粘弹介质中高斯束二维理论地震记录的合成

THE SYNTHESIS OF GAUSSIAN BEAN THEORETIC SEISMIC RECORDING IN 2-D VISCOELASTIC MEDIUM

本文对无限空间二维变化粘弹介质中的高斯束及有关过界面的情况进行了讨论。在讨论中发现,利用高斯束法既可不用定点射线追踪,还可保证处处规则,较近年来发展较快的标准射线方法有很大的灵活性,适于处理各种复杂地质情况。并对理论地震记录的合成方法作了简要介绍。

In recent years, there has been a great development in standard ray theory.With it we can obtain relatively excsllent effects in general in homogenous media, But in irregular regions, such as caustics and critical regions ect. The results are not ideal.This paper mainly discusses Gaussian Beam in the infinitely 2-D varying vis-coelastic media,and cases when the Beam crossing the interface. In discussion, we find, by using Gaussian Beam method, we can make synthesis without 2-point ray tracing, and yet the regularity is mantaiaed everywhere. It has a great flexibility compared with the standard ray method, and is capable to deal with various complex geologic problems which are difficult to manage with the standard ray method.Generally, The synthesis of theoretic seismic recording consists of four steps: (1) setting up a geologic model, (2) expanding the Source into Gaussina Beam series, (3) making geometric ray tracing and dynamic ray tracing, and obtaining elementary wave recordings, (4) making an addition of the elementary wave recordings. The practical computation is not very complex, it can be realized by a micro-computer.