Reprocessing of Suomi NPP CrIS sensor data records and impacts on radiometric and spectral long-term accuracy and stability

Abstract

Since early 2012, the Cross-track Infrared Sounder (CrI)S on board the Suomi National Polar-Orbiting Partnership (S-NPP) Satellite has continually provided the hyperspectral infrared observations for profiling atmospheric temperature, moisture and greenhouse gases. In this study, the CrIS Sensor Data Record (SDR) data are improved for climate applications with its fine-tuning of calibration coefficients in NOAA reprocessing project. One specific code for CrIS SDR reprocessing was developed. This code was updated with calibration algorithm, non-linearity, and geolocation to improve the scientific results. The calibration coefficients are refined with the latest updates based on the work from CrIS science team, and are inserted in the Engineering Packet (EP) in the Raw Data Record (RDR) data stream. The resampling wavelength was updated based on the metrology laser wavelength and resulting in zero sampling error in the spectral calibration. All the SDRs are generated with the same calibration coefficients, resulting in improved consistency during the CrIS lifetime mission. The reprocessed SDRs are essential for deriving the long-term climate trending such as tropical sea surface temperature trends and CO 2 trends. Evaluation of CrIS reprocessed SDR in term of spectral, and radiometric long-term accuracy and stability are presented.