Research On Simulation Technology Of Large Field Of View Multi-star Simulator

The star simulator is used to provide a point light source at an infinite distance from the measured object as the simulated star point,which can simulate the size,star equivalence and spectral characteristics of the target star.The research of conventional star simulator mainly focuses on the research of its simulation accuracy.In recent years,with the development of star sensor technology,star module technology has gradually transferred to the simulation of the real radiation characteristics of the target star,namely the stellar spectrum and the real magnitude.The precision of star simulator is more and more demanding,so it is of great significance to develop a high precision multi-star simulator with large field of view.In this paper,with 65 stars at infinity imaging target source simulation region establishment day stars area coordinate system,the J2000.0 celestial coordinate system coordinates into stars in simulator coordinates,through calculating optical axis pointing to the parallel light pipe,design base that meet the conditions,place all parallel light pipe according to the calculation results light pipe installation base,the parallel light pipe target source location can be simulated stars.The selection of optical tube and the stability of focal plane are analyzed.Cassegrain type optical tube is selected and the optical path is designed by CODE V.Finally,the MTF value of the optimized system reaches the diffraction limit.The LED was selected as the light source and the parallel optical tube assembly was designed.The magnitude adjustment is realized by using the adjustable constant current driving technology of duty cycle adjustment,which controls duty cycle,adjusts the output illumination of LED light source to simulate the magnitude of different stars,determines the required light intensity through the analysis of the magnitude energy calculation model,and calibrates the illumination and position of the light tube.The maximum measured position deviation of sky region star simulator is 2.5".The maximum relative error of measured magnitude and theoretical magnitude is 4.7%,and the maximum illumination error of 4 hours is 6.69%.Moreover,the magnitude can be adjusted within the range of ±1.5Mv,and the adjustment interval of magnitude is 0.05 mv.