In areas with structurally complex geology, tomographic velocity analysis is required to estimate velocities. This paper describes a tomographic velocity analysis algorithm which uses planewave synthesis imaging as a prestack migration. In reflection tomography, prestack migration is required for both event picking and traveltime error computation. Traveltime errors are often measured in the form of residual moveout (RMO) velocity in common surface location (CSL) gathers after prestack depth migration. It is shown that we can measure the residual moveout (RMO) velocity accurately with the help of reflector-dependent planewave synthesis imaging.