T/V Calibration for Microwave Humidity and Temperature Sounder onboard Chinese FY-3D satellite

The Microwave Humidity and Temperature Sounder, MWHTS, is being developed to fly on the new generation of FengYun polar orbiters, which is named FY-3D and due to be launched in the latter half of 2016. MWHTS with 15 channels in the range of 89 ~ 190 GHz is designed for atmospheric humidity and temperature sounding, and also for monitoring severe weather systems such as typhoons and rainstorms. Before the launch of MWHTS, a extensive series of experiments will be conducted in a thermal/vacuum (T/V) chamber to determine radiometric characteristics performance and verify the calibration method, which are of very importance before the launch. This paper presents an improved T/V Calibration design, which is useful in orbit operation and performance assessment and is necessary for better calibration accuracy.