MINES)

The determination of the background velocity model remains a challenging task in seismic imaging. It controls the kinematic of the wave propagation and is needed for subsequent full waveform inversion. We propose to investigate a new method, the “Stereo-Wave Tomogra- phy” (SWT) approach. It is defined under the ray theory and appeared to be successful on synthetic and real data (Lambaré, 2008). The input data set is decomposed into a sum of locally coherent events. This can be for example achieved via a curvelet decomposition (Nguyen and Chauris, 2010). Then the objective function consists of minimiing the misfit between observed and computed data in the curvelet domain. For the modelling part, two-way Green's functions are used, without relying on the high frequency approximation. Potentially, SWT is not limited to reflected data. In principle, SWT is also not restricted to smooth models. Compared to full waveform inversion, SWT offers the possibility to select part of the input data during the minimization process. This is an important aspect to avoid local minima in the objective function.

*Yubing was a former GPX Master student 2013-2014.