三维起伏地表条件下地震波走时计算的不等距迎风差分法  

Traveltime computation using the upwind finite difference method with nonuniform grid spacing in a 3D undulating surface condition

作　　者：孙章庆[1,2] 孙建国[1,2] 韩复兴[1,2] 

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026 [2]国土资源部应用地球物理综合解释理论开放实验室-波动理论与成像技术实验室,长春130026

出　　处：《地球物理学报》2012年第7期2441-2449,共9页Chinese Journal of Geophysics

基　　金：国家十二五重大研究专项(2011ZX05025-001-05);国家自然科学基金项目(40574052);吉林大学基本科研业务项目--青年教师创新项目(450060481203)资助

摘　　要：三维起伏地表条件下的地震波走时计算技术是研究三维起伏地表地区很多地震数据处理技术的基础性工具.为了获得适应于任意三维起伏地表且计算精度高的走时算法,提出三维不等距迎风差分法.该方法采用不等距网格剖分三维起伏地表模型,通过在迎风差分格式中引入不等距差分格式、Huygens原理及Fermat原理来建立地表附近的局部走时计算公式,并通过在窄带技术中设定新的网格节点类型来获得三维起伏地表条件下算法的整体实现步骤.精度及算例分析表明:三维不等距迎风差分法具有很高的计算精度且能够适应于任意三维起伏地表模型.The traveltime computation scheme in a 3D undulating surface condition has a great significance to some 3D seismic data processing techniques in complex topographical regions. To obtain a traveltime computation algorithm that can treat the 3D complex topography with high accuracy and good flexibility, we present an upwind finite difference method with nonuniform grid spacing. We use the grid with nonuniform grid spacing for dividing the velocity model. For obtaining the local traveltime computation formulas, we synthetically introduce the finitedifference scheme with nonuniform grid spacing, Huygens principle and Fermat principle into the conventional upwind finite difference scheme. To build up the implementation steps, we propose a new narrow-band technique in complex topographical conditions by improving the conventional narrow-band technique. The accuracy analysis and an example show that the new method can treat any 3D complex topography problems with high accuracy.

关 键 词：三维起伏地表 走时计算 不等距迎风差分法 窄带技术 

分 类 号：P631[天文地球—地质矿产勘探]