True amplitude Kirchhoff prestack depth migration in complex media

In this paper, we address the complex geological structures imaging problem, when the velocity macro-model is characterized by very strong lateral variations, and the ray fields may triplicate providing multiarrivals; we demonstrated that all the multi-arrivals have to be taken into account for a quantitative migration. Furthermore, we propose a common image gather strategy in angle domain to handle the strong artifacts appear in conventional common image gathers (offset or shot domain) when multi-arrivals occurs. In the multi-arrival case, we also propose a high efficient migration algorithm for 3-D prestack multi-arrival depth migration based on the fast reconstruction algorithms for the traveltime, phase rotation and amplitude of the migration operator.