Test Target for Beacon Alignment in Optical Ground Stations

Abstract

A key aspect of ensuring robust optical communication between a satellite and an optical ground station (OGS), is the proper alignment of the beacon lasers used for indicating the OGS location to the satellite. Current methods to verify beacon divergence and directional alignment often lack accuracy and reliability and they do not provide both adjustments at the same time. In this work, a device designed to support beacon alignment by combining image processing and measurements taken by photodetectors is presented. The system uses a camera and reflective foils to initially align the beacons as well as capturing its intensity distribution for divergence calculations. The fine directional adjustment is provided by photodetectors, and the received power is used to estimate the beacon's divergence. These two methods enable simultaneous directional and divergence adjustment of the beacons. It was evaluated outdoors under realistic conditions, demonstrating its potential as a practical tool for optimizing beacon alignment.