getijmeters

Getijmeters are instruments used to measure tidal phenomena, particularly variations in sea level caused by tides, and in some cases the flow of tidal currents. The term is often aligned with tide gauges or tidal current meters in English.

There are two main forms: water level instruments that record the height of the sea surface relative to a fixed reference frame, and current meters that estimate the velocity of tidal waters. Modern devices commonly combine sensors to capture both height and flow, enabling comprehensive coastal monitoring.

Water level measurements are typically obtained with pressure transducers, ultrasonic or radar sensors, or stilling wells. Current measurements rely on acoustic Doppler devices (ADCPs), vane meters, or impeller-based systems. Data are usually logged locally and transmitted for central processing and archiving.

The data from getijmeters support tide predictions, coastal flood risk assessment, maritime and harbor operations, and long-term studies of sea level rise. Time series are analyzed using harmonic analysis to model tides and with trend analysis to monitor changes in mean sea level. Quality control, calibration, and intercomparison are important to ensure consistency across networks.

Getijmeter networks are maintained by national and international bodies, including hydrographic offices and oceanographic institutions. Prominent data repositories and networks include regional tide gauge networks and organizations such as the Permanent Service for Mean Sea Level (PSMSL), which collate long-term sea level observations for global and regional analyses.