Abstract
Integer ambiguity fixing can significantly shorten the initialization time and improve the accuracy of precise point positioning (PPP), but it still takes approximate 15 min of time to achieve reliable integer ambiguity solutions. In this contribution, we present a new strategy to augment PPP estimation with a regional reference network, so that instantaneous ambiguity fixing is achievable for users within the network coverage. In the proposed method, precise zero-differenced atmospheric delays are derived from the PPP fixed solution of the reference stations, which are disseminated to, and interpolated at user stations to correct for L1, L2 phase observations or their combinations. With the corrected observations, instantaneous ambiguity resolution can be carried out within the user PPP software, thus achieving the position solutions equivalent to the network real-time kinematic positioning (NRTK). The strategy is validated experimentally. The derived atmospheric delays and the interpolated corrections are investigated. The ambiguity fixing performance and the resulted position accuracy are assessed. The validation confirms that the new strategy can provide comparable service with NRTK. Therefore, with this new processing strategy, it is possible to integrate PPP and NRTK into a seamless positioning service, which can provide an accuracy of about 10 cm anywhere, and upgrade to a few centimeters within a regional network.
Similar content being viewed by others
References
Banville S, Langley R (2009) Improving real-time kinematic PPP with instantaneous cycle-slip correction. In: Proceedings of ION GNSS, USA, 16–19 September
Bisnath S, Gao Y (2007) Current state of precise point positioning and future prospects and limitations. Observing our changing earth, International Association of Geodesy Symposia 133, Springer, Berlin
Boehm J, Niell A, Tregoning P, Schuh H (2006) Global mapping function (GMF): a new empirical mapping function based on numerical weather model data. Geophys Res Lett 33: L7304. doi:10.1029/2005GL025546
Collins P, Lahaye F, Hérous P, Bisnath S (2008) Precise point positioning with AR using the decoupled clock model. In: Proceedings of ION GNSS, USA, 16–19 September
Dai L (2002) Augmentation of GPS with GLONASS and pseudolite signals for carrier phase-based kinematic positioning. School of Surveying and Spatial Information Systems. The University of New South Wales, Sydney
Dow JM, Neilan RE, Rizos C (2009) The international GNSS service in a changing landscape of global navigation satellite systems. J Geod 83: 191–198. doi:10.1007/s00190-008-0300-3
Gabor MJ, Nerem RS (1999) GPS carrier phase AR using satellite-satellite single difference. In: Proceedings of 12th international technical meeting, Satellite Division, Institute of Navigation GPS 99, Nashville, 14–17 September
Gao Y, Li Z, McLellan JF (1997) Carrier phase based regional area differential GPS for decimeter-level positioning and navigation. In: Proceedings of 10th international technical meeting of the Satellite Division of US Institute of Navigation, Kansas City, 16–19 September, pp 1305–1313
Gao Y, Shen X (2001) Improving ambiguity convergence in carrier phase-based precise point positioning. In: Proceedings of ION GPS-2001, Salt Lake City, 11–14 September, pp 1532–1539
Ge M, Gendt G, Rothacher M, Shi C, Liu J (2008) Resolution of GPS carrier-phase ambiguities in precise point positioning(PPP) with daily observations. J Geod 82(7): 389–399. doi:10.1007/s00190-007-0187-4
Ge M, Chen J, Gendt G (2009) EPOS-RT: software for real-time GNSS data processing. Geophysical Research Abstracts. vol 11, EGU2009-8933, EGU General Assembly 2009. Vienna
Ge M, Zou X, Dick G, Jiang W Wickert J, Liu J (2010) An alternative Network RTK approach based on undifferenced observation corrections, ION GNSS 2010, Portland, Oregon
Geng J, Meng X, Dodson A, Ge M, Teferle F (2010) Rapid re-convergences to ambiguity-fixed solutions in precise point positioning. J Geod. doi:10.1007/s00190-010-0404-4
Han S (1997) Carrier phase-based long-range GPS kinematic positioning. PhD thesis, School of Geomatic Engineering, The University of New South Wales
Kouba J, Hérous P (2001) Precise point positioning using IGS orbit and clock products. GPS Solut 5(2): 12–28. doi:10.1007/PL00012883
Laurichesse D, Mercier F, Berthias JP, Bijac J (2008) Real time zero-difference ambiguities fixing and absolute RTK. In: Proceedings of ION national technical meeting, San Diego
Li X, Zhang X (2010) PPP-RTK: real-time precise point positioning with zero-difference ambiguity resolution. CPGPS 2010, August, Shanghai
Melgard T, Vigen E, Jong K, Lapucha D, Visser H, Oerpen O (2009) G2—the first real-time GPS and GLONASS precise orbit and clock service. In: Proceedings of ION GNSS 2009, Savannah, 22–25 September, pp 1885–1891
Mireault Y, Tétreault P, Lahaye F, Collins P, Caissy M (2008) Canadian RT/NRT products and services. IGS Workshop 2008, Miami Beach, 2–6 June 2008
Pérez J, Agrotis L, Fernàndez J, Garcia C, Dow J (2006) ESA/ESOC real time data processing. IGS Workshop 2006, Darmstadt, 8–11 May
Raquet J, Lachapelle G, Fortes L (1998) Use of a covariance analysis technique for predicting performance of regional area differential code and carrier-phase networks. In: 11th international technical meeting of the Satellite Division of the US Institute of Navigation, Nashville, 15–18 September, pp 1345–1354
Saastamoinen J (1972) Atmospheric correction for the troposphere and stratosphere in radio ranging of satellites. In: Henriksen SW, Mancini A, Chovitz BH (eds) The use of artificial satellites for Geodesy, Geophys. Monogr. Ser., vol 15. AGU, Washington, DC, pp 247–251
Teunissen PJG (1995) The least squares ambiguity decorrelation adjustment: a method for fast GPS integer estimation. J Geod 70: 65–82
Wanninger L (1995) Improved AR by regional differential modeling of the ionosphere. In: 8th international technical meeting of the Satellite Division of the US Institute of Navigation, Palm Springs, 12–15 September, pp 55–62
Wu JT, Wu SC, Hajj GA, Bertiger WI, Lichten SM (1993) Effects of antenna orientation on GPS carrier phase. Manuscr Geod 18(2): 91–98
Wübbena G, Bagge A, Seeber G, Boder V, Hankemeier P (1996) Reducing distance dependent errors for real-time precise DGPS applications by establishing reference station networks. In: 9th international technical meeting of the Satellite Division of the US Institute of Navigation, Kansas City, 17–20 September, pp 1845–1852
Zhang X, Li X (2010a) Instantaneous re-initialization in real-time kinematic PPP with cycle-slips fixing. GPS Solut (in press)
Zhang X, Li X (2010b) Satellite clock estimation at 1 Hz for realtime kinematic PPP applications. GPS Solut (in press)
Zumberge JF, Heflin MB, Jefferson DC, Watkins MM, Webb FH (1997) Precise point positioning for the efficient and robust analysis of GPS data from large networks. J Geophys Res 102(B3): 5005–5017. doi:10.1029/96JB03860
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Li, X., Zhang, X. & Ge, M. Regional reference network augmented precise point positioning for instantaneous ambiguity resolution. J Geod 85, 151–158 (2011). https://doi.org/10.1007/s00190-010-0424-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00190-010-0424-0