scholarly journals Pixel-Based Geometric Assessment of Channel Networks/Orders Derived from Global Spaceborne Digital Elevation Models

2019 ◽  
Vol 11 (3) ◽  
pp. 235 ◽  
Author(s):  
Mohamed Shawky ◽  
Adel Moussa ◽  
Quazi K. Hassan ◽  
Naser El-Sheimy
Keyword(s):  
Remote Sensing ◽  
Digital Elevation Models ◽  
Shuttle Radar Topography Mission ◽  
Surface Model ◽  
Kappa Index ◽  
Channel Networks ◽  
Digital Terrain ◽  
Terrain Models ◽  
Digital Elevation ◽  
Confusion Matrices

Digital Elevation Models (DEMs) contribute to geomorphological and hydrological applications. DEMs can be derived using different remote sensing-based datasets, such as Interferometric Synthetic Aperture Radar (InSAR) (e.g., Advanced Land Observing Satellite (ALOS) Phased Array type L-band SAR (PALSAR) and Shuttle Radar Topography Mission (SRTM) DEMs). In addition, there is also the Digital Surface Model (DSM) derived from optical tri-stereo ALOS Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) imagery. In this study, we evaluated satellite-based DEMs, SRTM (Global) GL1 DEM V003 28.5 m, ALOS DSM 28.5 m, and PALSAR DEMs 12.5 m and 28.5 m, and their derived channel networks/orders. We carried out these assessments using Light Detection and Ranging (LiDAR) Digital Surface Models (DSMs) and Digital Terrain Models (DTMs) and their derived channel networks and Strahler orders as reference datasets at comparable spatial resolutions. We introduced a pixel-based method for the quantitative horizontal evaluation of the channel networks and Strahler orders derived from global DEMs utilizing confusion matrices at different flow accumulation area thresholds (ATs) and pixel buffer tolerance values (PBTVs) in both ±X and ±Y directions. A new Python toolbox for ArcGIS was developed to automate the introduced method. A set of evaluation metrics—(i) producer accuracy (PA), (ii) user accuracy (UA), (iii) F-score (F), and (iv) Cohen’s kappa index (KI)—were computed to evaluate the accuracy of the horizontal matching between channel networks/orders extracted from global DEMs and those derived from LiDAR DTMs and DSMs. PALSAR DEM 12.5 m ranked first among the other global DEMs with the lowest root mean square error (RMSE) and mean difference (MD) values of 4.57 m and 0.78 m, respectively, when compared to the LiDAR DTM 12.5 m. The ALOS DSM 28.5 m had the highest vertical accuracy with the lowest recorded RMSE and MD values of 4.01 m and –0.29 m, respectively, when compared to the LiDAR DSM 28.5 m. PALSAR DEM 12.5 m and ALOS DSM 28.5 m-derived channel networks/orders yielded the highest horizontal accuracy when compared to those delineated from LiDAR DTM 12.5 m and LiDAR DSM 28.5 m, respectively. The number of unmatched channels decreased when the PBTV increased from 0 to 3 pixels using different ATs.

scholarly journals DETERMINING THE SUITABILITY OF DIFFERENT DIGITAL ELEVATION MODELS AND SATELLITE IMAGES FOR FANCY MAPS. AN EXAMPLE OF CYPRUS

2016 ◽  
Vol XLI-B4 ◽  
pp. 591-597
Author(s):  
J. Drachal ◽  
A. K. Kawel
Keyword(s):  
Small Area ◽  
Satellite Images ◽  
Digital Elevation Models ◽  
Test Area ◽  
Landsat 8 ◽  
Digital Terrain Models ◽  
Digital Terrain ◽  
Terrain Models ◽  
Digital Elevation ◽  
Shaded Relief

The article describes the possibility of developing an overall map of the selected area on the basis of publicly available data. Such a map would take the form designed by the author with the colors that meets his expectations and a content, which he considers to be appropriate. Among the data available it was considered the use of satellite images of the terrain in real colors and, in the form of shaded relief, digital terrain models with different resolutions of the terrain mesh. Specifically the considered data were: MODIS, Landsat 8, GTOPO-30, SRTM-30, SRTM-1, SRTM-3, ASTER. For the test area the island of Cyprus was chosen because of the importance in tourism, a relatively small area and a clearly defined boundary. In the paper there are shown and discussed various options of the Cyprus terrain image obtained synthetically from variants of Modis, Landsat and digital elevation models of different resolutions.

