scholarly journals Evaluation of the Accuracy of Digital Elevation Model Produced from Different Open Source Data

2019 ◽  
Vol 25 (8) ◽  
pp. 100-112
Author(s):  
Raghad Hadi Hasan

This study aims to estimate the accuracy of digital elevation models (DEM) which are created with exploitation of open source Google Earth data and comparing with the widely available DEM datasets, Shuttle Radar Topography Mission (SRTM), version 3, and Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), version 2. The GPS technique is used in this study to produce digital elevation raster with a high level of accuracy, as reference raster, compared to the DEM datasets. Baghdad University, Al Jadriya campus, is selected as a study area. Besides, 151 reference points were created within the study area to evaluate the results based on the values of RMS.Furthermore, the Geographic Information System (GIS) was utilized to analyze, imagine and interpolate data in this study. The result of the statistical analysis revealed that RMSE of DEM related to the differences between the reference points and Google Earth, SRTM DEM and ASTER GDEM are 6.9, 5.5 and 4.8, respectively. What is more, a finding of this study shows convergence the level of accuracy for all open sources used in this study.  

Author(s):  
Hailu Zewde Abili

DEM can be generated from a wide range of sources including land surveys, Photogrammetry, and Remote sensing satellites. SRTM 30m DEM by The Shuttle Radar Topography Mission (SRTM), the Global Digital Elevation Model by Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER GDEM) and a global surface model called ALOS Worldview 3D 30 meter (AW3D30) by Advanced Land Observing Satellite (ALOS) are satellite-based global DEMs open-source DEM datasets. This study aims to assess the vertical accuracy of ASTER GDEM2, SRTM 30m, and ALOS (AW3D30) global DEMs over Ethiopia in the study area-Adama by using DGPS points and available accurate reference DEM data. The method used to evaluate the vertical accuracy of those DEMs ranges from simple visual comparison to relative and absolute comparisons providing quantitative assessment (Statistical) that used the elevation differences between DEM datasets and reference datasets. The result of this assessment showed better accuracy of SRTM 30m DEM (having RMSE of ± 4.63 m) and closely followed by ALOS (AW3D30) DEM which scored RMSE of ± 5.25 m respectively. ASTER GDEM 2 showed the least accuracy by scoring RMSE of ± 11.18 m in the study area. The second accuracy assessment was done by the analysis of derived products such as slope and drainage networks. This also resulted in a better quality of DEM derived products for SRTM than ALOS DEM and ASTER GDEM.


2017 ◽  
Vol 66 (1) ◽  
pp. 137-148 ◽  
Author(s):  
Małgorzata Woroszkiewicz ◽  
Ireneusz Ewiak ◽  
Paulina Lulkowska

Abstract The TerraSAR-X add-on for Digital Elevation Measurement (TanDEM-X) mission launched in 2010 is another programme – after the Shuttle Radar Topography Mission (SRTM) in 2000 – that uses space-borne radar interferometry to build a global digital surface model. This article presents the accuracy assessment of the TanDEM-X intermediate Digital Elevation Model (IDEM) provided by the German Aerospace Center (DLR) under the project “Accuracy assessment of a Digital Elevation Model based on TanDEM-X data” for the southwestern territory of Poland. The study area included: open terrain, urban terrain and forested terrain. Based on a set of 17,498 reference points acquired by airborne laser scanning, the mean errors of average heights and standard deviations were calculated for areas with a terrain slope below 2 degrees, between 2 and 6 degrees and above 6 degrees. The absolute accuracy of the IDEM data for the analysed area, expressed as a root mean square error (Total RMSE), was 0.77 m.


Author(s):  
Bambang Trisakti ◽  
Ita Carolita ◽  
Firsan Ardi Pradana

Digital Elevation Model (DEM) is a source to produce contour map, slope, and aspect information, which is needed for other information such as disaster and water resources management. DEM can be generated by several methods. One of them is parallax calculations from stereoscopic data of optical sensor. Panchromatic Remote-Sensing Instrument for Stereo Mapping (PRISM) sensor from Advanced LAnd Observation Satellite (ALOS) satellite and advance space borne Thermal Emission and Reflection Radiometer (ASTER) sensor from Terra Satellite is Japanese optical satellite sensor which have abilityto produce stereoscopic data. This study showed DEM generations from PRISM (2.5 m spatial resolution) and ASTER (15m spatial resolution) stereoscopic data using image matching and collinear model based on Orthobase-pro software. The Generated DEM from each sensor was compared to the DEM from Shuttle Radar Topography Mission (SRTM) X-C band with 30 m spatial resolution. The dependent on the pixel size from the DEM produced were also discussed. The result showed that both DEMs have similiar elevation and distribution pattern to the referenced DEM, but DEM for PRISM had higher relative accuracy (RMSE is 6.5 m) and Smoother pattern comparing to DEM from ASTER (RMSE is 10.2 m) Keyword : ASTER, DEM, PRISM, SRTM, Stereoscopic satellite data


