Two-Pass 3D Prestack Time Migration

We describe a method to perform two-pass 3-D Kirchho prestack time migration whose com-<br>putation time is nearly the square-root of that required for the one-pass algorithm. To better<br>understand the conditions and restrictions associated with the application of the method we<br>discuss the kinematical approximations involved in its derivation. A real data example shows<br>that this approach can be applied with success in areas with moderate structural complexity.