This work investigates the vertical accuracy and relevance of two widely available digital elevation models (DEMs) in surveying and Geo-informatics using GPS (Global Positioning System) ground stations. The two DEMS assessed are SRTM3 (Shuttle Radar Topography Mission along with ASTER (Advanced Space borne Thermal Emission Reflectance Radiometer). These datasets are accessed using GPS ground control points in Rivers State, Nigeria. Assuming error (vertical) is distributed normally; the 1.9600 factor is used to calculate the linear error confidence statistical level of 95%. Vertical data accuracy with confidence level of 95% of the RMSE (Root Mean Square Error) is use as the standard measure of accuracy for Vertical Accuracy positioning. Their vertical accuracy with reference to GPS control station used in this study as true heights shows the RMSE for ASTER GDEM V2 and SRTM3 V2.1 is ± 8.861734m and ± 6.307187m, with vertical accuracy of ± 17.362089m and ± 12.362086m respectively. The SRTM3 and ASTER is suitable for mapping(topographic) within interval of contour of 14m and 18m interval in the region Other includes geomorphologic activities, and estimating the terrain corrections in quasi-geoid modelling in Rivers State.
Vertical accuracy assessment, ASTER GDEM, SRTM3, and GPS ground control
