Modeling of frequency-domain elastic-wave equation with a general optimal scheme

Frequency-domain numerical modeling is an important foundation of frequency-domain full waveform inversion.However, the conventional 9-point scheme for frequency-domain 2D elastic-wave equation requires lots of sampling grid points but with limited precision.In this paper, we develop a general optimal 9-point scheme for frequency-domain 2D elastic-wave equation to reduce sampling grid points and improve the accuracy.The numerical dispersion analysis shows that this scheme can effectively reduce the grid point of per wavelength.The new scheme can be applied to equal and unequal spatial sampling intervals, which is convenient for their applications in practice.Accuracy analysis demonstrates that the results of the optimal nine-point scheme are in better agreement with the analytic solutions relative to the conventional 9-point scheme.We deduce the perfectly matched layer (PML) absorbing boundary condition to eliminate the artificial boundary influence.Two numerical examples are used to demonstrate the effectiveness of the general optimal scheme for frequency-domainelastic-wave equation.