Development of an Inversion Method for Low Velocity Medium
| Autor: | Ahmad Syahputra, Afnimar Afnimar, Andri Dian Nugraha |
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| Rok vydání: | 2013 |
| Předmět: |
Multidisciplinary
Bending (metalworking) General Mathematics Mathematical analysis General Physics and Astronomy Inverse transform sampling Geometry General Chemistry General Medicine Fermat's principle Inversion (discrete mathematics) General Biochemistry Genetics and Molecular Biology symbols.namesake Knot (unit) Path (graph theory) symbols General Earth and Planetary Sciences Ray tracing (graphics) General Agricultural and Biological Sciences Mathematics Block (data storage) |
| Zdroj: | Journal of Mathematical and Fundamental Sciences. 45:93-103 |
| ISSN: | 2338-5510 2337-5760 |
| Popis: | The main problem with the inversion of a low velocity medium is the application of an appropriate ray tracing method after choosing a suitable model parameterization. Block parameterization is not suitable, because it is not capable of representing the velocity model well. A large amount of blocks with a small grid size are needed to express the model well, but in that case, a ray coverage problem will be encountered. A knot-point parameterization model is better suited than a block model, because it can express the velocity model well, while the number of variables is much smaller. Ray calculation using the pseudo- bending method is not appropriate for the velocity model because of an instability problem at high velocity gradients. The crucial problem of this method involves the initial ray-path that is optimized in order to obtain the "true" ray, but does not satisfy the Fermat principle. These problems can be solved by applying the eikonal-solver method, because this can handle high-velocity gradients and does not need an initial ray path. Using a suitable model parameterization and appropriate ray tracing method, the inversion can obtain good results that fit the desired output. Applying a block model and the pseudo- bending method will not produce the desired output. |
| Databáze: | OpenAIRE |
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