Migration Velocity Analysis Using Wave Packets - Geometric Approach

Current algorithms for imaging seismic reflection data can be subdivided into two classes: Kirchhoff (generalized Radon transform) and wave-equation (double-square-root and reverse-time) migration. Kirchhoff type methods rely on asymptotic and ray-geometrical considerations. Wave-equation imaging algorithms (one-way or twoway) appear to be more robust in the case of complicated velocity models and aim to account for finite-frequency effects. Integration of the two classes, using wave packets or “curvelets”, for the purpose of migration velocity analysis is the subject of this paper. One can represent full wave-form data in terms of wave packets with arbitrary accuracy on the one hand. On the other hand, every packet is characterized by a central point and direction that provides geometrical information that can be further utilized in “ray”-geometrical analysis, which is exploited, here, in the context of reflection tomography using annihilators derived from the wave-equation angle transform.