复杂地表条件下基于线性插值和窄带技术的地震波走时计算  

Travel times computation using linear interpolation and narrow band technique under complex topographical conditions

作　　者：孙章庆[1,2] 孙建国[1,2] 韩复兴[1,2] 

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026 [2]国土资源部应用地球物理综合解释理论开放实验室-波动理论与成像技术实验室,长春130026

出　　处：《地球物理学报》2009年第11期2846-2853,共8页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(40574052);国家重点基础研究发展计划(973)课题(2007CB209603);国家自然科学基金重点项目(40437018)

摘　　要：为了在复杂地表条件下实现地震波走时计算,提出了一种基于线性插值和窄带技术的走时计算新方法.其中,线性插值用于局部走时计算,窄带技术用于局部波前捕获和追踪.为了逼近起伏地表,采用三角网和矩形网相结合的方法对速度模型进行剖分.为了得到局部走时计算公式,利用费马(Fermat)原理和关于入射点位置的限定条件.有关编程实践和数值试验表明:新方法不仅可以有效、灵活地处理地表高程的剧烈变化,而且还具有很好的适应性和稳定性,得到的计算结果满足波前传播规律.For realizing the seismic traveltime computation under complex topographical conditions, we present a new method based on linear interpolation and narrow band technique. Here, the linear interpolation technique is used for carrying out the local traveltime computation, and the narrow band technique is used for capturing and propagating the wavefront. For fitting the complex topography, we use a hybrid grid, consisting of a triangular grid and a rectangular one, for dividing the velocity model into grid. For obtaining a formula for the local traveltime computation, we invoke the Fermat principle and a condition for limiting the position of the incident point. Programming practice and numerical tests show that the new method not only can treat the strong topographical change stability and consist with adaptability the laws on to the comp with effectiveness and flexibility, but also have satisfactory lex velocity model. The results given by the new method wave propagation.

关 键 词：复杂地表 线性插值 窄带技术 混合网格 走时计算 

分 类 号：P631[天文地球—地质矿产勘探]