白天卫星激光测距时,由于望远镜机架受太阳辐照和温度变化等因素影响,指向误差时变性较大,影响了对白天卫星的精确跟踪指向。针对卫星过境天区,提出了一种通过白天恒星监视,实现望远镜局部指向误差快速修正的方法,消除环境温度变化效应,实现高精度望远镜指向。以中国科学院上海天文台60 cm口径卫星激光测距系统为平台,应用短波截止滤光技术,实现了对亮于3等恒星的白天监视;并在卫星过境天区选择到6到7颗恒星进行观测,建立望远镜局部指向误差修正模型,以满足白天激光观测需求。该方法对白天卫星测距特别是高轨卫星等具有一定应用价值,也可推广到其他需白天目标观测的望远镜系统。
For SLR in the daytime,the time- varying characteristics of pointing error are large because of the influence of the solar irradiation and the temperature change,which will affect the pointing accuracy of tracking satellites.For the sky region where the satellites pass through in the daytime,the local pointing error correction method based on star monitor in the daylight is proposed to reduce the effect of atmosphere temperature variation and realize high accurate telescope pointing. Based on the SLR system with 60 cm aperture at Shanghai Astronomical Observatory,the ability of monitoring stars with the brightness brighter than the magnitudes of three has been achieved by using the short-wave cut- off filter in front of the camera. The 6 or 7 stars in the above mentioned sky region are selected to observe,and the local pointing error correction model is set up. The measuring results show that the pointing errors along the trajectory of satellite pass can meet the requirement of daylight tracking and telescope pointing. This method has certain practical value for daylight SLR,especially for high- orbit satellites and it can also be applied to the other telescope systems for daylight observation.