Operation
A permanent underground installation of seismometers communicates
with a central site Desktop Run-Time System (DRTS)
located on surface for real-time seismic monitoring of the rock mass.
A GPS timing module is used so that recorded seismic data may be
integrated with seismic data from another nearby system for
information about regional seismic events.
Communications
The RS485 protocol is used here to minimise cabling costs. With this
approach multiple
QS data acquisition units can be daisy-chained together with
inexpensive 2-core twisted pair copper cable. Repeaters must be used
if the distance between any two nodes exceeds 1.2km. Each link can
support up to 10 QS units, with the modem rack providing the
appropriate number of links.
Seismic Sensors
Each QS data acquisition unit can monitor and pre-process up to six
seismic signals, in any combination of uni-, bi- or tri-axial
seismic sensors. For each seismic channel up to 3
logical channels may be extracted with QS technology. Both
geophones and accelerometers (piezoelectric and Force-Balance) are
currently supported.
Seismic Data Processing & Interpretation
The seismograms of every seismic event that triggers multiple
stations are transmitted to the
DRTS and recorded. The seismic event is automatically processed
and seismic source parameters including the location, time, radiated
seismic energy and co-seismic inelastic deformation are
automatically calculated. This data is confirmed later by manual
processing with the software packages RMTS or XMTS. Spatial and
temporal trends made then be detected and analysed using the
interpretation packages
Xdi or
Jdi. |
