Connectivity Services Based on Optical Ground-to-Space Links

Abstract

Repeater systems in a geostationary orbit utilizing free space optical communication offer great potential to backup, process and archive large amounts of data collected or generated at remote locations. In contrast to existing or upcoming global satellite communication systems, such optical GEO relays are able to provide a huge return-channel data throughput with channel rates in the gigabit-per-second range. One of the most critical aspects of such data uplinks are atmospheric disturbances above the optical ground terminals used to connect to the space segment. In this study we analyse the design drivers of optical ground stations for land-based applications. In particular, the effects of atmospheric attenuation and index of refraction turbulence are investigated. Moreover, we present implementation ideas of the necessary ground infrastructure and exemplify our results in a case study on the applicability of free space optical satellite communication to the radio astronomy community. Our survey underpins pre-existing ventures to foster optical relay services like the Space-Data-Highway operating via the European Data Relay System. With well-designed, self-sufficient and small-sized ground terminals new user groups could be attracted, by offering alternatives to the emerging LEO mega-constellations and GEO-satellite communication systems, which operate at low return channel data rates across-the-board.