ASL QC ProceduresStatus and plans

GSNANSS Traditional Waveform Review

The “morning run”• Daily email summarizes problems with availability, timing, and

various data integrity values. Quick review of all LH waveform data for the previous 24 hours, PSD’s reviewed as needed

Weekly review• Similar to the morning run, but based on a 7-day dataset

Earth-tide comparison• Quick way to identify polarity issues and egregious gain errors

These traditional tools allow us to verify the short-term state-of-health of the network and identify most problems ….

GSNANSS

QAPs were swapped

QDP was swapped

Traditional Waveform Review

….however they do not catch everything

GSNANSS Data Quality Analyzer

The ASL has implemented several new tools to expand their capabilities

GSNANSS

Data Quality Analyzer – current parameters• Record parameters

Data availability Number of Gaps Timing quality

• Noise parameters Channel noise levels are measured with respect to a baseline Sampled at 4-8, 18-22, 90-110 and 200-400 s

• Coherence and Power difference Calculated at sites with 2 broadband sensors Sampled at 4-8, 18-22, 90-110 and 200-400 s

• Calibration parameters Days since last calibration Mean amplitude error between the calibration & current

metadata as measured in the flat part of the response Mean amplitude error between the calibration & current

metadata as measured at the long period corner

Data Quality Analyzer

GSNANSS

Data Quality Analyzer – future parameters• Noise parameters, coherence, and power difference at 1-5

Hz

• Noise values with respect to an absolute scale, as such as USGS low noise model or the GSN noise model

• Mass position values or some derived parameter thereof

• Comparison of the latest calibration to the nominal response in terms of the corner and flat part of the spectrum

• Orientation differences for sites with two broadband sensors

• Event windows, capturing station information for each major quake

Data Quality Analyzer

GSNANSS Event-based Review

With one plot we can identify response, timing, gains and polarity issues

Left: KIP for an event in 2007 Right: HIA for a 2011 event

GSNANSS Event-based Review Generating synthetics for all events

with CMTs M> 6.5• Multiple methods being explored

Long period: Princeton 3-D, Normal mode 1-D, W-phase Shorter period: Herrmann’s

wavenumber integration

Waveform comparison between both broad-band sensors and low-gain accelerometer data

Azimuth evaluation• Differential & absolute

GSNANSS ASL QC On-going Projects

Calibration analysis• Processing for the long-period corner

moving forward• Processing for the high-frequency corner

awaiting implementation SensOrLoc processing

• Determination of orientation and absolute calibration

• Performed during site visits• Values propagated backwards where

applicable Pre-deployment checks

• Thorough review of station performance prior to deployment

• Integration testing and review of equipment

Station Certification• Using all tools at our disposal, review each

station epoch verifying gain, lp-corner and orientation, updating metadata where needed

GSNANSS ASL QC Procedures summary

Daily waveform review• Earth-tide comparison

Data Quality Analyzer• Customizable format

Event-based review• Synthetics• Intra-sensor comparisons

Problem tracking• Using Report Tracker “RT” ticket system• Working with the field engineers to solve problems

Problem reporting• “Station issues” tab on the Network operations Web pages• Data Problem Reports (DPRs)

GSNANSS References

Hutt, C. R. and A. T. Ringler (2011). Some possible causes of and corrections for STS-1 gain changes in the Global Seismographic Network, Seismological Research Letters, 82, 484-495.

McNamara, D. E., C. R. Hutt, L. S. Gee, H. M. Benz, and R. P. Buland (2009). A Method to Establish Seismic Noise Baselines for Automated Station Assessment, Seismological Research Letters, 80, 628 - 637, 2009.

Ringler, A. T., L. S. Gee, C. R. Hutt, and D. E. McNamara (2010). Temporal variations in global seismic station ambient noise power levels, Seismological Research Letters, 81,605–613.

Ringler, A. T., C. R. Hutt, R. Aster, H. Bolton, L. S. Gee, and T. Storm (2012). Estimating pole/zero errors in GSN-IRIS/USGS network calibration metadata, Bulletin of the Seismological Society of America, in press.

Ringler, A. T., L. S. Gee, B. Marshall, and C. R. Hutt (2011). Data quality of seismic records from the Tohoku, Japan, earthquake as recorded across the Albuquerque Seismological Laboratory Networks, Seismological Research Letters, in review.

Ringler., A. T., J. D. Edwards, C. R. Hutt, and F. Shelly (2011). Relative azimuth inversion by way of damped maximum correlation estimates, Computers and Geosciences, in review.

GSNANSS

Calibrated Channel, time, duration: KIP 00 BHZ 2011 306 03 40 16 9999-14400Cal Analysis Date: 2011,308Software Version: 2.01Instrument: STS1VBBE3##Best Fit Amplitude Error (dB):     0.014383Best Fit Phase Error (degree):     0.18542Nominal Amplitude Error (dB):     0.041388Nominal Phase Error (degree):     0.24889##Existing RESP infoB050F03     Station:     KIP B050F16     Network:     IU B052F03     Location:    00 B052F04     Channel:     BHZ B052F22     Start date:  2010,281,19:16:59 B052F23     End date:    No Ending Time #Old Response Values Here (removed for clarity)#New Response Values Here (removed for clarity)#old BHZ A0:  3.948470E+03new BHZ A0:  3.947835E+03##old VHZ A0:  3.975050E+03new VHZ A0:  3.989613E+03

Calibration Analysis