Development of New Calibration Targets for FY-3 Satellites Microwave Radiometer

This work presents the development of ground-based calibration units for microwave radiometer on FY-3 meteorological satellites. These targets consist of two temperature adjusted calibration source and one cryogenic source operating in thermal vacuum chamber. Here, we focus on optimum balance design between the high electromagnetic emissivity and uniform temperature distribution for those targets. The engineering prototype of those targets finished in May 2020. Emissivity from 10GHz~183GHz and temperature uniformity were determined in ambient environment and vacuum chamber respectively, and the results show excellent consistent with expectancy.