TY - JOUR
T1 - Evaluating SWOT in the Coastal Zone
T2 - Comparisons with Tide Gauge and Airborne Lidar in the Bristol Channel and Severn Estuary, UK
AU - Rong, Youtong
AU - Bates, Paul D
AU - Neal, Jeff
AU - Bell , Paul
AU - Gommenginger, Christine
AU - Lichtman, Ian Dougal
AU - al , et
PY - 2025/12/4
Y1 - 2025/12/4
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 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 13cm within a 3km radius of tide gauges. Compared to LiDAR, SWOT's PIXC measurements have STD of 37cm, improving to 14cm over 100m grids and 9cm over 1km2 areas. This meets the SWOT science requirement of 10cm STD at 1km2 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 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 13cm within a 3km radius of tide gauges. Compared to LiDAR, SWOT's PIXC measurements have STD of 37cm, improving to 14cm over 100m grids and 9cm over 1km2 areas. This meets the SWOT science requirement of 10cm STD at 1km2 scale and extends satellite-based WSE monitoring into complex coastal environments.
M3 - Article (Academic Journal)
SN - 0094-8276
JO - Geophysical Research Letters
JF - Geophysical Research Letters
ER -