【摘要】 当存在低速异常体或弯曲界面时,地震波前出现的自相缠绕(或地震多值)现象是地震波在介质中传播的自然现象,但在以往的研究中时常被忽略。而这些后续波有可能携带低速区或不规则反射界面的有用信息,可以弥补射线覆盖不足等问题。本文在相空间方法的基础上,对波前构造法进行了改进,其中包括反射界面处理过程中采用连续波前映射法和射线追踪过程中采用检波器精确定位算法等。几种简单模型的数值模拟结果表明,改进后的波前构造法是一种计算地震多值射线路径行之有效的算法。更多还原

【Abstract】 Seismic wavefront self-interaction or multivalued seismic ray is a natural phenomenon when the seismic wave propagates through a media containing low-velocity abnormal bodies or bending interfaces,which is commonly ignored in previous study.However,it is true that the later arrivals may contain some useful information regarding to the low velocity zone or the irregular reflection interface and have a potential to improve the ray coverage.Based on the phase space method,we improve in this paper the wavefront construction method in two aspects:firstly,using a continuous wavefront mapping method to deal with the reflection interface;secondly,using aprecise receiverlocation algorithm in the ray tracing process.Several simple model simulations indicate that the improved wavefront construction method in phase space is an effective and accurate approach to trace multi-valued seismic rays.更多还原