scholarly journals Reassessment of Frankish Settlement Patterns - Maps

2021 ◽  
Author(s):  
Bogdan C. Smarandache
Keyword(s):  
Geographic Information Systems ◽  
Digital Elevation Model ◽  
Settlement Patterns ◽  
Thermal Emission ◽  
Aster Gdem ◽  
Rural And Urban ◽  
Digital Elevation ◽  
Urban Settlements ◽  
Elevation Model ◽  
Physical Features

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.

scholarly journals Reassessment of Frankish Settlement Patterns - Maps

2021 ◽  
Author(s):  
Bogdan C. Smarandache
Keyword(s):  
Geographic Information Systems ◽  
Digital Elevation Model ◽  
Settlement Patterns ◽  
Thermal Emission ◽  
Aster Gdem ◽  
Rural And Urban ◽  
Digital Elevation ◽  
Urban Settlements ◽  
Elevation Model ◽  
Physical Features

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.

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
Keyword(s):  
Open Source ◽  
Digital Elevation Model ◽  
Thermal Emission ◽  
Shuttle Radar Topography Mission ◽  
Google Earth ◽  
Reference Points ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Elevation Model ◽  
High Level

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.  

scholarly journals Evaluation of the Accuracy of SRTM3 and ASTER GDEM in the Tibetan Plateau Mountain Ranges

2020 ◽  
Vol 206 ◽  
pp. 01027
Author(s):  
Jin Yao ◽  
Yi Chao-lu ◽  
Fu Ping
Keyword(s):  
Tibetan Plateau ◽  
Digital Elevation Model ◽  
Thermal Emission ◽  
Field Measurements ◽  
The Tibetan Plateau ◽  
Mountain Areas ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Vertical Accuracy ◽  
Elevation Model

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.

scholarly journals European Digital Elevation Model Validation against Extensive Global Navigation Satellite Systems Data and Comparison with SRTM DEM and ASTER GDEM in Central Macedonia (Greece)

2019 ◽  
Vol 8 (3) ◽  
pp. 108 ◽  
Author(s):  
Antonios Mouratidis ◽  
Dimitrios Ampatzidis
Keyword(s):  
Digital Elevation Model ◽  
Thermal Emission ◽  
Regional Scale ◽  
Navigation Satellite ◽  
Srtm Dem ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Global Navigation ◽  
Elevation Model ◽  
Global Navigation Satellite

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.

scholarly journals Evaluasi Tingkat Akurasi Digital Elevation Model (DEM) SRTM dan ASTER GDEM dalam Pemodelan Daerah Aliran Sungai (DAS) Ciliwung

2019 ◽  
Vol 24 (2) ◽  
pp. 105
Author(s):  
Ade Suhendar Sutisna ◽  
Haryono Putro
Keyword(s):  
Digital Elevation Model ◽  
River Basin ◽  
Thermal Emission ◽  
Srtm Dem ◽  
Shuttle Radar Topographic Mission ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Regression Test ◽  
Accuracy Result ◽  
Elevation Model

Availability of Digital Elevation Model (DEM) dataset and Geographic Information System (GIS), makes the watershed properties can be extracted automatically. There are two DEM providers which are freely accessible for research purposes and commonly use that is the Shuttle Radar Topographic Mission (SRTM) - DEM (30m) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model Version 2 (GDEM V2). Based on the result of modeling conducted at Ciliwung River Basin with Qgis application, area generated from SRTM data is 5% smaller than Ciliwung River Basin which obtained from BPDAS Ciliwung-Citarum as a reference, while the result of ASTER-GDEM data is 87% larger than reference. Linear Regression Test and t-Test performed on three segments of the watershed shows that the upstream of both samples gives a good accuracy result that is R2 = 0,999; P = 0,499 (SRTM) and R2 = 0,999; P = 0,481 (ASTER-GDEM), while in the middle and downstream segments respectively for both samples are SRTM with R2 = 0,993; P = 0,413 and R2 = 0,734; P = 0,088; and then ASTER-GDEM with R2 = 0,784; P = 0,00038 and R2 = 0,376; P = 1,27209 x10-22.

scholarly journals Line Generalization Evaluation on Contour Map Generated From SRTM and ASTER GDEM

2018 ◽  
Vol 2 (1) ◽  
pp. 88-97
Author(s):  
Totok Wahyu Wibowo
Keyword(s):  
Digital Elevation Model ◽  
Thermal Emission ◽  
Contour Line ◽  
Topographic Map ◽  
Contour Map ◽  
Thematic Map ◽  
Shuttle Radar Topographic Mission ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Elevation Model

A contour map is one of many layers that composed Informasi Geospasial Dasar (IGD), which according to Act. No 4 2011 serves as a reference for any thematic map. The provision of contour map at a different level of scale is needed since mapping activities will always refer to map scale based on the mapping area. This research aims to analyze automated contour generation quality to produce 1:50.000 contour map, by means of using open access Digital Elevation Model (DEM) data, such as Shuttle Radar Topographic Mission (SRTM) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM). The automated contour generation was done by using contour interpolation in Quantum GIS software. Furthermore, simplification and smoothing algorithm was applied to both data, in order to improve their visual appearance. In this case, there are four algorithms used in the study, namely Douglas-Peucker, Visvalingam, Chaikin, and McMaster. Quality assessment, both qualitative and quantitative assessment, was done to each derived contour map to ensure the applicability of the procedure. The result shows that contour map generated from SRTM has a better quality than contour map generated from ASTER GDEM. Nevertheless, both data has a similar pattern on each topographical classes, which tends to produce bad quality contour line in the flat area. The more mountainous the area, the better the contour line. Meanwhile, of all generalization algorithm applied in this study, Chaikin’s algorithm is the best algorithm in terms of smoothing the contour line and improving visual quality, but still doesn’t significantly improved the metric accuracy. The contour line can be either directly added to the Digital Cartographic Model of Topographic Map (Rupabumi Map), or used as compliance data in a thematic map.

