Presentation is loading. Please wait.

Presentation is loading. Please wait.

Infrasound Workshop De Bilt, Netherlands 28-31 October 2002 Current Status of Infrasound Processing at the IDC Nicolas Brachet International Data Centre/Waveform.

Similar presentations


Presentation on theme: "Infrasound Workshop De Bilt, Netherlands 28-31 October 2002 Current Status of Infrasound Processing at the IDC Nicolas Brachet International Data Centre/Waveform."— Presentation transcript:

1 Infrasound Workshop De Bilt, Netherlands 28-31 October 2002 Current Status of Infrasound Processing at the IDC Nicolas Brachet 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: Nicolas.Brachet@ctbto.org

2 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 2 Outline of the talk Objective Understand and characterize the infrasound signals, assess the capabilities and limitations of the current software Long term: Station tuning, Propose design of enhanced IDC software Monitoring of the automatic system Develop basic tools that monitors (daily) the performance of the system eg. Weekly detection bulletin, Detection polar diagram, Event maps Support from interactive review (waveforms/detections) Install WinPMCC Cooperative work with IDC analysts Contract with DASE for reference event database

3 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 3 Weekly detection bulletins Weekly bulletins provide an overview of the detection time/azimuth/frequency for each infrasound station over long time period Station characteristics and monitoring Detection capability at each infrasound stations Highlight repetitive phenomena Show long duration meteorological phenomena (microbaroms, storms) Inform about detections associated in the automatic event bulletin Comparison of results from different detection processing DFX-libinfra vs DFX-PMCC Operations vs Testbed

4 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 4 Weekly detection bulletins long duration detection low frequency (microbaroms in North Sea) DFX-PMCC detections at I26DE Isolated detection high frequency Detection associated in SEL3 Station characteristics and monitoring

5 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 5 DFX-libinfra Comparison of automatic detection bulletins (I07AU) Seismic wave earthquake New Guinea Microbaroms Indian Ocean Microbaroms Pacific Ocean Local mine Az330 DFX-PMCC Weekly detection bulletins

6 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 6 Detections over long time period (I07AU example ) Local mine az=330deg (4sep2002) DFX-PMCC (Jun2002-Oct2002) DFX-Libinfra (Dec2001-Oct2002)

7 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 7 Detections: High level statistics Automatic detections: Station and period dependency Automatic detections: Processing dependency DFX-PMCC testing configuration software update Operations vs Testbed PMCC vs libinfra

8 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 8 Abundance of detections: attempt for categorization Detections: detailed review (I59US example) Surf noise (az 295 & 325deg) microbaroms (az 360deg)

9 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 9 Comparison of detection bulletins at I59US DFX-PMCC DFX-libinfra Detections: detailed review (I59US example)

10 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 10 Future design of the IDC software Instability of the libinfra detections

11 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 11 - Very different list of detections produced by DFX-libinfra and DFX-PMCC - Most frequencies of libinfra detections are centered around 0.31Hz - DFX-PMCC shows stable results for microbaroms and surf noise - Libinfra does not detect HF signals (incl. Surf noise) - Detections generate bogus associations with other IMS stations Detections: detailed review (I59US example)

12 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 12 Comparison of two software results: large differences DFX-PMCC DFX-libinfra Detections: detailed review (I10CA example)

13 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 13 - Very different list of detections produced by DFX-libinfra and DFX-PMCC - Libinfra strongly affected by wind conditions: large sequences of detections pointing to very different azimuths - Noise detections generate bogus associations with other IMS stations - Most frequencies of libinfra detections are centered around 0.3Hz (3 bands used) 30/0901/1002/1003/1004/1005/1006/10 Wind Channels Detections: detailed review (I10CA example)

14 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 14 Low velocity (v<300m/s) for 60% of the libinfra detections Detections: detailed review (I10CA example) Excluding v<300m/s Current status DFX-PMCC DFX-libinfra Waveforms (0.4-2.5Hz) Quarry blast

15 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 15 Bogus association of automatic detections Automatic associations of detections Detection in SEL3 event Sea of Japan (mb=3.4) MJAR (Pg) dist 6.2 deg I34MN (I) dist 20 deg ASAR (P) dist 64 deg I34MN DFX-PMCC DFX-libinfra 7Jul 2002

16 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 16 Purely infra eventsSHI events 1 2 34 5 6 7 8 9 10 11 12 I07AU+H I07AU+S I33MG+H I08BO+H I57US+I59US I59US+S I57US+S I26DE+SI10CA+I59US I34MN+H 1 2 I59US+H 3 4 5 I10CA+I26DE 6 7 8 9 10 11 12 13 Automatic associations of detections

17 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 17 REB event: Indonesia earthquake 10oct2002 mb=5.7, Ms=7.3, distance to I07AU=18deg P S I Lg,LR

18 Infrasound Workshop in De Bilt, Netherlands 28-31 October 2002 Page 18 Summary Running two detectors in parallel with support of interactive tools Results presented in a 3D weekly bulletin Station characteristics: work just started, to be continued... Visual comparison of the detection processing: Necessity and complexity of tuning the infrasound detector Problems of the automatic association of detections DFX-PMCC Higher detection rate Large variety of events detected Better stability of the detection attributes Fine frequency resolution (12 bands used) Seismic waves hardly detected (known problem corrected in WinPMCC) DFX-libinfra Lower detection rate Local HF signals often missed Frequent instability of the detection attributes Limited frequency resolution (3 bands used) Low velocity detections polluting the bulletin


Download ppt "Infrasound Workshop De Bilt, Netherlands 28-31 October 2002 Current Status of Infrasound Processing at the IDC Nicolas Brachet International Data Centre/Waveform."

Similar presentations


Ads by Google