The Surface Water and Ocean Topography (SWOT) project is pleased to announce the public release of Level 2 science data products from the onboard nadir altimeter (NALT) and advanced microwave radiometer (AMR).

The Surface Water and Ocean Topography (SWOT) project is pleased to announce the public release of Level 2 science data products from the onboard nadir altimeter (NALT) and advanced microwave radiometer (AMR). This release includes the Operational Geophysical Data Record (OGDR) and Interim Geophysical Data Record (IGDR) from each of the NALT and AMR instruments. SWOT is a joint mission between NASA and CNES and was launched on December 16, 2022. The onboard NALT is a Jason-class dual frequency (Ku/C) altimeter. The onboard AMR is also a Jason-class radiometer but with two active strings that facilitate measurements on the left and right sides of the satellite nadir point.
The datasets included in this release are from Cycle 559, pass 1 (on June 21, 2023) onward. They have been generated with post-launch calibrations for both the NALT and AMR. IGDR products from Cycle 475 (March 30) to Cycle 558 will be released by the end of August. Data from earlier will be provided when the Geophysical Data Record (GDR) will be released by the end of 2023.
The NALT and AMR data products in this release are accessible at both NASA’s PO.DAAC and CNES AVISO distribution centers. Information on accessing these data is provided below.
CNES AVISO
The SWOT Nadir Altimeter and Radiometer (O/I)-GDR products can be accessed on the AVISO+ web portal and through a new platform of the AVISO+ CNES Data Center's long-term archive catalog, accessible directly using AVISO+ credentials. Further information on SWOT data access can be found via the dedicated webpage on AVISO+:
https://www.aviso.altimetry.fr/en/missions/current-missions/swot/access-to-data.html
The (O/I)-GDR products in this release are listed below along with the corresponding Digital Object Identifier (DOI) landing pages:
Poseidon-3C Nadir Altimeter
SWOT_L2_NALT_OGDR_1.0 (https://doi.org/10.24400/527896/a01-2023.006)
SWOT_L2_NALT_IGDR_1.0 (https://doi.org/10.24400/527896/a01-2023.005)
Advanced Microwave Radiometer
SWOT_L2_RAD_OGDR_1.0 (https://doi.org/10.24400/527896/a01-2023.008)
SWOT_L2_RAD_IGDR_1.0 (https://doi.org/10.24400/527896/a01-2023.007)