Reverse time migration : Saving the boundaries

The need to save or regenerate the source or receiver wavefield is one of the computational challenges of Reverse Time Migration (RTM). The wavefield at each time step can be saved at the edge of the damping/boundary condition zone. The wave equation can be run in reverse, re-injecting these saved points to regenerate the wavefield. I show that this a better choice than checkpoint schemes as the domain grows larger and if the computation is performed on a streaming architecture.