Scientific Calibration And Control Plan For Microwave Sounder Of Chang'E-1 Satellite

Microwave Sounder is one of the main payloads of ChangE-1 lunar satellite. It is a multi-band microwave radiometer with operation frequencies of 3.0GHz, 7.8GHz, 19.35GHz and 37.0GHz, respectively. The scientific object of Microwave Sounder is to measure Lunar Regolith brightness temperature at different depths for retrieving Lunar Regolith depth and evaluating the number of He-3 and its distribution on the moon. It's the first time to detect the moon by using microwave radiometer in the world.Microwave Sounder's low brightness temperature calibration source will be provided by calibration antenna which is pointing towards the cold space. Because the sun sometimes runs into the view of the antenna, it becomes the primary affection to the cold source while the microwave radiometer is calibrating. In order to full and effective use all of the observation data obtained from Microwave Sounder, we provide the solutions from two different directions: direct way and indirect way. The direct way is mainly analyzing the solar radiation affections to the cold space calibration source. The indirect way is substituting cold space calibration source by using stable lunar Arctic and Antarctic brightness temperatures which can be obtained first and carrying out analogy calibration on orbit. We also summarize the on-orbit calibration plan for Microwave Sounder: While on forward-flight, Microwave Sounder calibrates at normal periodical way; while on sideward-flight, Microwave Sounder calibrates by using analogy calibration method.There is a relationship between environmental temperature and system gain and noise of Microwave Sounder's receiver. In order to make sure this relationship, we design a temperature experiment to test the performance of Microwave Sounder working in the normal temperature range. These results will not only improve the veracity of Microwave Sounder's on-orbit analogy calibration, but also will provide a theoretical reference for controlling Microwave Sounder working at high-point.The final purpose for Microwave Sounder's work is to retrieve Lunar Regolith depth, but the differences between these elements are representing as tiny outputs of Microwave Sounder. In order to get Lunar Regolith depth's information and find a way to analyze these tiny outputs, we should control Microwave Sounder under the effective output range. According to the solar radiation affections analyzed first and the temperature characteristics of Microwave Sounder, we provide the on-orbit control plan for Microwave Sounder by introducing particular adjusting way of AGC and Bias Voltage on three idiographic working states. When Microwave Sounder is on orbit, this plan will give necessary information for controlling and data injection.