论文部分内容阅读
正演模拟计算的一个关键是在有限空间中模拟地震波在无限空间中的传播。要消除由于把地震波的传播设定在有限区域而产生的边界反射,需要引入吸收边界条件。本文研究的完全匹配层(PM L)吸收边界条件是Berenger在1994年提出的一种新的人工边界条件,从横向各相同性(VT I)介质的一阶弹性波方程出发,给出方程在交错网格空间的高阶有限差分格式,并推导出适用于其的PM L吸收边界条件及边界的交错网格高阶有限差分格式。计算结果表明,PM L吸收边界条件可以完全吸收外行波场。
One of the keys to forward modeling is to simulate the propagation of seismic waves in an infinite space in a finite space. To eliminate the boundary reflection due to the setting of the seismic wave propagation in a limited area, it is necessary to introduce absorption boundary conditions. In this paper, the perfect matching layer (PM L) absorption boundary condition is a new artificial boundary condition proposed by Berenger in 1994. Starting from the first-order elastic wave equation of transversely isotropic (VT I) medium, The high-order finite difference scheme of staggered grid space is derived and the staggered-grid high-order finite difference scheme suitable for the PM L absorption boundary conditions and boundaries is derived. The calculated results show that PM L absorption boundary conditions can completely absorb the traveling wave field.