Comparison of two viscoacoustic propagators for Q-compensated reverse time migration

ABSTRACTWithout considering intrinsic attenuation, reverse time migration (RTM) of data from lossy media produces smeared migration images because of the Q effects (amplitude loss and velocity dispersion). To mitigate the Q effects during RTM, amplitudes need to be compensated and the propagation velocity of the compensated wavefield needs to be the same as in the attenuating wavefield. We have compared the decoupled constant Q (DCQ) viscoacoustic equation with the viscoacoustic equation based on the generalized standard linear solids (GSLS), for modeling and for Q compensation. The DCQ propagator separates amplitude loss and velocity dispersion operators; for the GSLS propagator, memory variables are used to introduce the Q effects. Amplitude loss and velocity dispersion are decoupled in the DCQ equation, whereas they are coupled in the GSLS equation. Viscoacoustic modeling by the two viscoacoustic propagators produces visually identical seismograms. To compensate for the Q effects, for the DCQ equation,...