Space and time discretization of the wave equation for the reverse time migration
Event details
| Date | 02.12.2009 |
| Hour | 16:15 |
| Speaker | Dr. Julien Diaz |
| Location |
MAA110
|
| Category | Conferences - Seminars |
Since the work of Hemon [1] in the 70s, it is well-known from the geophysical community that the seismic imaging methods based on the solution of the full wave equation are the most efficient and accurate to deal with very complex propagation media, when compared to the ones based on the solution of the one-way wave equation. Nowadays one of the most commonly used imaging technique is the Reverse Time Migration (RTM), which relies on many successive solutions of the wave equation.
As all the migration techniques, RTM follows the Claerbouts schedule : numerical propagation of the source function (propagation) and of the recorded wavefields (retropropagation) and next, construction of the image by applying an imaging condition. The retropropagation step can be realized accouting for the time reversibility of the wave equation. To be efficient, especially in three dimensional domain, the RTM requires the solution of the full wave equation by fast numerical methods. Finite element methods are considered as the best discretization method for solving the wave equation, even if they lead to the solution of huge systems with several millions of degrees of freedom, since they use meshes adapted to the domain topography and the boundary conditions are naturally taken into account in the variational
formulation. Among the different finite element families, the spectral element one (SEM) [2, 3, 4] is very interesting because it is compatible with the use of a Gauss Lobatto quadrature rule which leads
to a diagonal mass matrix and does not hamper the order of convergence of the finite element method.
Links
Practical information
- General public
- Free
Contact
- Dr. Imbo Sim