SWOT satellite for global hydrological applications: accuracy assessment and insights into surface water dynamics

Abstract

The Surface Water and Ocean Topography (SWOT) satellite, launched in December 2022, marks a significant breakthrough in hydrological monitoring. Equipped with a Ka-band radar interferometer, nadir altimeter, and radiometers, SWOT enables simultaneous measurements of water levels, widths, and slopes with unprecedented spatiotemporal resolution. This manuscript systematically reviews SWOT's satellite parameters, scientific missions, algorithm processes, and application products to provide a more comprehensive understanding of its capabilities. Validation with ICESat-2 and other reference datasets shows that SWOT’s WSE products achieve an accuracy of up to 0.18 m for inland water surface elevation measurements, thereby significantly improving the precision of water body monitoring. Additionally, SWOT demonstrates substantial potential in flood monitoring by capturing flood inundation dynamics with high spatiotemporal resolution, thereby enhancing rapid response and early warning capabilities. These advancements address critical limitations in existing satellite missions, improving global hydrological observation and supporting water resource management. SWOT’s data products offer essential insights into surface water dynamics, contributing to disaster mitigation and a better understanding of climate change impacts on water resources.