Prestack Depth Migration in VTI Media with Constrained Explicit Operators

F041 PRESTACK DEPTH MIGRATION IN VTI MEDIA WITH CONSTRAINED EXPLICIT OPERATORS Abstract 1 We present an efficient method for 3D wave equation prestack depth migration (PSDM) in laterally varying VTI media. The method accurately handles large lateral variations in the Thomsen anisotropy parameters ε and δ as well as vertical velocity. It performs wavefield extrapolation using a constrained explicit finite-difference operator. The constrained operator has a reduced number of independent coefficients leading to improved migration efficiency whilst retaining accuracy and flexibility for different maximum propagation angles and grid intervals in the inline and crossline directions. Our optimization process for the