Techniques enabling precise point positioning with ambiguity resolution (PPP-AR) were developed over a decade ago. Several analysis centers of the International GNSS Service (IGS) have implemented such strategies into their software packages and are generating (experimental) PPP-AR products including satellite clock and bias corrections. While the IGS combines individual orbit and clock products as standard to provide a more reliable solution, interoperability of these new PPP-AR products must be confirmed before they can be combined. As a first step, all products are transformed into a common observable-specific representation of biases. It is then confirmed that consistency is only ensured by considering both clock and bias products simultaneously. As a consequence, the satellite clock combination process currently used by the IGS must be revisited to consider not only clocks but also biases. A combination of PPP-AR products from six analysis centers over a one-week period is successfully achieved, showing that alignment of phase clocks can be achieved with millimeter precision thanks to the integer properties of the clocks. In the positioning domain, PPP-AR solutions for all products show improved longitude estimates of daily static positions by nearly 60% over float solutions. The combined products generally provide equivalent or better results than individual analysis center contributions, for both static and kinematic solutions.
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Several satellite orbit, clock and bias products used in this study are experimental and, therefore, not publicly available. The CNES/CLS products were retrieved from ftp://cddis.gsfc.nasa.gov, while the Wuhan University phase clock/bias products can be found at ftp://igs.gnsswhu.cn/pub/whu/phasebias. CODE products enabling PPP-AR are available for the rapid, final and MGEX analysis lines at the IGS data centers and from ftp://aiub.unibe.ch/CODE.
Beutler G, Kouba J, Springer T (1995) Combining the orbits of the IGS analysis centers. B Geod 69(4):200–222. https://doi.org/10.1007/BF00806733
Blewitt G (1989) Carrier-phase ambiguity resolution for the global positioning system applied to geodetic baselines up to 2000 km. J Geophys Res-Sol Ea 94(B8):10187–10203. https://doi.org/10.1029/JB094iB08p10187
Chen L, Song W, Yi W, Shi C, Lou Y, Guo H (2017) Research on a method of real-time combination of precise GPS clock corrections. GPS Solut 21(1):187–195. https://doi.org/10.1007/s10291-016-0515-3
Collins P, Gao Y, Lahaye F, Héroux P, MacLeod K, Chen K (2005) Accessing and processing real-time GPS corrections for precise point positioning—some user considerations. Proc ION GNSS 2005:1483–1491
Collins P, Bisnath S, Lahaye F, Héroux P (2010) Undifferenced GPS ambiguity resolution using the decoupled clock model and ambiguity datum fixing. Navigation 57(2):123–135
Gabor M (1999) GPS carrier phase ambiguity resolution using satellite–satellite single differences. Ph.D. Dissertation, University of Texas at Austin, USA
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. https://doi.org/10.1007/s00190-007-0187-4
Geng J, Shi C, Ge M, Dodson AH, Lou Y, Zhao Q, Liu J (2012) Improving the estimation of fractional-cycle biases for ambiguity resolution in precise point positioning. J Geod 86(8):579–589. https://doi.org/10.1007/s00190-011-0537-0
Geng J, Chen X, Pan Y, Zhao Q (2019) A modified phase clock/bias model to improve PPP ambiguity resolution at Wuhan University. J Geod 93(10):2053–2067. https://doi.org/10.1007/s00190-019-01301-6
Gurtner W, Estey L (2018) RINEX: The receiver independent exchange format version 3.04. ftp://igs.org/pub/data/format/rinex304.pdf. Accessed 4 Dec 2019
Hauschild A, Montenbruck O (2015) The effect of correlator and front-end design on GNSS pseudorange biases for geodetic receivers. In: Proceedings of ION GNSS + 2015, pp 2835–2844
IGS (2019) [IGSREPORT-26247] Wk 2026 IGS Final Orbits. https://lists.igs.org/pipermail/igsreport/2018-November/026266.html. Accessed 21 May 2019
Johnston G, Riddell A, Hausler G (2017) The international GNSS service. In: Teunissen PJG, Montenbruck O (eds) Springer handbook of global navigation satellite systems, 1st edn. Springer International Publishing, Berlin, pp 967–982. https://doi.org/10.1007/978-3-319-42928-1
