JPSS-2 CrIS L1B V4 Data Release

The Cross-track Infrared Sounder (CrIS) Level 1B Sounder Development Team at the University of Wisconsin-Madison and the Jet Propulsion Lab (JPL) Sounder Science Investigator-led Processing Systems (SIPS) group have released the CrIS Level 1B Version 4 data collection from the Joint Polar Satellite System 2 (JPSS-2) satellite, also known as NOAA-21. This data product was generated at the Goddard Earth Sciences Data and Information Services Center (GES DISC) using software authored by the University of Wisconsin-Madison and the University of Maryland-Baltimore County under NASA funding.

Applications using the CrIS L1B radiance products include retrievals of atmospheric and surface parameters — temperature, water vapor, cloud radiative properties, cloud top height and temperature, surface emissivity and temperature, and trace gases — as well as evaluations of radiative transfer models, climate trends, and climate process studies.

The current version (Version 4) is the first science-quality data product from the JPSS-2 CrIS sensor, superseding the preliminary JPSS-2 CrIS Level 1B Version 3 beta product released in 2023. Compared to the previous version, Version 4 contains improvements to the L1B calibration, geolocation, quality monitoring, and metadata. 

Additional details on these improvements can be found in the NASA Cross-track Infrared Sounder (CrIS) Level 1B Product Users’ Guide and the NASA Cross-track Infrared Sounder (CrIS) Level 1B Delta Algorithm Theoretical Basis Document (ATBD).

CrIS is a Fourier Transform Spectrometer onboard the SNPP satellite (launched October 2011), the JPSS-1 satellite (launched in November 2017; also known as NOAA-20), and the JPSS-2 satellite (launched November 2022; also known as NOAA-21). The SNPP, JPSS-1, and JPSS-2 satellites each move through sun-synchronous, near-polar orbits with an altitude of 824 km, an inclination angle of 98.7 degrees, and a 13:30±10 minutes afternoon local time ascending (northward moving) and 1:30 ±10 minutes morning (descending, or southward moving) equatorial crossing time with a 16-day repeat cycle.

The interferometer measures three infrared (IR) bands simultaneously using 27 detectors along three focal planes — long-wave, mid-wave, and short-wave — with each focal plane containing nine detectors arranged in a 3x3 pattern. Data products are partitioned into six-minute granules, with one granule per file and 240 granules per day.