Design of static star simulator based on testing of very high accuracy star sensor

Abstract

During the runtime of the spacecraft in space, spacecraft uses optical navigation sensor to capture and measure its flight attitude information.Very high accuracy star sensor is a kind of navigation sensors.Star simulator serves as the calibration equipment for star sensor on the ground has received more and more attention.In order to complete the testing of very high star sensor, according to the working principlestatic of the star simulator,an collimating optical system has been designed which can achieve high precision simulation of the star point.Using ZEMAX software to complete the design of the optical system and calculating the star point emitting precision at -45 °C ~ +65 °C with multiple structural function.The design results show that,the designed wavelength of the system is 500~900nm,wherein the center wavelength is 680nm.At 20°C,the distortion is 0.01%, MTF is higher than 0.5 at the frequency of 60 lp/mm within the filed of view of 7.2°.The collimation errors are both less than 1″ at the two limit temperatures.Applying ANSYS software to analysis the deformation of machine structure at different temperatures, the result shows that the overall deformation has the same tendency as the lens group，and can meet temperature requirements. Then making the precision analysis of the optical system and providing a group of measured data. Depended on the measurement results, the error of position for single star ≤7″, the error of angular distance between stars≤10″. The data shows that this design and the product meet the requirement of technique index.