scholarly journals Investigating the Impact of Digital Elevation Models on Sentinel-1 Backscatter and Coherence Observations

2020 ◽  
Vol 12 (18) ◽  
pp. 3016
Author(s):  
Ignacio Borlaf-Mena ◽  
Maurizio Santoro ◽  
Ludovic Villard ◽  
Ovidiu Badea ◽  
Mihai Andrei Tanase
Keyword(s):  
Remote Sensing ◽  
Laser Scanning ◽  
Digital Elevation Models ◽  
Shuttle Radar Topography Mission ◽  
Synthetic Aperture ◽  
Mountainous Regions ◽  
Aerial Laser Scanning ◽  
Digital Elevation ◽  
The Difference ◽  
The Impact

Spaceborne remote sensing can track ecosystems changes thanks to continuous and systematic coverage at short revisit intervals. Active remote sensing from synthetic aperture radar (SAR) sensors allows day and night imaging as they are not affected by cloud cover and solar illumination and can capture unique information about its targets. However, SAR observations are affected by the coupled effect of viewing geometry and terrain topography. The study aims to assess the impact of global digital elevation models (DEMs) on the normalization of Sentinel-1 backscattered intensity and interferometric coherence. For each DEM, we analyzed the difference between orbit tracks, the difference with results obtained with a high-resolution local DEM, and the impact on land cover classification. Tests were carried out at two sites located in mountainous regions in Romania and Spain using the SRTM (Shuttle Radar Topography Mission, 30 m), AW3D (ALOS (Advanced Land Observation Satellite) World 3D, 30 m), TanDEM-X (12.5, 30, 90 m), and Spain national ALS (aerial laser scanning) based DEM (5 m resolution). The TanDEM-X DEM was the global DEM most suitable for topographic normalization, since it provided the smallest differences between orbital tracks, up to 3.5 dB smaller than with other DEMs for peak landform, and 1.4–1.9 dB for pit and valley landforms.

scholarly journals Application of the global SRTM and AW3D30 digital elevation models to mapping folds at cave sites

2021 ◽  
Vol 50 (1) ◽  
pp. 75-89
Author(s):  
Mark Abolins ◽  
Albert Ogden
Keyword(s):  
Cell Size ◽  
Forest Canopy ◽  
Digital Elevation Models ◽  
Digital Terrain Model ◽  
Surface Model ◽  
M Cell ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
The Mean

A novel method to map and quantitatively describe very gentle folds (limb dip <5°) at cratonic cave sites was evaluated at Snail Shell and Nanna caves, central Tennessee, USA. Elevations from the global SRTM digital terrain model (DTM) were assigned to points on late Ordovician geologic contacts, and the elevations of the points were used to interpolate 28 m cell size natural neighbor digital elevation models (DEM’s) of the contacts. The global Forest Canopy Height Dataset was subtracted from the global 28 m cell size AW3D30 digital surface model (DSM) to create a DTM, and that DTM was applied in the same way. Comparison of mean and modal strikes of the interpolated surfaces with mean and modal cave passage trend shows that many passages are sub-parallel to the trend of an anticline. WithiSn 500 m of the caves, the SRTM- and AW3D30-based interpolated surfaces have mean strikes within 8° of the mean strike of an interpolated reference surface created with a high resolution (~0.76 m cell size and 10 cm RMSE) Tennessee, USA LiDAR DTM. This evaluation shows that the SRTM- and AW3D30-based method has the potential to reveal a relationship between the trend of a fold, on one hand, and cave passages, on the other, at sites where a geologic contact varies in elevation by >35 m within an area of <12.4 km2 and the mean dip of bedding is >0.9°.

scholarly journals GENERATION OF THE 30 M-MESH GLOBAL DIGITAL SURFACE MODEL BY ALOS PRISM

