Comparison of different Mercator projection systems for the topographical survey of the Buchanan-Tokadeh (Yekepa) railway, Liberia, Africa
DOI: https://doi.org/10.3846/gac.2025.21650Abstract
For this project of the Buchanan-Tokadeh (Yekepa) railway located in the Republic of Liberia, Africa, it is about carrying out comparative analysis of precisions between two projection systems, the Local Transverse Mercator (LTM), divided into 15 zones; and Hotine Oblique Mercator (HOM); as well as the projection heights of their Local Topographic Planes (LTP) both in orthometric heights to determine the scale factor, as well as ellipsoidal ones to extend the semi-axes of the ellipsoid of the WGS84 datum to give an scale factor equal to 1 of these systems, along 245 km of route, taking as reference tolerances precisions that must be within 1/40,000 or 2.5 cms per kilometer, and also that the difference in height does not exceed 150 meters. Getting results by performing survey traverse polygon made with a total station, in a way that the deformations using an LTM divided into 15 zones and the HOM expanding the semi-axes of the reference ellipsoid of the Datum WGS84 complying with the aforementioned standards.
Keywords:
LTM, HOM, LTP, projection height, mean sea level, ellipsoidal height, scale factor, WGS84 datum, deformationHow to Cite
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Copyright (c) 2025 The Author(s). Published by Vilnius Gediminas Technical University.
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This work is licensed under a Creative Commons Attribution 4.0 International License.