Previous formulations of coda wave interferometry make it possible to assess the average change of the medium, but they do not allow for the spatial localization of this change (Snieder et al., 2002; Snieder, 2002). We present an approach for localizing temporal changes in the medium using strongly scattered waves, and test it with numerical models for 2D scalar waves. Using an integral represe...

Traveltime computation is widely used in seismic modeling, imaging and velocity analysis. The two most commonly used methods are ray tracingand numerical solutions to the eikonal equation. Eikonal solvers are fast and robust, but are limited to computing only the first arrival traveltimes. Ray tracing can compute multiple arrivals, but lacks the robustness of eikonal solvers. Here, we propose a...

The article is concerned with accuracy and eÆciency issues for the numerical solution of the eikonal equation in heterogeneous media in three-dimensional space. A new second-order nite di erence scheme is introduced to approximate the traveltime derivatives exactly for elliptical wavefronts. Its ENO-variant, called the Quadratic ENO (QENO), is applied for the traveltime computation in realistic...

Seismic techniques incorporating high frequency asymptotic representation of the 3D elastic Green's function require eecient solution methods for the computation of traveltimes. For nite diierence eikonal solvers, upwind diierences are requisite to sharply resolve discontinuities in the traveltime derivatives. In anisotropic media the direction of energy propagation is not in general tangent to...

We present a dynamic ray tracing program for a spherically symmetric Earth that may be used to compute Fréchet kernels for traveltime and amplitude anomalies at finite frequency. The program works for arbitrarily defined phases and background models. The numerical precisions of kinematic and dynamic ray tracing are optimized to produce traveltime errors under 0.1 s, which is well below the data...

This paper introduces a neural network approach for solving two-dimensional traveltime tomography (TT) problems based on the eikonal equation. The mathematical problem of TT is to recover slowness field medium boundary measurement traveltimes waves going through medium. inverse map high-dimensional and nonlinear. For circular geometry, perturbative analysis shows that forward can be approximate...

This paper tackles the issue of computational load encountered in seismic imaging by Bayesian traveltime inversion. In inference, exploration posterior distribution velocity model parameters requires extensive sampling. The cost this sampling step can be prohibitive when first arrival prediction involves resolution an expensive number forward models based on eikonal equation. We propose to rely...

I exploit the theoretical link between the eikonal equation and Fermat’s principle to derive a variational interpretation of the recently developed method for fast traveltime computations. This method, known as fast marching, possesses remarkable computational properties. Based originally on the eikonal equation, it can be derived equally well from Fermat’s principle. The new variational formul...

The common-reflection surface (CRS) method is a powerful alternative to the traditional commonmidpoint (CMP) stacking, as it enables stacking using more traces than CMP. The CRS method is based on a traveltime that depends on three parameters in the 2D case, and in eight parameters in the 3D case. Traditionally, to keep computational costs low, these parameters are estimated based on a sequence...