CrIS raw data records (level 0) to sensor data records (level 1b) processing

The Cross-track Infrared Sounder (CrIS) is part of the National Polar-orbiting Operational Environmental Satellite System (NPOESS) series of polar-orbiting spacecrafts. The CrIS sensor forms a key component of the larger Cross-track Infrared/Microwave Sounding Suite (CrIMSS) and is intended to operate within the context of the CrIMSS architecture. The CrIS instrument is a Michelson interferometer infrared sounder covering the spectral range of approximately 3.9 to 15.4 microns. CrIS provides cross-track measurements of scene radiance to allow the calculation of temperature and moisture vertical distributions in the Earth's atmosphere. We present sensor data record (SDR) level 1B algorithms that are needed on ground in order to produce meaningful data meeting all requirements of the NPOESS CrIS instrument. Level 1B data are made of geolocated, radiometrically and spectrally (spatial frequency) calibrated spectra with annotated quality indicators. CrIS SDR algorithms include, among others, radiometric calibration with phase error correction, interferometer fringe count error handling and correction of the instrument line shape (ILS) distortion.