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Seismic Data Management at the Canadian National Data Centre

Seismic Data Management at the Canadian National Data Centre. Jim Lyons Geological Survey of Canada. Outline. Evolution of the National Seismic Network POLARIS (cooperating network) CNDC processing Waveform archive Data dissemination Ongoing challenges. Evolution of the CNSN - 1.

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Seismic Data Management at the Canadian National Data Centre

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  1. Seismic Data Management at the Canadian National Data Centre Jim Lyons Geological Survey of Canada

  2. Outline • Evolution of the National Seismic Network • POLARIS (cooperating network) • CNDC processing • Waveform archive • Data dissemination • Ongoing challenges

  3. Evolution of the CNSN - 1 1st Digital Data: regional seismograph networks: • operated Eastern Canada Telemetred Network (ECTN) and WCTN (in southwest BC), from 1975  1995 • only “event files” comprising triggered stations with fixed pre- and post-trigger header/trailer were kept for computer-based analysis &archive

  4. Evolution of the CNSN - 2 1st archive of continuous data: Yellowknife Array Upgrade 1988-9 • archived on 12" SONY WORM optical disks • data stored as 10-minute Full SEED volumes

  5. Evolution of the CNSN - 3 CNSN Upgrade • Rollout started in 1992, based on new in-house digitizer (GD-1)  CNSN packet structure, data compression scheme and serial transmission protocol

  6. Evolution of the CNSN - 4 CNSN Upgrade • we reverted from SEED to a simple file format “Canadian Archive” (CA)  ½ hour network volumes based on a contiguous array of CNSN data packets with short header • maintains full original data integrity including checksum, SOH and error/status codes • excellent compression (subsequently adopted by CTBTO for data payload in CD-1.x format)

  7. Evolution of the CNSN - 5 YKA revisited • started converting YKA data packets to CNSN packets in Yellowknife and transmitting as a real time stream to Ottawa for processing alongside CNSN data • allowed consolidation of CNSN & YKA onto common acquisition/archive systems

  8. CNSN station map - 2005

  9. POLARIS Network - 1 Portable Observatories for Lithospheric Analysis and Research Investigating Seismicity “a Canadian geophysical research consortium focusedon investigation of the structure and dynamics of the Earth's lithosphere and the prediction of earthquake ground motion”

  10. POLARIS Network - 2 • initially to comprise 90 BB seismographs in 3 sub-arrays, using NMX digitizers and Libra VSAT satellite telemetry • subsequently augmented to ~105 HBB Libra sets with 3 VSAT earthstation downlinks • deployments to last 4-5 years • includes co-located MT systems; GPS to come

  11. POLARIS Network - 3 GSC Role: • acquire, archive and disseminate waveform data • we reformat real-time data streams on-the fly to pseudo-CNSN packets and process/archive alongside CNSN data (daily volume now exceeds CNSN) • host POLARIS website ( www.polarisnet.ca ) • house and operate two NMX VSAT hubs

  12. Canadian Seismograph Stations

  13. CNDCProcessing Overview

  14. Waveform Archive - 1 • robotic DLT-tape library system installed in 1999 • allowed us to put all waveform holdings (near) on-line • reformatted all earlier data formats to CA • developed standard tools to handle and reformat (SEED, CD-1, GSE-2.0, IMS-1.0, Mk2, Integer)

  15. Waveform Archive - 2 • moved to 12 TB all-disc system in April 2005 • now all-online (no tape access delays)

  16. CD Archive Holdings 1 TB = 10244 bytes

  17. Data Dissemination - 1 Continuous data: • as CTBT NDC, forward IMS Primary SHI data to Vienna IDC in CD-1 format (currently ~194 MB/day) • share real-time data with USGS/NEIC (10), PTWC/ATWC (9), Montana Bureau of Mines (MB - 2) and UWashington (6) via orb2ew (Internet) • 10 FDSN stations to IRIS-DMC (daily ftp)

  18. Data Dissemination - 2 Request data: • AutoDRM has run continuously since May 1994 • NetDC since 2004 • Event archive • developed Web interfaces to ease usage

  19. Data Dissemination - 3

  20. CNDC AutoDRM Data Shipments Number of requests processedVolume in GB (1GB = 10243 B)

  21. Event Selection

  22. Ongoing challenges • serving non-specialist clients • archive and dissemination of non-seismic data (Infrasound, MT and GPS data)* • tracking network metadata over time* • automated quality control and display*

  23. Global Infrasound Archive(G I N A) • stored in CSS-3.0 wf format • convert to SEED, MSEED, SAC, & Integer on demand

  24. Magneto-telluric Data

  25. Tracking Network Metadata • tracking the complete history of Canadian and foreign stations of interest wrt: agency, affiliation(s), network/deployment(s), location, timing, instrumentation, and response over time has required rethinking our db schema • adopted some features of CSS-3.0 db schema • now reviewing and implementing some Antelope extensions to CSS (e.g., stage table)

  26. CNSN Station Book - 1

  27. CNSN Station Book - 2

  28. CNSN Station Book - 3

  29. Automatic Quality Control • need to track various measures of data quality including availability (completeness), timeliness (latency), stn timing, signal degradation (waveform quality), and metadata quality (e.g., degree to which response is known and trusted) • how to automate and display for potential data users?

  30. RUDY

  31. Bitter cold and wind affecting power (TEG) at YKW4

  32. Station Quality Plot

  33. Conclusion While the seismological community is reasonably well served, a number of challenges remain: • making data useful to a broader range of people • managing an increasingly heterogeneous data set • automating and displaying data quality Hopefully we can both contribute to and gain by the GEOSS initiatives.

  34. The End

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