Athermalization of star sensor optical system with large field of view and low distortion

Abstract

Star sensor is the key measurement equipment for satellite positioning and spacecraft attitude control. It provides high-precision measurement data for spacecraft attitude control and astronomical navigation. In order to realize the accurate measurement of star positioning and spacecraft attitude by star sensor in the environment with large temperature difference in space, according to the thermal compensation theory, an athermal star sensor lens with wide band, large field of view, low distortion is designed, which can work in wide temperature range. The working band is 450nm to about 850nm, the F number is 1.5, the field angle is 20°, and the diameter of the pupil is 30mm. The analysis results show that the relative distortion of the system is less than 0.06%, the lateral aberration of the full field is less than 3.7μm, the surrounding full field-of-view energy ratio within φ20mm is large than 80%, and temperature range is -50℃ to about 60℃. The change of relative distortion, lateral aberration, energy concentration and other indicators relative to 20℃ is no more than ±10%, which fully meets the application requirements of high-precision star sensor in space environment.