DOI QR코드

DOI QR Code

An Accuracy Analysis on the Broadcast Ephemeris and IGS RTS

방송궤도력과 IGS RTS의 정확도 분석

  • Kim, Mingyu (School of Aerospace and Mechanical Engineering, Korea Aerospace University) ;
  • Kim, Jeongrae (School of Aerospace and Mechanical Engineering, Korea Aerospace University)
  • 김민규 (한국항공대학교 항공우주 및 기계공학부) ;
  • 김정래 (한국항공대학교 항공우주 및 기계공학부)
  • Received : 2016.09.30
  • Accepted : 2016.10.19
  • Published : 2016.10.30

Abstract

When user estimates user's position, GPS positions can be obtained from the navigation message transmitted from the GPS. However, the broadcast ephemeris cannot be used in the applications required high-level accuracies because it can cause errors of several meters. To correct satellite positions and clocks, user can use RTS corrections provided by IGS. In this paper, the accuracy of broadcast and RTS corrections are analyzed by comparing with the IGS final for 3-months. The RTS errors are analyzed for each user's locations and satellite blocks. The correlations between errors and shadow condition, and solar and geomagnetic activities are analyzed. The latency is applied to the RTS corrections, and these are extrapolated by polynomial. Then, the extrapolated RTS are compared with true RTS. The single-day performances of the PPP by broadcast ephemeris and RTS corrected ephemeris are analyzed. As a result, RTS 3D orbit and clock errors are 1/20 and 1/3 less than broadcast ephemeris errors. 3D positioning error of the RTS is 1/5 less than that of broadcast ephemeris.

Acknowledgement

Supported by : 미래창조과학부

References

  1. International GNSS Service. The IGS product table of GNSS applications [Internet]. Available: http://www.igs.org/products
  2. M. Elsobeiey, and S. Al-Harbi, "Performance of real-time precise point positioning using IGS real-time service," GPS Solutions, Vol. 20, No. 3, pp. 565-571, Jul. 2016. https://doi.org/10.1007/s10291-015-0467-z
  3. T. Hadas and J. Bosy, "IGS RTS precise orbits and clocks verification and quality degradation over time," GPS Solution, Vol. 19, No. 1, pp. 93-105, Jan. 2015. https://doi.org/10.1007/s10291-014-0369-5
  4. M. Kim, and J. Kim, "An analysis on the long-term variation of the GPS broadcast ephemeris errors," Journal of Advanced Navigation Technology, Vol. 18, No. 5, pp. 421-428, Oct. 2014. https://doi.org/10.12673/jant.2014.18.5.421
  5. M. Kim and J. Kim, "An analysis on the real-time performance of the IGS RTS and ultra-rapid products," Journal of Advanced Navigation Technology, Vol. 19, No. 3, pp. 199-206, Jun. 2015. https://doi.org/10.12673/jant.2015.19.3.199
  6. M. El-Diasty and M. Elsobeiey, "Precise point positioning technique with IGS real-time service (RTS) for maritime applications," Positioning, Vol. 6, No. 4, pp. 71-80, Nov. 2015. https://doi.org/10.4236/pos.2015.64008
  7. L. Mervart, "BKG Ntrip Client (BNC) version 2.10 manual," Federal Agency for Cartography and Geodesy, Frankfurt, Germany, Dec. 2013.
  8. RTCM, "RTCM standard 10403.2 differential GNSS(global navigation satellite systems) services - version 3," RTCM Special Committee 104, RTCM, Arlington, Va, USA, 2013.
  9. J. S. Subriana, J. M. J. Zornoza, and M. Hernandez-Pajares, GNSS data processing volume I: fundamentals and algorithms, European Space Agency Communications, 2013.