Abstract's details
Cross-comparison at cross-over between SWOT LR SSH products and Sentinel-3 marine altimetry products
Event: 2025 SWOT Science Team Meeting
Session: Oceanography: Calibration and Validation
Presentation type: Poster
SWOT is an Earth-Observation science mission dedicated to measuring surface water and ocean topography and jointly developed by NASA and CNES, in partnership with the Canadian Space Agency and UK Space Agency. The primary payload on board SWOT is a Ka-Band swath radar altimeter (KaRIn) which is covering the ocean in Low-Rate (LR) operation mode. A Ku-band Poseidon-Class nadir radar altimeter and a microwave radiometer is also embarked to support and complement the KaRIn swath measurements.
Over the ocean, the SWOT Science Team provides the user community with the LR L2 SSH (Sea Surface Height) forward-processed products via the NASA and CNES distribution centres. These products are delivered on a 2x2 km geographically fixed grid with a short latency (usually few days) and they are now in version D, spanning the time-frame 28-April-2025 onward.
In this work, we assess the performance and data quality of this SWOT L2 D SSH dataset at cross-over points with the Copernicus Sentinel-3 altimeter marine data in term of variance and bias at the cross-over location. The cross-over time difference will be chosen as short as possible (< 2 hours) to limit the impact of the natural ocean variability and both satellites S3A/B will be used to improve the geographic coverage. Also, special case of collinear tracks between Sentinel-3 and SWOT will be analysed, if any.
The Sentinel-3 marine altimetry dataset to be used is an operational non-time-critical (NTC) dataset from baseline collection BC006.01 that was updated on 2024-12-04 to latest GDR-G standards.
In the cross-comparison exercise, we take care that the same “standards” are used in both datasets. The objective is to identify any residual long wavelength error or systematic sea-state bias dependency error which may be still persisting after the KaRIn cross-over calibration application.
Back to the list of abstractOver the ocean, the SWOT Science Team provides the user community with the LR L2 SSH (Sea Surface Height) forward-processed products via the NASA and CNES distribution centres. These products are delivered on a 2x2 km geographically fixed grid with a short latency (usually few days) and they are now in version D, spanning the time-frame 28-April-2025 onward.
In this work, we assess the performance and data quality of this SWOT L2 D SSH dataset at cross-over points with the Copernicus Sentinel-3 altimeter marine data in term of variance and bias at the cross-over location. The cross-over time difference will be chosen as short as possible (< 2 hours) to limit the impact of the natural ocean variability and both satellites S3A/B will be used to improve the geographic coverage. Also, special case of collinear tracks between Sentinel-3 and SWOT will be analysed, if any.
The Sentinel-3 marine altimetry dataset to be used is an operational non-time-critical (NTC) dataset from baseline collection BC006.01 that was updated on 2024-12-04 to latest GDR-G standards.
In the cross-comparison exercise, we take care that the same “standards” are used in both datasets. The objective is to identify any residual long wavelength error or systematic sea-state bias dependency error which may be still persisting after the KaRIn cross-over calibration application.