Bristol Channel, River Severn and Severn estuary

Sea level; Horizontal spatial co-ordinates

Sea level recorders

Satellite-derived data and data used for satellite data validation from the SWOT-UK project. Validation sea level elevation data are from tide gauges re-referenced to ETRS89 (WGS84) This data covers the Bristol Channel, Severn estuary and river Severn. The bulk of the data spans the period from the beginning of 2022 to the end of July 2023, but the data used for the validation of the Cryosat2 satellite goes back to 2012. These data came from the Environment Agency and National Network of Regional Coastal Monitoring Programmes (Channel Coastal Observatory) APIs, with three addition Global Navigation Satellite Systems Interferometric Reflectometry (GNSS-IR) systems installed by the project team. The data were transformed to ETRS89 (WGS84) Ellipsoid using a software utility provided by the Ordnance Survey, for comparison to satellite altimetry data. Stations measuring relative to chart or stage datum were corrected to ordnance datum before transformation to ETRS89 (WGS84). The data are supplied as water surface elevation (altitude) in metres, relative to ETRS89 (WGS84) Ellipsoid. These real-time in situ data have not been corrected for atmospheric pressure, to match the total water level measurements of the satellite.

British Oceanographic Data Centre
Joseph Proudman Building 6 Brownlow Street
Liverpool
Merseyside
L3 5DA
United Kingdom