Tomographic velocity estimation with plane-wave synthesis

In areas with structurally complex geology, tomographic velocity analysis is often required to estimate velocities. In this paper I describe an algorithm for tomographic velocity estimation that uses plane-wave synthesis imaging as a prestack migration. The classical iterative two-step process (measures the traveltime errors With the current velocity model and then update the velocity model) is performed as follows. The events are picked in the image space after prestack migration with surface-oriented plane-wave synthesis Imaging, the traveltime deviations are measured through residual-moveout (RMO) velocity analysis in common-surface-location (CSL) gathers obtained by reflector-oriented plane-wave synthesis imaging, and the velocity update is calculated by inverting the traveltime deviations through a conjugate gradient: The results from synthetic data indicate that the tomographic method successfully estimates interval-velocity models that lead to depth-migrated images with no residual moveout.