Data quality control tools used to monitor seismoacoustic research arrays in South Korea

Abstract

Data assessment tools designed to improve data quality and real-time delivery of seismic and infrasound data produced by six seismoacoustic research arrays in South Korea are documented and illustrated. Three distinct types of tools are used including the following: (1) data quality monitoring; (2) real-time station state of health (SOH) monitoring; and (3) data telemetry and archive monitoring. The data quality tools quantify data gaps, seismometer orientation, infrasound polarity, digitizer timing errors, absolute noise levels, and coherence between co-located sensors and instrument-generated signals. Some of the tools take advantage of co-located or closely spaced instruments in the arrays. Digitizer timing errors are identified by continuous estimates of the relative orientation of closely spaced horizontal seismic components based on the root-mean-square error between a reference seismometer and each seismometer in the array. Noise level estimates for seismic and infrasound data are used to assess local environmental effects, seasonal noise variations, and instrumentation changes for maintenance purposes. The SOH monitoring system includes the status of individual ancillary equipment (battery, solar power, or components associated with communication) and provides the operator the capability to compare the current status to the historical data and possibly make remote changes to the system. Finally, monitoring data telemetry and overall data archival provide an assessment of network performance. This collection of tools enables array operators to assess operational issues in near real-time associated with individual instruments or components of the system in order to improve data quality of each seismoacoustic array.