An improved method for detecting BeiDou signal-in-space anomalies from precise ephemerides


The signal-in-space (SIS) anomalies caused by satellites and control segments can greatly affect the reliability and safety of navigation and positioning users. The prior information associated with the failure of the Advanced Receiver Autonomous Integrity Monitoring (ARAIM) algorithm were obtained by the evaluation of SIS failure rates broadcasted with navigation ephemeris to investigate the integrity of navigation and positioning. For the existing ARAIM algorithm, the failure rate of satellites in the BeiDou Navigation Satellite System (BDS) is a conservative estimate, which is inconsistent with the actual SIS performance of BDS. Only the accurate detection of the SIS anomalies of BDS satellites can provide an effective reference to associate with failure. Therefore, to improve the accuracy of SIS anomaly detection for BDS satellites, and to provide higher integrity services for users, this study presents an improved method of SIS anomaly detection with precise ephemeris. The median method was used to detect a gross error in clock data before the calculation of clock datum, and the combination of an experience threshold and trimmed mean was used to determine the anomaly detection threshold. The feasibility and efficiency of the proposed method were also analyzed using data collected between 2015 and 2016. The detection results show that the constellation fault caused by erroneous clock data can be avoided, and the SIS anomalies can also be detected using the proposed method. Additionally, through the comprehensive tests performed in this study, it was found that from 2015 to 2016, the average accumulated duration of anomalies for BDS satellites was 10 h for geostationary orbit (GEO) and incline geosynchronous orbit (IGSO) and 55 h for medium earth orbit (MEO), respectively. These anomalies were primarily caused by the satellite clock.

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  1. Brown G, Hwang PYC (1986) GPS failure detection by autonomous means within the cockpit. Navigation 33(4):335–353.

    Article  Google Scholar 

  2. Chen G, Hu Z, Wang G, Chen G, Liu Z, Zhao Q (2015) Assessment of BDS signal-in-space accuracy and standard positioning performance during 2013 and 2014. In: 2015 Proceedings on China satellite navigation conference (CSNC), vol. I. Springer, Berlin, Heidelberg.

    Chapter  Google Scholar 

  3. China Satellite Navigation Office (2013) BeiDou navigation satellite system open service performance standard (Version 1.0)

  4. Cobb HS, Lawrence DG, Christie JRI, Walter T, Chao YC, Powell JD, Parkinson BW (1995) Observed GPS signal continuity interruptions. In: Proceedings of the 8th international technical meeting of the satellite division of the Institute of Navigation (ION GPS-1995), Palm Springs, CA, September 1995

  5. Cohenour C, Van Graas F (2011) GPS orbit and clock error distributions. Navigation 58(1):17–28.

    Article  Google Scholar 

  6. Cohenour C, Van Graas F (2013) GPS Orbit and Clock Error Distributions, 2005 to 2012. In: Proceedings of the ION 2013 Pacific PNT Meeting, Honolulu, Hawaii, April 2013, pp 946–958

  7. GPS WORLD (2014) Accessed 13 June 2014

  8. GPS-Galileo Working Group C (2015) RAIM technical subgroup milestone2 report. Accessed 18 Sept 2016

  9. Gunning K, Walter T, Enge P (2017) Characterization of GLONASS broadcast clock and ephemeris: nominal performance and fault trends for ARAIM. In: Proceedings of the 2017 international meeting of the institute of navigation, Monterey, California, January 2017, pp 170–183

  10. Hansen A, Walter T, Enge P, Lawrence D (1998) GPS satellite clock event on SVN impact on augmented navigation. In: Proceedings of the 11th international technical meeting of the satellite division of the Institute of Navigation (ION GPS 1998), Nashville, TN, September 1998, pp 1665–1673

  11. Heng L (2012) Safe satellite navigation with multiple constellations: global monitoring of GPS and GLONASS signal-in-space anomalies. Dissertation, Stanford University

  12. Heng L, Gao GX, Walter T, Enge P (2010) GPS signal-in-space anomalies in the last decade: data mining of 400,000,000 GPS navigation messages. In: Proceedings of the 23rd international technical meeting of the satellite division of the Institute of Navigation (ION GNSS 2010), Portland, OR, September, pp 3115–3122

  13. Heng L, Gao GX, Walter T, Enge P (2011a) Digging into GPS integrity: charting the evolution of signal-in-space performance by data mining 400,000,000 navigation messages. GPS World 22(11):44–49

