EGU21-316
https://doi.org/10.5194/egusphere-egu21-316
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Harmonic Correction for Residual Terrain Modelling (RTM) Technique in Physical Geodesy Applications

Meng Yang1, Xiao-Le Deng2, and Min Zhong1
Meng Yang et al.
  • 1School of Geospatial Engineering and Science, Sun Yat-Sen University, Zhuhai, 519082, China (yangmeng5@mail.sysu.edu.cn; zmzm@asch.whigg.ac.cn)
  • 2Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, 518055, China (dengxl@sustech.edu.cn )

       In physical geodesy, the harmonic correction (HC), as one of the main problems when using residual terrain modelling (RTM), has become a research focus of high-frequency gravity field modelling. Over past decades, though various methods have been proposed to handle the HC issues for RTM technique, most of them focused on the HC for RTM gravity anomaly rather than other gravity functionals, such as RTM geoid height and gravity gradient. In practice, the HC for RTM geoid height was generally assumed to be negligible, but a quantification is yet studied. In this study, besides the highlighted HC for gravity anomaly in previous studies, the expressions of HC terms for RTM geoid height are provided in the framework of the classical condensation method under infinite Bouguer plate approximation. The errors involved by various assumption of the classical condensation method, e.g., mass inconsistency between infinite masses in the HC and limited masses in the RTM, and planar assumption of the Earth’s surface, are further studied. Based on the derived formulas, the quantification of HC for RTM geoid height when reference surface is expanded to degree and order of 2,159 is given. Our results showed the significance of HC for RTM geoid height, with values up to ~10 cm, in cm-level and mm-level geoid determination. With integration masses extending up to a sufficient distance, such as 1° from calculation point for the determination of RTM geoid height, the errors due to an infinite Bouguer plate approximation are neglectable small. The validation through comparison with terrestrial measurements proved that the HC terms provided in this study can improve the accuracy of RTM derived geoid height and are expected to be useful for applications of RTM technique in regional and global gravity field modelling.

How to cite: Yang, M., Deng, X.-L., and Zhong, M.: Harmonic Correction for Residual Terrain Modelling (RTM) Technique in Physical Geodesy Applications, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-316, https://doi.org/10.5194/egusphere-egu21-316, 2020.

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