TY - JOUR
T1 - Evaluating SWOT in the Coastal Zone: Comparisons With Tide Gauge and Airborne LiDAR in the Bristol Channel and Severn Estuary, UK
AU - Rong, Youtong
AU - BATES, PA
AU - Neal, Jeff
AU - Bell, Paul
AU - Gommenginger, Christine
AU - Lichtman, Ian
AU - Banks, Christopher
AU - Calafat, Francisco
AU - Martin, Adrien C. H.
AU - Brown, Jennifer
AU - Cooke, Richard D.
AU - Balfour, C.
AU - De Dominicis, Michela
AU - Payo-Payo, Marta
AU - Williams, Simon
AU - Amoudry, Laurent
AU - Chuter, Stephen
AU - Neill, Simon
AU - Chisholm, Jude
AU - Gleason, Colin
AU - Kupiec, John
AU - Lewis, Matthew
PY - 2026/1/28
Y1 - 2026/1/28
N2 - Traditional nadir altimeters struggle with coastal water surface elevation (WSE) measurement and fine-scale river-estuary interactions, due to land-water signal interference and their wide inter-track spacing. The wide-swath Surface Water and Ocean Topography (SWOT) mission, using a new Ka-band radar interferometer, aims to address these issues by delivering 2D WSE measurements with unprecedented spatial resolution, accuracy, and precision. However, the mission's effectiveness in coastal WSE retrieval and its error characteristics remain unverified. This study leverages gauge and airborne LiDAR data to validate SWOT's WSE in the Bristol Channel and Severn Estuary. Assuming error-free in situ data, SWOT ocean products exhibit a standard deviation of difference (STD) of 13 cm within a 3 km radius of tide gauges. Compared to LiDAR, SWOT's PIXC measurements have STD of 37 cm, improving to 14 cm over 100 m grids and 9 cm over 1 km2 areas. This meets the SWOT science requirement of 10 cm STD at 1 km2 scale and extends satellite-based WSE monitoring into complex coastal environments.
AB - Traditional nadir altimeters struggle with coastal water surface elevation (WSE) measurement and fine-scale river-estuary interactions, due to land-water signal interference and their wide inter-track spacing. The wide-swath Surface Water and Ocean Topography (SWOT) mission, using a new Ka-band radar interferometer, aims to address these issues by delivering 2D WSE measurements with unprecedented spatial resolution, accuracy, and precision. However, the mission's effectiveness in coastal WSE retrieval and its error characteristics remain unverified. This study leverages gauge and airborne LiDAR data to validate SWOT's WSE in the Bristol Channel and Severn Estuary. Assuming error-free in situ data, SWOT ocean products exhibit a standard deviation of difference (STD) of 13 cm within a 3 km radius of tide gauges. Compared to LiDAR, SWOT's PIXC measurements have STD of 37 cm, improving to 14 cm over 100 m grids and 9 cm over 1 km2 areas. This meets the SWOT science requirement of 10 cm STD at 1 km2 scale and extends satellite-based WSE monitoring into complex coastal environments.
U2 - 10.1029/2025GL116590
DO - 10.1029/2025GL116590
M3 - Article
SN - 0094-8276
VL - 53
SP - 1
EP - 11
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 2
M1 - e2025GL116590
ER -