Infrasound Workshop De Bilt, Netherlands 28-31 October 2002

1. Infrasound WorkshopDe Bilt, Netherlands28-31 October 2002 Infrasound Processing at the IDC and its Near-term Development Petr Firbas International Data Centre/Waveform Integration 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: Petr.Firbas@ctbto.org

2. Outline of the talk • Overview of infrasound Processing at the IDC • Automatic data processing in Operations an testbed • Development and testing at the IDC • WinPMCC testing • Infrasound contracts • IDC infrasound reference database • Weekly detection bulletins • Strategy to be discussed • Bulletin issues • Future design of the IDC software Infrasound Workshop in De Bilt, Netherlands

3. Status of infrasound processing at the IDC • Basic Processing steps at the IDC • Data acquisition and forwarding • Signal processing (DFX) • Phase identification (StaPro) • Network processing (GA, EvLoc) for SHI data • Interactive processing (ARS) • Post processing (incl. event screening) • Product distribution (subscriptions, AutoDRM, WEB) • Archiving Infrasound Workshop in De Bilt, Netherlands

4. Radionuclide Infra- sound Hydro- acoustic Auxiliary Seismic Seismic Analyst Review Analyst Review Automatic Standard Event List 1 Automatic Standard Event List 2 Automatic Standard Event List 3 Status of infrasound processing at the IDC Inputs: Raw Data (archived and accessible as soon as it arrives) Automatic Fission Product Screening Conceptual FEB and ES production Automatic SHI Event Screening Outputs: Fused Event Bulletin & Executive Summaries (daily) Automatic Radnuc. Report Reviewed Atm. Radnuc. Meas. Report Fission Product Event Bulletin Reviewed & Standard Event Bulletins Automatic Standard Screened Event Bulletin 6 hrs 12 hrs 2 hrs <10 days Time after Event Occurrence Infrasound Workshop in De Bilt, Netherlands

5. Infrasound stations processed at the IDC as of October 2002 2-Apr-2001 (tbd) 11-Oct-2001 (ops) 19-Aug-2001 (tbd) 25-Nov-2001 (ops) 1-Sep-2001 (tbd) 15-Oct-2001 (ops) 29-Jul-2002 (tbd) 18-Jan-2002 (tbd) 4-Mar-2002 (ops) 5-Sep-2002 (tbd) 27-Sep-2001 (tbd) 2-Dec-2001 (ops) 3-Dec-2001 (tbd) 16-Aug-2002 (tbd) Infrasound Workshop in De Bilt, Netherlands

6. Automatic Data Processing Number of SEL3 events with infrasound arrivals idc3.0.58 idc3.0.62 I24 I08 I57 I59 I26, I10 I07, I10 I33 I59 I34 I07 I26 I34 Infrasound Workshop in De Bilt, Netherlands

7. Automatic Data Processing Type of phases contributing to infrasound automatic events I07AU, I33MG, I08BO Infrasound Workshop in De Bilt, Netherlands

8. Purely infra events Purely infra events SHI events SHI events IDC TESTBED IDC TESTBED SEL3 infrasound events 9 infrasound arrays 587 events between Oct2001 and Oct2002 Comparison of Automatic Ops/Testbed Processing IDC OPERATIONS SEL3 infrasound events 5 infrasound arrays 341 events between Oct2001 and Oct2002 Infrasound Workshop in De Bilt, Netherlands

9. Development and testing at the IDC • Objective • Understand the infrasound signals, assess the capabilities and limitations of the current software, propose design of enhanced IDC software. • Automatic processing • Station monitoring • Data quality check, Detection & event statistics, Problem report • Activation of DFX-PMCC in test mode for detection comparison • Software assessment and update • R3 patches, Bug reports, Parameter configuration changes, Designing software enhancements • Interactive processing • Install WinPMCC on testbed for interactive review of the infrasound signals Infrasound Workshop in De Bilt, Netherlands

10. Development and testing at the IDC • Objective (cont.) • Knowledge build-up • Create benchmarks for detection and event processing tuning • Build a catalogue of reference event database for the IDC analysts • (on contractual basis; voluntary contributions are welcome) • Training (internal/external) of IDC analysts (who actively participate in station data evaluation and software testing) • Gain experience in multi-technology processing Infrasound Workshop in De Bilt, Netherlands

11. WinPMCC testing • Objective • Install and assess a new tool for interactive infrasound analysis: WinPMCC • Familiarize with new techniques of signal analysis (correlation, 3D display) • Review and identify relevant infrasound signals at IMS stations • Timeline • Phase1: Apr 2001 - Jun 2002: Adapt WinPMCC to IDC environment • Cooperative work between DASE (France) and IDC • Several versions of WinPMCC delivered, installed and tested at the IDC • First assessment of WinPMCC (incl. IDC infrasound reference events) • Installation of WinPMCC on IDC testbed • Phase2:Jul - Aug 2002: WinPMCC testing by IDC analysts • Joint exercise between IDC Sections (Monitoring and Waveform Development) • Several days of continuous data reviewed in detail for 4 IMS infrasound arrays • (I0AU, I10CA, I26DE, I34MN) • Special event analysis (e.g. Canadian bolide, typhoon Japanese coast) Infrasound Workshop in De Bilt, Netherlands

12. WinPMCC testing • Achievements • Adapted and installed a new interactive tool running on IDC testbed • Positive experience of the IDC analysts using WinPMCC • Increased interest for Infrasonic method • Provided a list of recommendations for software design and enhancements • Opened new perspectives for interactive/automatic infra data processing • Demonstrated the efficiency of the cross-correlation/consistency algorithm • Introduced 3-Dimension representation- found very valuable • Conclusions • WinPMCC is an innovative powerful tool for interactive analysis of infrasound events • WinPMCC helps reviewing automatic detections and facilitates tuning the • automatic processing Infrasound Workshop in De Bilt, Netherlands

