Sentinel-6A MF: High-Resolution Ocean Altimetry

Sentinel-6A Michael Freilich's Poseidon-4 SAR altimeter provides Level 2 high-resolution non-time-critical data with a 60-day latency. The dataset contains 1 Hz and 20 Hz Ku-band measurements of sea surface height, sea surface height anomalies, significant wave height, and wind speed, processed from L1B altimetry. This standard product is analogous to the Jason-3 GDR product and includes altimetry corrections and geophysical parameters.

Use Cases

• Monitoring long-term sea-level rise trends based on sea surface height anomalies (SSHA).
• Analyzing ocean wave climate and storm impacts using significant wave height (SWH) measurements.
• Calibrating and validating ocean models with high-resolution (20 Hz) Ku-band range and orbital altitude data.
• Studying atmospheric effects on altimetry using integrated water vapor and wind-speed data from the AMR-C instrument.

Strengths

• Provides high-resolution (HR) data at both 1 Hz and 20 Hz sampling rates, enabling detailed analysis of ocean surface features.
• Contains a comprehensive suite of geophysical parameters including SSH, SSHA, SWH, and wind speed, derived from the advanced Poseidon-4 SAR altimeter.
• Cross-platform presence on Data.gov and NASA Earthdata signals its importance and reliability as a standard ocean topography product.

Limitations

• Key metadata such as row count, file size, and specific column names are not provided across any source, limiting precise assessment of dataset scale and structure.
• The license is ambiguously listed as 'other-license-specified' on Data.gov but is 'None' on NASA Earthdata, creating uncertainty for users.
• The dataset has a 60-day latency (Non-Time-Critical), making it unsuitable for near-real-time applications like weather forecasting or operational oceanography.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Satellite remote sensing via the Poseidon-4 SAR altimeter on the Sentinel-6A Michael Freilich spacecraft.

Freshness

2026-04-09 (from Data.gov)

Geography

Global ocean coverage from the satellite's orbit.