Next Article in Journal
Implementation of Tsunami Evacuation Maps at Setubal Municipality, Portugal
Previous Article in Journal
Influence of Flow Velocity on Tsunami Loss Estimation
Open AccessArticle

Towards the Selection of an Optimal Global Geopotential Model for the Computation of the Long-Wavelength Contribution: A Case Study of Ghana

1
School of Earth Sciences and Engineering, Hohai University, Nanjing 211100, China
2
Department of Geomatics Engineering, Kwame Nkrumah University of Science and Technology, Private Mail Bag, Kumasi AK000-AK911, Ghana
*
Author to whom correspondence should be addressed.
Geosciences 2017, 7(4), 113; https://doi.org/10.3390/geosciences7040113
Received: 17 October 2017 / Revised: 2 November 2017 / Accepted: 4 November 2017 / Published: 7 November 2017
The selection of a global geopotential model (GGM) for modeling the long-wavelength for geoid computation is imperative not only because of the plethora of GGMs available but more importantly because it influences the accuracy of a geoid model. In this study, we propose using the Gaussian averaging function for selecting an optimal GGM and degree and order (d/o) for the remove-compute-restore technique as a replacement for the direct comparison of terrestrial gravity anomalies and GGM anomalies, because ground data and GGM have different frequencies. Overall, EGM2008 performed better than all the tested GGMs and at an optimal d/o of 222. We verified the results by computing geoid models using Heck and Grüninger’s modification and validated them against GPS/trigonometric data. The results of the validation were consistent with those of the averaging process with EGM2008 giving the smallest standard deviation of 0.457 m at d/o 222, resulting in an 8% improvement over the previous geoid model. In addition, this geoid model, the Ghanaian Gravimetric Geoid 2017 (GGG 2017) may be used to replace second-order class II leveling, with an expected error of 6.8 mm/km for baselines ranging from 20 to 225 km. View Full-Text
Keywords: Heck and Grüninger’s modification; Gaussian averaging function; geoid; global geopotential models; remove-compute-restore Heck and Grüninger’s modification; Gaussian averaging function; geoid; global geopotential models; remove-compute-restore
Show Figures

Figure 1

MDPI and ACS Style

Yakubu, C.I.; Ferreira, V.G.; Asante, C.Y. Towards the Selection of an Optimal Global Geopotential Model for the Computation of the Long-Wavelength Contribution: A Case Study of Ghana. Geosciences 2017, 7, 113.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop