Finite Volume method for 2D PSV elastodynamic equations in frequency domain with velocity parsimonious formulation

International audienceA finite volume method, known as the Discontinuous Galerkin method using P0 interpolation scheme, is formulated for the 2D P-SV elastodynamic equations in the frequency domain. This modelling tool is dedicated to full waveform inversion and should allow efficient computation of particle velocities for many excitations required by the inversion strategy. A parsimonious formulation has been developed and implemented for minimal memory requirement including PML absorbing zones. Standard dispersion analysis shows that numerical dispersion is similar to the one for finite difference formulation of second-order precision when considering structured meshes. Canonical examples illustrate potentialities of the method especially when considering free surface when it has a complex shape discretized as straight segments. Finite volume methods is a quite attractive alternative to finite difference methods when considering elastic full waveform inversion since free surface effects are accurately modelled on waveforms when thirty points per wavelength are considered