13. Infrasound contracts in 2002 • RFP submitted by IDC for year 2002 • TOR task 2:Collection of reference events and noise • Collection of infrasonic reference event data and noise generated by a wide variety of natural and artificial sources from different regions of the world, preferably recorded using modern instrumentation similar to that used at the IMS stations, including the relevant meta-data and along with results of expert analysis. • TOR task 4:Automatic and interactive processing • Automatic and/or interactive processing of selected continuous I data (from IMS stations) provided by the IDC. • TOR task 6:Automatic and interactive processing • Collection of information on signal propagation effects (travel-time, attenuation and dominant signal frequency as a function of range, azimuth, phase type, source position and receiver position, including upper atmospheric winds and temperature structure, multipathing, multiple surface reflections, season (month) of the year and time of the day, etc.) of I waves recorded at the IMS stations; Assessment and/or validation of I wave propagation models and/or travel-times used at the IDC and proposals for their improvement; prototype software for long-distance signal propagation modelling. Infrasound Workshop in De Bilt, Netherlands

14. Infrasound contracts in 2002 • RFP submitted by IDC for year 2002 (cont.) • TOR task 8:Travel-time tables • Generation of seasonally (monthly), or if essential, diurnally varying and azimuth and range dependent travel-time tables for IMS I stations and relevant algorithms/software. • TOR task 9:Synergy between SHI data • Collection of reference events which demonstrate possible synergies (location accuracy, source type identification, etc.) between H, I and S data • TOR task 10:Training of IDC staff • Training of IDC staff on I data processing by experienced I experts Infrasound Workshop in De Bilt, Netherlands

15. Infrasound contracts in 2002 - Status • Contract signed with DASE (France) • Delivered • Delivery of semi-annual reports for task 2 and task 4 (July 2002) • Details on ~100 events analysed on 3 infra stations (I24FR, I25FR, Flers) • Comprehensive analysis of two days of bulletin at I34MN and I33MG • CSS Waveforms and results provided • Expected soon… • Annual report on task 9 • Training for IDC staff (task 10) • Contract signed with ANU (Australia), task 4 • Develop an advanced infrasound signal processing method using • 3D slowness-space correlator • basic pattern recognition system for detecting regions of consistent azimuth • Noise field characterisation • Automatic and interactive processing of selected continuous infrasound data • (I07AU, I10CA, I26DE, I33MG, I34MN, I59US) Infrasound Workshop in De Bilt, Netherlands

16. Infrasound contracts in 2002 - Status • Contract signed with University of Alaska Fairbanks, task2 • Collect reference events at Fairbanks and Windless Bight • Project just started • Other contracts awaiting to be signed Infrasound Workshop in De Bilt, Netherlands

17. IDC infrasound reference event database • Objective • Collection of infrasonic reference event data and noise generated by • a wide variety of natural and artificial sources from different regions • of the world, preferably recorded using modern instrumentation similar • to that used at the IMS stations, including the relevant meta-data and • along with results of expert analysis (TOR, task2). • Knowledge database for IDC analysts cataloguing • Infrasound signals of interest • Station characteristics • Build a detection and event benchmark for testing infrasound software • Timeline • Started in 2001, ongoing • Participants • Cooperative work between IDC Sections (Monitoring and Waveform Development) • On contractual basis; voluntary contributions are welcome Infrasound Workshop in De Bilt, Netherlands

18. IDC infrasound reference event database • Achievements • Collection of infrasound events of special interest (around 20) • Mine, hurricane, bolide and meteorite, earthquake, missile test, volcano, thunderstorm, surf noise • Known events detected (positive information) • Known events not detected (negative information) • Initial evaluation of the delivery from DASE contract • Future plans • Continue the special event analysis (targets of opportunity) • Store reference events provided by DASE and other future contractors in the reference database along with meta-data • Utilize common IDC database structure being developed for IDC calibration program Infrasound Workshop in De Bilt, Netherlands

19. Weekly detection bulletins • Weekly detection bulletins • are produced for all infrasound arrays • are updated automatically on a daily basis • display DFX-libinfra & DFX-PMCC results • display detections associated to SEL3 events Detections at I07AU (DFX-PMCC) Infrasound Workshop in De Bilt, Netherlands

20. Association issues - Strategy to be discussed • What should be the event definition at the IDC? • Type of events to be detected and to be reported in the IDC bulletins? • Long duration phenomena: microbaroms, volcano eruptions, surf noise ... • High frequency short duration: quarry blasts, military exercise… • Seismic phases from shallow earthquakes • Tag long-duration detections to limit their impact on network processing? Infrasound Workshop in De Bilt, Netherlands

21. DFX/S DFX/S GA/SHI GA/SH DFX/H DFX/H GA/SHI DFX/I DFX/I GA/I Alternative solution Current status Association issues - Strategy to be discussed • Should IDC process infrasound differently from S & H technologies? • Generate station detection bulletins • Only 2 REB events (1 mine, 1 earthquake) contain infrasound arrival in 1 year of IDC processing! • Increase of automatic SEL3 events with the number of IMS stations may cause problems in the future • Should IDC process infrasound independently from S & H technologies? • Separate infrasound pipeline from the other technologies, and merge SHI bulletin at a later stage? Infrasound Workshop in De Bilt, Netherlands

22. Azimuth Speed Future design of the IDC software 3D representation of infrasound information Infrasound Workshop in De Bilt, Netherlands