Short Note Reverse time migration in midpoint-offset coordinates

Reverse-time migration (Baysal et al., 1984) has some potential advantages with respect to downward-continuation migration. It can migrate overturned and prismatic reflections even in the presence of strong lateral velocity variations (Biondi, 2002). It also models the amplitude of the transmitted wavefield more accurately than downward-continuation in the presence of sharp interfaces. However, it has the drawback of being computationally intensive. In particular, shot profile migration of overturned events can be extremely expensive because we need to pad the computational domain with a huge number of zero traces to assure that it includes the reflectors that generated the overturned events.