Skip to main content
Log in

A procedure for the significance testing of unmodeled errors in GNSS observations

  • Original Article
  • Published:
Journal of Geodesy Aims and scope Submit manuscript

    We’re sorry, something doesn't seem to be working properly.

    Please try refreshing the page. If that doesn't work, please contact support so we can address the problem.

Abstract

It is a crucial task to establish a precise mathematical model for global navigation satellite system (GNSS) observations in precise positioning. Due to the spatiotemporal complexity of, and limited knowledge on, systematic errors in GNSS observations, some residual systematic errors would inevitably remain even after corrected with empirical model and parameterization. These residual systematic errors are referred to as unmodeled errors. However, most of the existing studies mainly focus on handling the systematic errors that can be properly modeled and then simply ignore the unmodeled errors that may actually exist. To further improve the accuracy and reliability of GNSS applications, such unmodeled errors must be handled especially when they are significant. Therefore, a very first question is how to statistically validate the significance of unmodeled errors. In this research, we will propose a procedure to examine the significance of these unmodeled errors by the combined use of the hypothesis tests. With this testing procedure, three components of unmodeled errors, i.e., the nonstationary signal, stationary signal and white noise, are identified. The procedure is tested by using simulated data and real BeiDou datasets with varying error sources. The results show that the unmodeled errors can be discriminated by our procedure with approximately 90% confidence. The efficiency of the proposed procedure is further reassured by applying the time-domain Allan variance analysis and frequency-domain fast Fourier transform. In summary, the spatiotemporally correlated unmodeled errors are commonly existent in GNSS observations and mainly governed by the residual atmospheric biases and multipath. Their patterns may also be impacted by the receiver.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others

References

  • Amiri-Simkooei A, Tiberius C (2007) Assessing receiver noise using GPS short baseline time series. GPS Solut 11:21–35

    Article  Google Scholar 

  • Axelrad P, Comp C, Macdoran P (1996) SNR-based multipath error correction for GPS differential phase. IEEE Trans Aerosp Electron Syst 32:650–660

    Article  Google Scholar 

  • Azarbad M, Mosavi M (2014) A new method to mitigate multipath error in single-frequency GPS receiver with wavelet transform. GPS Solut 18:189–198

    Article  Google Scholar 

  • Bilich A, Larson K, Axelrad P (2008) Modeling GPS phase multipath with SNR: Case study from the Salar de Uyuni, Boliva. J Geophys Res Solid Earth 113:1–12

    Article  Google Scholar 

  • Bischoff W, Heck B, Howind J, Teusch A (2005) A procedure for testing the assumption of homoscedasticity in least squares residuals: a case study of GPS carrier-phase observations. J Geod 78:397–404

    Article  Google Scholar 

  • Bock Y, Nikolaidis R, Jonge P, Bevis M (2000) Instantaneous geodetic positioning at medium distances with the Global Positioning System. J Geophys Res Solid Earth 105:28223–28253

    Article  Google Scholar 

  • Bona P (2000) Precision, cross correlation, and time correlation of GPS phase and code observations. GPS Solut 4:3–13

    Article  Google Scholar 

  • Bos M, Fernandes R, Williams S, Bastos L (2008) Fast error analysis of continuous GPS observations. J Geod 82:157–166

    Article  Google Scholar 

  • Cai C, He C, Santerre R et al (2016) A comparative analysis of measurement noise and multipath for four constellations: GPS, BeiDou, GLONASS and Galileo. Surv Rev 48:287–295

    Article  Google Scholar 

  • Commandeur J, Koopman S (2007) An introduction to state space time series analysis. Oxford University Press, Oxford

    Google Scholar 

  • de Bakker P, Tiberius C, van der Marel H, van Bree R (2012) Short and zero baseline analysis of GPS L1 C/A, L5Q, GIOVE E1B, and E5aQ signals. GPS Solut 16:53–64

