Author(s)

Ahmed Saadon¹, Basem Elsaka^2,3, Mohamed El-Ashquer¹, Gamal El-Fiky^1,4

¹Construction Engineering and Utilities Department, Faculty of Engineering, Zagazig University, Zagazig, Egypt.
²National Research Institute of Astronomy and Geophysics (NRIAG), Cairo, Egypt.
³Institute of Geodesy and Geoinformation, University of Bonn, Bonn, Germany.
⁴The Bilbies Higher Institute of Engineering, Bilbies, Egypt.

The gravity field and steady-state ocean circulation explorer (GOCE) satellite mission has provided numerous Global Geopotential Models (GGMs) with different processing methodologies and model accuracies. In the current contribution, the latest releases of GOCE-based GGMs are evaluated on the regional scale using the available terrestrial GPS/Levelling and gravity data collected over Egypt. To overcome the spectral inconsistency between the GOCE-based GGMs and the ground-based data, the spectral enhancement method (SEM) is applied. Five of GOCE-based GGMs have been used, namely GOSG01S, IGGT_R1, IfE_GOCE05s_ GO_CONS_GCF_2_SPW_R5 (SPW_R5 in the following) and NULP-02. The evaluation process of GOCE-based GGMs with the available ground data over Egypt considering the SEM method shows remarkable improvements obtained from the SPW_R5 model. The model provides lower differences of the standard deviations with respect to the EGM2008 and the other applied geopotential gravity models as well as the applied ground-based gravity and GPS/Levelling data. The findings regarding the ground-based data show obvious reductions of about 15.16% and 32.22% achieved by the GOCE-based model in term of standard deviations differences of gravity anomalies and geoid heights, respectively. Therefore, the SPW_R5 model is recommended to be applied as a reference model for compensating the long-to-short wavelength (up to spherical harmonics degree/order 280) components when modelling the gravimetric geoid over Egypt.

GOCE-Based GGMs, Gravity Anomalies, GNSS/Levelling, Spectral Enhancement Method (SEM)

Saadon, A. , Elsaka, B. , El-Ashquer, M. and El-Fiky, G. (2019) Regional Evaluation of GOCE-Based GGMs with Ground-Based Gravity and GPS/Levelling Data over Egypt. International Journal of Geosciences, 10, 652-668. doi: 10.4236/ijg.2019.106037.