1. GSN QC at the IRIS DMC Mary Templeton GSN Coordination Meeting Seattle, WA November 16, 2011

2. GSN QC at the DMC Began July 1, 2011 Looking to optimize 1/2 FTE Charges so far –Do what you do for US-REF –Extra attention to metadata –In situ response monitoring

3. Routine QC and Reporting Draft weekly report –In the internal feedback stage –Reference Network approach –report current problems to network operators

4. Report Content Current and recently resolved outages Real-time telemetry issues Excessive gap list Archive status of non-real-time stations Timing issues Instrumentation or site issues Metadata issues

5. Attention to Metadata Location Orientation Instrument type –Response –Instrument comment Sample rate –Channel (B052) –MiniSEED fixed section –Response high f c –Response cascade final sample rate

6. Metadata Consistency Checking Response checking –Evalresp SEED conformance Sensitivity (f norm in passband) Units FIR delays –Visual inspection

7. Metadata Consistency Checking Do changes that correspond to epoch changes agree for all appropriate SNCLs? –Epoch start/end times –Sensor or datalogger sensitivity –Pole/zero or FIR cascade

8. In Situ Response Monitoring The problem: find a way to see frequency-dependent STS-1 response changes reported by the Waveform Quality Center at the DMC. “In situ” - monitoring methods not requiring remote or local instrument control.

9. Ideal Method(s) assess single, as well as coincident sensors apply to vertical and horizontal channels measure amplitude and phase errors periods from 2t to at least 250s

10. Ideal Method(s) separate response issues from other amplitude issues (noise, model limitations, hardware performance) –strong correlation or coherence for synthetic or coincident sensor comparisons –“known” signal for single-sensor techniques redundant measurements at period(s) of interest

11. Techniques in Use TechniqueSensorsChannelsAmp/PhasePeriods Earth Tide syntheticssingleZ (all?)both44712s Event synthetics (WQC)singleallamplitude 2t-400s Event cross-spectracoincidentallbothcommon passband Microseism cross-specracoincidentallboth~7s PSD/PDF tools (DMC)singleallamplitude 2t-172 0 S 0 normal modessingleZ (all?)both1227.52s

12. Recommendations Prototype cross-spectra of coincident sensors

13. Mw=6.9 Sikkim, India (9/18/11) Cross-spectra

15. Recommendations Prototype cross-spectra of coincident sensors Evaluate what it would take to incorporate Princeton synthetics comparison

16. Recommendations Prototype cross-spectra of coincident sensors Evaluate what it would take to incorporate Princeton synthetics comparison Add ocean loading to existing tidal synthetics at the DMC

17. Recommendations Prototype cross-spectra of coincident sensors Evaluate what it would take to incorporate Princeton synthetics comparison Add ocean loading to existing tidal synthetics at the DMC Calculate PSDs over period range appropriate to sensor passband

18. Recommendations Prototype cross-spectra of coincident sensors Evaluate what it would take to incorporate Princeton synthetics comparison Add ocean loading to existing tidal synthetics at the DMC Calculate PSDs over T range appropriate to sensor passband Make calculated traces available to users

20. Mw=6.9 Sikkim, India (9/18/11) Cross-spectra (Davis)