    Article  Google Scholar 

  • de Bakker P, van der Marel H, Tiberius C (2009) Geometry-free undifferenced, single and double differenced analysis of single frequency GPS, EGNOS and GIOVE-A/B measurements. GPS Solut 13:305–314

    Article  Google Scholar 

  • Dickey D, Fuller W (1979) Distribution of the estimators for autoregressive time series with a unit root. J Am Stat Assoc 74:427–431

    Google Scholar 

  • Didova O, Gunter B, Riva R et al (2016) An approach for estimating time-variable rates from geodetic time series. J Geod 90:1207–1221

    Article  Google Scholar 

  • Dong D, Wang M, Chen W et al (2016) Mitigation of multipath effect in GNSS short baseline positioning by the multipath hemispherical map. J Geod 90:255–262

    Article  Google Scholar 

  • Dousa J, Bennitt G (2013) Estimation and evaluation of hourly updated global GPS Zenith Total Delays over ten months. GPS Solut 17:453–464

    Article  Google Scholar 

  • Durbin J, Koopman S (2012) Time series analysis by state space methods, 2nd edn. Oxford University Press, Oxford

    Book  Google Scholar 

  • El-Rabbany A (1994) The effect of physical correlations on the ambiguity resolution and accuracy estimation in GPS differential positioning. Department of Geodesy and Geomatics Engineering, University of New Brunswick, Fredericton

    Google Scholar 

  • Frigo M, Johnson S (1998) FFTW: an adaptive software architecture for the FFT. In: IEEE international conference on acoustics, pp 1381–1384

  • Fuhrmann T, Luo X, Knöpfler A, Mayer M (2015) Generating statistically robust multipath stacking maps using congruent cells. GPS Solut 19:83–92

    Article  Google Scholar 

  • Ge M, Gendt G, Rothacher M et al (2008) Resolution of GPS carrier-phase ambiguities in precise point positioning (PPP) with daily observations. J Geod 82:389–399

    Article  Google Scholar 

  • Hamilton J (1994) Time series analysis. Princeton University Press, Princeton

    Google Scholar 

  • Hauschild A, Montenbruck O, Sleewaegen J et al (2012) Characterization of compass M-1 signals. GPS Solut 16:117–126

    Article  Google Scholar 

  • Hopfield H (1969) Two-quartic tropospheric refractivity profile for correcting satellite data. J Geophys Res Atmos 74:4487–4499

    Article  Google Scholar 

  • Hoque M, Jakowski N (2007) Higher order ionospheric effects in precise GNSS positioning. J Geod 81:259–268

    Article  Google Scholar 

  • Howind J, Kutterer H, Heck B (1999) Impact of temporal correlations on GPS-derived relative point positions. J Geod 73:246–258

    Article  Google Scholar 

  • IEEE (2008a) Standard specification format guide and test procedure for single-axis laser gyros. IEEE Std

  • IEEE (2008b) Standard specification format guide and test procedure for linear, single-axis. Non-gyroscopic Accelerometers, IEEE Std

  • Jarque C, Bera A (1980) A test for normality of observations and regression residuals. Int Stat Rev 55:163–172

    Article  Google Scholar 

  • Jenkins W (1999) Fourier series, fourier transforms, and the DFT. In: Madisetti VK, Williams DB (eds) Digital signal processing handbook. CRC Press, Boca Raton

    Google Scholar 

  • Keele D (1973) The design and use of a simple pseudo random pink-noise generator. J Audio Eng Soc 21:33–41

    Google Scholar 

  • Kwiatkowski D, Phillips P, Schmidt P, Shin Y (1992) Testing the null hypothesis of stationarity against the alternative of a unit root: how sure are we that economic time series have a unit root? J Econom 54:159–178

    Article  Google Scholar 

  • Lau L, Cross P (2007) Development and testing of a new ray-tracing approach to GNSS carrier-phase multipath modelling. J Geod 81:713–732

