Wave equation calculation of most energetic traveltimes and amplitudes for Kirchhoff prestack migration

Because of its computational efficiency, Kirchhoff migration is the method of choice for 3D prestack depth migration, particularly in the initial velocity model-building stages where several iterations of migration are necessary. In the beginning, Kirchhoff migration used traveltimes calculated by either eikonal solvers or asymptotic ray theory, while amplitudes were calculated using relatively smooth geometrical spreading and obliquity considerations. More recently, Kirchhoff migration has been generalized to include more than one arrival time, with amplitudes calculated from geometrical optics, solution of the transport equations, or Gaussian beams (e.g., Hill, 2001).