摘要
为获得计算复杂地表条件下地震波走时的方法,对常规快速推进法(Fast marching method,简写为FMM)做了两点改进:①引入不等距差分格式,用于地表和界面处的局部走时计算;②增加新的网格节点类型,用于实现不规则边界条件下的窄带技术.通过对算法的计算精度、效率及实例的分析可得,算法计算精度高,其中反射波走时计算的精度高于初至波;不会因为处理不规则边界而引入过多额外的计算量;能灵活稳定地处理各种强起伏复杂地形、近地表及地下复杂介质等问题.计算结果满足复杂地表条件下地震波的传播规律.
Conventional fast marching method （FMM） is improved for traveltime computation. A non-equidistant difference scheme is used to carry local traveltime computation near surface and interface. New grid node type is used to realize narrow band technique under irregular boundary conditions. Analysis on accuracy, efficiency and numerical tests shows that the new method has high-accuracy and accuracy of the reflection wave is higher than that of the first-arrival wave. The new method does not need too more additional computing capacity in dealing with irregular boundaries. The new method can treat strong topographical change, near-surface and subsurface complex media effectively and flexibly. The results consist with laws of wave propagation under complex topographical conditions.
出处
《计算物理》
EI
CSCD
北大核心
2010年第2期281-286,共6页
Chinese Journal of Computational Physics
基金
国家自然科学基金(40574052)
国家重点基础研究发展计划(973)课题(2007CB209603)
国家自然科学基金重点项目(40437018)资助项目
关键词
复杂地表
不等距差分
快速推进法
走时计算
complex topography
non-equidistant difference scheme
fast marching method
traveltime computation
