Advanced Acquisition and Tracking Technology for Satellite Laser Communication

Space laser communication technology has the advantages of high communication rate, strong anti-interference performance, no need for spectrum authorization, less weight and low power consumption. Laser link acquisition and tracking is the core technology of space laser communication. With the construction of large-scale constellation, higher requirements are put forward for laser link acquisition and tracking technology. In order to quickly complete the acquisition and tracking of the laser link and keep the stability of the laser link for a long time, the acquisition and tracking technology of the laser communication system needs to be constantly improved. In this paper, a target acquisition and tracking technique based on variable beam divergence angle is proposed. The beam with large divergence angle is used to achieve fast capture of laser link, and the beam with small divergence angle is used to achieve long distance high-speed communication. By adjusting the collimator distance l from 995mm to 1005mm, the divergence angle can vary between 21.6μrad and 950μrad. The acquisition probability of different divergence angles is analyzed. When the standard deviation of random position angle is constant, the acquisition probability increases with the increase of divergence angle.