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Joint First-Arrival Traveltime Tomography and Waveform Inversion for Near-Surface Imaging
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 79th EAGE Conference and Exhibition 2017, Jun 2017, Volume 2017, p.1 - 5
Abstract
The initial model is the crucial to full waveform inversion. First arrival traveltime tomography can provide a more accurate near-surface model, improve the accuracy of the FWI and accelerate convergence. In this paper, the initial model is based on fast marching method (FMM) traveltime tomography to obtain the near-surface velocity model. The second-order FMM is used to solve the Eikonal equation; although our implementation belongs to the family of adjoint-state tomographies, we do not need to compute the adjoint-state variable as an intermediate product for the gradient. The first arrival traveltime tomography based on FMM can provide a more accurate near-surface initial model for FWI, and improve the convergence rate of FWI. On synthetic data examples, we show the advantages of the proposed approach. Moreover, the use of parallel computing improves computational efficiency.