HR: 1340h
AN: NG43B-0574    [Abstracts]
TI: An optimized Convolution-Perfectly Matched Layer (C-PML) absorbing technique for 3D seismic wave simulation based on a finite-difference method
AU: * MARTIN, R
EM: roland.martin@univ-pau.fr
AF: Universite de PAU.Laboratoire de Modelisation et d'Imagerie en Geosciences. FRE 2639., Avenue de l'Universite. Bat. IPRA., PAU, 64013 France
AU: KOMATITSCH, D
EM: dimitri.komatitsch@univ-pau.fr
AF: Universite de PAU.Laboratoire de Modelisation et d'Imagerie en Geosciences. FRE 2639., Avenue de l'Universite. Bat. IPRA., PAU, 64013 France
AU: Barucq, H
EM: helene.barucq@univ-pau.fr
AF: Laboratoire de Mathematiques appliquees., Avenue de l'Universite. Bat. IPRA., PAU, 64013 France
AB: The Perfectly Matched Layer (PML) technique, introduced in 1994 by B‚renger for Maxwell's equations, has become classical in the context of numerical simulations in electromagnetics, in particular for 3D finite difference in the time domain (FDTD) calculations. One of the most attractive properties of a PML model is that no reflection occurs at the interface between the physical domain and the absorbing layer before truncation to a finite-size layer and discretization by a numerical scheme. Therefore, the absorbing layer does not send spurious energy back into the medium. This property holds for any frequency and angle of incidence. However, the layer must be truncated in order to be able to perform numerical simulations, and such truncation creates a reflected wave whose amplitude is amplified by the discretization process. In 2001, Collino and Tsogka introduced a PML model for the elastodynamics equation written as a first-order system in velocity and stress with split unknowns, and discretized it based on the standard 2D staggered-grid FD scheme of Virieux (1986). Unfortunately, this standard PML suffers from two drawbacks: the fact that the unknowns are split adds to the memory cost of the simulations; and after numerical discretization, the numerical reflection coefficient between the physical domain and the PML region becomes large at grazing incidence and thus the efficiency of the absorbing layer is poor. In this work, we apply an idea introduced by Roden and Gedney (2000), for solving Maxwell's equations, in order to develop a Convolution-Perfectly Matched Layer (C-PML) formulation for the 3D seismic wave equation based on a velocity-stress staggered-grid FD technique. C-PML is based on the unsplit components of the wave field and optimized for grazing incidence and surface waves using an analytical integration of the convolution term. C-PML formulation allows one to use very thin mesh slices to study a given region of the Earth, thus significantly reducing the cost of 3D simulations, which is of particular interest in the context of inverse problems.
DE: 0545 Modeling (4255)
DE: 0560 Numerical solutions (4255)
DE: 0902 Computational methods: seismic
DE: 0935 Seismic methods (3025, 7294)
DE: 4255 Numerical modeling (0545, 0560)
SC: Nonlinear Geophysics [NG]
MN: Fall Meeting 2005