A Full-aperture Anisotropic Eikonal Solver For Quasi-P Traveltimes

The quasi-P traveltimes in general anisotropic media satisfy a nonlinear rst-order PDE which is implicitly de ned by quasi-P slowness surface. Given a point source as an initial condition, this nonlinear PDE is a stationary eikonal equation. The paraxial formulation for quasi-P eikonal equations provides a framework for obtaining high order accuracy by using explicit nite di erence methods. A full-aperture anisotropic eikonal solver results from combining the paraxial formulations in di erent marching directions with the down-n-out and post sweeping techniques. Numerical computations for arbitrary anisotropic quasi-P traveltimes illustrate the accuracy and e ciency of the proposed anisotropic eikonal solver.