一种层状介质条件下射线的全路径迭代追踪法

从射线在整条路径上满足Fermat原理出发,采用一阶Taylor展开等办法,推出一个适用于任意层状地质结构下近似求解射线路径的对称正定三对角矩阵方程,通过求解该方程并结合迭代技术,从而实现对整条射线路径的全路径迭代计算。模型计算表明,本方法对于任意复杂结构和随机速度分布情况,其计算速度比传统的打靶法快,精度可根据需要预先确定,为复杂结构的地震偏移和层析成像提供了一种有效的射线追踪方法。 

A kind of whole-path iterative ray-tracing method in stratum structure media

It starts in this paper from the fact that the ray-path satisfies the Fermat's principal in the whole ray-path. By use of one order Taylor expansion,a well-posed symmetry tridiagonal matrix equation that fits to approximately calculate ray-path adjustment is obtained.Then,combining solving this matrix equation and iterative technique,a whole-path iterative ray-tracing method is fulfilled.The procedure of the ray tracing is ended when the adjustments on the whole ray-path satisfy the preset precision.Numerical tests indicate that this algorithm is faster than traditional shooting method in the arbitrary interface velocity distribution and the precision can be predetermined.It offers a new kind of efficient ray-tracing method for seismic migration and tomography in complex structure.