高时空分辨率动态星模拟器设计

Design of high spatiotemporal resolution dynamic star simulator

针对大口径空间天文望远镜稳像精度测试的难题,提出了一种高时空分辨率运动导星模拟方案。利用硅基液晶作为运动导星模拟源,结合光束准直系统为空间天文望远镜提供无穷远运动导星,并且通过在光路中加入物镜来提高模拟导星的运动分辨率。针对望远镜像面结构的特殊分布,提出利用多路模拟的方法,分别为望远镜两侧精密导星仪以及巡天像面提供实时运动导星。最后,对影响运动导星模拟精度的各项误差进行分析,进而建立了误差模型。仿真结果表明:在运动导星模拟精度优于0.5″的概率为95%,时间分辨率为3 ms的前提下,动态星图星间角距误差小于0.04″,单星张角小于0.02″。通过实验验证了导星模拟模型的正确性,该模型基本满足空间天文望远镜稳像精度测试所需运动导星目标高时空分辨率的要求。

Aiming at the problem of image stabilization precision testing of large-aperture space telescopes being developed in China, this paper proposes a high spatiotemporal resolution motion guide star simulation scheme. Firstly, the silicon-based liquid crystal is used as the motion guide star simulation source, and the beam alignment system is combined to provide the infinite motion guide star for the space telescope. The objective lens is added to the light path to improve the motion resolution of the simulated guide star. Then, owing to the special distribution of the telescopic mirror surface structure, a method for simulating the multichannel optical path is proposed to provide real-time moving guide stars for the precision guide sensor on both sides of the telescope and the survey image surface. Finally, the error sources that affect the simulation accuracy of the moving guide star are analyzed, and the error model is established. The simulation results show that under the assumption that the simulation accuracy of the moving guide star is better than 0.5″, with probability of 95% and time-resolution of 3 ms, the precision simulation of the interstar angular distance error of the dynamic star map is less than 0.04″ and the angle is the single star of less than 0.02″. The simulation model was verified by experiments and meets the requirements of high spatiotemporal resolution of moving guide star targets for image stabilization accuracy testing of space telescopes.