Fast 3-D Kirchhoff poststack time migration with velocity analysis

John C. Bancroft

A fast and efficient algorithm is presented for 3-D Kirchhoff poststack time migration. The method forms migration gathers for each migrated trace before any time shifting, scaling, or filtering is required. Each migration gather contains all traces within the migration aperture, sorted and summed into bins based on the migration offset. The migration gathers are suitable for migration velocity analysis similar to conventional CMP gathers. The migration for each trace is completed by filtering, scaling, time shifting (NMO), and stacking the migration gather.