IMS NetworkIDC Processing

1
Summary of 2003 Infrasound Technology Workshop
Session Chairs
2
IMS Network/IDC Processing

• Rapid growth of IMS network 23 transmitting, 13
  certified, 12 under construction
• IDC Testbed 16 current
• IDC Operations 11 current
• Infrasound temporarily out of SHI data fusion
  process
• High number of detections
• Large scale automatic processing in November 2003
• Progress in modeling network performance
  incorporation of seasonal variance

3
New Developments

• Experimentation with new array configurations
• Noise filtering at extreme wind (gt 40m/s)
• Monitoring of volcanic eruptions and hurricanes
• Improved characterization of specific heat ratio
  of the atmosphere up to heights of 160 km
• Improvement of ANSII standard for attenuation
  coefficient at low frequencies and high altitudes

4
New Developments

• GINA prototype is available to infrasound
  community
• InfraMatics, AGU and AGU monograph
• Progress in IIC Collaborations are invited

5
Sources

• Discrimination between stationary and moving
  sources
• Studies of bolides, eruptions, MAW, aurora,
  microbaroms, earthquakes, ice avalanches, surf,
  man-made signals
• More work needed in detection, characterization,
  far and near-field location

6
Modeling

• Propagation modeling of signals from Columbia and
  explosions
• Source modeling of microbaroms
• Improvements in location and full wave modeling
  of infrasonic signals
• Time-domain PE (broadband modeling)
• Direct time-domain solutions of the wave equation
• Use of improved atmospheric estimates
• Need for implementation of improved absorption
  models

7
Processing

• Impact of noise levels on detection rate
• Importance of using more accurate atmospheric
  models for source localization
• Automatic associations, detection statistics,
  clutter rejection
• Data sets assembled for ROC curve analysis
• Studies of the relationship between array
  configuration/location and performance of
  detection and estimation algorithms
• Correlation detectors effective and robust

8
Processing

• 4D location of atmospheric explosions using
  ground observations of acoustic waves.
• GT data key to progress in location and
  characterization.
• PMCC love fest
• Deals well with different array geometries
• Must be optimized to find particular signal
  features

9
Noise Reduction

• Light-speed filters have obvious advantages over
  sound-speed filters but further
  research/engineering improvements required

10
Conclusions

• Continue to probe at basic, difficult but key,
  aspects of acoustic source phenomenology,
  propagation, modeling and reception
• Data processing must continue to advance rapidly
  to deal with mushrooming data volume
• Research community continues to make great
  progress in array design
• Essential that these results are used to optimize
  existing or new IMS stations