Multiple optical receive system for optical GEO feeder-links

Abstract

Optical feeder-links play crucial role in closing the global broadband coverage gaps. Point-to-point GEO satellite links provide advantage of uninterrupted availability limited only by ground conditions at the cost of higher SWaP to be able to close the link budget. By increasing field-of-view of the on-board optical terminals to approximately 1deg × 4deg, coverage over large enough area for exploitation of site diversity with more than ten optical ground stations and thus network availability above 99.9% can be achieved. We discuss design challenges and constraints together with trade-off evaluation towards the final design. We present optical and mechanical design of a payload prototype, including telescope with 250mm aperture, capable of tracking multiple optical ground stations over entire Mediterranean region. The tracking system concepts are presented to show potential compensation of the orbital effects that arise due to platform vibrations and orbital inclination. The preliminary results of the breadboard´s verification and acceptance process are presented. Insight into manufacturing, assembly, integration and testing stage of the individual prototype sub-assemblies will be given. Finally, system trade-off between various concepts as well as between the traditional use of multiple optical payloads and the presented baseline will be shown and discussed. The goal is to demonstrate the practical application potential of the multiple optical receive systems for future optical GEO feeder-links.