Elastodynamic full wavefield modeling

We extend in this paper the full wave-field modeling method to the elastodynamic situation. While, the acoustic case encompasses directional decomposition - where up-going and downgoing wavefields are modeled in addition to modal decomposition, through which heterogeneity is properly handled - the elastodynamic case encompasses one additional type of decomposition; the one related to polarisations, where the wavefield is separated into its constituent polarisations: quasi-P, quasi-SV, and quasi-SH waves. All three types of decomposition are present in the equations given in this paper. Although we begin with the most general form of equations for anisotropic inhomogeneous media, we reduce those equations to the isotropic case, and we consider only P-SV waves for simplicity. We implement only the squared wavenumber operator, whose implementation closely resembles that of the acoustic case.