SONEL – Système d’Observation du Niveau des Eaux Littorales

SONEL (Système d’Observation du Niveau des Eaux Littorales) is a French-led network that monitors sea level variations along coasts and estuaries using high-precision tide gauges and GNSS stations. It provides accurate time series of coastal water levels for oceanographic, geodetic, and climate research. SONEL data support sea level studies, coastal management, and the calibration of satellite altimetry measurements.

More Info: https://www.sonel.org/