Evaluation of the Accuracy of Digital Elevation Model Produced from Different Open Source Data (original) (raw)
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An Assessment of Digital Elevation Models (DEMs) From Different Spatial Data Sources
Digital Elevation Model (DEM) represents a very important geospatial data type in the analysis and modelling of different hydrological and ecological phenomenon which are required in preserving our immediate environment. DEMs are typically used to represent terrain relief. DEMs are particularly relevant for many applications such as lake and water volumes estimation, soil erosion volumes calculations, flood estimate, quantification of earth materials to be moved for channels, roads, dams, embankment etc.
ACCURACY ASSESSMENT OF DIGITAL ELEVATION MODELS OBTAINED FROM DIFFERENT DATA AND METHODS
ACCURACY ASSESSMENT OF DIGITAL ELEVATION MODELS OBTAINED FROM DIFFERENT DATA AND METHODS, 2017
Digital elevation model (DEM) is primarily a way of visualising 2D maps, photographs and images in 3D. Common uses of DEMs are creation of relief maps, rendering of 3D visualizations, rectification of satellites images and aerial photographs, creation of different physical models, etc. DEMs can be produced by different methods. In this study, DEMs are produced by 1:25000 digital topographic maps, Light Detection and Ranging (LIDAR) data, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Shuttle Radar Topographic Mission (SRTM) data, and the accuracy of these models are analysed.
Google Earth’s derived digital elevation model: A comparative assessment with Aster and SRTM data
This paper presents a statistical analysis showing additional evidence that Digital Elevation Model (DEM) derived from Google Earth is commendable and has a good correlation with ASTER (Advanced Space-borne Thermal Emission and Reflection Radiometer) and SRTM (Shuttle Radar Topography Mission) elevation data. The accuracy of DEM elevation points from Google Earth was compared against that of DEMs from ASTER and SRTM for flat, hilly and mountainous sections of a pre-selected rural watershed. For each section, a total of 5,000 DEM elevation points were extracted as samples from each type of DEM data. The DEM data from Google Earth and SRTM for flat and hilly sections are strongly correlated with the R 2 of 0.791 and 0.891 respectively. Even stronger correlation is shown for the mountainous section where the R 2 values between Google Earth's DEM and ASTER's and between Google Earth's DEM and SRTM's DEMs are respectively 0.917 and 0.865. Further accuracy testing was carried out by utilising the DEM dataset to delineate Muar River's watershed boundary using ArcSWAT2009, a hydrological modelling software. The result shows that the percentage differences of the watershed size delineated from Google Earth's DEM compared to those derived from Department of Irrigation and Drainage's data (using 20m-contour topographic map), ASTER and SRTM data are 9.6%, 10.6%, and 7.6% respectively. It is therefore justified to conclude that the DEM derived from Google Earth is relatively as acceptable as DEMs from other sources.
International Journal of Geomatics and Geosciences, 2011
Several geomatics applications depend on utilizing Digital Elevation Models (DEMs), such as geomorphologic applications of watershed management and flood hazard determination. Additionally, DEMs play a crucial role in geodetic applications, particularly for the determination of topographic effects in quasigeoid modelling. This study aims to investigate the accuracy performance of several global and national DEMs in order to define the suitability of them in engineering applications in Kingdom of Saudi Arabia (KSA). Two global DEMs have been exploited, namely the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the Shuttle Radar Topographic Mission (SRTM3), along with two national DEMs, belong to the center of research excellence in Hajj and Omrah, with 5 and 10 meter resolution. A dataset of 200 firstorder Global Positioning System (GPS) ground control points, that covers the Makkah (Mecca) metropolitan area in the western region of KSA, has been compiled and employed to judge the accuracy of all DEMs in a Geographic Information Systems (GIS) environment. The attained results showed that the 5meter resolution national DEM is the most accurate one, that produces mean height difference and standard deviations equal 0.01 ± 2.95 m respectively. That national DEM is more accurate by factors of 3 and 2 over the global ASTER and SRTM3 DEMs respectively. Guidelines have been drawn to apply each DEM in geodetic, topographic mapping, and geomorphologic studies in KSA.
Several geomatics applications depend on utilizing Digital Elevation Models (DEMs), such as geomorphologic applications of watershed management and flood hazard determination. Additionally, DEMs play a crucial role in geodetic applications, particularly for the determination of topographic effects in quasigeoid modelling. This study aims to investigate the accuracy performance of several global and national DEMs in order to define the suitability of them in engineering applications in Kingdom of Saudi Arabia (KSA). Two global DEMs have been exploited, namely the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the Shuttle Radar Topographic Mission (SRTM3), along with two national DEMs, belong to the center of research excellence in Hajj and Omrah, with 5 and 10 meter resolution. A dataset of 200 firstorder Global Positioning System (GPS) ground control points, that covers the Makkah (Mecca) metropolitan area in the western region of KSA, has been compiled and employed to judge the accuracy of all DEMs in a Geographic Information Systems (GIS) environment. The attained results showed that the 5meter resolution national DEM is the most accurate one, that produces mean height difference and standard deviations equal 0.01 ± 2.95 m respectively. That national DEM is more accurate by factors of 3 and 2 over the global ASTER and SRTM3 DEMs respectively. Guidelines have been drawn to apply each DEM in geodetic, topographic mapping, and geomorphologic studies in KSA.
