Seismic waves inversion in the complex frequency domain 3D reconstruction
Résumé
This project is a study of the full waveform inversion in the complex frequency domain. It uses seismic waves modeling and imaging in 2D and 3D. The inversion problem is set up to reconstruct inner earth parameters and thus estimate the utility of future prospection for example. The different steps of the inversion are developed. Wave sources and receivers are placed on the ground, the echo captured by the receivers from the sources gives a data experimental set. The waves propagation equation can define an expected model for those waves. The idea is to optimize the difference between the experiments and the expected model and thus reconstruct the unknown inner earth parameters. The first step is to implement an efficient solver for the Helmholtz wave propagation and predict the waves behavior. Considering the high scale 3D of the discretization, parallelization and fast algebra methods are the key factor of the implementation. We expect the use of Fourier-Laplace domain to give us more accurate results. Once modeling wave propagation is satisfying, the inversion problem will be solved using this solver. Different aspect will be studied to improve the computation in term of accuracy (model updating) and speed.