Abstract The main challenge in real-time precise point positioning (PPP) is that the data outages or large time lags in receiving precise orbit and clock corrections greatly degrade the continuity and real-time performance of PPP positioning. To solve this problem, instead of directly predicting orbit and clock corrections in previous researches, this paper presents an alternative approach of generating combined corrections including orbit error, satellite clock and receiver-related error with broadcast ephemeris. Using ambiguities and satellite fractional-cycle biases (FCBs) of previous epoch and the short-term predicted tropospheric delay through linear extrapolation model (LEM), combined corrections at current epoch are retrieved and weighted with multiple reference stations, and further broadcast to user for continuous enhanced positioning during outages of orbit and clock corrections. To validate the proposed method, two reference station network with different inter-station distance from National Geodetic Survey (NGS) network are used for experiments with six different time lags (i.e., 5 s, 10 s, 15 s, 30 s, 45 s and 60 s), and one set of data collected by unmanned aerial vehicle (UAV) is also used. The performance of LEM is investigated, and the troposphere prediction accuracy of low elevation (e.g., 10–20degrees) satellites has been improved by 44.1% to 79.0%. The average accuracy of combined corrections before and after LEM is used is improved by 12.5% to 77.3%. Without LEM, an accuracy of 2–3 cm can be maintained only in case of small time lags, while the accuracies with LEM are all better than 2 cm in case of different time lags. The performance of simulated kinematic PPP at user end is assessed in terms of positioning accuracy and epoch fix rate. In case of different time lags, after LEM is used, the average accuracy in horizontal direction is better than 3 cm, and the accuracy in up direction is better than 5 cm. At the same time, the epoch fix rate has also increased to varying degrees. The results of the UAV data show that in real kinematic environment, the proposed method can still maintain a positioning accuracy of several centimeters in case of 20 s time lag.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Comprehensive outage compensation of real-time orbit and clock corrections with broadcast ephemeris for ambiguity-fixed precise point positioning


    Beteiligte:
    Zhao, Qing (Autor:in) / Gao, Wang (Autor:in) / Gao, Chengfa (Autor:in) / Pan, Shuguo (Autor:in) / Yang, Xing (Autor:in) / Wang, Jun (Autor:in)

    Erschienen in:

    Advances in Space Research ; 67 , 3 ; 1124-1142


    Erscheinungsdatum :

    2020-11-03


    Format / Umfang :

    19 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch




    Real-Time Precise Point Positioning Method Considering Broadcast Ephemeris Discontinuities

    Quanrun Cheng / Junping Chen / Yize Zhang et al. | DOAJ | 2024

    Freier Zugriff


    Integer Satellite Clock Combination for Precise Point Positioning with Ambiguity Resolution

    Seepersad, Garrett / Banville, Simon / Collins, Paul et al. | British Library Conference Proceedings | 2016


    Precise Onboard Orbit Determination for LEO Satellites with Real-Time Orbit and Clock Corrections

    Hauschild, André / Tegedor, Javier / Montenbruck, Oliver et al. | British Library Conference Proceedings | 2016


    Real-time ephemeris and clock corrections for GPS and GLONASS satellites

    Romay-Merino, M. M. / European Space Agency | British Library Conference Proceedings | 1997