Improving Real-Time Kinematic PPP with Instantaneous Cycle-Slip Correction

S. Banville, R.B. Langley

Abstract:	Nowadays, still few people use precise point positioning (PPP) to process GPS data from a moving receiver because the quality of the solution is extremely vulnerable to interruptions in signal tracking. A loss of lock on all GPS signals simultaneously implies that users may have to wait for several minutes (even hours in certain cases) before obtaining cm-level precision. To avoid such a scenario, this paper proposes a method to instantaneously mitigate the impacts of signal interruptions (cycle slips). The approach is based on a time-differenced solution which allows estimating the size of cycle slips in a least-squares adjustment. Since cycle slips are integers by definition, a three-step method is proposed to increase the success rate of the integer-fixing procedure. With GPS observations available at a one-second sampling interval, the proposed algorithm corrected 99% of cycle slips in the three data sets presented. The success rate decreases gradually as data gaps are introduced in the observations due to a temporal decorrelation of error sources. Other factors degrading the performance of the approach are also identified, providing a clear overview of the aspects to be improved.
Published in:	Proceedings of the 22nd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2009) September 22 - 25, 2009 Savannah International Convention Center Savannah, GA
Pages:	2470 - 2478
Cite this article:	Updated citation: Published in NAVIGATION: Journal of the Institute of Navigation
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