Acta Geodaetica et Cartographica Sinica ›› 2020, Vol. 49 ›› Issue (8): 965-973.doi: 10.11947/j.AGCS.2020.20200044

• Geodesy and Navigation • Previous Articles     Next Articles

Torus approach in high degree gravity field model determination from GOCE satellite gradiometry observations

LIU Huanling1,2,3, WEN Hanjiang1,2, XU Xinyu4, ZHAO Yongqi4, CAI Jianqing5   

  1. 1. Chinese Academy of Surveying and Mapping, Beijing 100036, China;
    2. Key Laboratory of Surveying and Mapping Science and Geospatial Information Technology, Ministry of Natural Resources, Beijing 100036, China;
    3. Beijing Key Laboratory of Urban Spatial Information Engineering, Beijing 100038, China;
    4. School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China;
    5. Institute of Geodesy Universit't Stuttgart, Stuttgart 70174, Germany
  • Received:2020-02-13 Revised:2020-05-29 Published:2020-08-25
  • Supported by:
    The Major Project of High-Resolution Earth Observation System(No. 42-Y20A09-9001-17/18);The National Natural Science Foundation of China (Nos. 41574019;41774020);The German Academic Exchange Service (DAAD) Thematic Network Project (No. 57421148);The Basal Research Fund of Chinese Academy of Surveying and Mapping (No. AR1922);Beijing Key Laboratory of Urban Spatial Information Engineering (No. 2019211);The Key Laboratory of Geospace Environment and Geodesy, Ministry of Education, Wuhan University (No. 18-01-05)

Abstract: Currently, space-wise method, time-wise method and direct-wise method are widely used to deal with the GOCE satellite real observations. Different from these conventional methods, this paper proposes one Torus approach. As one refinement of the reference model, the GOCE earth gravity field model complete to 200 d/o is recovered using 71-day GOCE satellite gradiometry observations with Torus approach. Firstly, a Butterworth filter with zero-phase combining with remove-restore is used to deal with the colored noise in GOCE satellite gravitational gradient observations. These observations are reduced from the real orbits to nominal orbits using Taylor series expansion and Kriging is used for gridding on the nominal orbits. Then, 2D-FFT and the block-diagonal least-square adjustment are performed to process the gridded observations, so that the GOCE earth gravity field model complete to 200 d/o named as GOCE_Torus can be realized efficiently. GOCE_Torus is assessed with the GPS/leveling data in China and USA, respectively. GOCE_Torus and the first generation model released by ESA have a similar accuracy. In USA, EGM2008 complete to 200 d/o reveals a similar accuracy with GOCE_Torus. But in China, GOCE_Torus is improved by 4.6 cm due to the contribution of GOCE gravity gradiometry data. With the application of Torus approach the satellite gravity field model can be recovered quickly and accurately, and therefore this approach is useful in mission design, error analysis and in-orbit evaluation of gravity gradient satellites.

Key words: GOCE, earth's gravity field, Torus approach, refinement

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