Local Ray-Based Traveltime Computation Using the Linearized Eikonal Equation
Type
ThesisAuthors
Almubarak, Mohammed S.Advisors
Alkhalifah, Tariq Ali
Committee members
Mahmoud, SherifMai, Paul Martin

Program
Earth Science and EngineeringKAUST Department
Physical Science and Engineering (PSE) DivisionDate
2013-05Embargo End Date
2014-05-28Permanent link to this record
http://hdl.handle.net/10754/292969
Metadata
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At the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis became available to the public after the expiration of the embargo on 2014-05-28.Abstract
The computation of traveltimes plays a critical role in the conventional implementations of Kirchhoff migration. Finite-difference-based methods are considered one of the most effective approaches for traveltime calculations and are therefore widely used. However, these eikonal solvers are mainly used to obtain early-arrival traveltime. Ray tracing can be used to pick later traveltime branches, besides the early arrivals, which may lead to an improvement in velocity estimation or in seismic imaging. In this thesis, I improved the accuracy of the solution of the linearized eikonal equation by constructing a linear system of equations (LSE) based on finite-difference approximation, which is of second-order accuracy. The ill-conditioned LSE is initially regularized and subsequently solved to calculate the traveltime update. Numerical tests proved that this method is as accurate as the second-order eikonal solver. Later arrivals are picked using ray tracing. These traveltimes are binned to the nearest node on a regular grid and empty nodes are estimated by interpolating the known values. The resulting traveltime field is used as an input to the linearized eikonal algorithm, which improves the accuracy of the interpolated nodes and yields a local ray-based traveltime. This is a preliminary study and further investigation is required to test the efficiency and the convergence of the solutions.Citation
Almubarak, M. S. (2013). Local Ray-Based Traveltime Computation Using the Linearized Eikonal Equation. KAUST Research Repository. https://doi.org/10.25781/KAUST-K9X1Nae974a485f413a2113503eed53cd6c53
10.25781/KAUST-K9X1N