Abstract
This paper deals with creating a fine digital terrain model (DTM) for Africa and the surrounding region covering the window 42∘S ≤ ϕ ≤ 44∘N, 22∘W ≤ λ ≤ 62∘E using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) at a 3″ × 3″ resolution (which corresponds to roughly 90 m resolution on the earth’s surface). The ASTER-GDEM model, which is available only on land, has been smoothed from its original 1″ × 1″ resolution to the used 3″ × 3″ resolution using the block average operator technique employing special characteristics at the coastal boarders. The 30″ × 30″ SRTM30+ has been used, after being interpolated to 3″ × 3″ grid size, to fill-in the missing sea regions of the ASTER-GDEM model. The created 3″ × 3″ DTM has been compared with the available point data both on land and on sea areas for a set of more than one million points. Residuals follow perfectly the Gaussian normal distribution.
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Acknowledgements
This project was supported financially by the Science and Technology Fund (STDF), Egypt, Grant No. 7944. The support by the International Association of Geodesy (IAG) and the International Union of Geodesy and Geophysics (IUGG) is kindly acknowledged. The authors would like to thank the editor of the current paper and two anonymous reviewers for their useful comments.
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Abd-Elmotaa, H.A., Makhloof, A., Abd-Elbaky, M., Ashry, M. (2017). The African 3″× 3″ DTM and Its Validation. In: Vergos, G., Pail, R., Barzaghi, R. (eds) International Symposium on Gravity, Geoid and Height Systems 2016. International Association of Geodesy Symposia, vol 148. Springer, Cham. https://doi.org/10.1007/1345_2017_19
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DOI: https://doi.org/10.1007/1345_2017_19
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