SWOT L2 OGDR: Near-Real-Time Ocean Height and Wave Data

Data from the SWOT satellite's Poseidon-3C altimeter, launched December 16, 2022, provides near-real-time measurements along its nadir track. The dataset includes sea surface height, significant wave height, and wind speed measurements at sampling resolutions of approximately 6-km (1Hz) and 300-m (20Hz). It is processed using onboard DORIS orbit ephemeris with predicted auxiliary data and has a nominal latency of less than 7 hours.

Use Cases

• Monitoring ocean surface topography and currents based on sea surface height measurements.
• Assessing sea state conditions for maritime operations using significant wave height data.
• Analyzing wind patterns over the ocean using the altimeter-derived wind speed.
• Validating and assimilating near-real-time data into ocean forecasting models.

Strengths

• Provides data with low latency (< 7 hours), suitable for operational monitoring.
• Offers high-resolution sampling with approximately 300-m along-track measurements at 20Hz.
• Data is from a major joint NASA-CNES satellite mission launched in 2022.

Limitations

• Specific column names and dataset size (row count) are not provided in the source metadata.
• Uses predicted values for some auxiliary data and lacks GIM ionosphere model corrections, which may affect accuracy compared to final products.
• Conflicting license information is present ('other-license-specified' on some platforms, 'None' on others).

Provenance

Source

Surface Water and Ocean Topography (SWOT) mission, a joint project of NASA and CNES.

Collection Method

Satellite measurements from the Poseidon-3C nadir altimeter, processed into Operational Geophysical Data Records (OGDR).

Time Range

Data collection began after the SWOT satellite launch on December 16, 2022.

Freshness

Last updated on 2026-04-09 according to datagov platform entries.

Geography

Global coverage along the satellite's nadir ground track over oceans.