地震学报（英文版）2004，Vol.17Issue(6)：707-714,8.
Finite-difference calculation of traveltimes based on rectangular grid
Finite-difference calculation of traveltimes based on rectangular grid
摘要
Abstract
To the most of velocity fields, the traveltimes of the first break that seismic waves propagate along rays can be computed on a 2-D or 3-D numerical grid by finite-difference extrapolation. Under ensuring accuracy, to improve calculating efficiency and adaptability, the calculation method of first-arrival traveltime of finite-difference is derived based on any rectangular grid and a local plane wavefront approximation. In addition, head waves and scattering waves are properly treated and shadow and caustic zones cannot be encountered, which appear in traditional ray-tracing. The testes of two simple models and the complex Marmousi model show that the method has higher accuracy and adaptability to complex structure with strong vertical and lateral velocity variation, and Kirchhoff prestack depth migration based on this method can basically achieve the position imaging effects of wave equation prestack depth migration in major structures and targets. Because of not taking account of the later arrivals energy, the effect of its amplitude preservation is worse than that by wave equation method, but its computing efficiency is higher than that by total Green's function method and wave equation method.关键词
finite-difference/eikonal equation/first-arrival traveltime/rectangular grid/Kirchhoff prestack depth migration/Marmousi modelKey words
finite-difference/eikonal equation/first-arrival traveltime/rectangular grid/Kirchhoff prestack depth migration/Marmousi model分类
天文与地球科学引用本文复制引用
李振春,刘玉莲,张建磊,马在田,王华忠..Finite-difference calculation of traveltimes based on rectangular grid[J].地震学报（英文版）,2004,17(6):707-714,8.基金项目
National Natural Science Foundation of China (49894190-024) and Geophysical Prospecting Key Laboratory Foundation of China National Petroleum Corporation. （49894190-024）
