2D finite-difference modeling and imaging of viscoacoustic wave propagation using a PML absorbing boundary condition

Ali Fathalian, Kristopher A. Innanen

The constant-Q wave propagation by series of standard linear solid mechanisms using perfectly matched layers absorbing boundary condition (PML) are investigated. An PML with an unsplit field is derived for the viscoacoustic wave equation by introducing the auxiliary variables and their associated partial differential equations. The unsplit PML are tested on a homogeneous velocity and Marmousi velocity models by applying the 2-4 staggered grid finite-difference scheme. When the wave propagating in the subsurface the amplitude and phase of seismic wave distort due to attenuation. The acoustic reverse time migration (RTM) can not explain this distortion, so we used an unsplit viscoacoustic wave equation with constant Q-model. Comparing the numerical tests on synthetic data for unsplit viscoacoustic reverse time migration and acoustic reverse time migration show the advantages of our approch over acoustic RTM when the recorded data had strong attenuation effects.