scholarly journals Uso de Modelo Digital de Elevação Gerados a partir do ASTER GDEM e SRTM para Caracterização da Rede de Drenagem do Município de Renascença no Sudoeste do Estado do Paraná (Use of Digital Elevation Model Generated from the SRTM and ASTER GDEM for...)

2011 ◽  
Vol 4 (2) ◽  
pp. 365 ◽  
Author(s):  
Julio Caetano Tomazoni ◽  
Elisete Guimarães ◽  
Tayoná Cristina Gomes ◽  
Taisller Guimarães da Silva
Keyword(s):  
Digital Elevation Model ◽  
Digital Elevation Models ◽  
Drainage System ◽  
Drainage Network ◽  
Aster Data ◽  
Aster Gdem ◽  
Drainage Networks ◽  
Digital Elevation ◽  
Elevation Model ◽  
Spot 5

Este trabalho avalia a adequação do uso de modelos digitais de elevação, provenientes da manipulação de dados altimétricos da missão SRTM e do instrumento imageador ASTER, para atualização de mapas da rede de drenagem do município de Renascença PR. Para caracterização da rede de drenagem a partir de dados SRTM e ASTER utilizou-se o software SPRING 5.1.7. A rede hidrográfica, obtida por esses dois métodos foi cruzada com a malha hidrográfica extraída de cartas geográficas do exército e imagens ortorretificadas do satélite SPOT 5. Os resultados demonstram que a rede de drenagem, obtida a partir de dados SRTM e ASTER, não é satisfatória por não determinar a grande maioria dos cursos d’água de primeira e segunda ordens. Já os de terceira, quarta e quinta ordens, que são identificados, na grande maioria estão localizados fora do curso real encontrados pelas cartas do exército e imagens ortorretificadas. Os dados demonstram que a vegetação das matas ciliares são captadas pelo SRTM e ASTER e interferem nas variações de altitude e por conseguinte no mau delineamento das redes de drenagem.Palavras chaves – Rede de drenagem; hidrografia; modelos digitais de elevação; SRTM, ASTER.  Use of Digital Elevation Model Generated from the SRTM and ASTER GDEM for Characterization of Drainage  ABSTRACTThis paper assesses the suitability of using digital elevation models, resulting from manipulation of altimetric mission SRTM and ASTER instrument, to update maps of the drainage network in the municipality of Renaissance PR. To characterize the drainage network from SRTM and ASTER data used the software SPRING 5.1.7. The hydrographic network, obtained by these two methods was crossed with a mesh extracted from hydrographic maps of the army and orthorectified images of the SPOT 5 satellite. The results show that the drainage system, derived from SRTM and ASTER data is not satisfactory because they do not determine the vast majority of streams of first and second orders. Already the third, fourth and fifth orders, which are identified in the vast majority are located outside the actual course of the letters found by the army and orthorectified images. The data show that the riparian vegetation are acquired by SRTM and ASTER and interfere with the variations in altitude and therefore the bad design of drainage networks. Keywords - Drainage network; hydrography; digital elevation models; SRTM; ASTER GDEM.

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.

Lowlands Mapping in Forest Guinea

2013 ◽  
Vol 4 (1) ◽  
pp. 20-34 ◽  
Author(s):  
S. Saïdi ◽  
A. Camara ◽  
L. Gazull ◽  
M. Passouant ◽  
M. Soumaré
Keyword(s):  
Surface Topography ◽  
Digital Elevation Model ◽  
Low Cost ◽  
Mapping Method ◽  
Drainage Network ◽  
Digital Elevation ◽  
Agricultural Potential ◽  
Forested Areas ◽  
Main Index ◽  
Elevation Model

This article presents a lowland mapping method for the Forested Guinea (Guinée Forestière) using a 30 m resolution Digital Elevation Model (DEM) that is currently the best option to analyze large forested areas. This low cost DEM method applies surface topography analysis processes to better discriminate areas with stagnant and/or accumulated water. The main index selected is the immediate proximity of flat areas to drainage network, the former with slope gradients not exceeding 5% (2.86°). The mapped lowlands potential cover a surface of 4516 km2, i.e., 10% of the total area of the region with hydro-agricultural potential.

scholarly journals Automated Conflation of Digital Elevation Model with Reference Hydrographic Lines

2020 ◽  
Vol 9 (5) ◽  
pp. 334
Author(s):  
Timofey E. Samsonov
Keyword(s):  
Spatial Analysis ◽  
Digital Elevation Model ◽  
Spatial Data ◽  
Drainage Network ◽  
Map Generalization ◽  
Data Types ◽  
Digital Elevation ◽  
Elevation Data ◽  
Elevation Model ◽  
Different Sources

Combining misaligned spatial data from different sources complicates spatial analysis and creation of maps. Conflation is a process that solves the misalignment problem through spatial adjustment or attribute transfer between similar features in two datasets. Even though a combination of digital elevation model (DEM) and vector hydrographic lines is a common practice in spatial analysis and mapping, no method for automated conflation between these spatial data types has been developed so far. The problem of DEM and hydrography misalignment arises not only in map compilation, but also during the production of generalized datasets. There is a lack of automated solutions which can ensure that the drainage network represented in the surface of generalized DEM is spatially adjusted with independently generalized vector hydrography. We propose a new method that performs the conflation of DEM with linear hydrographic data and is embeddable into DEM generalization process. Given a set of reference hydrographic lines, our method automatically recognizes the most similar paths on DEM surface called counterpart streams. The elevation data extracted from DEM is then rubbersheeted locally using the links between counterpart streams and reference lines, and the conflated DEM is reconstructed from the rubbersheeted elevation data. The algorithm developed for extraction of counterpart streams ensures that the resulting set of lines comprises the network similar to the network of ordered reference lines. We also show how our approach can be seamlessly integrated into a TIN-based structural DEM generalization process with spatial adjustment to pre-generalized hydrographic lines as additional requirement. The combination of the GEBCO_2019 DEM and the Natural Earth 10M vector dataset is used to illustrate the effectiveness of DEM conflation both in map compilation and map generalization workflows. Resulting maps are geographically correct and are aesthetically more pleasing in comparison to a straightforward combination of misaligned DEM and hydrographic lines without conflation.

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 (± 25 m RMSE) from ICESat (compared to −13 m mean and ±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).

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