How to Cope with Smoothing Effect in Ray Based PSDM

Almost all implementations of ray based Kirchhoff prestack depth migration require a smoothed version of the velocity function. However, most velocity model building tools fit prestack traveltimes using blocky parameterizations with finite velocity jumps. This leads to an inconsistent scheme, in the sense that the smoothed migration velocity model is kinematically sub-optimal. Here, using a simple and efficient perturbation method, we show and demonstrate how we can correct for the smoothing effect in Kirchhoff PSDM.