Integrity monitoring for Positioning of intelligent transport systems using integrated RTK-GNSS, IMU and vehicle odometer

Integrity monitoring for Positioning of intelligent transport systems using integrated RTK-GNSS, IMU and vehicle odometer

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Reliable continuing positioning is a critical requirement for intelligent transportation systems (ITS). An integrated positioning system is presented, where the global navigation satellite systems (GNSS) real-time kinematic (RTK) method was mainly used. When RTK is not available, positioning was maintained by using Doppler measurements or by low-cost inertial measurement unit (IMU) coupled with vehicle odometer measurements. A new integrity monitoring (IM) method is presented that addresses each positioning mode of the proposed integrated system. Models for the protection levels (PLs) are presented to bound the position error (PE) along the direction of motion of the vehicle and for the cross-track direction. Both direction components are needed, for instance for collision avoidance and for lane identification. The method was assessed through a kinematic test performed in a dense urban environment. Results showed that by integrating GNSS RTK, Doppler with IMU + odometer, positioning was available all the time. For RTK, positioning accuracy was less than a decimetre and the IM availability was 99%, where the PLs bounded the PEs and were less than an alert limit of 1 m. Positioning using Doppler and IMU + odometer measurements bridged RTK breaks but at the sub-meter level accuracy when used for short periods.


