A network of seismometers (combination of the seismic sensor and data acquisition unit) independently records regional seismicity. Stations either communicate with the central computer via digital radios, satellite data link or cellular modem. Alternatively, seismic data can be recorded to a portable USB drive, using StandAlone mode. Seismic processors and netADC’s are linked to GPS modules to provide accurate time synchronization between regional stations.
- Off-line: Use of common cellular modems minimises infrastructural set-up costs. At midnight every day all seismic stations are contacted and seismic information downloaded. Seismograms of common events are post-associated for off-line processing and interpretation.
- Real-time: The stations communicate with a central server via digital satellite data links, a local Internet connection or a WiFi link to the Internet or central server.
The low power consumption of the seismometer (less than 0.6W/channel) and digital radio allows use of an inexpensive solar panel and battery unit, making the seismic station completely independent.
Typically a 1 Hz tri-axial geophones are used for this application. A vault is constructed to house the sensor and seismic station. Each netADC data acquisition unit can monitor up to 8 seismic signals, but usually only 3 channels are used here.
Seismic Data Processing & Interpretation
The seismograms of every seismic event that triggers multiple stations are post-associated on the seismic controller. Seismograms are then exported to SEISAN format for processing with a tectonic seismology package. Additionally, SeedLink (MiniSEED) data sources (such as those provided by SeisComP) can be added, allowing for the simultaneous use of local and remote data. With the addition of any combination of the IMS automatic processing and web-based data monitoring interfaces, various configurations are possible to seamlessly integrate the IMS system with existing regional and global monitoring operations.