Abstract: A method is disclosed for a two-step residual migration of dipping seismic events. A first migration pass is done using a fully-vertically-variable but laterally-invariable migration velocity that is selected from a first-stage mmigration velocity function. The first-stage velocity function approaches, but is less than, the velocity minima as determined by scanning the true velocity field in an area of interest. The second migration pass is performed with the aid of a dip-dependent residual migration velocity. The residual migration velocity is defined as the square root of the difference between the true migration velocity and a second migration velocity appropriate to the migrated time following the first migration pass.

Abstract: This invention provides a method for compensating for the deleterious effects of irregular spatial sampling of seismic data. The imbalance caused by sparse sampling is corrected by decomposing a processed data gather into its constituent dip and azimuth components, analyzing the movement and scaling of selected attributes of those components and applying an inverse sampling operator to the processed data based upon the analytical results.