Performance evaluation of atmospheric tip-tilt computing algorithms based on lunar surface images

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