Radiometric characterization of AMSU-B

The Advanced Microwave Sounding Unit, AMSU, is being developed to fly on the new generation of NOAA polar orbiters due to be launched in the latter half of the 1990's. The UK Meteorological Office (UKMO) are procuring the high frequency component of AMSU (AMSU-B) with five channels in the range 88-191 GHz. In order to determine the radiometric performance and verify the method for calibration of AMSU-B an extensive series of tests have been performed by the UKMO on the engineering and three flight models. The instruments were placed in a 3 m thermal-vacuum chamber where their temperature could he controlled over the full range expected in orbit and an Earth target and a space target could be viewed. For the first flight model the measured Ne/spl Delta/T values were all >