Dongwoo Yang

TL;DR: In this paper, the authors exploit the numerical structure of the finite element method, modern sparse matrix technology, and source-receiver reciprocity to develop an algorithm that explicitly calculates the Jacobian matrix at only the cost of a forward model solution.

TL;DR: In this article, the authors developed an accurate and economical algorithm to calculate first-arrival traveltimes and amplitudes for an arbitrarily complex earth model based on numerical solutions of the wave equation obtained by using well-established finite-difference or finite-element modeling algorithms in the Laplace domain.

TL;DR: In this article, the first arrival and the approximately most energetic traveltimes at each depth point were computed by modifying existing frequency-domain wave-equation downward-continuation software.

TL;DR: In this article, the Laplace-domain waveform inversion algorithm for 3D elastic media is implemented, where the wave equation is formulated in weak form by the finite element method and solved using the preconditioned conjugate gradient method.

TL;DR: In this paper, the authors generalized the Kirchhoff migration to include more than one arrival time, with amplitudes calculated from geometrical optics, solution of the transport equations, or Gaussian beams (e.g., Hill, 2001).