Interpretation of time reversal focal spots based on point-source homogenization - INSU - Institut national des sciences de l'Univers
Article Dans Une Revue Geophysical Journal International Année : 2022

Interpretation of time reversal focal spots based on point-source homogenization

Zoé Renat
  • Fonction : Auteur
Paul Cupillard

Résumé

The time reversal method is based on the backpropagation of seismic waveforms recorded at a set of receivers. When this set forms a closed surface and the elastic properties of the medium are correct, the seismic energy focuses at the source location, creating a focal spot. Such a spot is smooth in space, whereas the original wavefield usually shows a displacement discontinuity at the source. The goal of this paper is to discuss the link between the focal spot and the original source using the concept of homogenized point source. We show that the backpropagated wavefield is equivalent to the sum of two low-wavenumber fields resulting from the homogenization of the original point source. In other words, the homogenized point source is the equivalent force for producing the focal spot. In addition to the demonstration in the general 3-D heterogeneous case, we present some numerical examples in 2-D.
Fichier principal
Vignette du fichier
Renat_etal_GJI2022.pdf (7.67 Mo) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

insu-03779249 , version 1 (16-02-2023)

Identifiants

Citer

Zoé Renat, Paul Cupillard, Yann Capdeville. Interpretation of time reversal focal spots based on point-source homogenization. Geophysical Journal International, 2022, 231 (3), pp.1653-1671. ⟨10.1093/gji/ggac275⟩. ⟨insu-03779249⟩
63 Consultations
69 Téléchargements

Altmetric

Partager

More