Evalutation of the imaging condition for pre-stack depth migration

In the 1980's, pre-stack depth migration was judged important and yet not always worth the considerable cost. During the last years, through improvements in algorithms and in computer-hardware perfomance, pre-stack depth migration became a less expensive process. Pre-stack migration has proven to be useful method in giving a correct image of the subsurface and in estimating velocity by evaluating the migration output.