Large-Scale Computation for Seismic Applications

该研究项目致力于发展用于求解声波和弹性波方程的改进技术。这项工作在地震勘探、无损检测、声纳解释等领域都有应用。目前的目标是改进所谓正问题的数值方法，在正问题中，假设初始边界数据和材料性质是已知的。然而，这项研究的最终目标是以迭代的方式使用精确的正演解算器来攻击反问题，在反问题中，人们寻求对给定介质对地震波的观测响应的材料属性(波速)的估计。该项目代表了怀俄明州早期研究的延续，在该研究中，开发了用于求解三维空间中的声波和弹性波方程的代码。该项目涉及几种数值方法。其中包括具有不同波速的地层之间界面的表示，在高度非均匀介质中产生精确离散的空间网格的构建，有效时间步进格式和相关数值线性代数的设计，以及数值程序对并行和向量建筑机器的适应。该项目的另一个重要内容是继续开发面向对象的图形软件，以协助显示大型模型结果。

This research project focuses on the development of improved techniques for solving the acoustic and elastic wave equations. The work has applications to seismic exploration, nondestructive testing, sonar interpretation, and other fields. The immediate aim is to enhance numerical methods for the so-called forward problem, in which initial-boundary data and material properties are assumed known. However, the research has the ultimate objective of using accurate forward solvers in an iterative fashion to attack the inverse problem, in which one seeks estimates of material properties (wave velocities) given observed responses of the medium to seismic waves. The project represents a continuation of earlier research at Wyoming, in which codes were developed for solving the acoustic and elastic wave equations in three space dimensions. The project addresses several numerical approaches. Among these are the representation of interfaces between strata having different wave velocities, the construction of spatial grids that will yield accurate discretizations in highly heterogeneous media, the design of efficient time-stepping schemes and associated numerical linear algebra, and the adaptation of numerical procedures to parallel- and vector architecture machines. Another important element of the project is the continued development of object-oriented graphics software to aid in the visualization of large-scale model results.