Figure shows the migration result. Figure shows three angle gathers. Observe the residual moveout in these angle gathers. This indicates errors in the velocity model.
Figure 1 PP migration result with the original P-velocity model
I perform Stolt residual migration Sava (1999) over this migration result. There is not a single value of that fixes the whole section. Figure shows the same three angle domain common image gathers, as in Figure . Moreover, each angle domain common image gather corresponds to a different value of , from left to right, and . Note how different events correct better for different values.
By updating the velocity model with different values at different depths and lateral positions, I perform a new migration. Figure shows this final migration result. Figure shows again the same different angle domain common image gathers for the migration result of Figure .
Figure 4 Migration result after updating the P velocity model with different values of at different depth and lateral locations.