Mitigating refraction and ambiguity in field-deployed FSO alignment: a robust multibody calibration framework

Abstract

This paper validates a software-defined, multibody celestial calibration framework that enables rapid, high-precision alignment of optical ground terminals for proliferated Low Earth Orbit (pLEO) networks. The research demonstrates a ”self-alignment” procedure that uses the terminal’s own acquisition sensor to observe the Sun and the Moon, systematically correcting for atmospheric refraction and the geometric ambiguity inherent in single-body observations. Validation was performed on a production space-qualified optical terminal, correcting a large field-setup error to a residual error of less than 2 mrad. This result validates the ”common-hardware” paradigm, confirming that mass-produced space hardware can be utilized for ground applications, enabling significant reductions in cost, logistics, and deployment time for tactical free-space optical (FSO) communications.