SWOT L2 Nadir Altimeter: Sea Surface Height, Waves, and Wind

Data from the SWOT mission's Poseidon-3C altimeter, launched December 16, 2022, provides measurements along the satellite's ground track. It records sea surface height, significant wave height, and wind speed at two sampling resolutions: approximately 6-km at 1Hz and 300-m at 20Hz. The dataset is processed with precise orbit data and distributed in netCDF-4 format with a latency of less than 90 days.

Use Cases

• Monitoring ocean circulation and eddy dynamics based on high-resolution sea surface height measurements.
• Analyzing wave climate and storm impacts using the significant wave height data.
• Studying wind patterns over the ocean surface from the altimeter-derived wind speed.
• Validating and calibrating oceanographic models with along-track geophysical data records.

Strengths

• Provides dual-frequency (Ku/C band) measurements from a Jason-class altimeter, a proven technology.
• Offers high spatial resolution with sampling at approximately 300-meter intervals at 20Hz.
• Data is processed using Precise Orbit Ephemeris (POE) for accurate geolocation.
• Cross-platform presence on NASA Earthdata and Data.gov signals its importance and curation.

Limitations

• Key metadata such as row count, file size, and specific column names are not provided across any source.
• The license is ambiguously listed as 'other-license-specified' without details on terms or restrictions.
• The dataset's structure is complex, with a parent collection and multiple sub-collections, which may complicate data discovery and access.

Provenance

Source

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

Collection Method

Satellite remote sensing via the Poseidon-3C nadir altimeter.

Time Range

From mission launch on December 16, 2022, onward.

Freshness

2026-04-09 21:52:13.404654

Geography

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