|Network RTK is a navigation technology that can secure cm-level position accuracy using carrier phase measurements. The coverage of network RTK is known to be 50-70 km. The reason why the coverage of network RTK is limited is that the user's residual error cannot satisfy the integer ambiguity determinable level as the network expands. If the user's residual error can be maintained at the integer ambiguity determinable level, the coverage can be expanded. Network RTK user’s residual error mainly consists of ionospheric delay error and tropospheric delay error. Therefore, even if the network is expanded, if the ionospheric delay error and the tropospheric delay error can be effectively eliminated, the coverage of the network RTK can be expanded. Therefore, in this study, the possibility of expanding the coverage of network RTK was analyzed by suggesting the use of the Kriging based weight model and the determination of the integer ambiguity using the ionospheric free combination measurements. In order to test the effectiveness of the proposed method, the conventional 50-70km network and the expanded 100-150km network were constructed using the CORS reference stations, and the network RTK performance on sunny day and rainy days was analyzed. As a result, when the conventional methods were used, the integer ambiguity determination rate of less than 50% was confirmed in the expanded network, and the position error of 10 cm or more occurred because the integer ambiguities were incorrectly determined. In particular, on the day with precipitation, it was not possible to secure network RTK availability because the integer ambiguity determination rate was decreased and position error were further increased. On the other hand, using the proposed method, it was confirmed that the integer ambiguity determination rate of 80% or more can be secured in the extended network regardless of the troposphere environment. Moreover, it was determined that the coverage of network RTK can be expanded by checking the cm level position accuracy as all integer ambiguities were corretly determined.
Proceedings of the 35th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2022)
September 19 - 23, 2022
Hyatt Regency Denver
|2664 - 2678
|Cite this article:
Kim, Bu-Gyeom, Kee, Changdon, Kim, Donguk, "Kriging Based Weighting Model for Network RTK Coverage Expansion," Proceedings of the 35th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2022), Denver, Colorado, September 2022, pp. 2664-2678.
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