The clouds and the earth's radiant energy system (CERES) experiment will provide consistent data bases of radiation and cloud fields. The CERES instrument consists of a scanning thermistor bolometer package with built-in flight calibration systems. Two bolometer packages will be launched on the earth observing system (EOS) platforms to measure the Earth/atmosphere-reflected solar shortwave and Earth/atmosphere-emitted long wave radiances with measurement accuracy goals approaching 1.0% and 0.5%, respectively. In each package, there are three different bolometers. All bolometers will be calibrated in a unique TRW vacuum facility equipped with blackbodies, a cryogenically cooled active-cavity radiometer, shortwave sources, and other specialized calibration devices. The blackbodies are tied to the International Temperature Scale of 1990 (ITS'90). Using math models, the calibration measurements will define the instrument filtered gains and offsets. This paper outlines the CERES instrument design and radiometric calibrations.
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