Parameterized random boundary condition and its application on seismic RTM
ZHANG Li-Mei1, CHENG Gu1, 2
1.School of Earth Sciences and Engineering,Sun Yat-Sen University,Guangzhou 510275,China; 2.Guangdong Key Laboratory of Geological Process and Mineral Resources Exploration,Guangzhou 510275,China
Abstract：Pre-stack seismic reverse time migration has important application in high accuracy subsurface imaging.However enormous memory is needed in RTM.Using random boundary in RTM can reduce memory need of RTM effectively.In this paper,random media expressed by correlation function,correlation length,root mean square velocity perturbation is used,the meanings and values of parameters are analyzed and the optimal parameter group(exponential correlation function,the correlation length being equal to wave length and root mean square velocity perturbation being 30%) are obtained.Numerical simulation shows that using random boundary with optimal parameter group can destroy the coherence of artificial boundary reflection wave fields effectively and obtain high accuracy imaging result with less memory at the same time.
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