Calibration of the Microwave Limb Sounder on the Upper Atmosphere Research SatelliteThis paper describes pre-launch radiometric and spectral calibrations of the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS). Use of in-flight data for validation or refinement of calibration is described. The estimated uncertaint in calibrated radiance from pre-launch radiometric and spectral calibration data is better than 2% in most bands.