The Effect Of Thermal Environment On Optical System Dimension Stability

Importance of thermal design for space optical remote sensor by means of the integrated Thermal Structure Optical method refer to the research of dimension stability for a large space optical remote sensor is stated briefly in this paper. It also has some guiding significance for engineering design. The present apply condition of thermal analysis and thermal control for space remote sensor is introduced. After several evaluating methods of thermal analysis are compared, it is adopted the integrated analysis method to evaluate the effect of space remote sensor's thermal design.Thermal analysis theory for space vehicle on orbit is stated briefly in this paper. Thermal calculation model of optical system for a space optical remote sensor is built by using the I-DEAS software. Calculation of the thermal field of the optical system is performed. Primary Factors that influence the optical system's thermal field are analyzed. Principle of thermal control is proposed. Then the finite element models of primary mirror and segmented mirror are built by using the MSC Patran software based on the thermal structure coupled theory. Thermal deformation is calculated with different three points restrict displacements. Discipline that different restrict displacement influences primary mirror thermal displacement is received. The slightest restrict displacement to the primary mirror thermal deformation is obtained. Influences of different temperature environment to the dimension stability of the primary mirror are calculated. It also compares the different thermal deforming with different materials for the primary mirror and found that the largest factor to the primary mirror thermal deformation is the heat expansion coefficient of the material. All those can provide consultations for the optical system's thermal control. The paper elaborates the theory and the fitting processes of the Zernike polynomial refer to the integrated Thermal Structure Optical method. The thermal deformation data of primary mirror is fitted by non-spherical surface equations. It can provide initial conditions for further optical analysis. Factors that different thermal environment influences curvature radius r of the quadratic surface equations is analyzed.The integrated Thermal Structure Optical method doesn't have been deeply launched at home. The paper has been given an attempt and settled basis for its theory research and practical application.