Angle‐domain common‐image gathers by wavefield continuation methods

Abstract

Migration in the angle domain creates seismic images for different reflection angles. We present a method for computing angle‐domain common‐image gathers from seismic images obtained by depth migration using wave‐field continuation. Our method operates on prestack migrated images and produces the output as a function of the reflection angle, not as a function of offset ray parameter as in other alternative approaches. The method amounts to a radial‐trace transform in the Fourier domain and is equivalent to a slant stack in the space domain. We obtain the angle gathers using a stretch technique that enables us to impose smoothness through regularization. Several examples show that our method is accurate, fast, robust, and easy to implement. The main anticipated applications of our method are in the areas of migration‐velocity analysis and amplitude‐versus‐angle analysis.