Optical communications terminals for multi-media applications

Constellations of satellites will perform a key role in the provision of multi-media services both on a continental and global scale. Such constellations are likely to involve satellites in GEO, LEO and MEO orbits - either in a single orbital system such as GEO or LEO, or in combinations eg MEO and GEO. In some of these systems ISLs are fundamental to their operation while others derive significant additional benefit from the inclusion of ISLs. MMS is developing terminal designs to meet these various anticipated requirements under both MMS and ESA funded programmes. This paper outlines some of the European multimedia initiatives that MMS is involved in and discusses the technology choices for the ISLs. In particular, the terminal requirements for both long and short range GEO to GEO links are presented. Two critical technologies which MMS is developing for these applications are described - namely, silicon carbide telescopes and acquisition and rear-tracking (ARTS) sensors. These are important building blocks for robust and cost-effective optical terminals for multimedia applications.