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Least Squares Rotated Staggered-grid Finite-difference Method for Anisotropic Pseudo-acoustic Wave Modeling and RTM
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition 2015, Jun 2015, Volume 2015, p.1 - 5
Abstract
The anisotropy exists widely underground, ignoring anisotropy in migration may lead to large positional errors. In the aspects of computational cost and efficiency, acoustic approximated anisotropic first-order stress-velocity qP-wave equations are better the elastic one. Considering the advantages of avoiding elastic modulus interpolation in rotated staggered-grid finite-difference (RSFD) scheme, so it’s more suitable for anisotropic qP-wave modeling and reverse time migration. However, RSFD scheme tends to cause numerical dispersion due to the need of larger steps. Using the optimal RSFD operator based on dispersion relation and least squares scheme can suppress spatial dispersion efficiently and enhance modeling accuracy, and further improve the imaing quality. Therefore, we construct the anisotropic wave-field extrapolator by LS-RSFD method, and implement accurate VTI and TTI pseudo-acoustic wave numerical modeling and reverse time migration.