The spectral characterization of the Crosstrack Infrared Sounder engineering model: Updated methodology and initial test results

For the proper radiometric calibration of the Crosstrack Infrared Sounder (CrIS) sensor it is imperative to provide high quality characterizations of the instrument line shape (ILS) and the spectral uncertainty of the sensor. The methodology for determining the self-apodized ILS using both a laser and gas cell measurements is discussed with emphasis on the updates to the gas cell methodology. These methods for characterizing the self-apodized ILS have recently been exercised using the CrIS Engineering Development Unit (EDU). A description of the test configuration, data collection and data analysis is presented. Finally the results are presented for the ILS determination are presented.