Study On The Stability Constraint Condition Of Bidirectional Beam Tracking In Inter-satellite Optical Communication

As the countries have operated in-orbit tests in recent years, high-speed satelliteoptical communication technology is moving to the engineering applications. The latesttest results from Europe and Japan show that the current inter-satellite link iscomparatively unstable，in which only accounting for4.0%of the total experiment time.It affects the communication data transmission seriously. Therefore, further studies ofthe stability characteristics of bidirectional tracking process and clarify bidirectionalbeam tracking constraints are importance to improve the stability of the communicationlink and extending the maintain time of link.In this paper, the stability of bidirectional beam tracking in inter-satellite opticalcommunication was studied in theory, simulation and experiment. The researchbackground and development in the word in the PAT system in the inter-satellitesoptical communication were introduced summarily, firstly,. The control method, systemcontrollers and algorithms of the PAT system were introduced in detail. The currentsuccessfully bidirectional optical inter-satellite communication experiments wereanalyzed and summarized. The main factors inducing pointing errors were analyzed, thebeam transmission delay, relative movement between the satellites, micro vibration anddetector inaccuracy of measurement. Indicate the problems of current theory based onresearching of the single and bidirectional tracking progress. Then the effect of thereceive power, angle error of the detector and the stability of the tracking process werestudied. The iteration convergence process of the bidirectional beam tracking wasanalyzed, by building the model of the aiming error angle which imaged in the arraydetector in the receiving terminal, with considering the affects of signal noise ratio.Tracking steady constraint conditions theoretical formula, which is closer to the actualsituation, was deduced.At last, the simulation in the computer and the experimental simulation on theground was operated and verified and modified the theoretical result The stabilityconditions in difference conditions of the system and the compensation effect of theaiming angle error were obtained from numerical experiments. The experiments datawas compared with the theoretical result.It verified the theoretical results werecoincidence with actual conditions. This constraint conditions are important tointer-satellites optical communication terminal modified design.