Post-launch calibration of meteorological satellite sensors

Vicarious calibration techniques which are used to characterize the post-launch performance of meteorological satellite sensors in the visible and near-infrared regions of the spectrum in the absence of onboard calibration devices are briefly reviewed. Their application is illustrated with examples drawn from the post-launch calibration of the visible (channel 1: ≈0.58–0.68μm) and near-infrared (channel 2: ≈0.72–1.1μm) of the Advanced Very High Resolution Radiometer (AVHRR), flown on NOAA's Polar-orbiting Operational Environmental Satellite (POES), and of the visible channel (≈0.52–0.72μm) of the imager flown on NOAA's Geostationary Operational Environmental Satellite (GOES). The basic elements of a calibration strategy to address the blended geophysical data needs of the future are presented.