Tracking and Aiming System of Satellite Optical Communication and Its Optimal Design

Satellite laser communication has high communication speed, good confidentiality, and wide application prospect. At the same time, with the development of the era, the satellite optical communication link with large capacity and high availability needs to calibrate the optical communication terminals between satellites; so, it is necessary to further optimize the tracking and aiming system of the satellite optical communication terminals. Compared with the design layout of general tracking and aiming system, the integrated structure layout is adopted to make the tracking and aiming system structure more compact; meanwhile, the communication link is simpler, and the signal transmission is more reliable. TMS320F2812 is used as the main control chip for data processing and control operation. The control method and relevant parameters of the motor are referred, and the corresponding drive circuit of the motor is designed; then, according to the requirements of the communication interface, the corresponding communication circuit is designed, and a large number of photodetectors are arranged around the tracking hardware; after the hardware design of the tracking and aiming system is completed, the source of tracking and aiming error is analyzed. According to the types of tracking and aiming error (error without static bias and error with static bias), the mathematical model of tracking and aiming error is proposed to reduce the tracking and aiming error, and the functional relationship between tracking and aiming error and link reliability is derived. In the experiment, the relationship between link reliability and beam angle is tested first. The results show that the link reliability increases first and then decreases with the increase in beam angle; in the error analysis without static deviation, the reliability of the link can be improved by using the optimal beam angle, and the reliability of the link can be increased first and then decreased by increasing the communication rate; in the error analysis of static deviation, it is confirmed that there is an optimal beam angle which can make the reliability of optical communication link reach the highest value.