PREFIRE Satellite 2: Polar Surface Emissivity at 18.6 µm

PREFIRE_SAT2_2B-SFC_COG19um contains Cloud-Optimized GeoTIFF files providing retrieved surface emissivity values for a spectral channel centered at about 18.6 µm. The data are derived from a push broom spectrometer with 63 channels measuring radiation from 5 to 53 µm aboard one of two CubeSats, aiming to fill knowledge gaps in the polar far-infrared emissions for the global energy budget. Retrieved values are computed via an Optimal Estimation method using spectral radiance, cloud mask, and meteorological auxiliary data, and are rendered onto a global grid with raster elements approximately 2.23 km wide.

Use Cases

• Assimilating polar surface emissivity into global circulation models to improve climate predictions.
• Analyzing spatial patterns of far-infrared surface emissions in clear-sky polar regions.
• Validating radiative transfer models using satellite-derived emissivity from 63 spectral channels.
• Studying the surface radiative properties of land and ice in the under-sampled far-infrared spectrum.

Strengths

• Data fills a specific observational gap for polar far-infrared emissions, which have not been measured on a large scale.
• Employs a sophisticated retrieval method (Optimal Estimation) using inputs from three distinct data products (radiance, cloud mask, meteorological).
• Available as Cloud-Optimized GeoTIFFs, facilitating use in geographic information systems.

Limitations

• Surface emissivity values are only available for clear-sky conditions, limiting spatial coverage.
• The rendered GeoTIFF raster elements (2.23 km) are much smaller than the actual instrument footprints, which are about 80x larger in area, which may misrepresent the native data resolution.
• Key metadata such as row count, column names, and exact file size are not provided across platforms.

Provenance

Source

PREFIRE Thermal Infrared Spectrometer (TIRS-PREFIRE) aboard the PREFIRE-SAT2 CubeSat.

Collection Method

Derived from PREFIRE Spectral Radiance (PREFIRE_SAT2_1B-RAD) data using an Optimal Estimation retrieval via a radiative transfer model, with inputs from cloud mask and meteorological auxiliary data.

Freshness

2026-04-09 23:04:12.906802

Geography

Global, with a focus on polar regions.