Reflectors reflectivity of the MADRAS spaceborne radiometer

MADRAS (Microwave Analysis & Detection of Rain & Atmospheric Structures) is a conical scan radiometer providing imaging capability in the 18-157 GHz range. MADRAS is one of the three instruments of the MEGHA-TROPIQUES Satellite launched in October 2011. The MEGHA-TROPIQUES Satellite will study the water cycle and energy exchanges in the tropical belt. The Satellite is jointly developed by the Indian Space Research organisation (ISRO) and the French Space Agency (CNES). EADS ASTRIUM provides the main part of the MADRAS Radiometer, including the Antenna & Calibration System and the Receiver equipments. It is a nine channels self-calibrating passive microwave radiometer. This instrument places stringent requirements on antenna electrical performance due to the low-noise signal levels and the high beam efficiency involved. The present paper focuses on the reflectivity performance verification of the two reflectors involved in the instrument: the main one used for Earth brightness temperature remote sensing and the calibration one.