中文摘要：

本文从激光测距回波方程及噪声方程出发阐明了降低背景噪声（滤波）是提高激光测距回波信噪比的关键；并通过对望远镜轴系进行指向修正并采用可变光阑减小望远镜视场来实现“空间滤波”，采用窄带滤光片实现“光谱滤波”，采用高精度距离门选通技术实现“时间滤波”，北京房山人卫观测站的激光测距系统具备了白天观测人造地球卫星的能力。本文还引入了C-SPAD“敏感度”的概念并且提出了一种依靠C-SPAD来调整可变光阑位置及滤光片角度的方法。

英文摘要：

This paper analyzed the echo formula and the noise formula then found out that decreasing the background noise is the key to increase the signal noise ratio, which focuses on three filtering methods which are spatial filtering method, spectral filtering method and temporal filtering method to achieve the ability of ranging satellites by daylight. Through the research and implement ation on these filtering methods, Fangshan satellite laser ranging station was upgraded to range the satellites by daylight. Furthermore this paper introduced the definition of sensitivity of C-SPAD and brought forward a method of adjusting the position of diaphragm and the an- gle of the spectral filter.