https://orcid.org/0000-0001-5279-5747
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Abstract
In this contribution, two gravimetric geoid models for Egypt; EGY-LGM2019 and EGY-FGM2019 are developed using the least-squares collocation and the Fast-Fourier Transformation methods, applying Remove-Restore procedure. Different datasets are used in terms of gravity anomalies obtained from GOCE-based SPW-R5 and EGM2008 models, and from 1015 terrestrial gravity stations. Two gravimetric geoid models, EGY-FLGM2019 derived by the LSC method and EGY-FFGM2019 derived by 1D-FFT method are computed and fitted using the 17 GPS/levelling measurements to adjust the gravimetric geoid model with the national local vertical datum for Egypt. Our findings between the 6 GPS/levelling geoid undulations and the developed fitted geoid models EGY-FFGM2019 and EGY-FLGM2019 are about 7.57 and 18.46 cm, respectively. In addition, the former model improves the geoid heights of about 72-65% over Egypt w.r.t. the EGM2008 and GECO models, respectively. Therefore, the EGY-FFGM2019 model is recommended as a reliable model that improves the geoid heights over Egypt.
Additional information
Notes on contributors
Ahmed Saadon
Ahmed Saadon received his M.Sc. degree in geodesy engineering from the Construction Engineering and Utilities Department, Faculty of Engineering, Zagazig University, Zagazig, Egypt in 2019. His research interests include modeling of geoid heights and hydrological loading using time series of Satellite-based products and GNSS datasets.
Mohamed El-Ashquer
Dr. Mohamed El-Ashquer received the Ph.D. degree in geodesy engineering from the Construction Engineering and Utilities Department, Faculty of Engineering, Zagazig University, Zagazig, Egypt in 2017. His research interests include satellite gravimetry, geoid heights modeling, and the GNSS positioning to monitor geodynamic processes.
Basem Elsaka
Dr. Basem Elsaka received the Ph.D. degree in geodesy engineering from the Institute of Geodesy and Geoinformation, the University of Bonn, Germany, in 2010. He has more than 15 year-experience in the fields of satellite and physical geodesy with a focus on optimal design for satellite configurations in low-low mode, determination of static and temporal variations of the Earth's gravity field and geoid modeling using different terrestrial and satellite-based datasets.
Gamal El-Fiky
Prof. Gamal El-Fiky received Doctor of Science degree (D. Sc.) in Geodesy (Crustal Deformation), in March 1998, from Earthquake Research Institute, The University of Tokyo, Japan. He has more than 30 years of experience in the study of crustal deformation of the active seismo-tectonic regions of Egypt and the Japanese Islands, using GPS and terrestrial geodetic data. His main research interest is to investigate the mechanism of crustal process with special reference to the generation of earthquakes from this GPS dense array and terrestrial geodetic data.