Effects of staggered-grid and rotated staggered-grid on the wavefield separation in VTI media

Wavefield separation is an important part of multi-component seismic data processing， and the wavefield numerical simulation method is one of the necessary tools to this process. When staggered-grid finite difference scheme and rotated staggered-grid finite difference scheme are utilized to elastic wavefield simulation in anisotropic media， the definition of the particle velocity components and that of the stress tensor are different among these two grids. Furthermore， these two types of definitions will affect the wavefield separation. So we take the case of transversely isotropic media with a vertical axis (VTI media) as an example to analyze. Firstly， we analyze the parameter definition of these two grids and details about the wavefield separation in VTI media. Then， we focus on the analysis on the separation effects caused by the different parameter definition of these two grids. Considering the aspects of wavefront continuation and the purity of wavefield separation， numerical experiments are utilized to verify the results. Finally we draw the conclusion that the parameter definition of rotated staggered-grid is more beneficial to the anisotropic numerical simulation and the wavefield separation.