Study On The Stability Of Composite Tracking In Inter-satellite Optical Communication Link

Comparing with traditional satellite microwave communications, satellite optical communications has huge advantages, and it has become a national competing technology. With the development of satellite optical communication, improving tracking accuracy is much more important, especially in the use of optical fiber coupling technology. The traditional theoretical discussion about beam tracking convergence criteria can not meet the requirements. It is required that communication link tracking error not only meets the condition of tracking angle error convergence, but is less than a certain accuracy requirement.In this paper, the tacking stability of the composite tracking method commonly used in satellite optical communication was studied. First we introduce three international successful inter-satellite optical communication experiments. It is worth mentioning that the link experiment of NFIRE to Terra SAR-X conducted by Germany without using beacon light makes the terminal precision further improved. This paper gave a brief introduction and analysis about existing optical communication theory and tracking angle error convergence constraints. We discovered the shortcomings of the existing literature and make improvements about convergence constraint formula. Then this paper defined the tracking stability and analyzed the factors affecting tracking stability including satellite platform angular vibration, coarse and fine tracking noise, satellite relative angular movement and CCD angle measurement error. A optical communication stable tracking time estimation formula was proposed.This paper set up a Simulink simulation model of bidirectional optical communication link and the results of simulation matches theory. The paper studied and analyzed the “Ocean No. 2” satellite optical communication terminal and established a ground analog tracking link using the terminal. Finally this paper analyzed the optical configuration of the terminal and set up a simulation model of the terminal. The trend of experience matches simulation and the deviation was analyzed.