The residual moveout velocity analysis, measuring ,that was described in the previous section is an indirect way of measuring traveltime errors ,which are required to compute the perturbation in reference slowness as shown in equation ().
The traveltime errors are the differences between the observed traveltimes and the computed traveltimes using an assumed slowness model
(33) |
(34) |
(35) |
By substituting into equation (), we get
(36) |
Therefore, we calculate from the picked and average reference slowness along the the ray trajectory.