Comparing the Nigerian GNSS Reference Network’s Zenith Total Delays from Precise Point Positioning to a Numerical Weather Model

  • A. O. MayakiEmail author
  • T. Nikolaidou
  • M. Santos
  • C. J. Okolie
Conference paper
Part of the International Association of Geodesy Symposia book series (IAG SYMPOSIA, volume 149)


As a pivotal infrastructure for the socio-economic development of Nigeria, the Nigerian Global Navigation Satellite Systems (GNSS) Reference Network – NIGNET – can serve as a tool for weather and climate monitoring, by obtaining and analyzing the neutral atmospheric Zenith Total Delays (ZTD) from processed GNSS data. With the use of surface meteorological measurements, the ZTD can be transformed to the integrated water vapor content in the neutral atmosphere, which is an essential parameter in weather forecasting, and climate change and variability analysis. The focus of this research is to assess the adaptability of the NIGNET for meteorological applications using the global positioning system precise point positioning (PPP) derived ZTD at the stations. ZTD estimates are derived from daily data obtained from the NIGNET and International GNSS Service (IGS) stations spanning the years 2011–2016. These estimates are compared with ray-traced delay estimates from the National Centre for Environmental Prediction Reanalysis II (NCEP II) global Numerical Weather Model (NWM) and the IGS zenith path delay products. A comprehensive analysis is performed to assess the level of agreement of the different ZTD estimates and to identify possible systematic effects from the different sources. Comparisons between the PPP and NCEP II NWM ZTD estimates show a range of mean offsets from −6.4 to 23.9 mm, and standard deviations from 33.1 to 44.9 mm. With the PPP and IGS ZTD estimates, mean offsets of −2.4 and −0.1 mm, and standard deviations of 9.9 and 13.8 mm are obtained.


Global Positioning System Nigerian GNSS Reference Network Numerical Weather Model Precise Point Positioning Zenith Total Delay 


