Overview of the InfraMAP Tool Kit and Related Propagation Modeling Technologies

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• Overview of the InfraMAP Tool Kit and Related
  Propagation Modeling Technologies
•  
• Robert Gibson and David Norris
• BBN Technologies
• Arlington, VA
• 2nd NSF Infrasound Workshop, Stevenson WA
• 8 June 2005

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Agenda

• InfraMAP Tool Kit
• Recent Propagation Modeling Developments
• Example studies

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InfraMAP Overview

• InfraMAP - Infrasonic Modeling of Atmospheric
  Propagation
• Designed for researchers and analysts active in
  the infrasound community
• Supports infrasonic-relevant RD and can be
  applied to specific source mechanisms and
  propagation paths of interest
• InfraMAP is a software toolkit
• menu interface built with MATLAB GUIs
• link to FORTRAN and C program executables
• integrates propagation and environmental models
  to perform infrasound studies
• BBN is continuing to enhance the capabilities of
  InfraMAP and are experts at applying it to the
  study of complex infrasonic problems

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Environmental Analysis

• Empirical characterizations are built-in
• Near-real-time characterizations can be imported
• View Environment functions via GUI
• Seamless integration with propagation models

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Propagation Analysis
3-D Ray Tracing
Normal Modes
Parabolic Equation
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Variability Analysis
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Localization Analysis
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Time-Domain PE

• Waveform prediction capability
• Accounts for refraction and diffraction
• Examples of TDPE model output shown

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TPDE waveform predictions for bolide

• Time-domain Parabolic Equation (TDPE) model
  (broadband, complex boundary conditions,
  range-dependent environment)
• Bolide over El Paso, TX, USA, observed 09 Oct
  1997 at TXIAR station 359 km away
• Source height estimated to be 29 km
• TDPE broadband prediction, 0 2 Hz.
• 3 dominant arrivals predicted. Mismatch for
  early and late arrival

Observation
TDPE Prediction over all receiver heights
TDPE Prediction at ground
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Infrasound Propagation Modeling using
Near-Real-Time Environmental Updates

• InfraMAP can import near-real-time atmospheric
  characterizations for use with propagation models
• NRL-G2S semi-empirical specification
• Global spectral representation
• NOGAPS numerical weather prediction model
• To 35 km, merged with climatology above
• Mesoscale characterizations, e.g., COAMPS, will
  be integrated
• Figures below show zonal winds (0-50 km) over a
  path from Cape Kennedy, FL to I10CA
• Fine-scale structure in near-real-time grids

Mesoscale Atmospheric Characterization COAMPS
Climatology
NOGAPS
NRL-G2S
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Etna Eruption

• Explosive eruption 2001-July-29
• 0600 GMT
• Observed at Deelen, NL and elsewhere in Europe
• Ground truth from Deelen
• 1750 km
• 152.4 degrees

• Observed azimuth of arrival
• 156 degrees
• 3.6 degrees of azimuth deviation
• Data analysis by L. Evers (KNMI)
• Predicted azimuth using InfraMAP
• 156.4 degrees
• Thermospheric paths
• Using empirical atmospheric models

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Observations of Space Shuttle Launches
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Space Shuttle Columbia Disaster Analysis

• Conducted for DoD, to assist NASA investigation.

Trajectory - (white) Arrays - (red)
CPAs - (yellow)
Good agreement between data (?s) and models
Example Results for Pinon Flat, CA Array
Azimuth (deg)
Time (GMT)
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InfraMAP Objectives

• Integrate the software tools needed to perform
  infrasound propagation modeling.
• Define the state of the atmosphere (temperature,
  wind) as required for input to propagation
  models.
• Predict phases (travel times, bearings,
  amplitudes) from atmospheric explosions as
  measured by infrasound sensors.
• Apply tools to support nuclear explosion
  monitoring RD and resolve operational issues
• environmental variability and propagation
  sensitivity
• prediction of localization area of uncertainty
  and detection performance
• performance model of an infrasound network
• Interfaces, models and algorithms are readily
  applicable to scientific investigations.