Study On The Reconition And Tracking Algorithm Of The Beacon For Intersatellite Laser Communications Based On Optical Flow Method

Satellite laser communication technology has gradually become an international research hotspot.For the satellite-to-satellite optical communications,the two communication terminals are required to track the beacon in time.In the tracking process,stars background light in the space may enter the optical terminal,forming a spot in the CCD receiver surface,which makes it difficult for the system to determine the exact location of the beacon.The background spots have an influence on the beam pointing control and lead to a decrease in the stability of the entire system,and even cause the laser link interruption in severe cases.In view of the problems above,this paper mainly studies how to accurately identify and track the beacon,reducing or eliminating the influences of stars background light on the system.Initially,this paper summarizes the current research situation of suppressing the background light and identifying the beacon.According to the characteristics of the inter satellite laser communication system,the research direction of this paper is clarified.Secondly,in order to extract and track the beacon,this paper presents a method of tracking the beacon based on the optical flow method.In the case of partial coincidence of the spots,this paper presents a method for calculating the centroid of the beacon.In order to quickly remove the noise spot,based on the results of the light spot traced by the optical flow method,a denoising method based on statistical centroid coordinate sequence is proposed.Thirdly,in order to meet the real-time tracking requirements of the system,this paper proposes an adaptive prediction algorithm.The algorithm is used to predict the motion trajectory of the beacon by simulation analysis.In this paper,the effectiveness of the optical flow tracking method and the adaptive prediction method are verified by the simulation experiment,the vibration of the satellite platform is simulated by the fast steering mirror,and the CCD is used as the terminal receiving detector.In these simulation experiments,the typical satellite platform vibration frequency is used to verify the algorithm's environmental adaptability and reliability in a variety of typical vibration conditions.