Tide gauges are instruments that measure sea level relative to a local geodetic benchmark. Two primary reasons for measuring sea level are observing global sea level change and sea level hazard event research. Acoustic, hydrostatic pressure and radar tide gauges provide precise relative sea level data but can be greatly influenced by variances caused by vertical land signals and the stability of the surface they are built upon. Furthermore, accurately tying relative sea level to a global reference frame is an ongoing challenge for geodesists. At selected tide gauge locations, UNAVCO has installed two cGNSS in the vicinity of the tide instruments in order to constrain these measurements within a global frame of reference. One cGNSS installed on the pier or structure that supports the tide instrument and a second cGNSS within five kilometers to provide a short baseline to a more stable reference timeseries. This layout provides a near real-time position of the tide gauge instrument, both relative to the potential changing apparent sea level height as well as the dynamic global reference frame.
UNAVCO tide locations include Trimble NetR9 receivers with Trimble GNSS chokering antennas. cGNSS data undergo standard UNAVCO processing producing 15-second daily and 1-Hz hourly solutions. When possible, cGNSS locations also support real-time data streams (e.g. COCONet Realtime GPS Data). GPS data are available at the COCONet website.
Tide instruments supported by UNAVCO include the Sutron Radar LevelRecorder and INW PT12 Pressure Sensor with the Sutron XLite data logger. These instruments are configured to transmit 1 minute samples via GOES telemetry and current and archived data are available at the UNESCO-IOC tide gauge archive.
Last modified: 2019-12-24 01:47:04 America/Denver