HSGPS Signal Analysis and Performance Under Various Indoor Conditions

G. Lachapelle, H. Kuusniemi, D.T.H. Dao, G. MacGougan, M.E. Cannon

Abstract:	High-Sensitivity GPS (HSGPS) receivers permit GPS signal measurements to be acquired and to track in certain indoor environments where previously not possible. However, position solution reliability and accuracy are significantly degraded due to the non-availability of some satellites, multipath errors, measurement noise associated with the low-power of the remaining signals, and echo-only and cross-correlation signal tracking. Provided that a GPS receiver has already acquired signals outdoor, additional information aiding is not a prerequisite for indoor tracking. The prime characteristics for indoor tracking are coherent signal integration and non-coherent signal accumulation over periods of up to several hundred milliseconds. The focus of this paper is to improve static mode HSGPS positioning performance in terms of accuracy and reliability and, thus, various techniques such as height fixing, simulation-based noise modeling, reliability and integrity testing, and batch processing are implemented in order to improve to positioning accuracy and reliability. A XTrac-LP(tm) (Extended Tracking - Low Power) HSGPS evaluation kit, developed by SiRF Technologies Inc., is used to investigate some indoor environments, namely a residential house and a concrete and steel commercial building, by analysing the fading and pseudorange error conditions. In addition, the measurements provided by the XTrac-LP(tm) receiver are used to test the performance of the positioning algorithms intended to improve the HSGPS positioning capability.
Published in:	Proceedings of the 16th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS/GNSS 2003) September 9 - 12, 2003 Oregon Convention Center Portland, OR
Pages:	1171 - 1184
Cite this article:	Updated citation: Published in NAVIGATION: Journal of the Institute of Navigation
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