Monitoring of Data Quality of the IMS Seismic Station AS050

Abstract

Continuous data acquisition, now frequent in many seismic networks, comes with the problem of accumulating huge data masses. In the context of the needs of CTBTO reliability and quality of data acquisition is a crucial issue. Severe malfunctions of the system (such as power failure, system hang-up, etc) can be easily detected, as these show up in absent data or zeroes in the transmitted data packages. Other problems, not so evident but nonetheless seriously affecting data availability, arise when data transmission is disturbed to some degree, causing disruptions which may easily escape the attention of the operators. For the station VAE we have set up a number of diagnostic tools for the identification of such problems. One of them is the analysis of the arrival times of data packages, which are expected to be ordered to a high degree. Others exploit concepts of continuous representation of the frequency content of the signals, such as short time FFT or wavelet transforms. With the latter it is possible to effectively visualize large time windows and to identify critical frames which may need further inspection. The concepts of the diagnostics outlined here has proven to be useful both for trouble shooting purposes as well as the configuration of parameters governing the data acquisition.