    Article  Google Scholar 

  • Lau L, Mok E (1999) Improvement of GPS relative positioning accuracy by using SNR. J Surv Eng 125:185–202

    Article  Google Scholar 

  • Leandro R, Langley R, Santos M (2008) UNB3m_pack: a neutral atmosphere delay package for radiometric space techniques. GPS Solut 12:65–70

    Article  Google Scholar 

  • Leick A, Rapoport L, Tatarnikov D (2015) GPS satellite surveying. Wiley, New York

    Book  Google Scholar 

  • Li B (2016) Stochastic modeling of triple-frequency BeiDou signals: estimation, assessment and impact analysis. J Geod 90:593–610

    Article  Google Scholar 

  • Li B, Feng Y, Shen Y, Wang C (2010) Geometry-specified troposphere decorrelation for subcentimeter real-time kinematic solutions over long baselines. J Geophys Res Solid Earth 115:B11404

    Article  Google Scholar 

  • Li B, Shen Y, Xu P (2008) Assessment of stochastic models for GPS measurements with different types of receivers. Chin Sci Bull 53:3219–3225

    Google Scholar 

  • Lilliefors H (1967) On the Kolmogorov–Smirnov test for normality with mean and variance unknown. J Am Stat Assoc 62:399–402

    Article  Google Scholar 

  • Luo X (2013) GPS stochastic modelling: signal quality measures and ARMA processes. Springer, New York

    Book  Google Scholar 

  • Luo X, Mayer M, Heck B (2011) On the probability distribution of GNSS carrier phase observations. GPS Solut 15:369–379

    Article  Google Scholar 

  • Marques H, Monico J, Aquino M (2011) RINEX_HO: second- and third-order ionospheric corrections for RINEX observation files. GPS Solut 15:305–314

    Article  Google Scholar 

  • Moore M, Watson C, King M et al (2014) Empirical modelling of site-specific errors in continuous GPS data. J Geod 88:887–900

    Article  Google Scholar 

  • Niu X, Chen Q, Zhang Q et al (2014) Using Allan variance to analyze the error characteristics of GNSS positioning. GPS Solut 18:231–242

    Article  Google Scholar 

  • Phan Q, Tan S, Mcloughlin I (2013) GPS multipath mitigation: a nonlinear regression approach. GPS Solut 17:371–380

    Google Scholar 

  • Pugliano G, Robustelli U, Rossi F, Santamaria R (2016) A new method for specular and diffuse pseudorange multipath error extraction using wavelet analysis. GPS Solut 20:499–508

    Article  Google Scholar 

  • Ragheb A, Clarke P, Edwards S (2007) GPS sidereal filtering: coordinate- and carrier-phase-level strategies. J Geod 81:325–335

    Article  Google Scholar 

  • Riley W (2008) Handbook of frequency stability analysis. National Institute of Standards and Technology, Gaithersburg

    Book  Google Scholar 

  • Saastamoinen J (1973) Contributions to the theory of atmospheric refraction. Part II. Refraction corrections in satellite geodesy. Bull Géod 107:13–34

    Article  Google Scholar 

  • Said S, Dickey D (1984) Testing for unit roots in auto-regressive moving average models of unknown order. Biometrika 71:599–607

    Article  Google Scholar 

  • Schön S (2005) Accurate tropospheric correction for local GPS monitoring networks with height differences. In: Proceedings of international technical meeting of the satellite division of the institute of navigation, pp 250–260

  • Schön S, Brunner F (2008) Atmospheric turbulence theory applied to GPS carrier-phase data. J Geod 82:47–57

    Article  Google Scholar 

  • Schüler T (2006) Impact of systematic errors on precise long-baseline kinematic GPS positioning. GPS Solut 10:108–125

    Article  Google Scholar 

  • Schüler T, Diessongo H, Poku-Gyamfi Y (2011) Precise ionosphere-free single-frequency GNSS positioning. GPS Solut 15:139–147

