A pure viscoacoustic equation for VTI media applied in anisotropic RTM

Neglecting anisotropy and attenuation in seismic wave propagation will result in inaccurate images, with problems such as diffracted wave convergence and seismic wave attenuation. It is therefore important to take anisotropy and viscosity into account. In this paper, based on the dissipation mechanism of the standard linear solid model, we derive a pure viscoacoustic wave equation for vertical transversely isotropic (VTI) media in the time-space domain, which describes the attenuation characteristics of seismic waves through a pseudo-differential operator in the equations. The numerical results show that the VTI viscoacoustic wave equation not only describes the propagation of waves in anisotropic media accurately, but it also reflects the effects of absorption and attenuation. The reverse time migration results for the VTI_HESS model show that we can obtain accurate and reliable amplitude-preserved images based on the anisotropic viscoacoustic wave equation.