Quality Assessment of Globally Available Digital Elevation Model (DEM) for Mountainous Region

2021 ◽  
Vol 5 (1) ◽  
pp. 11-21
Author(s):  
Sangay Gyeltshen ◽  
Krisha Kumar Subedi ◽  
Laylo Zaridinova Kamoliddinovna ◽  
Jigme Tenzin
Keyword(s):  
Digital Elevation Model ◽  
Vertical Displacement ◽  
Satellite System ◽  
Topographic Map ◽  
Alos Palsar ◽  
Aster Gdem ◽  
Digital Elevation ◽  
The Government ◽  
Elevation Model ◽  
The Individual

The study assessed the accuracies of globally available Digital Elevation Models (DEM’s) i.e., SRTM v3, ASTER GDEM v2 and ALOS PALSAR DEM with respect to Topo-DEM derived from topographic map of 5m contour interval. 100 ground control points of the elevation data were collected with the help of kinematic hand held GNSS (Global Navigation Satellite System), randomly distributed over the study area. The widely used RMSE statistic, NCC correlation and sub-pixel-based approach were applied to evaluate the erroneous, correlation, horizontal and vertical displacement in terms of pixels for the individual Digital Elevation Model. Following these evaluations, SRTM DEM was found to be highly accurate in terms of RMSE and displacement compared to other DEMs. This study is intended to provide the researchers, GIS specialists and the government agencies dealing with remote sensing and GIS, a basic clue on accuracy of the DEMs so that the best model can be selected for application on various purposes of the similar region.

scholarly journals A new 100-m Digital Elevation Model of the Antarctic Peninsula derived from ASTER Global DEM: methods and accuracy assessment

2012 ◽  
Vol 4 (1) ◽  
pp. 129-142 ◽  
Author(s):  
A. J. Cook ◽  
T. Murray ◽  
A. Luckman ◽  
D. G. Vaughan ◽  
N. E. Barrand
Keyword(s):  
Digital Elevation Model ◽  
Antarctic Peninsula ◽  
Accuracy Assessment ◽  
Correction Method ◽  
Pixel Size ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Vertical Accuracy ◽  
Elevation Model ◽  
The Antarctic

Abstract. A high resolution surface topography Digital Elevation Model (DEM) is required to underpin studies of the complex glacier system on the Antarctic Peninsula. A complete DEM with better than 200 m pixel size and high positional and vertical accuracy would enable mapping of all significant glacial basins and provide a dataset for glacier morphology analyses. No currently available DEM meets these specifications. We present a new 100-m DEM of the Antarctic Peninsula (63–70° S), based on ASTER Global Digital Elevation Model (GDEM) data. The raw GDEM products are of high-quality on the rugged terrain and coastal-regions of the Antarctic Peninsula and have good geospatial accuracy, but they also contain large errors on ice-covered terrain and we seek to minimise these artefacts. Conventional data correction techniques do not work so we have developed a method that significantly improves the dataset, smoothing the erroneous regions and hence creating a DEM with a pixel size of 100 m that will be suitable for many glaciological applications. We evaluate the new DEM using ICESat-derived elevations, and perform horizontal and vertical accuracy assessments based on GPS positions, SPOT-5 DEMs and the Landsat Image Mosaic of Antarctica (LIMA) imagery. The new DEM has a mean elevation difference of −4 m (&amp;pm; 25 m RMSE) from ICESat (compared to −13 m mean and &amp;pm;97 m RMSE for the original ASTER GDEM), and a horizontal error of less than 2 pixels, although elevation accuracies are lower on mountain peaks and steep-sided slopes. The correction method significantly reduces errors on low relief slopes and therefore the DEM can be regarded as suitable for topographical studies such as measuring the geometry and ice flow properties of glaciers on the Antarctic Peninsula. The DEM is available for download from the NSIDC website: http://nsidc.org/data/nsidc-0516.html (doi:10.5060/D47P8W9D).

scholarly journals Comparison of Vertical Accuracy of Open-Source Global Digital Elevation Models: A Case Study of Adama City, Ethiopia

2021 ◽  
Vol 12 (4) ◽  
pp. 1731-1744
Author(s):  
Hailu Zewde Abili
Keyword(s):  
Open Source ◽  
Thermal Emission ◽  
Accuracy Assessment ◽  
Shuttle Radar Topography Mission ◽  
Surface Model ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Wide Range ◽  
Vertical Accuracy ◽  
Elevation Model

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.

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