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GPS and Galileo Triple-Carrier Ionosphere-Free Combinations for Improved Convergence in Precise Point Positioning

Published online by Cambridge University Press:  16 November 2020

Francesco Basile
Affiliation:
(Nottingham Geospatial Institute, University of Nottingham)
Terry Moore*
Affiliation:
(Nottingham Geospatial Institute, University of Nottingham)
Chris Hill
Affiliation:
(Nottingham Geospatial Institute, University of Nottingham)
Gary McGraw
Affiliation:
(Collins Aerospace)

Abstract

In recent years, global navigation satellite system (GNSS) precise point positioning (PPP) has become a standard positioning technique for many applications with typically favourable open sky conditions, e.g. precision agriculture. Unfortunately, the long convergence (and reconvergence) time of PPP often significantly limits its use in difficult and restricted signal environments typically associated with urban areas. The modernisation of GNSS will positively affect and improve the convergence time of the PPP solutions, thanks to the higher number of satellites in view that broadcast multifrequency measurements. The number and geometry of the available satellites is a key factor that impacts on the convergence time in PPP, while triple-frequency observables have been shown to greatly benefit the fixing of the carrier phase integer ambiguities. On the other hand, many studies have shown that triple-frequency combinations do not usefully contribute to a reduction of the convergence time of float PPP solutions.

This paper proposes novel GPS and Galileo triple-carrier ionosphere-free combinations that aim to enhance the observability of the narrow-lane ambiguities. Tests based on simulated data have shown that these combinations can reduce the convergence time of the float PPP solution by a factor of up to 2·38 with respect to the two-frequency combinations. This approach becomes effective only after the extra wide-lane and wide-lane ambiguities have been fixed. For this reason, a new fixing method based on low-noise pseudo-range combinations corrected by the smoothed ionosphere correction is presented. By exploiting this algorithm, no more than a few minutes are required to fix the WL ambiguities for Galileo, even in cases of severe multipath environments.

Type
Research Article
Copyright
Copyright © The Royal Institute of Navigation 2020

