Evaluation of the SENTINEL-3A water levels over large hydrological basins
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 Poster
Contribution: not provided
Since the launch, the SENTINEL-3A altimetry data have been distributed in a variety of versions. We processed the LAN data in version 1.2 for cycles >= 17 and version 1.5 for cycles up to 16, reprocessed consistently with version 1.2.
For this analysis, we identified 465 sites in the Congo basin and 1140 sites in the AMAZON basin where SENTINEL-3A groundtracks cross the river network and can potentially collect water levels. Note that some of these sites are included in the onboard DEM mask when others are not.
Since almost no gauge is maintained by the national agencies in the Congo basin, we installed two automatic gauges for the validation of the SENTINEL-3A measurements, right under orbit groundtracks. Similarly, we installed gauges in the Amazon basin in order to complement the national network of gauges maintained by Brazil.
We present preliminary assessments of the amount of data collected, or missing, the RMS difference with gauge readings and the absolute bias, for both the OCEAN and OCOG range retracking algorithms.