The African 3" x 3" DHM
20/09/2016 | 17:45 | Session 3: Local/regional geoid determination methods and models
Author(s): Hussein Abd-Elmotaal, Atef Makhloof, Mostafa Abd-Elbaky and Mostafa Ashry
Hussein Abd-Elmotaal, Atef Makhloof, Mostafa Abd-Elbaky and Mostafa Ashry
This paper deals with creating a fine digital height model (DHM) for Africa and the surrounding region covering the window -40 < latitude < 42; -20 < longitude < 60 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 smoothing average operator technique implying special characteristics at coastal boarders. The gaps of the ASTER-GDEM model have been filled using the 30" × 30" SRTM30+ after interpolation to the same grid size. The Kriging interpolation technique with zero error variance has been used. The created 3" × 3" DHM has been compared with the available point data both on land and ocean areas for a set of more than one million points. Differences follow perfectly the Gaussian normal distribution.