A GPS Method for Real-Time Parallel Track Resolution

Patrick Y.C. Hwang

Abstract:	There are many different positioning requirements in the railroad environment. Most of these are easily met by the use of GPS. Perhaps the most stringent among them is that of determining if a train is in fact traveling on one track or on another that is no more than 15 feet away and parallel to it. The problem requires a high level of positioning accuracy while operating in a railroad operating environment that may likely provide very restrictive line-of-sight coverage over extensive durations of the track which potentially causes situations of poor satellite geometry. This paper introduces a carrier phase-based technique to solve the problem of parallel track resolution as a train passes a switchpolnt and also takes advantage of the one-dimensional nature of the railroad track to improve the measurement situation thereby making it more robust for real-time operation. The resolution of the parallel tracks is solved as a statistical hypothesis test. Computer simulation and experimental results are included to demonstrate the capability of this technique to resolve parallel tracks with a high level of confidence. Discussion on factors that reduce the effectiveness of this method to resolve tracks, including the role of satellite geometry, is included.
Published in:	Proceedings of the 4th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1991) September 11 - 13, 1991 Albuquerque, NM
Pages:	727 - 736
Cite this article:	Hwang, Patrick Y.C., "A GPS Method for Real-Time Parallel Track Resolution," Proceedings of the 4th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1991), Albuquerque, NM, September 1991, pp. 727-736.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In