MEASUREMENTS OF THE AMSU-B ANTENNA PATTERN

Measurements of the antenna patterns for the high frequency component of the Advanced Microwave Sounding Unit (AMSU-B), to fly on the NOAA-K LM polar orbiting satellites, are reported here. They were made on the Compact Antenna Test Range at Queen Mary and Westfield College, Londo n, at three frequencies within the AMSU-B receiver's channels, centere d at 89, 150, and 183.31 GHz. The main reflector of AMSU-B's antenna i s an offset parabola with a 219-mm diameter aperture. This paper descr ibes the measurements that were made and presents the results of an an alysis of them for the three AMSU-B flight models. Measurements of bea mwidths, main beam efficiencies, and sensitivity to cross-polarization are all reported. These data are then used to compute simulated anten na temperatures for the space and Earth views and recommendations for correcting the space view and Earth view data due to antenna effects a re proposed. The implications for the operational radiometric calibrat ion of AMSU-B are also discussed.