3D Multi-Valued Traveltime and Amplitude Maps

Abstract

Ray theorectic modeling with stable and accurate amplitude requires a velocity model that has a continuous first derviative. After studying alternatives, we concluded that a standard smoothed physical model on a Cartesian grid is likely to lead to a computer code of competitive CPU speed, when amplitude accuracy is of as much concern as traveltime accuracy. We use a wave front construction technique, in which the size of triangular plates connecting three nearby rays on the isochron (surface of constant traveltime) are used as an indicator of adequate density of rays. When the criteria for density of rays are violated, data at new points on the wave front are interpolated into the family of rays and the wavefront construction continues. In this manner, the method does not require excessing density of rays at small traveltimes in order to maintain adequate density of rays at larger traveltimes. The technique allows for multi pathing (caustics) and for amplitude propagation along each of the branches of the wavefront.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1998
Accession Number
ADA342605

Entities

People

  • Lan Wang
  • Norman Bleistein

Organizations

  • Colorado School of Mines

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Abstracts
  • Accuracy
  • Algorithms
  • Amplitude
  • Cartesian Coordinates
  • Computations
  • Coordinate Systems
  • Elastic Waves
  • Equations
  • Grids
  • Integral Equations
  • Phase Shift
  • Ray Tracing
  • Three Dimensional
  • Wave Phenomena
  • Wavefronts
  • Waves

Fields of Study

  • Physics

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Wave Propagation and Nonlinear Chaotic Dynamics.