    Google Scholar 

  14. Heng L, Gao GX, Walter T, Enge P (2011b) Statistical characterization of GLONASS broadcast ephemeris errors. Accessed 10 Oct 2013

  15. Heng L, Gao GX, Walter T, Enge P (2012) GLONASS signal-in-space anomalies since 2009. In: Proceedings of the 25th international technical meeting of the satellite division of the Institute of Navigation (ION GNSS 2012), Nashville, TN, September 2012

  16. Heng L, Gao GX, Walter T (2013) GPS signal-in-space integrity performance evolution in the last decade: data mining 400,000,000 navigation messages from a global network of 400 receivers. IEEE Trans Aerosp Electron Syst 48(4):2932–2946.

    Article  Google Scholar 

  17. Huang G, Cui B, Zhang Q, Fu W, Li P (2018) An improved predicted model for BDS ultra-rapid satellite clock offsets. Remote Sens 10(1):60.

    Article  Google Scholar 

  18. Jonkman N, Jong KD (2000) Integrity monitoring of IGEX-98 data-part iii: broadcast navigation message validation. GPS solut 4(2):45–53.

    Article  Google Scholar 

  19. Kovach K, Berg J, Lin V (2008) Investigation of upload anomalies affecting IIR satellites in October 2007. In: Proceedings of the 21st international technical meeting of the satellite division of the Institute of Navigation (ION GNSS 2008), Savannah, GA, September 2008, pp 1679–1687

  20. Misra P, Enge P (2011) Global positioning system: signals, measurements, and performance. Ganga-Jamuna Press, Lincoln

    Google Scholar 

  21. Montenbruck O, Steigenberger P, Hauschild A (2014) Broadcast versus precise ephemerides: a multi-GNSS perspective. GPS Solut 19(2):321–333.

    Article  Google Scholar 

  22. Polívka A, Houdek M, Ober PB, Tossaint M (2015) Satellite navigation data mining (SENDAI). In: 2015 International Association of Institutes of Navigation World Congress (IAIN), Prague, 2015, pp 1–6.

  23. Rivers MH (2000) 2 SOPS anomaly resolution on an aging constellation. In: Proceedings of the 13th international technical meeting of the satellite division of the Institute of Navigation (ION GPS 2000), Salt Lake City, UT, September 2000, pp 2547–2550

  24. Walter T, Blanch J (2015) Characterization of GPS clock and ephemeris errors to support ARAIM. In: Proceedings of the 2015 institute of navigation (ION) Pacific PNT conference, Honolulu, Hawaii

  25. Warren DLM, Raquet JF (2003) Broadcast vs precise GPS ephemerides: a historical perspective. GPS Solut 7(3):151–156.

    Article  Google Scholar 

  26. Wu Y, Ren J, Liu W (2016) Preliminary analyses of beidou signal-in-space anomaly since 2013. Int Arch Photogramm Remote Sens Spat Inf Sci 41:517–523.

    Article  Google Scholar 

  27. Yang YX, Li JL, Xu JY, Tang J, Guo HR, He HB (2011) Contribution of the compass satellite navigation system to global pnt users. Chin Sci Bull 56:2813–2819.

    Article  Google Scholar 

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This work was supported partly by the Chinese Academy of Sciences (CAS) program of “Light of the West” (Grant No. Y916YRa701, Y712YR4701), the Program of National Natural Science Foundation of China (Grant Nos. 41674034, 41974032), National Key Research and Development Plan of China (Grant No. 2016YFB0501804) and Chinese Academy of Sciences (CAS) programs of “Pioneer Hundred Talents”, “The Frontier Science Research Project” (Grant No. QYZDB-SSW-DQC028), National time service center (NTSC) programs of “Young creative talents” (Grant No: Y824SC1S06), and the State Key Laboratory of Geo-information Engineering (No. SKLGIE2017-Z-2-1). We also thank the IGS and iGMAS authorities for providing the data and products for this study.

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Correspondence to Rui Tu.

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Fan, L., Tu, R., Zhang, R. et al. An improved method for detecting BeiDou signal-in-space anomalies from precise ephemerides. Acta Geod Geophys 54, 567–581 (2019).

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  • BeiDou
  • Signal-in-space anomaly
  • Anomaly detection
  • Clock anomaly
  • Orbit anomaly