水平子午环微光探测系统  

A Detector System for Fainter Light on the Meridian Circle

作　　者：李志刚[1] 许林生[1] 

机构地区：[1]中国科学院陕西天文台

出　　处：《计量学报》1995年第3期226-229,共4页Acta Metrologica Sinica

摘　　要：来自遥远天体的信号相当微弱，往往被夜天光所淹没，无法提取有用的信号，因此天文微光探测力求尽可能减少夜天光的影响，获得尽可能高的信噪比，活动光栅是减少夜天光影响的最佳方案。光子计数的应用可直接获得星光信号的数字量，为噪声的研究提供了可能。本文介绍的微光探测系统就是基于上述原则设计的，已成功地用于中国与丹麦合作研制的全自动水平子午环上，其系统精度为０．０３角秒。另一方面应选取合适的数学模型，以期结果更接近于无偏估计，作者提出了一种相关处理方法，其特点是无需任何假定，因此这种归算更接近于无偏估计，特别适用于暗星观测的归算。The stellar light from deep sky is very faint. Frequently, it is inundated by night sky light. So, it is not possible to separate a useful signal from noises.Therefore, a detection of fainter stellar light of astronomy needs to avoid the effect of night sky light on it. Based on above principle, an optimum scheme for reducing the effect of night sky light is to use active slits. While a technique of photon counter is employed, research of noises is to be possible A detector system for fainter light has been designed and used on the Danish-Chinese meridian circle successfully. The systematic uncertainty is about 0' .03. For procedure, it is necessary to select a suitable model. A technique of cross-correlation for the determination of stellar positions is proposed. An advantage of this process is that there is no hypothesis required for modelling image profile and for the noise. It is closed to unbiased estimation. The procedure is suitable to process data of observations for the fainter stars.

关 键 词：光子计数 微光探测器 光栅 天体测量 子午仪 

分 类 号：TH752.103[机械工程—仪器科学与技术]