Development Of The Full-polarization Microwave Radiometer Calibration

It is widely known that the ocean occupies 71% area of the earth and our humans spread culture and economy through the ocean.As the world develops,it is more and more important to understand the ocean as it is the bridge to connect the world.Therefore,a lot of researches were going on for the ocean research topic.The research project of development of the polarimetric microwave radiometer calibration load structure was conducted by the department of mechnical engineering at Jilin University.This project was also coorperated with the National Space Science Center,Chinese Academy of Sciences.The goal of this project was to develop a key technology of the polarimetric microwave radiometer,which could be used to watch the wind speed and direction on the sea surface.In order to develop a polarimetric microwave radiometer,calibration step of the radiometer was paramount because the precision of radiation measurement was decided by the calibration step.Therefore,this thesis studied the structure the calirbration load part to improve the performance and the manufacturing process.This thesis mainly include:(1)Via literature search,the development of polarimetric microwave radiometer and its calibration technology is described,and the objectives of this thesis is demonstrated.(2)The principle of the polarimetric microwave radiometer calibration is researched.The structure design of the calibration load was conducted according to the instructions giving by the National Space Sciecne Center.Firstly,this chapter stated the whole structure of the calibration load part.Afterwards,this chapter explained the main shell,phase generator,non-standard thrust bearing and so on in detail.(3)Finite element analysis of the calibration load structure.ANSYS Workbench and Hypermesh were applied in this chapter to the static force and model analysis of the calibration load structure under the influence of gravity,static force analysis under the influence of heat when in working status and the random vibration analysis when in transporting status.(4)Development process of the antiradar coating material which would be applied to the blackbody and the test process.This chapter also described the coating process and assembling process of the blackbody.(5)Assembling and testing of the calibration load structure.In order to fulfill the instructions giving by the National Space Science Center,this chapter designed the wire gird structure and developed a method to assemble and test the thrust bearing.This thesis studied the key technologies of the polarimetric microwave radiometer calibration load structure,mainly includes the shell,the source of calibration load,the phase generator and so on.Especially,designing a new set of non-standard bearings used on polarimetric microwave radiometer calibration load structure.And the preparation method of absorbing coatings used for coating black body was studied,to promote the localization process of absorbing coatings.Introducing the method of manufacture,assembly and debugging.After testing and,this developed equipment satisfied the requriements of the working conditions.It provides a valuable scheme for the furture development of the polarimetric microwave radiometer.