Acta Geodaetica et Cartographica Sinica ›› 2022, Vol. 51 ›› Issue (2): 201-211.doi: 10.11947/j.AGCS.2022.20200367

• Geodesy and Navigation • Previous Articles     Next Articles

Sea level estimation using the combination of GNSS observations

WANG Jie1,2, WANG Nazi1,3, XU Tianhe1, GAO Fan1, HE Yunqiao1   

  1. 1. Institute of Space Sciences, Shandong University, Weihai 264209, China;
    2. School of Geological Engineering and Geomatics, Chang'an University, Xi'an 710000, China;
    3. State Key Laboratory of Geodesy and Earth's Dynamics, Innovation Academy for Precision Measurement Science and Technology, CAS, Wuhan 430077, China
  • Received:2020-07-31 Revised:2021-11-08 Published:2022-02-28
  • Supported by:
    The Key Research and Development Program of Shandong Province (Major Technological Innovation Project) (No. 2021ZDSYS01); The National Key Research and Development Program of China (No. 2020YFB0505800); The National Natural Science Foundation of China (No. 41704017); The State Key Laboratory of Geodesy and Earth's Dynamics (No. SKLGED2020-3-6-E)

Abstract: Comparing with tide gauge, GNSS-IR is used to monitor the sea level at low-cost, and the measurements are not susceptible to crustal subsidence. Moreover, sea level can be retrieved using the data provided by the existing coastal continuously operating reference stations (CORS).Signal-to-noise ratio (SNR) values provided by high-precision geodetic GNSS equipment, are the usual observations for GNSS-IR sea level estimation, however, this observations are not always exist, especially in early GNSS files. Fortunately, the classical observations-carrier phase and the code phase-also contains the information of sea surface height. Therefore, this paper aims to realize GNSS-IR sea level estimation based on two combinations of code pseudorange and carrier phase. In this paper, simulation data is used to prove that the accuracy of the GNSS-IR sea level measurements based on the former combination is affected by the residual of ionospheric delay, while the latter combination can avoid the influence of this error term. In order to verify the effectiveness of the used methods, different observations of the Global Positioning System (GPS) and BeiDou Satellite navigation system (BDS), which are obtained from the station installed at Weihai coastal trestle were processed and analyzed. The results show that there exists good agreement between the sea level results of proposed method and that recorded by an in-situ radar altimeter, and correlation coefficient is better than 85%. The experimental results show that the two combination methods of code pseudorange and carrier phase both can be used for GNSS-IR sea level estimation. In addition, because GNSS-IR sea level measurements are affected by various error terms, the inversion accuracy is low, so that the superiority of the latter combination in avoiding ionospheric delay residuals is not clearly shown. The proposed methods increases the diversity of sea level estimation methods, and provides more feasibility for sea level estimation using GNSS reflectometry technology.

Key words: GNSS-IR, sea level, SNR, code pseudorange, carrier phase

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