Overview of SWOT ocean surface topography performance

The SWOT mission was launched in December 2022. Its first of a kind KaRIn instruments provides two dimensionnal images of ocean surface topography over a 120 km wide swath. Ocean surface topography data quality and mission performance have been assessed and monitored over the first year of SWOT mission, as part of mission performance activities performed by the mission project. Here we present a synthesis of SWOT mission performances over ocean: from data availability and validity to end-to-end performance metrics (eg SSH differences at crossovers, wavenumber spectrum and comparison with the current nadir altimetry constellation). We also discuss the performance of cross-calibration algorithms at level 2 (based on crossovers) and level 3 (based on other altimeters). Results presented here are based on the analysis of the 2 km product during both the calval (1 day repeat orbit) and science (21 day repeat orbit) phases and focused on ocean surface topography retrievals. All mission CalVal metrics highlight the excellent performance of KaRIn measurements. We also present some known limitations of current SWOT products that are of interest to science users.