地震波旅行时二次/线性联合插值法  

Quadratic/linear travel time interpolation of seismic ray-tracing

作　　者：聂建新[1] 杨慧珠[1] 

机构地区：[1]清华大学工程力学系,北京100084

出　　处：《清华大学学报（自然科学版）》2003年第11期1495-1498,共4页Journal of Tsinghua University(Science and Technology)

摘　　要：为了提高地震波旅行时的计算精度,基于Asakawa的旅行时线性插值法(LTI)提出了一种改进的射线追踪法——旅行时二次/线性联合插值法(QLTI),即在震源的近场采用二次插值计算旅行时,在远场仍用LTI算法。QLTI算法改善了近场旅行时的精度,降低了累加误差,进而提高了全场(尤其是远场)旅行时的计算精度。数值模拟和模型实验的结果表明,本文提出的QLTI算法较传统的LTI算法更为精确。An improved ray-tracing method called quadratic/linear travel time interpolation (QLTI) was developed based on the linear travel time interpolation (LTI) method given by Asakawa to increase seismic travel time measurement accuracy. In the field near the source point, the travel time of the interpolation point was calculated using quadratic travel time interpolation (QTI), while LTI was used to calculate the travel time far from the source. The method improved the travel time accuracy and reduced the accumulated error by replacing the LTI algorithm by the QTI algorithm in the near field. Thus, the travel time accuracy was increased in the full field (especially in the far field). Comparison of numerical and experimental results shows that the present algorithm is more accurate than the conventional LTI method. This seismic ray-tracing algorithm is also more precise and more suitable for complicated conditions such as large velocity variations.

关 键 词：地震波 射线追踪 旅行时线性插值 旅行时二次插值 误差分析 

分 类 号：P315.31[天文地球—地震学]