基于波前扩展的线性走时插值射线追踪算法

基于波前扩展的线性走时插值射线追踪算法 Linear Traveltime Interpolation Algorithm Based on Expanding Wavefronts 张东 ZHANG Dong1 1 first-author 童海杰 TONG Haijie1 1 杨艳 YANG Yan1 1 秦前清 QIN Qiangqin2 2 徐凌 XU Lin3 3 武汉大学物理科学与技术学院 武汉大学物理科学与技术学院 School of Physics and Technology,Wuhan University School of Physics and Technology,Wuhan University 武汉大学测绘遥感信息工程国家重点实验室 武汉大学测绘遥感信息工程国家重点实验室 State Key Laboratory of Information Engineering in Surveying of Mapping and Remote Sensing,Wuhan University State Key Laboratory of Information Engineering in Surveying of Mapping and Remote Sensing,Wuhan University 中国石油勘探开发研究院物探技术研究所 中国石油勘探开发研究院物探技术研究所 Research Institute of Petroleuum Exploration and Production,China National Petroleum Corporation Research Institute of Petroleuum Exploration and Production,China National Petroleum Corporation 线性走时插值算法（LTI）在走时的计算中由于考虑的射线方向有限,计算得到的节点走时不一定最小,导致追踪的射线路径无法满足最小走时.针对这一问题,本文提出了一种改进的LTI射线追踪算法,该算法通过模拟真实波传播过程,采用波前扩展方法计算节点走时使节点走时更接近真实最小值,以确保射线追踪的精度.模拟算例结果表明,该算法在有效地提高射线追踪精度的同时,兼顾了计算的效率. Grid point traveltimes calculated by linear traveltime interpolation （LTI） are not certainly the minimum values for not considering all the possible directions that rays come from.It induces that Fermat condition of the minimum traveltime can not be really satisfied in ray tracing.In the paper an improved LTI algorithm is presented,which introduces the mode of expanding wavefronts to calculate traveltimes of grid points.Traveltime data obtained in this way is more approximating to the real minimum values due to simulating the real wave transmitting.Thus the precision of ray tracing is improved.The calculation results show that the algorithm in the paper can increase the precision effectively and ensure the efficiency as well. 层析成像 射线追踪 线性走时插值 最小走时 波前扩展 tomography ray tracing linear traveling interpolation minimum traveltimes wavefront expanding 10.14188/j.1671-8836.2010.06.006 P631.4 国家重点基础研究发展计划（973）项目（2006CB701303） 2010-06-01 2021-04-01 6 56