Acta Geodaetica et Cartographica Sinica ›› 2024, Vol. 53 ›› Issue (11): 2099-2110.doi: 10.11947/j. AGCS.2024.20240249.

• Geodesy and Navigation • Previous Articles    

Sea surface height inversion based on inverse modeling of multi-GNSS and multi-frequency SNR data

Lingqiu CHEN1,2(), Hongzhou CHAI1(), Jingyang BAO3, Min WANG1,2, Naiquan ZHENG4   

  1. 1.Institute of Geospatial Information, Information Engineering University, Zhengzhou 450001, China
    2.Key Laboratory of Smart Earth, Xi'an 710000, China
    3.School of Smart Marine Science and Technology, Fujian University of Technology, Fuzhou 350118, China
    4.College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266590, China
  • Received:2024-06-19 Published:2024-12-13
  • Contact: Hongzhou CHAI E-mail:clqseu@126.com;chaihz1969@163.com
  • About author:CHEN Lingqiu (1988—), female, PhD candidate, lecturer, majors in GNSS remote sensing. E-mail: clqseu@126.com
  • Supported by:
    The National Natural Science Foundation of China(42304043);Key Laboratory of Smart Earth(KF2023YB01-11)

Abstract:

The inverse modeling utilizing signal-to-noise ratio (SNR) data enables the inversion of sea surface height (SSH) and its variations. However, the accuracy and stability of the inversion process hinge on the precision of the initial values and the temporal continuity of the SNR data. Further investigation is required into the performance of inverse modeling based on multi-mode and multi-frequency SNR data for inverting sea-level changes and its application in tidal analysis. This study introduces a dynamic correction for sea surface variations into the inversion results of the Lomb-Scargle periodogram (LSP), which is utilized for initializing parameters in the inverse modeling process. This approach yields stable and uniform high-precision SSH inversion values, which are then employed to conduct tidal harmonic analysis. Three stations with large tidal ranges, namely MAYG, BRST, and SC02, were selected for inverse modeling and inversion experiments using their one-year multi-mode and multi-frequency SNR data. Algorithm validation was conducted through comparative analysis with in-situ SSH measurements from tide gauges. The results indicate that the root-mean-square error (RMSE) of the SSH inversion via inverse modeling is 5.97 cm for MAYG, 8.78 cm for BRST, and 2.38 cm for SC02, demonstrating centimeter-level accuracy in SSH inversion. When compared with the tidal harmonic analysis results of the observed SSH, the annual and monthly fitting residuals exhibit high consistency in terms of mean square error. The mean absolute error (MAE) of the extracted tidal constituent amplitudes is better than 1 cm, and the MAE of the extracted tidal phase lags is within 3°. Both the tidal components and non-tidal water levels extracted from the tidal analysis demonstrate high consistency. Therefore, the inversion of SSH using multi-mode and multi-frequency SNR data can serve as a viable alternative to in-situ SSH measurements for tidal harmonic analysis.

Key words: GNSS-IR, sea surface height inversion, inverse modeling, LSP, SNR data

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