GPS/GNSS RECEIVERS AND APPLICATIONS FOR SMALL SATELLITES IN LOW AND HIGH EARTH ORBIT

GNSS receivers (specifically GPS receivers) have been used successfully in low Earth orbit satellite missions for several years and have become a standard part of many attitude and orbit determination systems on spacecraft in Low Earth Orbit (LEO). Other applications of GPS in space, formerly of great research interest, such as use of GPS at GEO, or GPS for attitude determination have not been taken up widely by the space industry. Some of this is due to the difficulty of demonstration, but it is also to some extent an indicator of the needs of the space industry. This paper looks at some of the technologies and trends in spaceborne GPS, using the concept of the Gartner Hype Cycle and tries to identify needs from trends. SSTL has developed its own range of COTS-based spaceborne GNSS receivers (SGR) and has a long history of successful operation on SSTL satellites and commercial sales for external satellite missions. Different customer needs dictate a range of space GPS products, each tailored to its own application from navigation to remote sensing. A new receiver, the SGR-07 has been developed to address the needs of current space missions, rapid delivery, modular standardised design and robustness. The first flight of the SGR-07 is due later in 2009. Future GPS / GNSS technologies are discussed, and their potential role in the space industry.