Derivation of JPSS-2 CRIS Pre-Launch Spectral Calibration Parameters from the Thermal Vacuum Test Data

The Cross-track Infrared Sounder (CrIS) on board the Suomi National Polar-Orbiting Partnership (S-NPP) Satellite, NOAA-20, and future Joint Polar Satellite System (JPSS) satellites J2 to J4 provide the hyperspectral infrared observations for profiling atmospheric temperature, moisture and greenhouse gases globally. In this study, the J2 CrIS prelaunch spectral calibration parameters including detector focal plane geometry (FOV size and offset angles, referred to as instrument line shape (ILS)) and Neon lamp effective wavelength are derived from the thermal vacuum (TVAC) gas cell test data. These derived parameters are evaluated using the spectral cross-correlation method by comparing with the simulated spectral lines from the line-by-line radiative transfer model (LBLRTM).