Quality Assessment of Sentinel-3a PDGS land products for the Monitoring of Lakes and Rivers Water Level
Event: 2017 Ocean Surface Topography Science Team Meeting
Session: Science IV: 25 years of satellite altimetry for Cryosphere and Hydrology: from experimental to emerging operational applications
Presentation type: Type Oral
Though the quality of their measurements over inland waters is lower than over oceans, the existing altimetry data allows a massive live and historical access to a wide network of information: on the THEIA/Hydroweb and Copernicus Global Land service, over 150 lakes and 1200 virtuals stations (intersection between altimeter ground track and river) have been computed with an accuracy of 10-40 cm. The operational products –63 lakes and 58 virtual stations – are currently based on Jason-3. The offline products are based on the whole past and present altimetry constellation. A large part of the lake product covers from 1993 to today.
Sentinel-3a, launched early 2016, will make a major contribution to the monitoring of rivers and lakes and is currently integrated in the products. Thanks to this new operational mission, the lake water level accuracy will be increased and the network will be expanded by 800 new virtual stations by the end of 2017.
The quality assessement of the Sentinel-3a PDGS land products from level 2 to level 3 is essential before the release of the products. In this study, we propose a set of diagnoses to assess routinely the quality of altimetry measurements at global and basin scale. These diagnoses are then applied to the reprocessed Sentinel-3a PDGS land products from the beginning of the missions onwards.