一种改进的线性走时插值射线追踪算法

线性走时插值法（LTI）在走时的计算中，由于射线方向考虑不全，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射线追踪算法，通过采用多方向的循环计算，得到所有计算节点的最小走时，使追踪到的射线路径能真正满足最小走时，以确保射线追踪的精度.模拟实验结果表明，在介质速度变化剧烈的结构中，该算法与传统的LTI算法相比，有效地提高了射线追踪的精度.

A ray tracing method based on improved linear traveltime interpolation

Grid point traveltimes calculated by linear traveltime interpolation (LTI) are not always the minimum values for not considering all the possible ray directions. It induces that Fermat condition of minimum traveltime can not be really satisfied in ray tracing. In the paper an improved method for ray tracing is presented to solve this problem. By making use of multi-directional loop computation the minimum traveltimes of all grid points are obtained, which will conform the traced ray path to the condition of minimum traveltime. The tracing precision can be ensured in this way. The calculation examples show that the improved method can increase the precision effectively comparing with the traditional LTI in the velocity structure of great difference.