Author(s):  
J. Takaku ◽  
T. Tadono ◽  
M. Doutsu ◽  
F. Ohgushi ◽  
H. Kai

Abstract. In 2016, the first processing of the semi-global digital surface models (DSMs) utilizing all the archives of stereo imageries derived from the Panchromatic Remote sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS) was successfully completed. The dataset was freely released to the public in 30 m grid spacing as the ‘ALOS World 3D - 30m (AW3D30)’, which was generated from its original version processed in 5 m or 2.5 m grid spacing. The dataset has been updated since then to improve the absolute/relative height accuracies with additional calibrations. However, the most significant update that should be applied for improving the data usability is the filling of void areas, which correspond to approx. 10% of semiglobal coverage, mostly due to cloud covers. In 2020, we completed the filling process by using other open-access digital elevation models (DEMs) such as Shuttle Radar Topography Mission (SRTM) DEM, Advanced Spaceborne Thermal Emission and Reflection Radiometer Global DEM (ASTER GDEM), ArcticDEM, etc., except for Antarctica. In this paper, we report on the filling process of the remaining voids in Antarctica by using other open-access DEMs such as Reference Elevation Model of Antarctica (REMA) DSM, TerraSAR-X add-on for Digital Elevation Measurement (TanDEM-X, TDX) 90m DEM, and ASTER GDEM to complete the void-free semi-global AW3D30 datasets.


2015 ◽  
Vol 26 (45) ◽  
pp. 151
Author(s):  
Erika Rodrigues Dias

<p>Uma das grandes preocupações da atualidade encontra-se no uso racional das terras, conciliando aspectos sociais, econômicos e ambientais tornando necessário o planejamento territorial através de um conhecimento detalhado da superfície territorial. Dessa forma, é de fundamental importância a representação do terreno. Assim, este trabalho teve por objetivo gerar um modelo digital de elevação – MDE, utilizando imagens de radar SRTM com a finalidade de servir como subsídio à gestão e planejamento territorial. Os materiais utilizados nesse trabalho foram imagens de radar da missão Shuttle Radar Topography Mission – SRTM, imagens obtidas do Google Earth e softwares específicos. Como resultados foram gerados diversos produtos cartográficos que possibilitaram o reconhecimento territorial do município como os mapas de hipsometria e clinografia da área em estudo e a representação tridimensional do relevo visando servir como subsídio à gestão territorial e planejamento do meio físico.</p><p><strong>Palavras-Chave</strong>: Modelo Digital de Elevação, SRTM, Geotecnologias.</p><p><strong>Abstract</strong></p><p>A major concern of today is in the rational use of land, combining social, economic and environmental aspects making it necessary to territorial planning with a detailed knowledge of land area. Thus, it is fundamental to representation of the terrain. Thus, this study aimed to generate a digital elevation model - MDE using SRTM radar images in order to serve as a resource management and territorial planning. The materials used in this work were the mission radar images Shuttle Radar Topography Mission - SRTM, images obtained from Google Earth and specific software. The results were generated several cartographic products enabled the territorial recognition of the city as hypsometry maps and clinografia of the study area and the three-dimensional relief representation to serve as subsidy for territorial planning and management of the physical environment.<strong> </strong></p><p><strong> Keywords</strong>:Digital Elevation Model, SRTM, Geotechnology.</p><p> </p><p> </p>


Author(s):  
J. Takaku ◽  
T. Tadono ◽  
M. Doutsu ◽  
F. Ohgushi ◽  
H. Kai

Abstract. In 2016 we first completed the global data processing of digital surface models (DSMs) by using the whole archives of stereo imageries derived from the Panchromatic Remote sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS). The dataset was freely released to the public in 30 m grid spacing as the ‘ALOS World 3D - 30m (AW3D30)’, which was generated from its original version processed in 5 m or 2.5 m grid spacing. The dataset has been updated since then to improve the absolute/relative height accuracies with additional calibrations. However the most significant update that should be applied for improving the data usability is the filling of void areas, which correspond to approx. 10% of global coverage, mostly due to cloud covers. In this paper we introduce the updates of AW3D30 filling the voids with other open-access DSMs such as Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM), Advanced Spaceborne Thermal Emission and Reflection Radiometer Global DEM (ASTER GDEM), ArcticDEM, etc., through inter-comparisons among these datasets.


