Elimination of Seismic Multiples by Anisotropic, Pre Stack Depth Migration and Filtering

Group and phase velocities are derived such that, when used in constant velocity migration, a set of seismic multiples from the sea surface are focused such that they separate from reflection primaries. The velocities are found to be homogeneous but anisotropic. The focused multiples are then deleted from the data and surrounding data are used to fill in the deleted areas. Unmigration restores the data to it's input stat sans the multiples. A before and after comparison using synthetic data verifies that this is a very clean process in that multiples are removed without loss of primaries.