Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : DEM


Accuracy Assessment of Digital Elevation Models Produced From Different Geomatics Data

Imzahim Abdulkareem; Zina Walid Samuel; Qassim K. Abdullah

Engineering and Technology Journal, 2020, Volume 38, Issue 11, Pages 1580-1592
DOI: 10.30684/etj.v38i11A.1318

Digital Elevation Models (DEM) are now being used in several geospatial applications. DEMs play an important role in the preliminary surveys for constructing dams and reservoirs, highways, canals, and projects in which earth work is essential. In many remote sensing applications, DEMs have become a significant tool for InSAR (Interferometric Synthetic Aperture Radar) processing, ground cover classification and images ortho-rectification. In this study, the accuracy of DEMs obtained from ALOS V1.1, ASTER V2, SRTM V3 and other obtained from a pair of Pleiades high-resolution (PHR) 1B satellites in a study area were evaluated after comparing them with high accuracy GNSS/RTK checkpoints. The SRTM3, ALOS V1.1, ASTER V2 DEM revealed a Root Mean Square Error (RMSE) of 2.234m, 0.838m, and 15.116m respectively; while the DEM which is produced from a 0.5m resolution of Pleiades 0.5m shows an RMSE of 0.642m. The correct bias Linear transformation algorithm was used and the RMSE results were: SRTM V3 (1.319m), ALOS V1.1 (0.830m), ASTER V2 (3.815m), and PHR (0.433m). The results showed that the ALOS V1.1 model is the most accurate of the open source models followed by the SRTM V3 model and then followed by ASTER V2. The results obtained from a pair by Pleiades high-resolution (PHR) 1B satellites show a higher accuracy than the results obtained from the open source models.

Shirkat Town Monitoring Using Digital Elevation Model

Iman A. Shawkat; Mothana M. Al-Hadithy; Abdul-Razzak T. Ziboon

Engineering and Technology Journal, 2011, Volume 29, Issue 2, Pages 312-321

In this search, a colored image of French satellite SPOT, of Shirkat country in
Salahadeen was used with resolution about (5m) for an area with dimensions
(4km×8km), and a digital elevation model (DEM) with grids (20m×20m) and
levels reach to (1m) resolution from the same satellite for the same country, with
an image taken from the IKONOS satellite with (1m) resolution, in addition to
master plan and administrative map for the same area.
The IKONOS satellite image processed digitally, and intersected with the
DEM, to create a three dimensional model for the area under study, with
resolution about (1mm), by the use of AutoCAD and GIS programs, and making a
comparison between the field survey and the images information, resulting
extensive information about the levels in shirkat country streets and the
surrounding buildings, and an attributive results about the agricultural or desert
spaces around the country.