Paper Summary
Due to the accuracy of the Reverse Time Migration (RTM) algorithm, RTM angle gathers show more coherent and correct moveout subsalt events than Kirchhoff offset gathers, potentially providing a more reliable input for tomography. We have developed a robust, efficient, RTM angle gather generation method. It has the flexibility to incorporate geological knowledge for low signal-to-noise (S/N) areas. Because angle gather tomography targets subsalt areas, it is not necessary to trace rays through salt, thus avoiding the limitations of ray-based tomography, making it a useful tool for subsalt velocity model building.