SWOT Nadir Altimeter OGDR: Sea Surface Height and Wave Data

Global ocean and inland water measurements from the NASA-CNES Surface Water and Ocean Topography (SWOT) satellite mission, which launched on December 16, 2022. The dataset provides discrete measurements of sea surface height, significant wave height, and wind speed along the satellite's nadir track. Data is processed with onboard DORIS orbit ephemeris and distributed in netCDF-4 format with a nominal latency of less than 7 hours.

Use Cases

• Monitoring near-real-time sea state for maritime operations based on the <7 hour latency and wind speed measurements.
• Analyzing ocean surface topography and circulation patterns based on high-resolution sea surface height data.
• Studying wave climate and energy distribution using the significant wave height measurements.
• Calibrating and validating hydrodynamic models with the along-track 1Hz (~6-km) and 20Hz (~300-m) sampling resolutions.

Strengths

• Provides data with high temporal resolution, available with a nominal latency of less than 7 hours.
• Offers dual sampling resolutions of approximately 6-km at 1Hz and 300-m at 20Hz for detailed along-track analysis.
• Data originates from a major joint space mission between NASA and CNES, launched on December 16, 2022.

Limitations

• Dataset uses predicted values for some auxiliary data and lacks GIM ionosphere model values, which may affect accuracy for certain applications.
• Metadata completeness is low; specific column names, row counts, and file sizes are not provided across platforms.
• The license is ambiguously listed as 'other-license-specified' without explicit details.

Provenance

Source

National Aeronautics and Space Administration (NASA) and Centre National d'Études Spatiales (CNES) via the SWOT mission.

Collection Method

Satellite remote sensing via the Poseidon-3C nadir altimeter, a Jason-class dual frequency (Ku/C) altimeter.

Time Range

From mission launch on December 16, 2022, onward.

Freshness

2026-04-09 21:51:48.437507

Geography

Global coverage of oceans and inland water bodies along the satellite's ground track.