Evaluation of vertical accuracy of different digital elevation models sources for Buraydah city

2021 ◽  
Author(s):  
Ramadan H. Abdel-Maguid
Keyword(s):  
Digital Elevation Models ◽  
Digital Elevation ◽  
Vertical Accuracy

scholarly journals Assessment of open source digital elevation models (SRTM-30, ASTER, ALOS) for erosion processes modeling

2019 ◽  
Vol 28 (1) ◽  
pp. 95-105 ◽  
Author(s):  
I. P. Kovalchuk ◽  
K. A. Lukianchuk ◽  
V. A. Bogdanets
Keyword(s):  
Open Source ◽  
Correlation Coefficient ◽  
Root Mean Square ◽  
Digital Elevation Models ◽  
Mean Square ◽  
Erosion Processes ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Vertical Accuracy ◽  
Mean Square Errors

The relief has a major impact on the landscape`s hydrological, geomorphological and biological processes. Many geographic information systems used elevation data as the primary data for analysis, modeling, etc. A digital elevation model (DEM) is a modern representation of the continuous variations of relief over space in digital form. Digital Elevation Models (DEMs) are important source for prediction of soil erosion parameters. The potential of global open source DEMs (SRTM, ASTER, ALOS) and their suitability for using in modeling of erosion processes are assessed in this study. Shumsky district of Ternopil region, which is located in the Western part of Ukraine, is the area of our study. The soils of Shumsky district are adverselyaffected by erosion processes. The analysis was performed on the basis of the characteristics of the hydrological network and relief. The reference DEM was generated from the hypsographic data(contours) on the 1:50000 topographical map series compiled by production units of the Main Department of Geodesy and Cartography under the Council of Ministers. The differences between the reference DEM and open source DEMs (SRTM, ASTER and ALOS) are examined. Methods of visual detection of DEM defects, profiling, correlation, and statistics were used in the comparative analysis. This research included the analysis oferrors that occurred during the generation of DEM. The vertical accuracy of these DEMs, root mean square error (RMSE), absolute and relative errors, maximum deviation, and correlation coefficient have been calculated. Vertical accuracy of DEMs has been assessed using actual heights of the sample points. The analysis shows that SRTM and ALOS DEMs are more reliable and accurate than ASTER GDEM. The results indicate that vertical accuracy of DEMs is 7,02m, 7,12 m, 7,60 mand 8,71 m for ALOS, SRTM 30, SRTM 90 and ASTER DEMs respectively. ASTER GDEM had the highest absolute, relative and root mean square errors, the highest maximum positive and negative deviation, a large difference with reference heights, and the lowest correlation coefficient. Therefore, ASTER GDEM is the least acceptable for studying the intensity and development of erosion processes. The use of global open source DEMs, compared with the vectorization of topographic maps,greatly simplifies and accelerates the modeling of erosion processes and the assessment of the erosion risk in the administrative district.

scholarly journals Assessment of vertical accuracy of open source 30m resolution space-borne digital elevation models

2021 ◽  
Vol 12 (1) ◽  
pp. 939-960
Author(s):  
Rocky Talchabhadel ◽  
Hajime Nakagawa ◽  
Kenji Kawaike ◽  
Kazuki Yamanoi ◽  
Bhesh Raj Thapa
Keyword(s):  
Open Source ◽  
Digital Elevation Models ◽  
Digital Elevation ◽  
Vertical Accuracy

scholarly journals Vertical Accuracy of Freely Available Global Digital Elevation Models (ASTER, AW3D30, MERIT, TanDEM-X, SRTM, and NASADEM)

2020 ◽  
Vol 12 (21) ◽  
pp. 3482
Author(s):  
Evelyn Uuemaa ◽  
Sander Ahi ◽  
Bruno Montibeller ◽  
Merle Muru ◽  
Alexander Kmoch
Keyword(s):  
Land Cover ◽  
Reference Model ◽  
Digital Elevation Models ◽  
Systematic Evaluation ◽  
Slope Aspect ◽  
Research Fields ◽  
Digital Elevation ◽  
Geographic Regions ◽  
Vertical Accuracy ◽  
Dem Accuracy

Freely available global digital elevation models (DEMs) are important inputs for many research fields and applications. During the last decade, several global DEMs have been released based on satellite data. ASTER and SRTM are the most widely used DEMs, but the more recently released, AW3D30, TanDEM-X and MERIT, are being increasingly used. Many researchers have studied the quality of these DEM products in recent years. However, there has been no comprehensive and systematic evaluation of their quality over areas with variable topography and land cover conditions. To provide this comparison, we examined the accuracy of six freely available global DEMs (ASTER, AW3D30, MERIT, TanDEM-X, SRTM, and NASADEM) in four geographic regions with different topographic and land use conditions. We used local high-precision elevation models (Light Detection and Ranging (LiDAR), Pleiades-1A) as reference models and all global models were resampled to reference model resolution (1m). In total, 608 million 1x1 m pixels were analyzed. To estimate the accuracy, we generated error rasters by subtracting each reference model from the corresponding global DEM and calculated descriptive statistics for this difference (e.g., median, mean, root-mean-square error (RMSE)). We also assessed the vertical accuracy as a function of the slope, slope aspect, and land cover. We found that slope had the strongest effect on DEM accuracy, with no relationship for slope aspect. The AW3D30 was the most robust and had the most stable performance in most of the tests and is therefore the best choice for an analysis of multiple geographic regions. SRTM and NASADEM also performed well where available, whereas NASADEM, as a successor of SRTM, showed only slight improvement in comparison to SRTM. MERIT and TanDEM-X also performed well despite their lower spatial resolution.

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