摘要
使用不规则网格单元划分下的最短路径算法,结合分区多步计算技术实现了二维和三维复杂层状起伏介质中的多次透射、反射及转换波的追踪计算.其原理是将模型按速度界面分成若干个独立的计算区域(在速度界面和起伏地表处采用一种不规则网格单元划分),采用分步计算技术进行多次波的追踪计算.通过与有限差分下快速行进法的比较,表明无论是计算精度还是CPU时间,不规则最短路径算法均好于快速行进法算法.最后,实例模拟中给出了二维、三维复杂层状模型(包括Marmousi模型及含低速体的模型)中的多次透射、反射及转换波的追踪计算,验证了不规则最短路径算法的功能.
This study introduces the multistage scheme incorporating with an irregular shortest path method （ISPM） for tracking multiple arrivals composed of any kind of combinations of transmissions,conversions and reflections in complex 2D/3D layered media.The principle is first to divide the layered model into several different computational domains using irregular cells at the interface and the Earth’s undulated surface,and then to apply the multistage technique to trace the multiple arrivals.It is possible to realize the multiple arrival tracking with the multistage technique,because the multiple arrivals are different combinations or conjugations of the simple incident,transmitted and reflected waves via the velocity discontinuities.Benchmark tests against the multistage fast marching method （FMM） are undertaken to assess the solution accuracy and the computational efficiency.The results show that the multistage ISPM method is advantageous over FMM method in both solution accuracy and CPU times.
出处
《地震学报》
CSCD
北大核心
2010年第4期433-444,共12页
Acta Seismologica Sinica
基金
国家自然科学基金面上项目(40774020)资助
关键词
不规则最短路径算法
分区多步计算
多次波追踪
快速行进法
irregular shortest path method
multistage scheme different computational domain
multiple arrival tracing
fast marching method
