Rosales et al. (2001) describe three possible ways to perform residual migration. The most precise method is an exact derivation which involves the combination of the , and parameters. This method attempts to simultaneously correct the effect of two inaccurate velocity fields.
Assuming that the initial migration was done with the velocities v0p and v0s, and that the correct velocities are vmp and vms, we can then write
Solving for in the first equation of (1) and substituting it in the second equation of (1), we obtain the expression for prestack Stolt depth residual migration for converted waves:
where is the transformation kernel defined as:
and , , and .
This formulation depends only on velocity ratios. This fact implies that it is a valid formulation for non-constant velocity media, as suggested by Sava (2000).