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A New Strategy on Precise Clock Combination of IGS Analysis Centers

  • Kang-kang ChenEmail author
  • Tian-he Xu
Conference paper
Part of the Lecture Notes in Electrical Engineering book series (LNEE, volume 304)

Abstract

Precise clock correction is the important basic data for estimating troposphere parameters, precise point positioning (PPP) and satellite precise orbit determination. In this paper, a strict and reliable clock combination approach is proposed. The main idea is as follows: the compatibility corrections of satellite orbit, station coordinates and geocenter offset are applied to Analysis Center (AC) clock solutions firstly. It aims at maintaining the consistency of all IGS combined products. The individual AC clock solutions’ offset and drift parameters with respect to the broadcast clock solutions are estimated using robust least square method. Then individual AC solutions are aligned to a common reference time-frame. The initial weights of clock combination are determined by posteriori mean square error of parameters estimate. Using robust estimation with high-breakpoint of pollution rate resists gross error. At last the final clock combination is obtained based on the weighted average method by iteratively calculating equivalent weights. The results show that combined clock solution obtained by the proposed method has commendable consistency with IGS final clock solution. The RMS of the discrepancy between combination clock and IGS final clock is about 0.03–0.05 ns, which is significantly better than the results of AC clock solutions. Combination clock correction is also more stable and reliable. Finally, static PPP test proves that the combination clock maintains the consistency of orbit and clock at millimeter level.

Keywords

Clock combination Reference time-frame Robust estimation High-breakpoint of pollution rate 

Notes

Acknowledgments

This work was supported by the State key laboratory of geodesy and geodynamics open funded projects (SKLGED2013-4-2-EZ) and the national natural science fund project (41174008) and the Open Foundation of State Key Laboratory of Astronautic and Dynamics (2014ADL-DW0101).

References

  1. 1.
    Kouba J, Mireault Y, Lahaye F (1995, 1994) IGS orbit/clock combination and evaluation, Appendix I of the analysis coordinator report, International GPS service for geodynamics (IGS) 1994 annual report, pp 70–94Google Scholar
  2. 2.
    Kouba J, Springer Tim (2001) New IGS station and satellite clock combination. GPS Solution 4(4):31–36CrossRefGoogle Scholar
  3. 3.
    Springer TA, Zumberge JF, Kouba J (1998) The IGS analysis products and consistency of the combined solutions, IGS analysis center workshop, Darmstadt, 9–11 Feb 1998Google Scholar
  4. 4.
    Kouba J, Mireault Y (1997) Analysis coordinator report international GPS service for geodynamics (IGS) 1996 annual report, pp 55–100Google Scholar
  5. 5.
    Wei EH, Chai H (2006) Comparative study on the interpolation method of GPS precise ephemeris, GNSS World of China. 5:13–15 (In Chinese)Google Scholar
  6. 6.
    Jiang Nan, Xu TH, Xu Yan (2012) An improved method for determination of GOCE orbital velocity of the geometric method, Bulletin of Surveying and Mapping. 11:7–10 (In Chinese)Google Scholar
  7. 7.
    Qiu WN (2003) Selecting weight iteration method with reliable initial values. Geomatics and Information Science of Wuhan University 8:452–454 (In Chinese) Google Scholar
  8. 8.
    Zhou JW, Huang YC, Yang YX, Ou JK (1997) Robust least square method. Huazhong University of Science and Technology Press, Wuhan (In Chinese)Google Scholar
  9. 9.
    Lauknes TR, Zebker HA, Larsen Y (2010) InSAR deformation time series using an L1-Norm small-baseline approach. IEEE Trans Geosci Remote Sens 114:2097–2109 Google Scholar
  10. 10.
    Yang YX, Wu FM (2006) Robust estimation equivalent weight function with variable threshold. J Geomatics Sci Technol 10:317–320 (In Chinese)Google Scholar
  11. 11.
    Yang YX (1993) Robust estimation theory and it’s applications. Bayi Publishing House, Beijing (In Chinese)Google Scholar
  12. 12.
    Ou JK (1996) An design of three-step robust solutions. Acta Geodaetica et Cartographica Sinica, 8:173–179 (In Chinese)Google Scholar
  13. 13.
    Kouba J, Heroux P (2001) Precise point positioning using IGS orbit and clock products. GPS Solution 5(2):12–28CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.School of Geology Engineering and SurveyingChang’an UniversityXi’anChina
  2. 2.State Key Laboratory of Geo-information EngineeringXi’anChina
  3. 3.State Key Laboratory of Astronautic and DynamicsXi’anChina
  4. 4.State Key Laboratory of Geodesy and Earth’s DynamicsWuhanChina
  5. 5.Xian Research Institute of Surveying and MappingXi’anChina

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