    Article  Google Scholar 

  • Teunissen P (1995) The least-squares ambiguity decorrelation adjustment: a method for fast GPS integer ambiguity estimation. J Geod 70:65–82

    Article  Google Scholar 

  • Teunissen P (1997a) A canonical theory for short GPS baselines. Part I: The baseline precision. J Geod 71:320–336

    Article  Google Scholar 

  • Teunissen P (1997b) A canonical theory for short GPS baselines. Part II: The ambiguity precision and correlation. J Geod 71:389–401

    Article  Google Scholar 

  • Tiberius C, Borre K (1999) Probability distribution of GPS code and phase data. Z Für Vermess 124:264–273

    Google Scholar 

  • Tiberius C, Borre K (2000) Are GPS data normally distributed. In: Geodesy beyond 2000. Springer, pp 243–248

  • Tiberius C, De Bakker P, Marel H, van Bree R (2001) Geometry-free analysis of GIOVE-A/B E1-E5a, and GPS L1-L5 measurements. In: Proceedings of the 22nd international technical meeting of the satellite division of the institute of navigation (ION GNSS 2009), pp 2911–2925

  • Tinin M (2015) Eliminating diffraction effects during multi-frequency correction in global navigation satellite systems. J Geod 89:491–503

    Article  Google Scholar 

  • Wang G, de Jong K, Zhao Q et al (2015) Multipath analysis of code measurements for BeiDou geostationary satellites. GPS Solut 19:129–139

    Article  Google Scholar 

  • Wanninger L, Beer S (2015) BeiDou satellite-induced code pseudorange variations: diagnosis and therapy. GPS Solut 19:639–648

    Article  Google Scholar 

  • Weng D, Ji S, Chen W et al (2014) Assessing and mitigating the effects of the ionospheric variability on DGPS. GPS Solut 19:107–116

    Article  Google Scholar 

  • Williams S, Bock Y, Fang P et al (2004) Error analysis of continuous GPS position time series. J Geophys Res Solid Earth 109:B03412

    Google Scholar 

  • Wu H, Li K, Shi W et al (2015) A wavelet-based hybrid approach to remove the flicker noise and the white noise from GPS coordinate time series. GPS Solut 19:511–523

    Article  Google Scholar 

  • Yang Y, Zhang S (2005) Adaptive fitting of systematic errors in navigation. J Geod 79:43–49

    Article  Google Scholar 

  • Zhang Z, Li B, Shen Y (2017a) Comparison and analysis of unmodelled errors in GPS and BeiDou signals. Geod Geodyn 8:41–48

    Article  Google Scholar 

  • Zhang Z, Li B, Shen Y, Yang L (2017b) A noise analysis method for GNSS signals of a standalone receiver. Acta Geod Geophys 52:301–316

    Article  Google Scholar 

  • Zhong P, Ding X, Yuan L et al (2010) Sidereal filtering based on single differences for mitigating GPS multipath effects on short baselines. J Geod 84:145–158

    Article  Google Scholar 

  • Zhong P, Ding X, Zheng D et al (2008) Adaptive wavelet transform based on cross-validation method and its application to GPS multipath mitigation. GPS Solut 12:109–117

    Article  Google Scholar 

Download references

Acknowledgements

This study is sponsored by the National Natural Science Foundation of China (41574023, 41622401, 41504022), the Technology Innovation Action Plan of Shanghai Science and Technology Committee (17511109501), the National Key Research and Development Program of China (2016YFB0501802), and the Fundamental Research Funds for the Central Universities. The authors are grateful to the editor and three reviewers for giving constructive comments, which greatly improved this paper.

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to Bofeng Li or Zhetao Zhang.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Li, B., Zhang, Z., Shen, Y. et al. A procedure for the significance testing of unmodeled errors in GNSS observations. J Geod 92, 1171–1186 (2018). https://doi.org/10.1007/s00190-018-1111-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00190-018-1111-9

Keywords

Navigation