Kouba J, Héroux P (2001) Precise point positioning using IGS orbit and clock products. GPS Solut 5(2):12–28. https://doi.org/10.1007/PL00012883
Kouba J, Springer T (2001) New IGS station and satellite clock combination. GPS Solut 4(4):31–36. https://doi.org/10.1007/PL00012863
Lannes A, Prieur JL (2013) Calibration of the clock-phase biases of GNSS networks: the closure-ambiguity approach. J Geod 87(8):709–731. https://doi.org/10.1007/s00190-013-0641-4
Laurichesse D, Mercier F, Berthias JP, Broca P, Cerri L (2009) Integer ambiguity resolution on undifferenced GPS phase measurements and its application to PPP and satellite precise orbit determination. Navigation 56(2):135–149
Loyer S (2015) Receiver type depending part of observed satellite wide lane delays. In: IGS Workshop on GNSS Biases, 5–6 Nov, Bern, Switzerland
Loyer S, Perosanz F, Mercier F, Capdeville H, Marty JC (2012) Zero-difference GPS ambiguity resolution at CNES-CLS IGS analysis center. J Geod 86(11):991–1003. https://doi.org/10.1007/s00190-012-0559-2
Loyer S, Banville S, Perosanz F, Mercier F (2017) Disseminating GNSS satellite attitude for improved clock correction consistency. In: IGS Workshop 2017, 3–7 July, Paris, France
Odijk D, Zhang B, Khodabandeh A, Odolinski R, Teunissen PJG (2016) On the estimability of parameters in undifferenced, uncombined GNSS network and PPP-RTK user models by means of S-system theory. J Geod 90(1):15–44. https://doi.org/10.1007/s00190-015-0854-9
Petit G, Kanj A, Loyer S, Delporte J, Mercier F, Perosanz F (2015) 1 × 10 − 16 frequency transfer by GPS PPP with integer ambiguity resolution. Metrologia 52(2):301–309. https://doi.org/10.1088/0026-1394/52/2/301
Schaer S (1999) Mapping and predicting the Earth’s ionosphere using the global positioning system. Ph.D. dissertation, Astronomical Institute, University of Berne, Switzerland
Schaer S (2016) Bias-SINEX format and implications for IGS bias products. In: IGS Workshop, 8–12 February, Sydney, Australia
Schaer S, Villiger A, Dach R, Prange L, Jäggi A (2018) New ambiguity-fixed IGS clock analysis products at CODE. In: IGS workshop 2018, 29 Oct–2 Nov, Wuhan, China
Schaer S, Villiger A, Arnold D, Dach R, Jäggi A, Prange L (2019) The CODE ambiguity-fixed clock and phase bias analysis products and their properties and performance. Manuscript in preparation
Seepersad G, Banville S, Collins P, Bisnath S, Lahaye F (2016) Integer satellite clock combination for precise point positioning with ambiguity resolution. Proc ION GNSS + 2016. https://doi.org/10.33012/2016.14631
Strasser S, Mayer-Gürr T, Zehentner N (2018) Processing of GNSS constellations and ground station networks using the raw observation approach. J Geod. https://doi.org/10.1007/s00190-018-1223-2
Teunissen PJG, Khodabandeh A (2015) Review and principles of PPP-RTK methods. J Geod 89(3):217–240. https://doi.org/10.1007/s00190-014-0771-3
Villiger A, Schaer S, Dach R, Prange L, Susnik A, Jäggi A (2019) Determination of GNSS pseudo-absolute code biases and their long-term combination. J Geod. https://doi.org/10.1007/s00190-019-01262-w
Zhang B, Chen Y, Yuan Y (2018) PPP-RTK based on undifferenced and uncombined observations: theoretical and practical aspects. J Geod. https://doi.org/10.1007/s00190-018-1220-5
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-Sol Ea 102(B3):5005–5017. https://doi.org/10.1029/96JB03860
This research was conducted under the initiative of the IGS PPP-AR working group. Thanks to Paul Collins of NRCan for providing feedback on the initial version of this paper, and to three anonymous reviewers for their comments and suggestions. This manuscript is published as Natural Resources Canada contribution number 20190080.
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Banville, S., Geng, J., Loyer, S. et al. On the interoperability of IGS products for precise point positioning with ambiguity resolution. J Geod 94, 10 (2020). https://doi.org/10.1007/s00190-019-01335-w
- Precise point positioning (PPP)
- Ambiguity resolution
- Satellite clock combination
- Observable-specific biases