2015年上海天文台卫星激光测距观测报告

Report on Satellite Laser Ranging Observations at Shanghai Astronomical Observatory in 2015

介绍了2015年上海天文台卫星激光测距系统的常规观测、系统升级改造及科研实验情况。激光观测数据质量已成为国际激光测距台站关注的重要问题。2015年度对上海天文台激光测距系统的接收系统、控制系统和地靶校准系统等进行了改进，使观测数据质量明显提高，数据稳定性达到国际标准；为提升激光测距能力，开展了效率更高、噪声极低的超导纳米线单光子探测器（superconducting nanowire single photon detector，SNSPDl测距技术研究，在国际上首次采用SNSPD技术成功实现最远20000km卫星测量试验，为实现远距离、小尺寸空间目标的激光测距突破提供了途径：针对白天激光测距望远镜精确指向的关键问题，研究了恒星与大气散射光谱曲线的峰值差异性，并应用短波截止滤光技术，实现了对星等小于3mag的恒星的白天监视，使望远镜白天指向误差均方根优于10”。该研究成果己应用于本站白天卫星激光测距，尤其是高轨卫星激光测距，并起到了重要作用。

The routine observations, upgrading and scientific experiments of satellite laser ranging （SLR） system of Shanghai Astronomical Observatory in 2015 are reported. The data quality has become an important issue concerned by the international SLR stations. In 2015, the receiving terminal system, controlling system and calibration target have been improved, so that the data quality has been significantly improved and has met the international standard in data stabilization. In order to further increase ability of laser echo detection, the technical research of superconducting nanowires single photon detector （SNSPD） which has higher efficiency and lower noise than other detectors is carried out in SLR experiments. As far as 20000 km satellite has been measured successfully by using SNSPD for the first time in the world, which provides one way for further and smaller targets obser- vation. For the key problem of telescope precision pointing, spectral curve of stars and atmosphere scattering are investigated respectively and the short wave cutoff filters are used to realize star observation which is brighter than star magnitudes of 3 during daytime. Through processing the telescope pointing error model, root mean square of telescope pointing is better than 10 ＂ in daylight, which is applied SLR measurement and plays an important role, especially for the measurement of high earth orbit satellites during daytime.