三维结构下逐段迭代射线追踪方法

Department of Iterative ray-tracing method segment by segment under 3-D construction.

高尔根 ,徐果明 ,蒋先艺 ,罗开云 ,刘同庆 ,谢端 ,史进良 .三维结构下逐段迭代射线追踪方法 .石油地球物理勘探 ,2 0 0 2 ,37(1) :11～ 16本文基于 Snell定律和 Fermat原理对三维任意界面情况下的两点间射线追踪问题进行了研究。文中采用一阶不完全 Taylor展开等方法 ,推导出一个适用于三维介质分布情况下计算反 (折 )射点的 2× 2阶正定矩阵 ;从任意给定的初始路径出发 ,对射线路径进行逐段迭代计算 ,当整条射线路径的校正量之和满足一定的精度要求时 ,迭代计算过程结束 ,以最后一次迭代计算所得的射线路径作为最终的三维射线路径 ,进而实现三维结构下射线追踪计算。模型计算结果表明 ,该方法计算速度相当快 。

Based on Snell law and Fermat principle, the two-point ray-tracing method for three dimensional arbitrary interface is studied in this paper. First,by use of one-order Taylor incomplete expansion,a positive definite matrix two by two, which is suitable to calculate reflection or refraction point in three-dimensional constructs,is obtained.Then,starting from an arbitrary given initial ray path,ray-tracing is iteratively calculated segment by segment.The procedure is kept on until the sum of adjustment quantity in the whole path is in the range of precision and the last iterative result is regarded as final three dimensional ray path.Now,the iterative ray-tracing segment by segment in three dimensional construct is finished.Numerical tests show that this algorithm is fast and its calculating precision can reach any requirements needed.