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Application of the Improved Perfectly Matched Layer in 2D Finite-difference Modeling with an Irregular Free Surface
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 77th EAGE Conference and Exhibition 2015, Jun 2015, Volume 2015, p.1 - 5
Abstract
Classical finite-difference method has some problems when dealing with irregular topography, including artifacts caused by staircase approximation to irregular free surface. Body-fitted grid is usually termed as “boundary conforming grid”, and it can solve the problem. On the other hand, Perfectly Matched Layer (PML) absorbing boundary is certified an efficient method to suppress spurious edge reflections. However, classical PML has the defects of its inherent instability and the effects of grazing incidence and some improved algorithms are developed. This paper models seismic wave in elastic media with irregular free surface by using the Lebedev Grid which is usually used in anisotropy media. In simulation process, the traction image method is used to implement the free surface conditions. And for other boundaries the improved perfectly matched layer technologies are chosen to absorb waves. Numerical tests on synthetic data demonstrate the validity of the proposed method. Finally we compare absorb effects and stability of some perfectly matched layer technologies.