为了提高月球激光测距试验中的回波光子数,考虑将自适应光学技术应用于云南天文台1.2 m光学望远镜,以实时校正望远镜跟踪误差和由于大气湍流的影响而造成的到达月球表面的激光束的扩展与漂移效应。针对月面为低对比度扩展源的特点,利用互相关函数法及绝对差分算法对采集的月面图像进行了大气波前倾斜量的提取。模拟了未去除和去除大气波前倾斜量的月面长曝光图像,发现去除大气波前倾斜量后的图像对比度较未去除有了相应提高。研究表明:月球激光测距试验中,绝对差分算法更适合用来提取大气波前倾斜量。

In order to enhance the returned photon numbers in lunar laser ranging,adaptive optics is considered to be applied to the 1.2 m telescope of Yunnan observatory to correct the telescope tracking error and the laser beam jitter caused by the turbulence. According to the low contrast extended character of the lunar surface,atmospheric tip-tilts were computed with cross correlation and absolute difference algorithms based on the collected lunar surface images. Long exposure images of the lunar surface were simulated with atmospheric tip-tilts being and not being compensated. The contrast of the lunar surface images were enhanced when the atmospheric tip-tilts were compensated. It is revealed that the absolute difference algorithm is better in computing the atmospheric tip-tilt in lunar laser ranging.