Study On Thermal Control Technique Of Space Hyperspectral Imager Based On The Sensitivity Analysis

With the highest spatial resolution and integrative spectral index in China,Tiangong-1hyperspectral imager (HSI) is a space spectral imager which is running inorbit at present. Tiangong-1HSI reaches international standards on spatial resolution,band numbers and range, and ground object classification. The high spatial resolution,high spectral resolution, and high radiation resolution of Tiangong-1HIS bringforward new challenge to thermal control relative to traditional multi-spectral remotecensor. As a complex optical instrument, the structure, restraint and payload ofTiangong-1HSI are all with asymmetry form. Furthermore, Tiangong-1HSI hasmany optical elements and rigorous thermal control index. These difficulties bringnew problems and new requirements to thermal control of the Tiangong-1HSI.Because of the problems mentioned above, the limitation of the traditional thermalcontrol technique is taken out. Sensitivity analysis of thermal design parameter(SATDP) is used to guide thermal design for the first time in this dissertation. Thethermal control technique based on sensitivity analysis is studied and explicated.SATDP could obtain the effect of their variety on system temperature distribution,which is a research field with important significance in thermal design. Furthermore,SATDP could help to carry out an optimum thermal design. Due to the rigorousenvironment and assembly technique, there is some deviation between the realparameters and the thermal design parameters of a space optical remote sensor (SORS)in orbit. The deviation might effects thermal design accuracy of complete appliances. In course of thermal design and thermal analysis for SORS, SATDP could find thesection which has effect on temperature field. For the sake of optimum design forthermal control system, SATDP is necessary. It could identify when or which, thermaldesign parameters play a significant role in the temperature field for SORS. Thepertinence and validity of thermal design can be enhanced through sensitivity analysis.Furthermore, SATDP could improve work efficiency, reduce cost and increasereliability. The Tiangong-1HSI is regarded as research object and the thermal controltechnique based on sensitivity analysis is summarized and studied in this dissertation.The SATDP of Tiangong-1HSI are discussed and analyzed. The generalizedconclusion are given and verified through test and simulation. The guidingsuggestions are given to practical engineering development and manufacturing. Theconcrete contents are given as below.The present research status of SATDP throughout the world is summarized andthe characters of structure and payload in Tiangong-1HSI are stated. The charactersand difficulties of thermal control technique are generalized. Against the characters ofthermal control technique with high degree of difficulty in Tiangong-1HSI, thethermal control technique based on sensitivity analysis is analyzed and set up. Thetheory and analytical method of sensitivity analysis are researched systematically.According to the structure style, mounting fashion and thermal design scheme,thermal design parameters of thermal control system are analyzed; and sensitivityanalysis contents for every thermal design parameter are given.SATDP for major structure and focal plane assembly in Tiangong-1HSI areresearched. The in-orbit heat balance equations of major structure and focal planeassembly are established, respectively. Under the design variable analysis of the heatbalance equations, SATDP for major structure and focal plane assembly ofTiangong-1HSI are developed. The main parameters which affect thermal design ofmajor structure and focal plane assembly are found through sensitivity analysis. Thethermal design of major structure and the key components such as focal planeassembly are developed and the optimum design of thermal design scheme of opticalelements and the key components are put forward. The thermal control index of Tiangong-1HSI is modified reasonably and its rationality is analyzed.The thermal test of Tiangong-1HSI is discussed. The technical difficulty andsimulation error of thermal test condition are analyzed. The correctness of thermaldesign scheme is verified through thermal test results. Temperature variation ofTiangong-1HSI is generalized in course of performance testing in orbit. Performancetesting results indicate that thermal control system of Tiangong-1HSI is runningperfectly. The temperature distribution and the temperature difference meet all theindex of thermal control. The accuracy and the reliability of the thermal controlsystem are estimated. The control accuracy of thermal control system is verifiedthrough thermal test. Several reliability model of thermal control system in SORS areintroduced. The reliability of thermal control system in Tiangong-1HSI is analyzed.