Beam divergence angle optimization for the compensation of the elliptical pointing error in nanosatellite optical communication

With the rapid increase in the deployment of nanosatellites, free-space optical (FSO) communication has become widely utilized to mitigate possible RF interference between inter-satellite links. Failing to optimize the beam for pointing errors during the design phase can result in degraded pointing, acquisition, and tracking (PAT) accuracy or reduced transmission gain. In this study, we analyzed the causes of elliptical pointing errors in nanosatellites and mathematically modeled their elliptical formation. Furthermore, an algorithm for optimizing the beam divergence angle based on given pointing errors is proposed. The proposed algorithm is demonstrated to maximize transmitter gain, enhance the link budget, and significantly improve the performance of optical communication systems. Additionally, the influence of pointing error parameters on the optimization of the beam divergence angle is investigated, providing valuable guidelines for designing optimal beam divergence angles in nanosatellite optical communication systems.