Effective Optimization to One-Way Wave Equation Migration

Downward-continuation migration algorithms are a powerful tool for imaging complicated subsurface structures. The phase-shift plus interpolation (PSPI) algorithm is a downward-continuation algorithm that is still widely used in the industry due to its computational efficiency compared to other methods and its reasonable ability to handle lateral velocity variations. In this type of extrapolation, downward-continuing the data from a depth level to the next requires extrapolating the data with a number of reference velocities. The number of these velocities depends on the lateral velocity variations within the depth interval. The reference wavefields are then interpolated before invoking the imaging condition to approximate the reflectivity at a given depth level. In this paper, we show an optimization to the PSPI algorithm based on the spatial resampling technique that improves its computational efficiency and accuracy.