2016 ◽  
Vol XLI-B4 ◽  
pp. 157-162 ◽  
Author(s):  
T. Tadono ◽  
H. Nagai ◽  
H. Ishida ◽  
F. Oda ◽  
S. Naito ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Thermal Emission ◽  
Shuttle Radar Topography Mission ◽  
Surface Model ◽  
Digital Surface Model ◽  
Aster Gdem ◽  
Sensing Technology ◽  
Preliminary Validation ◽  
Digital Elevation ◽  
Elevation Model

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.

scholarly journals GENERATION OF THE 30 M-MESH GLOBAL DIGITAL SURFACE MODEL BY ALOS PRISM

2016 ◽  
Vol XLI-B4 ◽  
pp. 157-162 ◽  
Author(s):  
T. Tadono ◽  
H. Nagai ◽  
H. Ishida ◽  
F. Oda ◽  
S. Naito ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Thermal Emission ◽  
Shuttle Radar Topography Mission ◽  
Surface Model ◽  
Digital Surface Model ◽  
Aster Gdem ◽  
Sensing Technology ◽  
Preliminary Validation ◽  
Digital Elevation ◽  
Elevation Model

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.

scholarly journals DETERMINING THE SUITABILITY OF DIFFERENT DIGITAL ELEVATION MODELS AND SATELLITE IMAGES FOR FANCY MAPS. AN EXAMPLE OF CYPRUS

2016 ◽  
Vol XLI-B4 ◽  
pp. 591-597
Author(s):  
J. Drachal ◽  
A. K. Kawel
Keyword(s):  
Small Area ◽  
Satellite Images ◽  
Digital Elevation Models ◽  
Test Area ◽  
Landsat 8 ◽  
Digital Terrain Models ◽  
Digital Terrain ◽  
Terrain Models ◽  
Digital Elevation ◽  
Shaded Relief

The article describes the possibility of developing an overall map of the selected area on the basis of publicly available data. Such a map would take the form designed by the author with the colors that meets his expectations and a content, which he considers to be appropriate. Among the data available it was considered the use of satellite images of the terrain in real colors and, in the form of shaded relief, digital terrain models with different resolutions of the terrain mesh. Specifically the considered data were: MODIS, Landsat 8, GTOPO-30, SRTM-30, SRTM-1, SRTM-3, ASTER. For the test area the island of Cyprus was chosen because of the importance in tourism, a relatively small area and a clearly defined boundary. In the paper there are shown and discussed various options of the Cyprus terrain image obtained synthetically from variants of Modis, Landsat and digital elevation models of different resolutions.

scholarly journals IMG2nDSM: Height Estimation from Single Airborne RGB Images with Deep Learning

2021 ◽  
Vol 13 (12) ◽  
pp. 2417
Author(s):  
Savvas Karatsiolis ◽  
Andreas Kamilaris ◽  
Ian Cole
Keyword(s):  
Deep Learning ◽  
State Of The Art ◽  
Aerial Imagery ◽  
Aerial Images ◽  
Surface Model ◽  
Large Area ◽  
Digital Terrain ◽  
Terrain Models ◽  
Architectural Features ◽  
Rgb Images

Estimating the height of buildings and vegetation in single aerial images is a challenging problem. A task-focused Deep Learning (DL) model that combines architectural features from successful DL models (U-NET and Residual Networks) and learns the mapping from a single aerial imagery to a normalized Digital Surface Model (nDSM) was proposed. The model was trained on aerial images whose corresponding DSM and Digital Terrain Models (DTM) were available and was then used to infer the nDSM of images with no elevation information. The model was evaluated with a dataset covering a large area of Manchester, UK, as well as the 2018 IEEE GRSS Data Fusion Contest LiDAR dataset. The results suggest that the proposed DL architecture is suitable for the task and surpasses other state-of-the-art DL approaches by a large margin.

scholarly journals A Formação de Dolinas em Áreas Urbanas: o Caso do Bairro de Cruz das Armas em João Pessoa-PB (The Formation of Dolines in Urban Areas: The Case of Cruz das Armas in João Pessoa-PB)

