Accurate 3-D finite difference computation of traveltimes in strongly heterogeneous media

Mark Noble 1 Alexandrine Gesret 1 Nidhal Belayouni 2, 1
1 GEOSCIENCES - Centre de Géosciences
2 Magnitude, Research and Development
Abstract : Seismic traveltimes and their spatial derivatives are the basis of many imaging methods such as pre-stack depth migration and tomography. A common approach to compute these quantities is to solve the eikonal equation with a finite-difference scheme. If many recently published algorithms for resolving the eikonal equation do now yield fairly accurate traveltimes for most applications, the spatial derivatives of traveltimes remain very approximate. To address this accuracy issue, we develop a new hybrid eikonal solver that combines a spherical approximation when close to the source and a plane wave approximation when far away. This algorithm reproduces properly the spherical behaviour of wave fronts in the vicinity of the source. We implement a combination of 16 local operators that enables us to handle velocity models with sharp vertical and horizontal velocity contrasts. We associate to these local operators a global fast sweeping method to take into account all possible directions of wave propagation. Our formulation allows us to introduce a variable grid spacing in all three directions of space. We demonstrate the efficiency of this algorithm in terms of computational time and the gain in accuracy of the computed traveltimes and their derivatives on several numerical examples.
Type de document :
Article dans une revue
Liste complète des métadonnées
https://hal-mines-paristech.archives-ouvertes.fr/hal-01074989
Contributeur : Mark Noble <>
Soumis le : jeudi 16 octobre 2014 - 12:14:48
Dernière modification le : mercredi 18 décembre 2019 - 17:35:20

Lien texte intégral

openaccess

Identifiants

Collections

ENSMP | ENSMP_GEOSCIENCES | INSTITUT-TELECOM | PSL | PARISTECH

Citation

Mark Noble, Alexandrine Gesret, Nidhal Belayouni. Accurate 3-D finite difference computation of traveltimes in strongly heterogeneous media. Geophysical Journal International, Oxford University Press (OUP), 2014, 199 (3), pp.1572-1585. ⟨10.1093/gji/ggu358⟩. ⟨hal-01074989⟩

Exporter

BibTeX TEI DC DCterms EndNote

Partager

Métriques

Consultations de la notice

204

Contact

Informations

CCSD