Seismic ray-tracing calculation based on parabolic travel-time interpolation^①

来源期刊：中南大学学报(英文版)2004年第2期

论文作者：周竹生 张赛民 陈灵君

文章页码：199 - 205

Key words：ray-tracing; parabolic travel-time interpolation method; linear travel-time interpolation method;travel-time; ray-path; grid cell

Abstract: A new seismic ray-tracing method is put forward based on parabolic travel-time interpolation(PTI) method,which is more accurate than the linear travel-time interpolation (LTI) method. Both PTI method and LTI method are used to compute seismic travel-time and ray-path in a 2-D grid cell model. Firstly, some basic concepts are introduced.The calculations of travel-time and ray-path are carried out only at cell boundaries. So, the ray-path is always straight in the same cells with uniform velocity. Two steps are applied in PTI and LTI method, step 1 computes travel-time and step 2 traces ray-path. Then, the derivation of LTI formulas is described. Because of the presence of refraction wave in shot cell, the formula aiming at shot cell is also derived. Finally, PTI method is presented. The calculation of PTI method is more complex than that of LTI method, but the error is limited. The results of numerical model show that PTI method can trace ray-path more accurately and efficiently than LTI method does. Key words:ray-tracing; parabolic travel-time interpolation method; linear travel-time interpolation method;travel-time; ray-path; grid cell