PREFIRE (Polar Radiant Energy in the Far InfraRed Experiment) Spectral Radiance from PREFIRE Satellite 2 (PREFIRE_SAT2_1B-RAD) contains calibrated and geolocated radiance data retrieved from data collected by the PREFIRE Thermal Infrared Spectrometer (TIRS-PREFIRE) aboard PREFIRE-SAT2. Dual CubeSats each carry a TIRS-PREFIRE, a push broom spectrometer with 63 channels measuring mid- and far-infrared (FIR) radiation from approximately 5 to 53 µm. Most polar emissions are in the FIR but have not been measured on a large scale. PREFIRE aims to fill knowledge gaps in the global energy budget by more accurately characterizing polar emissions. This information will then be assimilated into global circulation and other climate models to predict future climates more accurately.
PREFIRE_SAT2_1B-RAD data are processed by geolocating the calibrated radiance data in PREFIRE_SAT2_1A-RAD using the pointing and position telemeters in PREFIRE_SAT2_0-BUS-TLM and a Digital Elevation Map.

The PREFIRE_SAT2_1B-RAD data are used to analyze the radiative budget in polar regions and as an input for Level 2 products: top-of-atmosphere spectral flux, surface spectral emissivity, and atmospheric properties such as cloud cover, temperature profiles, and water vapor profiles.

Science data retrieval started June 29, 2024, and is ongoing. Geographic coverage is global, with the greatest concentration of data in the polar regions. Within the orbital swath there are eight distinct tracks of data associated with the eight separate spatial scenes for each PREFIRE-TIRS. At the beginning of the mission, the approximate scene footprint sizes were 11.8 km x 34.8 km (cross-track x along-track), with gaps between each scene of approximately 24.2 km. The entire swath was ~264 km across. Note that the scene footprint and swath sizes quoted here are for the orbit altitude soon after launch. However, the footprint size will slowly become smaller as the orbit altitude decreases with time. This data has a temporal resolution of 0.707 seconds and is available in netCDF-4.

Calibrated and geolocated radiance data for the sister instrument aboard PREFIRE-SAT1 can be found in the PREFIRE_SAT1_1B-RAD collection.