Efficient traveltime solutions of the acoustic TI eikonal equation

Journal Article · Sun Feb 01 04:00:00 EST 2015 · Journal of Computational Physics

DOI:https://doi.org/10.1016/J.JCP.2014.11.006· OSTI ID:22382180

Alkhalifah, Tariq; Wang, Hui

Numerical solutions of the eikonal (Hamilton–Jacobi) equation for transversely isotropic (TI) media are essential for imaging and traveltime tomography applications. Such solutions, however, suffer from the inherent higher-order nonlinearity of the TI eikonal equation, which requires solving a quartic polynomial for every grid point. Analytical solutions of the quartic polynomial yield numerically unstable formulations. Thus, it requires a numerical root finding algorithm, adding significantly to the computational load. Using perturbation theory we approximate, in a first order discretized form, the TI eikonal equation with a series of simpler equations for the coefficients of a polynomial expansion of the eikonal solution, in terms of the anellipticity anisotropy parameter. Such perturbation, applied to the discretized form of the eikonal equation, does not impose any restrictions on the complexity of the perturbed parameter field. Therefore, it provides accurate traveltime solutions even for models with complex distribution of velocity and anisotropic anellipticity parameter, such as that for the complicated Marmousi model. The formulation allows for large cost reduction compared to using the direct TI eikonal solver. Furthermore, comparative tests with previously developed approximations illustrate remarkable gain in accuracy in the proposed algorithm, without any addition to the computational cost.

• OSTI ID: 22382180
• Journal Information: Journal of Computational Physics, Journal Name: Journal of Computational Physics Vol. 282; ISSN JCTPAH; ISSN 0021-9991
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALGORITHMS
ANALYTICAL SOLUTION
ANISOTROPY
COMPARATIVE EVALUATIONS
EIKONAL APPROXIMATION
GAIN
HAMILTON-JACOBI EQUATIONS
ISOTROPY
MATHEMATICAL MODELS
NONLINEAR PROBLEMS
NUMERICAL SOLUTION
PERTURBATION THEORY
POLYNOMIALS