ON THE DESIGN OF GROUND-BASED RADIOMETER ANTENNAS

This paper deals with the design of ground-based radiometer antennas. In order to investigate the interaction of the antenna pattern with it s noisy surroundings, a model for the brightness temperature of the en vironment is presented. This is followed by a description of a method for finding a template for the antenna pattern which assures a prescri bed measurement accuracy. Therefore, different contributions of the an tenna to the uncertainty of the measured brightness temperature are di scussed, such as those due to the sidelobes, the non-zero beamwidth an d the pointing errors of the positioner. A theoretically optimal anten na configuration is presented and the performance parameters of two of ten applied reflector antennas are compared with those of the optimal system. Finally, the resulting radiometer-antenna design procedure is presented.