SWOT Nadir Altimeter GDR: Sea Surface Height and Wave Data

SWOT Level 2 Nadir Altimeter Geophysical Data Record provides discrete measurements of sea surface height, significant wave height, and wind speed along the satellite ground track. The dataset uses restituted auxiliary data and the Precise Orbit Ephemeris (POE), with a latency of less than 90 days. Data is delivered in netCDF-4 format, similar to products from ongoing missions like Jason-3.

Use Cases

• Monitoring sea level anomalies based on sea surface height measurements.
• Analyzing ocean wave climate and storm impacts using significant wave height data.
• Studying ocean-atmosphere interactions using wind speed measurements from the altimeter.
• Validating and calibrating other nadir altimeter missions like Jason-3 against this dataset.

Strengths

• Data is produced by NASA, a leading space agency.
• Provides three core oceanographic variables: sea surface height, significant wave height, and wind speed.
• Uses Precise Orbit Ephemeris (POE) for accurate geolocation.
• Available with a defined latency of less than 90 days.

Limitations

• Key metadata like row count, file size, and specific license terms are missing or inconsistent across platforms.
• Column names and detailed data structure are not provided, limiting immediate usability.
• The dataset description is repeated verbatim across platforms, suggesting potential metadata stagnation.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Satellite nadir altimeter measurements, processed into a Geophysical Data Record (GDR).

Time Range

null

Freshness

Last updated on 2026-04-09 according to one datagov entry.

Geography

Global ocean coverage along the satellite ground track.