地面地震高斯射线束正演  

Gaussian Beam Forward Modeling on the Surface Seismic

作　　者：成林[1] CHENG Lin(School of Earth Sciences and Engineering, Xi＇an Shiyou University, Xi＇an 710065, China)

机构地区：[1]西安石油大学地球科学与工程学院,西安710065

出　　处：《西安文理学院学报（自然科学版）》2016年第6期86-91,共6页Journal of Xi’an University(Natural Science Edition)

基　　金：中国地质调查局地质项目(1212011085499)

摘　　要：高斯射线束正演方法是将射线理论和波动方程理论相结合的一种地震正演方法,充分利用了射线理论计算速度快、波动方程理论计算精度高的优点.通过高斯射线束表达式和编程实现地震记录合成的基础上,给出了水平地质模型的计算实例,并对比分析了高斯射线束法、普通射线法、波动方程法正演的特点.通过理论分析和实际地质模型可以得出:(1)高斯射线束正演方法效率高,计算速度快,在复杂模型中甚至超过普通射线法的计算速度;(2)高斯束法由于在断点处存在绕射能量,计算中不存在奇异区(阴影区、焦散区等);(3)高斯束法合成记录不仅反映地震波的运动学特点,而且反映波的高频动力学特点,计算结果可与波动方程法计算结果一致.The forward modeling by Gaussian beam method is essentially a seismic forward mod- eling method that combines wave equation and ray theory, which makes full use of the advanta- ges of the fast calculation of ray theory and the high accuracy of wave equation theory. In this paper, based on Gaussian beam function and programming to achieve the synthesis of seismic records, the calculation example of horizontal geological model is given, and the characteristics of Gaussian beam method, ordinary ray method and wave equation method are compared and analyzed. Through the theoretical analysis and the practical geological model test, it can be concluded that as follows. Firstly, forward modeling by Gaussian beam method is of high effi- ciency, fast calculation speed, and its calculation speed is even faster than that of the ordinary ray method in the complex model. Secondly, due to the presence of diffraction energy at the break-point, the singular region （region of a shadow area, etc. ） does not exist in the calcula- tion of Gaussian beam method. Thirdly and lastly, the synthetic record of Gauss beam method not only reflects the kinematic characteristics of seismic waves, but also reflects the high fre- quency dynamic characteristics of the wave. The calculation results are consistent with the cal- culation results of the wave equation method.

关 键 词：高斯射线束 射线追踪 波动方程 地震正演 合成地震记录 

分 类 号：P315.2[天文地球—地震学]