Decorrelation and phase-shift of coda waves induced by local changes: multiple scattering approach and numerical validation

Thomas Planès (1) , Éric Larose (1) , Ludovic Margerin (2) , Vincent Rossetto (3) , Christoph Sens-Schönfelder (4)

1 ISTerre - Institut des Sciences de la Terre
2 IRAP - Institut de recherche en astrophysique et planétologie
3 LPM2C - Laboratoire de physique et modélisation des milieux condensés
4 GFZ - German Research Centre for Geosciences - Helmholtz-Centre Potsdam

We report on theoretical predictions of the decorrelation and phase-shift of coda waves induced by local changes in multiple scattering media. Using the multiple scattering formalism, we show that both expressions (decorrelation and phase-shift) involve a same sensitivity kernel based on the intensity transport in the medium. We compare the kernels based on the diffusion approximation with the ones based on the radiative transfer approximation, showing that the latter is more accurate at short times or for changes located close to the source or the receiver. We also perform a series of numerical simulations of wave propagation (finite differences) to validate our models in different configurations.

Domaines: Acoustique [physics.class-ph]; Mécanique des solides [physics.class-ph]

Thomas Planès, Éric Larose, Ludovic Margerin, Vincent Rossetto, Christoph Sens-Schönfelder. Decorrelation and phase-shift of coda waves induced by local changes: multiple scattering approach and numerical validation. Waves in Random and Complex Media, 2014, 24 (1), pp.99. ⟨10.1080/17455030.2014.880821⟩. ⟨hal-01075279⟩