Intelligent Urban Positioning using Multi-Constellation GNSS with 3D Mapping and NLOS Signal Detection

Paul D. Groves, Ziyi Jiang, Lei Wang, Marek K. Ziebart

Abstract:	Reliable metres-level positioning in dense urban areas is difficult to achieve cost-effectively using a single method. The way forward is to combine multiple positioning techniques. This paper introduces the concept of intelligent urban positioning (IUP), which combines ? Multi-constellation GNSS; ? Multiple techniques for detecting non-line-of-sight (NLOS) signal propagation; and ? Multiple techniques using three-dimensional mapping. IUP may also be extended to incorporate other position-fixing and dead-reckoning sensors. The paper begins by explaining the limitations of conventional GNSS positioning in dense urban environments. It then introduces the potential ingredients of intelligent urban positioning, a mixture of new and established techniques, and discusses how they might be combined. 3D mapping may be used for conventional map matching, height aiding, NLOS signal detection, reflection prediction and shadow matching, a new method for determining position by comparing measured and predicted satellite visibility. NLOS reception may also be detected using consistency checking, C/N0 measurement, dual-polarization antenna technology, an antenna array and a sky-pointing camera. The results of a preliminary demonstration of the IUP concept using GPS and GLONASS data collected in London are then presented. In this test, conventional GNSS positioning, aided by consistency-based LOS detection is combined with shadow matching. In the example presented, a horizontal position error of less than 2m was obtained, compared to about 25m for conventional GNSS positioning. This clearly demonstrates the potential of the IUP approach. Note, however, that further research is needed to improve the reliability.
Published in:	Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012) September 17 - 21, 2012 Nashville Convention Center, Nashville, Tennessee Nashville, TN
Pages:	458 - 472
Cite this article:	Groves, Paul D., Jiang, Ziyi, Wang, Lei, Ziebart, Marek K., "Intelligent Urban Positioning using Multi-Constellation GNSS with 3D Mapping and NLOS Signal Detection," Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012), Nashville, TN, September 2012, pp. 458-472.
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