Abstract:The study on the acquisition and tracking simulation system in satellite-ground optical communications is presented here. By applying global positioning system (GPS) coordinate calculation, the time needed in initial acquisition of light beacon can be reduced largely. Smith predictor is applied to compensate the mechanical hysteresis of tracking system and to improve the dynamic performance of the system. Tracking experiments over a 16 km distance on the ground are conducted to verify the tracking of light beacon in satellite-ground optical communications. The standard deviation of horizontal coordinates is 35.3568 μrad and the maximum offset is 209.3675 μrad in stable tracking.