梁全^1,2,,
毛伟建^1,,,
李武群¹,
欧阳威¹,
钱忠平³
1. 中国科学院测量与地球物理研究所计算与勘探地球物理研究中心; 大地测量与地球动力学国家重点实验室, 武汉 430077
2. 中国科学院大学, 北京 100049
3. 中国石油集团公司东方地球物理公司物探技术研究中心, 河北涿州 072751

基金项目: 国家重点研发计划项目（2016YFC0601100），国家自然科学基金（U1562216，41704143）和国家科技重大专项项目（2017ZX05018-001）联合资助


详细信息

作者简介: 梁全, 男, 博士研究生, 主要从事地震波正演、偏移和反演成像研究.E-mail:liangquan@whigg.ac.cn

通讯作者: 毛伟建, 男, 研究员, 博士生导师, 主要从事地震数据处理、成像和反演研究.E-mail:wjmao@whigg.ac.cn

中图分类号: P631

收稿日期:2018-08-13
修回日期:2019-06-03
上线日期:2019-11-05

Multistep fast ray tracing and high accuracy traveltime extrapolation with truncated cone

LIANG Quan^1,2,,
MAO WeiJian^1,,,
LI WuQun¹,
OUYANG Wei¹,
QIAN ZhongPing³
1. Center for Computational & Exploration Geophysics, Institute of Geodesy and Geophysics, Chinese Academy of Science; State Key Laboratory of Geodesy and Earth's Dynamics, Wuhan 430077, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
3. Research & Development Center, BGP, CNPC, Zhuozhou Hebei 072751, China


More Information

Corresponding author: MAO WeiJian,E-mail:wjmao@whigg.ac.cn

MSC: P631

--> Received Date: 13 August 2018
Revised Date: 03 June 2019
Available Online: 05 November 2019


摘要
摘要:为更好地适应复杂构造的地震偏移成像，本文提出了一套快速射线追踪算法和一种高精度的走时外插计算方法.采用线性多步法的预测-校正公式求解射线追踪方程组，与传统的四阶Runge-Kutta法相比，提高了计算效率.在网格节点上的走时计算中，应用一种基于圆台的外插方法，该方法以射线的方向为轴确定圆台，将轴上的走时外插到圆台内的网格节点上.与传统的矩形体外插方法相比，圆台走时外插方法提高了计算精度，且具有更好的稳定性.另外，该方法利用稀疏分布的射线即可获得高精度的走时表，节省计算量，对复杂构造的偏移成像非常有利，尤其是三维偏移.最后通过逆散射偏移成像算例，验证了算法的有效性和适用性.
关键词: 线性多步法/
射线追踪/
走时计算/
圆台外插

Abstract:In order to better adapt to seismic migration imaging of complex structures, this paper proposes a fast ray tracing algorithm and a high accuracy traveltime calculation method. In the proposed ray tracing approach, the predictor-corrector formula of linear multistep method is used to solve ray tracing equations, which improves the computational efficiency compared with classical fourth-order Runge-Kutta method. In the processing of calculating traveltimes at grids, we define a truncated cone (TC) which takes the ray direction as the axis, and extrapolate the traveltimes on the axis to the grids inside the TC. The presented extrapolation method with TC improves the computing accuracy, and shows higher stability in contrast to the traditional extrapolation method with a cubic box. Furthermore, this extrapolation method can obtain high-accuracy traveltime table even if sparsely distributed rays is applied, which effectively saves the computing time and is well beneficial for imaging complex structures, especially for 3D migration. Finally, we numerically validate our method by inverse scattering migration.
Key words:Linear multistep method/
Ray tracing/
Traveltime calculation/
Extrapolation with truncated cone



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