Absolute, spectrally-resolved, thermal radiance: a benchmark for climate monitoring from space

Spectrally resolved thermal radiances measured from orbit with an accuracy in brightness temperature of 100 mK constitute a critical observation for climate monitoring. The design of a small, low-cost instrument capable of accuracies of better than 100 mK, demonstrated on-orbit, is presented and analyzed. It is shown that systematic and random errors inherent in observations from space can be reduced to levels commensurate with the instrumental accuracy of 100 mK. Monitoring spectrally resolved radiance, accurate to 100 mK, is feasible, and constitutes a versatile climate Benchmark observation that is needed in the national research strategy. (C) 2003 Elsevier Ltd. All rights reserved.