Instrumentation

Geophysical instruments such as GPS/GNSS (Global Navigation Satellite System) receivers, strainmeters, seismometers, tiltmeters, and LiDAR are essential to data collection and analysis performed by UNAVCO community members. UNAVCO loans equipment, provides expertise in station and instrument design, builds sites and installs the instruments. Following installation, UNAVCO tests and troubleshoots the instruments and the data collection, power and communications systems required to record and access data from continuously operating and often remote sites. Available instrumentation and equipment technologies include: geophysical instruments, communication technologies, and ancillary hardware.

Geophysical Instruments

Geophysical instruments collect data of interest to the UNAVCO science community.

• GNSS receivers (GPS, GLONASS, etc) collect GNSS data which, after processing, is used to measure millimeter-level surface motion measurements at specific points over a period of time; the datasets include temporary, episodic campaign surveys and permanent installations.
• Geodetic Imaging uses electromagnetic waves to quantify centimeter-scale motions at the Earth’s surface over several square meters to hundreds of square kilometers.
  • Terrestrial Laser Scanning (TLS) uses ground based LiDAR measurements to support a wide spectrum of Earth science research applications.
  • InSAR uses radar satellite measurements for geodesy and other research applications.
  • Airborne Laser Scanning (ALS) uses aircraft based LiDAR measurements to support a wide spectrum of science research applications.
• Borehole instruments are buried 100 to 200 m below the ground to operate at the low noise levels required to capture small, short term transients.
  • Borehole Strainmeters measure crustal deformation on a timescale of less than a second to weeks or months. Pore pressure, temperature, and other instruments are often co-located in the borehole
  • Borehole Seismometers detect seismic waves at periods of several minutes or less.
  • Tiltmeters detect crustal deformation from deep earth processes such as volcanism and water table recharge/discharge over periods of seconds to weeks.
• Laser Strainmeters are long-baseline (450-meter) measurements of deformation on the Earth’s surface.
• Meteorological sensors are co-located with other geodetic instruments and provide surface measurements of atmospheric conditions at a given location.

Communication Technologies

Communication technologies ensure that data collected in the field can be retrieved and reaches scientists and/or the UNAVCO data repository. Various types of communication technologies are installed along with the geophysical sensors. This equipment allows data to be pushed automatically from the sensor to the data archive. In other cases, the communication method allows for manual data retrieval.

• Satellite communications are used when stations are remote or where no cellular or land-based methods are available.
• Cellular technologies are the most common method used to retrieve data from geodetic stations.
• Land-based communications involve internet connections, such as DSL, cable, WISP, dial-up modem and other analog systems.
• Radio Modems also be used for line-of-sight communications over tens of miles in remote locations.

Ancillary Equipment & Monumentation

UNAVCO designs, engineers, and installs ancillary hardware and equipment to secure geodetic instruments in place for permanent stations, as well as installs power systems and enclosures to protect instruments.

• Power systems are optimized to provide continuous or cycled power through a variety of environmental conditions and include a combination of: solar, battery, AC, wind, fuel-cells and timing systems.
• Monumentation supports GNSS antennas and is chosen depending on the type of project, whether permanent, long-term, or campaign site occupations.
• Enclosures protect equipment and instruments from the elements, including those specifically designed for solar systems.