3D angle decomposition for elastic reverse time migration

We propose 3D angle decomposition methods from elastic reverse time migration using timeand space-lag common image point gathers, time-lag common image gathers, and space-lag common image gathers computed by elastic wavefield migration. We compute time-lag common image gathers at multiple contiguous locations, instead of isolated positions as is commonly done with common image gathers. Then, we transform the extended images to the angle domain using slant stacks along surfaces that connect neighboring positions, instead of line slant stacks for isolated common image gathers. We demonstrate our methods using 2D and 3D synthetic examples and show that our techniques provide accurate opening and azimuth angles, and that they can handle steeply dipping reflectors and converted wave modes.