摘要
在弹性波有限差分正演模拟中,完全匹配层(PML)吸收边界条件是使用广泛、吸收效果最好的吸收边界条件.在目前的两种PML实现方法中,分裂形式的完全匹配层(SPML)方法计算存储量大、编程实现复杂;非分裂形式的完全匹配层(NPML)方法计算效率低、计算过程复杂.针对传统PML吸收边界条件在实现过程中存在的问题,推导出了一种简洁有效的非卷积实现的NPML吸收边界条件,既不需要对场分量进行分裂,也不需要做复杂的卷积运算.分析结果表明,本文实现的NPML吸收边界条件不仅具有良好的吸收衰减性能,而且计算方程简单,编程实现容易,占有内存更小.
In finite-difference time-domain modeling of elastic waves, absorbing boundary conditions are used to mitigate undes ired reflections from the model＇s truncation boundaries. The perfectly matched layer （PML） is generally acknowledged as the best available absorbing boundary condition and very efficient to absorb both body waves and surface waves. The classical splitting PML （SPML） has some disadvantages： it needs much computer memory and has complex programming process. And the conventional non-splitting PML （NPML） based on time convolution needs more auxiliary equations or fields and computing time. We have induced a simple and efficient NPML based on non-convolution technology in this paper. The NPML we induced does not have to split the velocity and stress fields and also doesn＇t need to involve in complex convolution in time domain. The analysis result shows the new PML method not only has perfect absorbing performance, but also has simple computing equations, easier programming and less memory consumption.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
2009年第4期658-664,共7页
Earth Science-Journal of China University of Geosciences
基金
国家自然科学基金项目(No.40274038)
关键词
PML
吸收边界条件
弹性波
正演模拟
地球物理
perfectly matched layer
absorbing boundaries
elastic wave
forward modeling
geophysics.
