3D Beamlet migration in VTI medium

Beamlet migration is a wave equation based migration approach. The use of local background velocity and local perturbations results in a two-scale decomposition of beamlet propagators: a background propagator for largescale structures and a local phase screen correction for small-scale local perturbations. The beamlet propagator can handle strong lateral velocity variations with improved accuracy. Local cosine basis beamlet propagator was proposed and developed recently. It has been successfully applied to poststack and prestack depth migration for media with large lateral velocity variations. Here we extend the beamlet propagator into transversely isotropic medium with vertical symmetric axis (VTI) medium. We tested impulse responses, a synthetic dataset and a field dataset. The results demonstrated the validity of the VTI beamlet propagator.