Prestack Phase-Shift Migration of Separate Offsets in Laterally Inhomogeneous Media

A-45 PRESTACK PHASE-SHIFT MIGRATION OF SEPARATE OFFSETS IN LATERALLY INHOMOGENEOUS MEDIA TARIQ ALKHALIFAH Summary 1 Using the stationary-phase method prestack phase-shift migration is implemented one offset at a time. This separate-offset implementation allows for a Fourier (reasonably fast) wave-equation type migration on data with irregular offset sampling. However the separate-offset phase-shift migration like its zero-offset counterpart handles only vertically inhomogeneous media. Using the combination of the split-step and the phase-shift-plusinterpolation (PSPI) approaches the separate-offset phase-shift migration is extended to handle laterally inhomogeneous media. Like any PSPI-based method the cost of the new migration relies heavily on the complexity of the