Relative Navigation Using Reflected GPS Signals

Ian R. Cohen

Abstract:	Relative autonomous navigation is currently a hot research area. The enabling technologies for autonomous navigation are the relative navigation sensors. Reflected GPS signals may be used to provide a relative navigation measurement between spacecraft, allowing the user to have a passive relative navigation sensor with little additional mass and no extra power. This paper examines the design and implementation of an autonomous relative navigation filter using reflected GPS measurements implemented in an Extended Kalman filter. The dynamic model implemented in the Kalman filter is the well-known Hill’s equations for relative spacecraft dynamics. The filter is then examined with a specific scenario tailored to a Shuttle rendezvous with the Hubble Space Telescope (HST). The scenarios tested were an uncontrolled collision, and a controlled docking to the Hubble Space Telescope. This algorithm is intended to fly on the Hubble Servicing Mission 4, Relative Navigation Sensor (RNS) experiment. The paper discusses the implementation and the actual algorithm scheduled to fly on-board the space shuttle in August 2008.
Published in:	Proceedings of the 2008 National Technical Meeting of The Institute of Navigation January 28 - 30, 2008 The Catamaran Resort Hotel San Diego, CA
Pages:	224 - 230
Cite this article:	Cohen, Ian R., "Relative Navigation Using Reflected GPS Signals," Proceedings of the 2008 National Technical Meeting of The Institute of Navigation, San Diego, CA, January 2008, pp. 224-230.
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