1. November 2008Infrasound Technology Workshop, BermudaPage 1 Presented to: Infrasound Technology Workshop Bermuda PTS Portable Infrasound Array John Coyne, Nicolas Brachet, David Brown, Pierrick Mialle, Patrick Grenard, Paola Campus, Pavel Martysevich, Stefka Stefanova, Alfred Kramer, Ekrem Demirovic International Data Centre Division International Monitoring System Division Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization Provisional Technical Secretariat Vienna International Centre P.O. Box 1200 A-1400 Vienna Austria E-mail: John.Coyne@ctbto.org

2. Infrasound Technology Workshop, Bermuda November 2008 Page 2 Outline Introduction Equipment Progress Status Future Activities

3. Infrasound Technology Workshop, Bermuda November 2008 Page 3 Introduction Recognizing the direct relationship between optimizing measurement systems and data analysis techniques, the PTS is implementing a cross-divisional project for developing and deploying a portable infrasound array High Level Objective: to improve the contribution of infrasound detections at IMS stations into the Reviewed Event Bulletin (REB) For example: Deployment to improve the understanding of local and regional sources of infrasound Participate in field exercises with controlled sources to collect ground truth data and improve modeling of acoustic propagation Evaluate the impact of station configurations on data processing Evaluate the positioning of an IMS station which is influenced by known infrasound sources

4. Infrasound Technology Workshop, Bermuda November 2008 Page 4 Experimental Array: Equipment Geometry Equipment to meet IMS specifications Each of the 4 sites consists of: Microbarometer Digitizer with storage (> 3 months) Power supply (batteries and solar panels) Wind reduction system Met data recorded at the central element One set of spare equipment Geometry of 4-element infrasound array

5. Infrasound Technology Workshop, Bermuda November 2008 Page 5 Experimental Array: Equipment Housing Figure showing the organization of the electronic equipment in the plastic box and their connection to the external devices

6. Infrasound Technology Workshop, Bermuda November 2008 Page 6 Experimental Array: Wind Reduction System Rosette filter configuration Six porous hoses Each hose 15 metres long

7. Infrasound Technology Workshop, Bermuda November 2008 Page 7 Experimental Array: Equipment List

8. Infrasound Technology Workshop, Bermuda November 2008 Page 8 Experimental Array: Equipment in Vienna Met StationEquipment Box GPS

9. Infrasound Technology Workshop, Bermuda November 2008 Page 9 Experimental Array: Equipment with model

10. Infrasound Technology Workshop, Bermuda November 2008 Page 10 Experimental Array: Equipment Housing

11. Infrasound Technology Workshop, Bermuda November 2008 Page 11 Experimental Array: Wind Reduction System

12. Infrasound Technology Workshop, Bermuda November 2008 Page 12 Testing in Vienna, October 2008 Alarm system test Signal polarity test Digitizer self-noise test GPS time synchronization test (disable the antenna) Power supply test System noise test (microbarometer plugged) Array element reset test (power off/on)

13. Infrasound Technology Workshop, Bermuda November 2008 Page 13 Initial Deployment anticipated in Chile Purpose Improve understanding of local and regional sources Evaluate positioning of the array near active volcanoes Context Several potentially active volcanoes in the region Exchange of letters ongoing Site selection ongoing (following slides)

14. Infrasound Technology Workshop, Bermuda November 2008 Page 14 Initial Deployment anticipated in Chile Potential deployment area identified based on relative location of potential sources (towns and volcanoes) Different sources should be at different azimuths from the array I40PG is planned to be 25 km from an active volcano

15. Infrasound Technology Workshop, Bermuda November 2008 Page 15 Regional Context Chile Argentina PLCA I01AR 105 km Potential Deployment Area

16. Infrasound Technology Workshop, Bermuda November 2008 Page 16 Initial Deployment: Planned for Chile Argentina Chile Llama Villarrica Nearby towns 53 km

17. Infrasound Technology Workshop, Bermuda November 2008 Page 17 Volcanic eruption earlier this year in Chile

18. Infrasound Technology Workshop, Bermuda November 2008 Page 18 Field deployments Deployments are not just a matter of taking a trip with some equipment and beginning measurements Many factors are needed for a successful campaign: Sufficient planning Proper site selection Logistic issues Equipment import issues Security Success also depends on dedication, effort and support from all parties involved

19. Infrasound Technology Workshop, Bermuda November 2008 Page 19 Summary A sound understanding of infrasound sources is essential for interpreting infrasound signals Many genuine signals of unknown origin are routinely observed at IMS infrasound station The experimental array is expected to assist in understanding and categorizing infrasound signals. Also assess impact of station configurations on data processing Equipment has been procured, and first experiment should take place in early 2009 First results should be presented at the next Infrasound Workshop Interested parties should contact us concerning future collaboration