    1. 1)
      • 1. Imparato, D., El-Mowafy, A., Rizos, C., et al: ‘A review of SBAS and RTK vulnerabilities in intelligent transport systems applications’. Proc. IGNSS Symp. 2018, Sydney, 7–9 February 2018, pp. 118.
    2. 2)
      • 2. Yang, Y., Mao, X., Tain, W.: ‘A novel method for low-cost MIMU aiding GNSS attitude determination’, Meas. Sci. Technol., 2016, 27, (7), p. 075003.
    3. 3)
      • 3. Yand, L., Wu, Y., Li, Y., et al: ‘An enhanced MEMS-INS/GNSS integrated system with fault detection and exclusion capability for land vehicle navigation in urban areas’, GPS Solut., 2014, 18, (4), pp. 593603.
    4. 4)
      • 4. Misra, P., Enge, P.: ‘Global position system: signals, measurements, and performance’ (Ganga-Jamuna Press, Lincoln, MA, USA, 2006).
    5. 5)
      • 5. Zumberge, J.F., Heflin, M.B., Jefferson, D.C., et al: ‘Precise point positioning for the efficient and robust analysis of GPS data from large networks’, J. Geophys. Res., 1997, 102, (B3), pp. 50055017.
    6. 6)
      • 6. Kouba, J.: ‘A guide to using international GNSS service (IGS) products’,, 2015, accessed December 2017.
    7. 7)
      • 7. El-Mowafy, A.: ‘Pilot evaluation of integrating GLONASS, Galileo and BeiDou with GPS in ARAIM’, Artif. Satell., 2016, 51, (1), pp. 3144.
    8. 8)
      • 8. Blanch, J., Walter, T., Enge, P.: ‘Optimal positioning for advanced RAIM’, Navigation, 2014, 60, (4), pp. 279289.
    9. 9)
      • 9. Rippl, M., Martini, I., Belabbas, B., et al: ‘ARAIM operational performance tested in flight’. Proc. ION ITM 2014, San Diego, CA, 27–29 January 2014, pp. 601615.
    10. 10)
      • 10. El-Mowafy, A., Yang, C.: ‘Limited sensitivity analysis of ARAIM availability for LPV-200 over Australia using real data’, Adv. Space Res., 2016, 57, (2), pp. 659670.
    11. 11)
      • 11. Khanafesh, S., Pervan, P.: ‘New approach for calculating position domain integrity risk for cycle resolution in carrier phase navigation systems’, IEEE Trans. Aerosp. Electron. Syst., 2010, 46, (1), pp. 296306.
    12. 12)
      • 12. Khanafesh, S., Langel, S.: ‘Implementation and experimental validation of cycle ambiguity resolution with position domain integrity risk constraints’, Navigation, 2011, 58, (1), pp. 4558.
    13. 13)
      • 13. Cezón, A., Cueto, M., Fernández, I.: ‘Analysis of multi-GNSS service performance assessment: ARAIM vs. IBPL performances’. Proc. ION GNSS 2013, Nashville, 16–20 September 2013, pp. 26542663.
    14. 14)
      • 14. El-Mowafy, A., Kubo, N.: ‘Integrity monitoring of vehicle positioning in urban environment using RTK-GNSS, IMU and speedometer’, Meas. Sci. Technol., 2017, 28, (5), p. 055102, 1–12.
    15. 15)
      • 15. El-Mowafy, A.: ‘Performance analysis of the RTK technique in an urban environment’, Aust. Surveyor (currently J. Spatial Sci.), 2000, 45, (1), pp. 4754.
    16. 16)
      • 16. El-Mowafy, A.: ‘Precise real-time positioning using network RTK’, in ‘Global navigation satellite systems: signal, theory and applications’ (InTech, London, UK, 2012), ch. 7, pp. 161188, InTech. ISBN: 978-953-307-674-4.
    17. 17)
      • 17. Godha, S., Canon, M.E.: ‘GPS/MEMS INS integrated system for navigation in urban areas’, GPS Solut., 2007, 11, (3), pp. 193203.
    18. 18)
      • 18. El-Sheimy, N., Hou, H., Niu, X.: ‘Analysis and modeling of inertial sensors using AV’, IEEE Trans. Instrum. Meas., 2008, 57, (1), pp. 140149.
    19. 19)
      • 19. Zhao, Y.: ‘GPS/IMU integrated system for land vehicle navigation based on MEMS’. Thesis, Royal Institute of Technology, Stockholm, Sweden, 2011.
    20. 20)
      • 20. El-Mowafy, A.: ‘GNSS multi-frequency receiver single-satellite measurement validation method’, GPS Solut., 2014, 18, pp. 553561.
    21. 21)
      • 21. Estey, L., Meertens, C.: ‘TEQC: the multi-purpose toolkit for GPS/GLONASS data’, GPS Solut., 1999, 3, (1), pp. 4249.
    22. 22)
      • 22. Vaclavovic, P., Dousa, J.: ‘G-nut's anubis – open-source tool for multi-GNSS data checking and editing’. Proc. IAG Scientific Assembly, Potsdam, September 1–6 2013, pp. 17.
    23. 23)
      • 23. Teunissen, P.J.G.: ‘Testing theory: an introduction’ (Delft VSSD, The Netherlands, 2006, 2nd edn.).
    24. 24)
      • 24. El-Mowafy, A.: ‘Diagnostic tools using a multi-constellation single-receiver single-satellite data validation method’, J. Navig., 2015, 68, (1), pp. 196214.
    25. 25)
      • 25. Baarda, W.A.: ‘Testing procedure for use in geodetic networks’ (Netherlands Geodetic Commission, Publications on Geodesy, New Series, 1968), p. 5.
    26. 26)
      • 26. Chalko, T.J..: ‘Estimating accuracy of GPS Doppler speed measurement using speed dilution of precision parameter’, NU J. Discov., 2009, 6, pp. 49.
    27. 27)
      • 27. Imparato, D., El-Mowafy, A., Kubo, N.: ‘Integrity assessment of vehicle positioning for journey planning in urban environment using RTK and 3D city models’, J. Intell. Transp. Syst.: Technol. Plan. Oper., in press.
    28. 28)
      • 28. Margaria, D., Falletti, E.: ‘A novel local integrity concept for GNSS receivers in urban vehicular contexts’. Proc. IEEE/ION PLANS 2014, Monterey, CA, USA, 5–8 May 2014, pp. 413425.
    29. 29)
      • 29. El-Mowafy, A., Deo, M., Rizos, C.: ‘On biases in precise point positioning with multi-constellation and multi-frequency GNSS data’, Meas. Sci. Technol., 2016, 27, (3), p. 035102.

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