Acquisition analysis for small-satellite optical crosslinks

Small satellites are increasingly exploited for the realization of low Earth orbit (LEO) constellations for Earth imaging, global connectivity and data relay. Optical crosslinks between satellites can drastically increase the constellation capability to transmit data to ground stations with reduced latency and increased total throughput. One critical aspect of optical crosslink is the acquisition phase, which requires that each satellite scans its field of view looking for the beacon laser transmitted by the partner terminal before starting communication. In this paper, the problem of beacon acquisition for optical crosslinks is analyzed, with focus on the small satellite case. Numerical simulations and a simplified, yet representative laboratory experiment are carried out to evaluate and compare two different scanning techniques quantitatively.