PS转换波界面二次源法射线追踪

Interface points as secondary sources method raytracing PS converted waves

界面二次源法是最近提出的一种最小走时射线追踪方法,尤其适合层状介质中走时和射线路径的计算.该方法相对于传统的最小走时树方法(如Moser法),仅在物性界面上设置二次源,射线路径的方向只在层界面处发生改变,该方法最大程度地消除了射线路径的锯齿状现象,同时也避免了低变速区的射线路径多值现象,因此,它具有更高的追踪精度和效率.本文采用界面二次源法在各向同性介质中实现了PS转换波射线追踪,理论模型的计算证实了界面二次源法追踪PS转换波的准确性和高效性,同时该方法在各向异性介质中也很好地追踪出分离的PSV波和PSH波,因此该方法有利于横波分裂在地震勘探中的研究和应用.

The interface as second sources method applied to minimal traveltime raytrace is presented recently. It is a kind of new method especially appropriating for traveltime and raypaths computation in layered media. Compared with traditional method such as Moser, this method only sets the second sources on the interface between two adjacent layers, and on which the ray directions make changes. This method utmost eliminates zigzag phenomenon and avoids multivalue problem in flat areas with low velocity variation. Therefore it is more accurate and efficient. The paper carries out the raytrace process of PS converted waves in homogeneous medium. Computation of theoretical models proves that the method has more accuracy and efficiency, and at the same time it can also be applied to the ray tracing of decoupled PSV and PSH conversions in anisotropic medium, therefore the interface as second sources method will be great help to the study of transverse wave separating in seismic exploration.