摘要
利用线性旅行时插值射线追踪对近地表模型进行正演计算,可以快捷、准确地获得初至波走时和射线路径。由于该算法计算的初至波不局限于折射波,因此很好地解决了浅层折射勘探中的低速“隐蔽层”问题;而且,由于该算法是基于网格划分和线性插值,因此它不仅可以追踪任意复杂介质的初至波,而且可以使得追踪的初至波射线路径逼于真实,避免了同类算法直接连接网络节点形成射线路径的缺陷(路径过于弯折,计算走时偏大)。将LTI算法同其他几种算法的追踪结果进行的对比和分析表明,LTI算法在计算初至波走时和射线路径方面较其他算法更为精准、稳定,是一种有效的射线追踪方法。
We can quickly and properly acquire the travehime and ray path of first-break through forward calculation on the near-surface model by using linear traveltime interpolation ray tracing. As the first-breaks calculated by this method not only contain refraction but also other parameters, the problem of shielding layer in shallow refraction exploration caused by a low velocity can be satisfactorily solved. Moreover, based on gridding division and linear interpolation, this method can trace first-breaks in any complex media and can make the traced ray path approach the real condition, thus avoiding the direct connection of web nodes to form ray paths which causes a bigger travehime value due to the serious bending of the ray path. Several other methods are compared with the LTI method in this paper, and the result shows that the LTI method is more precise and stable than other methods in calculating traveltime and ray path of first-breaks. It is thus concluded that LTI is an effective ray tracing method.
出处
《物探与化探》
CAS
CSCD
2006年第2期148-153,共6页
Geophysical and Geochemical Exploration
关键词
线性旅行插值
射线追踪
近地表
初至波
折射波
屏蔽层
网格剖分
linear travehime interpolation
ray tracing
near-surface
first-break
refraction
shielding layer
gridding division
