SWOT Mission Validation of Sea Surface Height Measurements at Sub‐100 km Scales Geophysical Research Letters

After two decades of development, the Surface Water and Ocean Topography (SWOT) mission launched on 16 December 2022, pioneering the use of Ka‐band Radar Interferometry (KaRIn) for measuring water surface elevation and achieving two‐dimensional altimetry on two 50 km swaths separated by a 20 km nadir gap. Rigorous validation against in situ observations in this study demonstrates that KaRIn achieves enough accuracy to resolve sub‐100 km oceanic processes, with measurement errors 2–4 times smaller than anticipated. These results confirm SWOT's transformative capabilities for advancing oceanographic research and establishing a robust foundation for future applications of the swath altimetry. The results also underscore the innovative advancements in mooring system design, driven by the stringent science requirements of the SWOT mission.