Two-point Paraxial Traveltime in Inhomogeneous Isotropic/Anisotropic Media - Tests of Accuracy

We analyze the efficiency and accuracy of the two-point paraxial traveltime formula. It provides the approximate traveltime between two points arbitrarily chosen in a paraxial vicinity of a single reference ray, along which the ray propagator matrix in a ray-centered coordinates has been determined. The reference ray can be traced in an arbitrary, smoothly varying, layered medium of arbitrary anisotropy. We illustrate the potential of the two-point paraxial traveltime formula and its Shanks transform representation, which provides much higher accuracy, on smoothly inhomogeneous, isotropic and weakly anisotropic models. The formulation offers several interesting applications including fast traveltime computations, velocity-independent interpolation and datuming.