We are funded by NSF, as part of the Global CMT Project, to operate a Waveform Quality Center (WQC). The activities of the WQC concern the quality of digital waveforms from the IRIS Global Seismographic Network, and from other networks with similar instrumentation. Quality is here understood broadly, with a focus on the utility of the data for research.
The WQC reports routinely on the quality of IRIS GSN data, primarily based on observations made in the routine processing of data in the Global CMT Project. Specific data problems, such as instrument polarity reversals, response function errors, timing problems, and dead channels, are reported to the IRIS DMC through the filing of Data Problem Reports.
A second WQC activity is related to the collection and processing of near real-time data distributed via the internet by the Data Collection Centers (DCCs) and by the Data Management Center (DMC). The focus in this activity is to provide rapid assessment of signal and noise characteristics of long-period signals, and to evaluate the distribution methods.
The WQC also conducts longitudinal studies aimed at (1) verifying instrument response descriptions provided by the network operators, (2) identifying historical data problems, and (3) determining noise levels, and temporal changes in these noise levels with time.
The WQC was previously funded through a subaward from the IRIS DMC.
Other WQC Reports:
Göran Ekström and Meredith Nettles, Lamont-Doherty Earth Observatory, Columbia University