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Systems Check

Systems Check. IMPLEMENTATION OF INFRASONIC DETECTION ALGORITHMS AT I59US. Milton Garces and Claus Hetzer Infrasound Laboratory, University of Hawaii, Manoa Alexis Le Pichon Commissariat à l’Energie Atomique. 2002 Infrasound Technology Workshop, Netherlands. Outline.

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Systems Check

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  1. Systems Check

  2. IMPLEMENTATION OF INFRASONIC DETECTION ALGORITHMS AT I59US Milton Garces and Claus Hetzer Infrasound Laboratory, University of Hawaii, Manoa Alexis Le Pichon Commissariat à l’Energie Atomique 2002 Infrasound Technology Workshop, Netherlands

  3. Outline • Detection methods evaluated at IS59 • Event identification and characterization I59US

  4. Evaluation Period: STA/LTA and Infratool • STA/LTA for high frequencies • Infratool for emergent events • Problem with high-frequency, low S/N emergent arrivals • Problems with aliasing

  5. Hand Picked and Post-processing: STA/LTA and Infratool • Analyst-picked events from June 2000 to October 23, 2001: Matsound • Total arrivals: 1487 • its: 8 • ia: 206 • ik: 547 • iws: 344 • im: 242 • iep: 20 • iw: 120

  6. PMCC: Consistency Consistency is based on closure relationship for plane waves arriving on elements i,j,k: Dtij+Dtjk+Dtki = 0 • Define consistency threshold • Can also define correlation filter • Select different frequency bands • Provides detailed frequency information • Can add F-stat for further screening April 23, 2001

  7. Infratool: April 23 0.5-4 Hz

  8. Infratool 0.1-1 Hz 1- 4 Hz

  9. Infratooland PMCC 1- 4 Hz

  10. Automatic processing at IS59: Testing • Automatic detections using PMCC, Jan 1-Feb 25, 2002 • Max consistency for 0.5-4 Hz: 0.2 • Max consistency for im (0.1-0.5 Hz): 0.5

  11. Automatic processing at IS59: Testing • January 1 – February 25, 2002 • Number of arrivals: 7072 • ia: 0 -- No provision for ia in azimuth filtering • ik: 641 • iws: 934 • im: 4123 • iep: 1 -- Set by analyst review • its: 0 • iw: 434 -- Before 'iu' began to be used • iv: 9 • ip: 179 • in: 1 -- Set by analyst review • iu: 750

  12. Automatic processing at IS59: Operations

  13. Automatic processing at IS59: HF • Automatic detections using PMCC, Jan 1-October 24, 2002 • Max consistency for 0.5-4 Hz: 0.2 s • Units on radar plot are slowness, 0-400 sec/deg ip: 3161 - Pass between Hualalai and Mauna Loa iu: 9505 - Unknown ik: 26368 - Surf iws: 16829 - Surf iv: 1025 - Mauna Loa and Kilauea Total: 56888 automatic picks

  14. Automatic processing at IS59Microbaroms • 14415 arrivals, Jan 1-Oct 24 • Max consistency for im (0.1-0.5 Hz): 0.5 s

  15. Automatic processing at IS59: HS • 692 arrivals, May 30-Oct 24 • Max consistency for hs (0.5-4 Hz): 0.2 s • Units on radar plot are slowness, 0-300 sec/deg • Aircraft • Small bolides • Seismic coupling from local earthquakes • Chaparral 5 less sensitive to microphonics than MB2000 • C5: M~2.7 • MB2000: M~2.1 (2 weeks sampling)

  16. Automatic processing at IS59: VLF • 8907 arrivals, Jun 18-Oct 24 • Max consistency for vlf (0.033-0.1 Hz): 5 s • Mountain waves • Severe weather

  17. VLF: Turbulence and Atmospheric Waves • Clear air turbulence monitoring • Lower, middle and upper atmosphere dynamics

  18. VLF: Atmospheric Waves • Untapped potential for applications

  19. HS: 2001 Leonid Bolide • Diameter of ~10cm • Max Kinetic Energy of ~109 J, or yield equivalent of 1/4 ton of TNT • Travel time of ~220s • Source height of ~50 km

  20. HS: 2001 Leonid Bolide • Adjust for topography of array • Slowness of 2.1 s/km (speed correction of 20 m/s) • Azimuth of 155 degrees (3 degree correction) • Used travel time of ~220 s

  21. Its: Bolides • Large bolide impacts in the Pacific, away from population centers April 23, 2001

  22. Im: Severe Weather • Microbaroms: storm tracking with infrasound Microbaroms and surf (800x)

  23. Im: Severe Weather Polar diagram showing arrival azimuth, trace slowness, and median frequency of microbarom events detected from January 1-October 24, 2002. Radial units are seconds per degree, increments of 100.

  24. Ik, Iws: Littoral Processes • Coastal surf activity Kualanui 100X

  25. Ik, Iws: Littoral Processes

  26. Ik, Iws: Littoral Processes • Surf statistics at IS59:

  27. Lightning (Thunder) 400x

  28. Thunder: Time Progression and VLF

  29. Multiple Sources: High NW Swell (Ironman Day) Thunder? Blasting Surf

  30. Fireworks

  31. Iv: Volcanoes • Mauna Loa is inflating • Ongoing activity from Kilauea is effusive IS59: Kilauea, Mauna Loa, and Hualalai

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