Suomi-NPP Cross-Track Infrared Sounder (CrIS): Radiometric Calibration and Validation

The Cross-track Infrared Sounder (CrIS) is the high spectral resolution spectroradiometer on the Suomi National Polar-Orbiting Partnership (NPP) satellite. Here we describe the CrIS radiometric calibration uncertainty (RU) based on pre-launch and on-orbit efforts to estimate calibration parameter uncertainties, and provide example results of post-launch validation efforts to assess the predicted uncertainty. This RU parameterization provides essential information on the use of the CrIS data for weather, intercalibration, and climate applications. Resulting on-orbit RU estimates for Earth view spectra are less than 0.2 K 3-sigma in the midwave and shortwave bands, and less than 0.3 K 3-sigma in the longwave band. In general, post-launch validation results to date indicate that the on-orbit RU estimates are representative. Efforts to validate CrIS calibration and to minimize remaining calibration artifacts will be presented.