DTIC ADA516178: Infrasound Signals from Ground Motion pdf

DTIC ADA516178: Infrasound Signals from Ground Motion

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Description of the Book:

This report presents progress on an ongoing research project looking at near-field infrasound signals as a basis for discriminants between underground nuclear tests (UGT) and earthquakes (EQ). In an earlier program, infrasound signals from UGTs and EQs were collected at ranges of a few hundred kilometers, in the far-field. Analysis of these data revealed two parameters that had potential for discrimination purposes: signal duration and wind-corrected amplitudes. These far-field differences should be present in the near-field signals as well. To study the near-field signals, we are using computational techniques based on modeled ground motions from UGTs and EQs. One is the closed form numerical integration of the Rayleigh integral (RI), and the other is the application of a time-domain, finite-difference computational fluid dynamics (CFD) program, CAVEAT. This report summarizes recent progress in modeling these signals, showing comparisons of waveforms and power spectra from the two techniques. There is also a discussion of the effects of spatial and temporal zoning on the quality of the results.

Application of Fourier techniques to the basic ground models is introduced as an analytic path to the radiation patterns of the ground-motion sources

• Creator/s: Defense Technical Information Center
• Date: 9/1/2008
• Year: 2008
• Book Topics/Themes: DTIC Archive, , LOS ALAMOS NATIONAL LAB ALBUQUERQUE NM, *RADIATION PATTERNS, *COMPUTATIONAL FLUID DYNAMICS, *INFRASOUND, *GROUND MOTION, *UNDERGROUND EXPLOSIONS, EARTHQUAKES, AMPLITUDE, NEAR FIELD, FOURIER ANALYSIS, NUMERICAL INTEGRATION, FINITE DIFFERENCE THEORY, NUCLEAR EXPLOSION TESTING, POWER SPECTRA, SYMPOSIA, MODELS

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