Abhatoo - Centre Nationale de Documentation

In this study, we have compared and evaluated the following models: ASTER GDEM2, SRTM1 V3, SRTM3 V4.1 and ETOPO1, over the Niger Republic from 11° North to 24° North and 0° to 16° East. The comparison and the assessment of precision are based on points from the General Levelling of Niger, points from various surveying campaigns in road construction projects, mining, etc. As an application in geophysics and physical geodesy, we have calculated the topographic effects on the gravity anomaly and the geoid by two Remove-Restore(R-R) approaches: the Residual Terrain Model and the Helmert’s Condensation Method.