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References

REFERENCES

Abou-Galala, M., Rabah, M., Kaloop, M. and Zidan, Z. M. (2017). Assessment of the accuracy and convergence period of Precise Point Positioning. Alexandria Engineering Journal, 57, 17211726.CrossRefGoogle Scholar
Afifi, A. and El-Rabbany, A. (2015). Performance analysis of several GPS/Galileo precise point positioning models. Sensors (Basel), 15, 1470114726.CrossRefGoogle ScholarPubMed
Basile, F., Moore, T., Hill, C. and Mcgraw, G. (2018a). Performance Analysis of Triple Carrier Ambiguity Resolution in Precise Point Positioning with Smoothed Ionosphere Corrections. 31st International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2018), Miami, FL, USA, pp. 38683880.CrossRefGoogle Scholar
Basile, F., Moore, T., Hill, C., Mcgraw, G. and Johnson, A. (2018b). Multi-Frequency Precise Point Positioning using GPS and Galileo Data with Smoothed Ionospheric Corrections. IEEE/ION PLANS, Monterey, CA, USA, pp. 13881398.CrossRefGoogle Scholar
Basile, F., Moore, T., Hill, C., Mcgraw, G. and Johnson, A. (2018c). Two are better than one: Multi-Frequency Precise Point Positioning Using GPS and Galileo. GPS World, 29, 2737.Google Scholar
Basile, F., Moore, T. and Hill, C. (2019). Analysis on the potential performance of GPS and Galileo precise point positioning using simulated real-time products. Journal of Navigation, 72, 1933.CrossRefGoogle Scholar
Deo, M. and El-Mowafy, A. (2016). Triple-frequency GNSS models for PPP with float ambiguity estimation: performance comparison using GPS. Survey Review, 50, 249261.CrossRefGoogle Scholar
Douša, J. (2009). The impact of errors in predicted GPS orbits on zenith troposphere delay estimation. GPS Solutions, 14, 229239.CrossRefGoogle Scholar
Elsobeiey, M. (2014). Precise point positioning using triple-frequency GPS measurements. Journal of Navigation, 68, 480492.CrossRefGoogle Scholar
Garcia, A. M., Piriz, R. and Samper, M. D. L. (2010). Multisystem Real Time Precise-Point-Positioning, Today with GPS + GLONASS in the Near Future also with QZSS, Galileo, Compass, IRNSS. International Symposium on GPS/GNSS. Taipei, Taiwan.Google Scholar
Geng, J. and Bock, Y. (2013). Triple-frequency GPS precise point positioning with rapid ambiguity resolution. Journal of Geodesy, 87, 449460.CrossRefGoogle Scholar
Geng, J., Teferle, F. N., Meng, X. and Dodson, A. H. (2010). Kinematic precise point positioning at remote marine platforms. GPS Solutions, 14, 343350.CrossRefGoogle Scholar
Hatch, R. (1982). The Synergism of GPS Code and Carrier Measurements. International Geodetic Symposium on Satellite Doppler Positioning. Las Cruces, NM, USA, pp. 12131231.Google Scholar
Henkel, P. and Gunther, C. (2008). Precise Point Positioning With Multiple Galileo Frequencies. ION PLANS. Monterey, CA: IEEE.Google Scholar
Jokinen, A., Feng, S., Ochieng, W., Hide, C., Moore, T. and Hill, C. (2012). Fixed Ambiguity Precise Point Positioning (PPP) with FDE RAIM. ION PLANS. Myrtle Beach, SC: IEEE.Google Scholar
Juan, J. M., Hernandez-Pajares, M., Sanz, J., Ramos-Bosch, P., Aragon-AngeL, A., Orus, R., Ochieng, W., Feng, S., Jofre, M., Coutinho, P., Samson, J. and Tossaint, M. (2012). Enhanced precise point positioning for GNSS users. IEEE Transactions on Geoscience and Remote Sensing, 50, 42134222.CrossRefGoogle Scholar
Khanafseh, S., Kujur, B., Joerger, M., Walter, T., Pullen, S., Blanch, J., Doherty, K., Norman, L., De Groot, L. and Pervan, B. (2018). GNSS Multipath Error Modeling for Automotive Applications. 31st International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2018). Miami, FL, USA. pp. 1573–1589.CrossRefGoogle Scholar
Li, X., Zhang, X., Ren, X., Fritsche, M., Wickert, J. and Schuh, H. (2015). Precise positioning with current multi-constellation Global Navigation Satellite Systems: GPS, GLONASS, Galileo and BeiDou. Sci Rep, 5, 8328.CrossRefGoogle ScholarPubMed
Melbourne, W. G. (1985). The Case for Ranging in GPS-based Geodetic Systems. International Symposium on Precise Positioning with the Global Positioning System, Rockville, MD, USA. pp. 373386.Google Scholar
Miguez, J., Gisbert, J. V. P., Perez, R. O., Garcia-Molina, J. A., Serena, X., Gonzales, F., Granados, G. S. and Crisci, M. (2016). Multi-GNSS PPP Performance Assessment with Different Ranging Accuracies in Challenging Scenarios. International Technical Meeting of The Satellite Division of the Institute of Navigation. Portland, OR, USA. pp. 20692081.CrossRefGoogle Scholar
Mondal, P. and Tewari, V. K. (2007). Present status of precision farming: a review. International Journal of Agricultural Research, 2, 110.CrossRefGoogle Scholar
Shen, X. and Gao, Y. (2006). Analyzing the Impacts of Galileo and Modernized GPS on Precise Point Positioning. National Meeting of the Institute of Navigation. Monterey, CA, USA. pp. 837846.Google Scholar
Shi, C., Lou, Y., Zhang, H., Zhao, Q., Geng, J., Wang, R., Fang, R. and Liu, J. (2010). Seismic deformation of the Mw 8.0 Wenchuan earthquake from high-rate GPS observations. Advances in Space Research, 46, 228235.CrossRefGoogle Scholar
Wubbena, G. (1985). Software Developments for Geodetic Positioning with GPS using TI-4100 Code and Carrier Measurements. International Symposium on Precise Positioning with the Global Positioning System. Rockville, MD, USA. pp. 403412.Google Scholar
Zhang, B., Ou, J., Yuan, Y. and Li, Z. (2012). Extraction of line-of-sight ionospheric observables from GPS data using precise point positioning. Science China Earth Sciences, 55, 19191928.CrossRefGoogle Scholar
Zumberge, J. F., Heflin, M. B., Jefferson, D. C., Watkins, M. M. and Webb, F. H. (1997). Precise point positioning for the efficient and robust analysis of GPS data from large networks. Journal of Geophysical Research: Solid Earth, 102, 50055017.CrossRefGoogle Scholar