2021 ◽  
Author(s):  
Bogdan C. Smarandache

Map 1. The Distribution of Frankish and Muslim Populations (1099‐1187) <br>Map 2. Frankish and Muslim Populations in Samaria (1099‐1187)<br>Map 3. Frankish and Muslim Populations in Galilee and around the Lebanon (1099‐1187)<br>Map 4. Frankish Rural and Urban Settlements (1099‐1114)<br>Map 5. Frankish Rural and Urban Settlements (1115‐1167)<br>Map 6. Frankish Rural and Urban Settlements (1168‐1187)<br><div>Map 7. Christian Pilgrimage Sites (pre‐1099)</div><div><br></div><div>Only places with populations that can be reliably dated are pinned here. Diacritical marks are omitted from place names. Question marks indicate sites that are plotted according to approximate coordinates.<br></div><div><br></div>Credits (for all maps):<br>All maps generated using Quantum Geographic Information Systems (QGIS) 3.8 Zanzibar (https://www.qgis.org/en/site/).<br>Physical features layers downloaded from Natural Earth (http://naturalearthdata.com).<br>Contours rendered using Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM) (NASA/METI/AIST/Japan Spacesystems, and U.S./Japan ASTER Science Team, ASTER Global Digital Elevation Model V003. 2019, distributed by NASA EOSDIS Land Processes DAAC, https://doi.org/10.5067/ASTER/ASTGTM.003. Accessed on 1 November 2020 at https://search.earthdata.nasa.gov). <br>Roman roads layer, produced by McCormick et al. (2013), downloaded from ‘Mapping Past Societies’ (MAPS), Cambridge, MA, 2007 (https://darmc.harvard.edu, accessed in 2016). Approximate routes of Frankish roads reconstructed using Riley-Smith, The Atlas of the Crusades.


Author(s):  
T. Tadono ◽  
H. Nagai ◽  
H. Ishida ◽  
F. Oda ◽  
S. Naito ◽  
...  

Topographical information is fundamental to many geo-spatial related information and applications on Earth. Remote sensing satellites have the advantage in such fields because they are capable of global observation and repeatedly. Several satellite-based digital elevation datasets were provided to examine global terrains with medium resolutions e.g. the Shuttle Radar Topography Mission (SRTM), the global digital elevation model by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER GDEM). A new global digital surface model (DSM) dataset using the archived data of the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) onboard the Advanced Land Observing Satellite (ALOS, nicknamed “Daichi”) has been completed on March 2016 by Japan Aerospace Exploration Agency (JAXA) collaborating with NTT DATA Corp. and Remote Sensing Technology Center, Japan. This project is called “ALOS World 3D” (AW3D), and its dataset consists of the global DSM dataset with 0.15 arcsec. pixel spacing (approx. 5&thinsp;m mesh) and ortho-rectified PRISM image with 2.5&thinsp;m resolution. JAXA is also processing the global DSM with 1&thinsp;arcsec. spacing (approx. 30&thinsp;m mesh) based on the AW3D DSM dataset, and partially releasing it free of charge, which calls “ALOS World 3D 30&thinsp;m mesh” (AW3D30). The global AW3D30 dataset will be released on May 2016. This paper describes the processing status, a preliminary validation result of the AW3D30 DSM dataset, and its public release status. As a summary of the preliminary validation of AW3D30 DSM, 4.40&thinsp;m (RMSE) of the height accuracy of the dataset was confirmed using 5,121 independent check points distributed in the world.


2020 ◽  
Vol 206 ◽  
pp. 01027
Author(s):  
Jin Yao ◽  
Yi Chao-lu ◽  
Fu Ping

Topographic data on The Tibetan Plateau (TP) terrain are fundamental for geoscientific research, but are difficult to obtain. The Shuttle Radar Topographic Mission (SRTM) Digital Elevation Model (DEM) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM) are two commonly used GDEM data. Verifying the accuracy of the two dataset for the TP mountain areas provides a reference point for the application of both DEMs. For evaluating the elevation accuracy and topographic information, we used 8242 field measurements from Differential Global Positioning System (DGPS) points and DEM data generated from 1:100,000 topographic maps to examine the accuracy of ASTER GDEM V2 and SRTM3 V4.1 elevation results. The average RMSE for elevation differences between DGPS and ASTER GDEM across the study areas was 18.56m while the average RMSE between DGPS and SRTM3 was 10.39m. The average RMSEs of ASTER GDEM and SRTM3 in glaciated areas were 8.55m and 5.87m, respectively. The vertical accuracy of SRTM3 is better than that of ASTER GDEM. The vertical accuracy of both DEMs do not vary with altitude, but is related to aspect and slope.


2019 ◽  
Vol 8 (3) ◽  
pp. 108 ◽  
Author(s):  
Antonios Mouratidis ◽  
Dimitrios Ampatzidis

Digital elevation models (DEMs) are a widely used form of topographic information, with some of the most popular being the Shuttle Radar Topography Mission (SRTM) DEM and the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM). These two sources of topographical information are the main constituents of the European Union Digital Elevation Model (EU-DEM), which is a relatively new dataset of the EU’s Copernicus Land Monitoring Service. In this context, the purpose of this study was to validate EU-DEM for its vertical accuracy and to compare it with SRTM DEM and ASTER GDEM data. This was achieved in a Geographic Information System (GIS) environment, using extensive—in the order of tens of thousands of points—geodetic Global Navigation Satellite System (GNSS) measurements and appropriate pre-processing steps. The absolute elevation errors results had a Root Mean Square Error (RMSE) of 2.7 m at a 90% confidence level and characterize the performance of EU-DEM from local to regional scale, generally confirming that it is an enhanced source of elevation information when compared with its predecessors.


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