2011 ◽  
Vol 4 (1) ◽  
pp. 161
Author(s):  
Max Furrier ◽  
Saulo Roberto de Oliveira Vital
Keyword(s):  
Key Words ◽  
Urban Areas ◽  
Shuttle Radar Topography Mission ◽  
Dynamic Interaction ◽  
The State ◽  
Digital Terrain ◽  
Terrain Models ◽  
Geological Map ◽  
Major Factors ◽  
The City

Evidências de dolinas são bastante comuns na cidade de João Pessoa-PB, mas ainda pouco estudadas. As dolinas são consideradas depressões fechadas, circulares, associadas a rebaixamento topográfico coadjuvado por fenômenos cársticos de sub-superfície, caracterizando um carste inumado. Assim como as encostas e os vales entalhados, as dolinas também são alvo da intensa ocupação nas cidades por parte da camada social menos favorecida, tendo em vista, serem áreas bastante deprimidas e susceptíveis a enchentes. A partir de então, esta pesquisa tem como objetivo, identificar os principais fatores de predisposição do terreno para criação de relevo do tipo carste, exclusivamente as dolinas e os riscos associados. Para isso, foram levantados dados sobre o embasamento geológico a partir do mapa geológico do Estado da Paraíba, e informações sobre a morfologia do terreno, coletadas a partir do radar SRTM (Shuttle Radar Topography Mission), além das observações de campo. Como produto, obteve-se os Modelos Digitais do Terreno, por meio dos quais se tornou possível realçar as evidências de subsidência do relevo local, corroborado pelas informações sobre a geologia local, marcada por uma intensa interação dinâmica entre as Formações Barreiras e Gramame (Sub-bacia Sedimentar Alhandra). Concluiu-se que os planos de falha existentes nos calcários da Formação Gramame contribuem de forma conspícua para percolação da água nessa formação perfazendo uma reação química capaz de dissolver o calcário, rebaixando a Formação Barreiras que se encontra sobreposta, dando origem a depressões circulares.Palavras-Chave: Dolinas, Formação Gramame, Formação Barreiras, João Pessoa. The Formation of Dolines in Urban Areas: The Case of Cruz das Armas in João Pessoa-PB ABSTRACTEvidence of dolines are much common in João Pessoa, the capital of the state of Paraíba, but they are still poorly studied. The dolines are considered to be closed and circled depressions, associated to a topographic smoothing assisted by subsurface karstic phenomenons, characterizing an inhumed karst. As well as the slopes and the carved valleys, the dolines are also intensively occupied in the city by people who are less favoured, what represents a serious problem considering that these are depressed areas and susceptible to flooding. The research aims to verify the major factors of the terrain susceptibility to the karst features formation, exclusively the dolines, and the associated risks. In view of this objective, the geological basement data were gathered from the geological map of the State of Paraíba and the terrain morphological information were collected from the SRTM radar (Shuttle Radar Topography Mission), besides the observations of the fieldwork developed. As result, the Digital Terrain Models were achieved enabling to present the evidences of the local subsidence features, corroborated by the information about the local geography marked by a intense dynamic interaction between Barreiras and Gramame Formation (Alhandra Sedimentary Sub-Basin). The analysis showed that the failed plans presented in the limestones of the Gramame Formation contribute evidently to the percolation of water on this formation totalizing a chemical reaction able to dissolve the limestone, lowering the superposed Barreiras Formation, what give rise to circular depressions.   Key-Words: Dolines, Gramame Formation, Barreiras Formation, João Pessoa.

A robust interpolation method for constructing digital elevation models from remote sensing data

Geomorphology ◽  
2016 ◽  
Vol 268 ◽  
pp. 275-287 ◽  
Author(s):  
Chuanfa Chen ◽  
Fengying Liu ◽  
Yanyan Li ◽  
Changqing Yan ◽  
Guolin Liu
Keyword(s):  
Remote Sensing ◽  
Interpolation Method ◽  
Digital Elevation Models ◽  
Remote Sensing Data ◽  
Sensing Data ◽  
Digital Elevation
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