Abstract: In order to ensure the on-orbit performance of high-precision spaceborne antennas, thermal deformation measurement tests are required in the development stage. The protection of measuring equipment in high and low temperature environments has always been the focus of thermal deformation measurement research. Based on the method of automatic photogrammetry of thermal deformation and different from the traditional vacuum measurement environment, a measuring camera protection method suitable for high and low temperature environment at atmospheric pressure is proposed. The whole structure adopts a positive pressure sealed protective tank with the quartz glass, temperature and pressure sensors. The hot and cold gas equipment is used to control the temperature of the camera under stable normal temperature through the automatic adjustment control system in the environment of normal pressure and high-low temperature. The theoretical analysis results prove the rationality and effectiveness of the design method. The practical results show that the proposed measurement camera protection method satisfies the ability of the camera temperature to maintain a normal operating temperature of (20±10)℃ at high temperature of 100℃ and low temperature of -70℃.

Key words: thermal deformation, photogrammetry, camera protection, normal temperature