Comparison of Accuracy of Two Global DEMs, and the Extracted DEM from the Topographic Map of the Tafilah Governorate

Abstract

SRTM DEM (shuttle radar topographic mission digital elevation model) and ASTEMR DEM (advanced space-borne thermal emission and reflection radiometer digital elevation model) are now freely available in two resolutions: 90 m and 30 m. DEM is a computerized representation of the Earth's relief, and is used in many applications such as hydrology, climatology, geomorphology and ecology. There are some important differences in assessing the accuracy of digital elevation models for specific applications. The purpose of this study is to investigate the errors in digital elevation models obtained globally from DEMs 90 m, 30 m ground resolution, and the extracted DEM from a topographic map by digitized contour lines of 1:50,000 scale in a rugged mountainous region and a heterogeneous landscape, using KS (kernel smoothing) interpolation method. For validation purposes, datasets of 250-GCPs (ground control points) distributed over the study area were used to evaluate and compare the accuracy of the two global Dems and the DEM extracted from TM. The main results showed that the 30 m resolution global (DEM) is the most accurate one among the three. According to the validation results, SRTM with maximum (+) and minimum (-) error elevation is -10_9. M, with mean deviation of KS is -0.00238667, and RMS (root-mean-square) error of 0.98, and currently the most accurate model is 30 m DEM of the study area with no significant differences compared with DEM 90 m.

Detection of the Land Surface Temperature Changes in Ma’an Governorate using Remote Sensing Data during the Period (1990-2018)

“…Image acquisition and pre-processing, for ArcMap software was used to combine the visible and near infrared (NIR) bands and create stacking layers. Landsat were corrected using ground features such as road crosses, before the Landsat images were mosaicked, subset and clipped to the borders of the study area (Al-husban, 2017;Farhan and Al-Bakri, 2012). The Landsat images used multi-bands with varying wavelengths (Barsi et al, 2014), as presented in Table 2.…”