Paired Water Surface Elevation Data in the United States and Canada from the Surface Water Ocean Topography (SWOT) Satellite and In Situ Gage Data from 2023 to 2025

This dataset contains paired in situ and satellite-derived water surface elevation (WSE) observations compiled to evaluate the accuracy of the Surface Water and Ocean Topography (SWOT) mission water surface elevation data over rivers and lakes. In situ WSE measurements were obtained from the U.S. Geological Survey (USGS), U.S. Bureau of Reclamation (BOR), Environment and Climate Change Canada (ECCC), and the Ministry of the Environment in Quebec. These observations were paired with coincident SWOT Level-2 River and Lake Single Pass (SP) product water surface elevations (Version C & D) collected between January 1, 2023 and December 31, 2025. The dataset includes SWOT data and associated quality flags, gage-observed WSE, and associated metadata. Data are organized by river reach (SWOT data aggregated over a river reach ~ 10 km in length), river node (SWOT data aggregated over a smaller region ~ 200 m in length), and lake data, where SWOT elevations are aggregated over the entire observed lake area. Gage-observed WSE data have been converted to SWOT's vertical datum (Earth Gravitational Model EGM2008) where possible. The compiled tabular outputs support evaluation of SWOT WSE performance across hydrologic conditions, site characteristics, and filtering strategies. A subset of possible SWOT data quality filters and remaining data percentage and accuracy are included as well, supporting a Pareto analysis for these given filters.