物探化探计算技术2025，Vol.47Issue(6)：806-816,11.DOI:10.12474/wthtjs.20241216-0001
基于复频移-卷积型完美匹配层的时间四阶-空间高阶有限差分逆时偏移方法
A temporal fourth-order and spatial high-order finite-difference reverse-time migration method based on CFS-CPML
摘要
Abstract
Reverse-time migration(RTM)methods are mostly based on finite-difference(FD)numerical solutions of wave equations.To avoid the impacts of numerical dispersion of the FD operators on RTM results,we adopt dispersion relation-based high-order FD schemes to approximate the wave equations.The high-order FD schemes can suppress both time and space dispersion simultaneously.To avoid spurious edge reflections caused by truncated boundaries,we design a convolutional perfectly matched layer(CFS-CPML)absorbing boundary scheme for FD solutions of the second-order wave equation.The CFS-CPML is incorporated into the discrete temporal fourth-order and spatial high-order FD formula directly.Specifically,the FD formula is equivalently decomposed into weighted combinations of multiple second-order difference operators,and the convolution terms related to CFS-CPML are introduced item by item.Finally,the weighted combination result is regarded as a differential approximation of the first-order derivative,and an outer-layer convolution term is introduced as well.As a result,the temporal fourth-order and spatial high-order FD scheme with the CFS-CPML embedded is obtained.The advantage of the developed CFS-CPML implementation strategy is that it does not require the derivation of any continuous matching equations,which makes it highly efficient.Based on the high-precision FD scheme and CFS-CPML boundary,we form an efficient temporal fourth-order and spatial high-order FD RTM method.Numerical tests with synthetic and field data have verified that the developed RTM method works well in improving the quality of the migration profile by suppressing numerical dispersion and boundary reflections.关键词
逆时偏移/有限差分/时间四阶/二阶波动方程/完美匹配层Key words
reverse-time migration/finite-difference method/temporal fourth-order/second-order wave equation/perfectly matched layer分类
天文与地球科学引用本文复制引用
张文祥,邓聪,杨文博,盖永浩..基于复频移-卷积型完美匹配层的时间四阶-空间高阶有限差分逆时偏移方法[J].物探化探计算技术,2025,47(6):806-816,11.基金项目
"十四五"重大科技项目(KJGG2022-0304) （KJGG2022-0304）