Accuracy Assessment of Digital Elevation Model (DEM) Data Obtained from ASTER Satellite in Flat Land
IOP Conference Series: Materials Science and Engineering
It is important to investigate the accuracy of Digital Elevation Models (DEMs) because of their crucial impact on all engineering and scientific disciplines. Photogrammetry, traditional surveying, remote sensing systems and satellite whole DEMs output methods. In this paper include the DEM data produced by the ASTER satellite (Band near-infrared wavelength region from 0.78 to 0.86 μm), where tested and evaluation DEM data for an area of 100 square kilometers in Al-Shtra city. The technique used to evaluate was twofold: first method was to use statistical methods; second method is to take advantage of applied linear transformation equation to detect the gap between Z-DEM and Z-Global Navigation Satellite System (GNSS) (which represents reality (. The result of a root means square error (RMSE) is 5.087m, where it was calculated based on the observed data in the field using GNSS. And standard deviation error (SDT err) was 5.088 m, while after applied linear transformation equation the RMSE reduction to about 80%, which indicates a large bias between the Z-DEM and Z-GPS.
Evaluation of vertical accuracy of open source Digital Elevation Model (DEM)
International Journal of …
Digital Elevation Model (DEM) is a quantitative representation of terrain and is important for Earth science and hydrological applications. DEM can be generated using photogrammetry, interferometry, ground and laser surveying and other techniques. Some of the DEMs such as ASTER, SRTM, and GTOPO 30 are freely available open source products. Each DEM contains intrinsic errors due to primary data acquisition technology and processing methodology in relation with a particular terrain and land cover type. The accuracy of these datasets is often unknown and is non-uniform within each dataset. In this study we evaluate open source DEMs (ASTER and SRTM) and their derived attributes using high postings Cartosat DEM and Survey of India (SOI) height information. It was found that representation of terrain characteristics is affected in the coarse postings DEM. The overall vertical accuracy shows RMS error of 12.62 m and 17.76 m for ASTER and SRTM DEM respectively, when compared with Cartosat DEM. The slope and drainage network delineation are also violated. The terrain morphology strongly influences the DEM accuracy. These results can be highly useful for researchers using such products in various modeling exercises.
Digital elevation model (DEM) is a digital representation of ground surface topography and have been used in various applications. The introduction of global coverage DEM available for free or at reasonable cost was a new phenomenon in mapping. The issue is how accurate are these datasets and can it be used for topographic mapping. This paper aims to evaluate the height accuracy of DEMs generated from different sources. Results presented in this paper is part of a study to evaluate the suitable use of different DEMs and high resolution imagery for topographic map updating. For this paper, Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), Intermap Airborne Interferometric Synthetic Aperture Radar Digital Terrain Model (IFSAR DTM), IFSAR Digital Surface Model (IFSAR DSM), digital topographic map (with a 5m contour interval) and Light Detection and Ranging (LiDAR) datasets are used to generate the contours, height points and height profiles. LiDAR dataset is used as reference DEM to evaluate the accuracy of NEXTMap IFSAR DTM and Digital Terrain Model (DTM) generated from digital topographic maps acquired from the Department of Survey and Mapping Malaysia. The vertical accuracy of ASTER GDEM is obtained by comparing wih the heights of IFSAR DSM. The Root Mean Squares Error (RMSE) of the height points generated from IFSAR DTM and digital topographic map of the non-vegetated areas within the study area are 1.458 m and 2.960 m respectively. For the vegetated area, the RMSE of IFSAR DTM and digital topographic map are 4.736 m and 9.848 m respectively. The accuracy of ASTER GDEM in the vegetated and non-vegetated areas are 8.442 m and 18.900 m respectively. Visual comparison between the contours generated from IFSAR DTM and LiDAR has shown promising result. ASTER GDEM can be used to capture the general characteristic of the terrain. Future work will include the evaluation of factors that contribute to the accuracy of DEMs generated from different sources.
Remote Sensing, 2022
Publicly available Digital Elevation Models (DEM) derived from various space-based platforms (Satellite/Space Shuttle Endeavour) have had a tremendous impact on the quantification of landscape characteristics, and the related processes and products. The accuracy of elevation data from six major public domain satellite-derived Digital Elevation Models (a 30 m grid size—ASTER GDEM version 3 (Ast30), SRTM version 3 (Srt30), CartoDEM version V3R1 (Crt30)—and 90 m grid size—SRTM version 4.1 (Srt90), MERIT (MRT90), and TanDEM-X (TDX90)), as well as the improvement in accuracy achieved by applying a correction (linear fit) using Differential Global Positioning System (DGPS) estimates at Ground Control Points (GCPs) is examined in detail. The study area is a hard rock terrain that overall is flat-like with undulating and uneven surfaces (IIT (ISM) Campus and its environs) where the statistical analysis (corrected and uncorrected DEMs), correlation statistics and statistical tests (for eleva...
International Journal of Innovation and Applied Studies, 2016
Digital elevation models (DEMs), as its name suggests, is a digital representation of ground in terms of altitude. It provides information not only on landforms but also on their geolocation; this is why it is considered one of the most useful digital data sets for a wide range of users. Various field, remote, and laboratory techniques can generate DEMs. Some of the DEMs such as ASTER, SRTM, and GTOPO30 are freely available open source products; however, the accuracy of these data sets is often unknown and is uneven within each dataset due to radar characteristics, type of topography, and physical properties of the surface. In this study, we evaluate open source DEMs (ASTER and SRTM) and their derived attributes using a reference DEM produced by contours maps interpolation and ground control points. In fact, the quality of derived attributes of DEMs such as slopes and drainage network is closely linked to accuracy of DEMs. While Open source DEMs partially show low accuracy in high e...