SWOT Radiometer: Atmospheric Water and Sea Surface Brightness Temperatures

SWOT Level 2 Radiometer Brightness Temperatures and Troposphere GDR data provide atmospheric water vapor, liquid water content, and sea surface brightness temperatures from the Advanced Microwave Radiometer. The dataset is derived from measurements at three microwave frequencies (18.7, 23.8, and 34 GHz) along two tracks approximately 30 km from the satellite nadir. These geophysical estimates are used to correct altimeter range delays for the Surface Water and Ocean Topography mission, a joint NASA-CNES project launched on December 16, 2022.

Use Cases

• Correcting altimeter range delays based on estimated wet troposphere content.
• Analyzing atmospheric attenuation to backscatter for radar signal interpretation.
• Estimating cloud liquid water and water vapor content from multi-frequency brightness temperatures.
• Deriving wind speed coincident with nadir altimeter measurements.
• Mapping inland water bodies and ocean topography with radiometer-corrected data.

Strengths

• Data is from a joint NASA-CNES satellite mission with a specific launch date of December 16, 2022.
• Measurements are taken at three specific microwave frequencies: 18.7, 23.8, and 34 GHz.
• Data has a defined processing latency of less than 90 days and is distributed in netCDF-4 format.
• Cross-platform presence on datagov and nasa_earthdata signals official importance and availability.

Limitations

• Key metadata such as row count, file size, and specific column names are unavailable across all sources.
• License is ambiguously listed as 'other-license-specified' without detailed terms.
• The 'last updated' metadata from datagov (2026-04 09) is a future date, indicating a potential metadata error or conflict.

Provenance

Source

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

Collection Method

Satellite measurements from the Advanced Microwave Radiometer (AMR), processed using Precise Orbit Ephemeris (POE) and analyzed calibrations.

Time Range

Data collection began after the mission launch on December 16, 2022; specific end date is not provided.

Freshness

2026-04-09 21:51:32.236962 (Note: This is a future date, which may be an error.)

Geography

Global coverage, with discrete measurements along two tracks approximately 30 km left and right of satellite nadir over oceans and inland water bodies.