ABSTRACTWe describe a method to update the velocity model from the residual move-out information contained in 3-D angle-domain common-image gathers. The 3-D angle-domain common-image gathers computed after wave-equation migration are functions of the aperture angle and the reflection azimuth angle. We perform a velocity error analysis by semblance using 2-D and 3-D residual move-out functions. Both functions enable us to update the velocity model. The 3-D function leads to a better estimation of the velocity error in the case of 3-D events. |