Sentinel-3 radar altimetry for river monitoring – a catchment-scale evaluation of satellite water surface elevation from Sentinel-3A and Sentinel-3B

Abstract. Sentinel-3 is the first satellite altimetry mission to operate both in synthetic aperture radar (SAR) mode and open-loop tracking nearly globally. Both features are expected improve ability of altimeters observe inland water bodies. Additionally, two-satellite constellation offers a unique compromise between spatial temporal resolution with over 65 000 potential targets sensed In this study, we evaluate possibility extracting river surface elevation (WSE) at catchment level from Sentinel-3A Sentinel-3B using Level-1b Level-2 data two public platforms: Copernicus Open Access Hub (SciHub) Grid Processing on Demand (GPOD). The objectives study demonstrate that by publicly available processing platforms, such databases can be created suit specific areas for any wide range applications hydrology. We select Zambezi River as area. basin, 156 virtual stations (VSs) contain useful WSE information datasets. root-mean-square deviation (RMSD) 2.9 31.3 cm six VSs, where situ available, all VSs reflect observed climatology throughout basin. Some exclusive either SciHub or GPOD datasets, highlighting value considering multiple options beyond global altimetry-based databases. particular, show affect number VSs; specifically, extending size receiving window considerably improved 13 VSs. This was largely related implementation parameters. While correct on-board crucial, postprocessing must adapted handle steep changes position. Finally, extract observations key wetlands clear seasonal patterns captured WSE, reflecting flooding events floodplains. These results highlight benefit high spatiotemporal dual-satellite constellation.