  1. Abdallah A (2015) The effect of convergence time on the static-PPP solution. Presented at 2nd international workshop on “Integration of point- and area-wise geodetic monitoring for structures and natural objects”, Stuttgart, 23–24 Mar 2015Google Scholar
  2. Ahmed F, Teferle N, Bingley R, Hunegnaw A (2014) A comparative analysis of tropospheric delay estimates from network and precise point positioning processing strategies. Poster presented at: IGS workshop, Pasadena, 23–27 June 2014Google Scholar
  3. Ahmed F, Teferle FN, Bingley RM, Laurichesse D (2015) The status of GNSS data processing systems to estimate integrated water vapour for use in numerical weather prediction models. In: Rizos C, Willis P (eds) IAG 150 years, International Association of Geodesy symposia. Springer, Cham, p 143Google Scholar
  4. Altamimi Z, Collileux X, Métivier L (2011) ITRF2008: an improved solution of the International Terrestrial Reference Frame. J Geod 85(8):457–473. CrossRefGoogle Scholar
  5. Balidakis K, Nilsson T, Zus F, Glaser S, Heinkelmann R, Deng Z, Schuh H (2018) Estimating integrated water vapor trends from VLBI, GPS, and numerical weather models: sensitivity to tropospheric parameterization. J Geophys Res Atmos 123:6356–6372. CrossRefGoogle Scholar
  6. Boehm J, Werl B, Schuh H (2006) Troposphere mapping functions for GPS and very long baseline interferometry from European Centre for Medium-Range Weather Forecasts operational analysis data. J Geophys Res 111.
  7. Bolbol S, Ali AH, El-Sayed MS, Elbeah MN (2017) Performance evaluation of precise point positioning (PPP) using CSRS-PPP online service. Am J Geographic Inform Syst 6(4):156–167. CrossRefGoogle Scholar
  8. Byram S, Hackman C (2014) IGS final troposphere product update. Poster presented at IGS workshop 2014, Pasadena, 23–27 June 2014Google Scholar
  9. Byun SH, Bar-Sever YE (2009) A new type of troposphere zenith path delay product of the International GNSS Service. J Geod 83:367–373CrossRefGoogle Scholar
  10. Dousa J, Bennitt GV (2013) Estimation and evaluation of hourly updated global GPS Zenith Total Delays over ten months. GPS Solutions 17(4):453–464. CrossRefGoogle Scholar
  11. Eludoyin OM, Adelekan IO, Webster R, Eludoyin AO (2014) Air temperature, relative humidity, climate regionalization and thermal comfort of Nigeria. Int J Climatol 34:2000–2018CrossRefGoogle Scholar
  12. Farah H (2009) The African Reference Frame (AFREF) project: a fundamental geodetic tool for Africa. Geophys Res Abstr 11:EGU2009–EG13950Google Scholar
  13. Guo Q (2015) Precision comparison and analysis of four online free PPP services in static positioning and tropospheric delay estimation. GPS Solutions 19(4):537–544. CrossRefGoogle Scholar
  14. Isioye OA, Combrinck L, Botai J (2015) Performance evaluation of Blind Tropospheric delay correction models over Africa. S Afr J Geom 4(4):502–525. CrossRefGoogle Scholar
  15. Isioye OA, Combrinck L, Botai J (2016) Modelling weighted mean temperature in the West African region: implications for GNSS meteorology. Meteorol Appl 23:614–632. CrossRefGoogle Scholar
  16. Jatau B, Fernandes R, Adebomehin A, Gonçalves N (2010) NIGNET – the new permanent GNSS network of Nigeria. In: Proceedings of FIG congress 2010, SydneyGoogle Scholar
  17. Kanamitsu M, Ebisuzaki W, Woollen J, Yang SK, Hnilo JJ, Fiorino M, Potter GL (2002) NCEP-DOE AMIP-II reanalysis (R-2). Bull Am Meteorol Soc 83:1631–1643CrossRefGoogle Scholar
  18. Leandro R, Santos M, Langley R (2010) Analyzing GNSS data in precise point positioning software. GPS Solutions 15(1):1–13. CrossRefGoogle Scholar
  19. Li X, Zus F, Lu C, Dick G, Ning T, Ge M, Wickert J, Schuh H (2015) Retrieving of atmospheric parameters from multi-GNSS in real time: validation with water vapor radiometer and numerical weather model. J Geophys Res Atmos 120:7189–7204. CrossRefGoogle Scholar
  20. Nievinski FG, Santos MC (2010) Ray-tracing options to mitigate the neutral atmosphere delay in GPS. Geomatica 64(2):191–207Google Scholar
  21. Nikolaidou T, Nievinski F, Balidakis K, Schuh H, Santos M (2018) PPP without troposphere estimation: impact assessment of regional versus global numerical weather models and delay parametrization. International Association of Geodesy symposia. Accepted manuscript submitted for publicationGoogle Scholar
  22. Ogungbenro SB, Eniolu T, Morakinyo TE (2014) Rainfall distribution and change detection across climatic zones in Nigeria. Weather Clim Extrem 5:1–6Google Scholar
  23. Olusola O, Kayode A, Israel E (2015) Spatial analysis of rainfall in the climatic regions of Nigeria using insitu data. J Environ Earth Sci 5(18):64–73Google Scholar
  24. UCAR (2011) The troposphere – overview. Accessed 1 Sept 2017
  25. Urquhart L, Santos M (2011) Development of VMF1-like service. White paper, Department of Geodesy and Geomatics, University of New Brunswick, New BrunswickGoogle Scholar
  26. Urquhart L, Santos MC, Garcia CA, Langley RB, Leandro RF (2014) Global assessment of UNB’s online precise point positioning software. IAG Symp Ser 139:585–592. CrossRefGoogle Scholar
  27. Willoughby AA, Aro TO, Owolabi IE (2002) Seasonal variations of radio refractivity gradients in Nigeria. J Atmos Sol Terr Phys 64:417–425CrossRefGoogle Scholar
  28. 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. CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  • A. O. Mayaki
    • 1
    Email author
  • T. Nikolaidou
    • 1
  • M. Santos
    • 1
  • C. J. Okolie
    • 2
  1. 1.Geodesy and Geomatics EngineeringUniversity of New BrunswickFrederictonCanada
  2. 2.Surveying and GeoinformaticsUniversity of LagosLagosNigeria

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