一种新程函方程差分法层析成像

Seismic tomography based on new finite difference scheme of eikonal equation

本文改进了Vidale（1988）提出的有限差分计算旅行时的算法。在此基础上，通过给出已知二维空间网格点上的初至旅行时，求出接收点至激发点之间的地震初至波射线路径，从而利用同时迭代重建技术（SIRT）实现任意二维介质速度分布情况下的弯曲射线法层析成像。理论模型计算表明，本方法是一种层析成像反演的有效手段。

We advance here a new finite-difference calculation of traveltimes that is betterthan Vidale's (1988). First-break ray paths between sources to receivers can be derived from known first break times at knots of 2-D grid.Then,curved-ray seismictomography in any velocity distributioss inD me medium can be achieved by takingsimultaneously iterative reconstruction technique.Theoretical modeling shows thatthe method is an effective one for tomographic inversion.