APPLICATION OF DSM IN OBSTACLE CLEARANCE SURVEYING OF AERODROME

Compared to the wide use of digital elevation model (DEM), digital surface model (DSM) receives less attention because that it is composed by not only terrain surface, but also vegetations and man-made objects which are usually regarded as useless information. Nevertheless, these objects are useful for the identification of obstacles around an aerodrome. The primary objective of the study was to determine the applicability of DSM in obstacle clearance surveying of aerodrome. According to the requirements of obstacle clearance surveying at QT airport, aerial and satellite imagery were used to generate DSM, by means of photogrammetry, which was spatially analyzed with the hypothetical 3D obstacle limitation surfaces (OLS) to identify the potential obstacles. Field surveying was then carried out to retrieve the accurate horizontal position and height of the obstacles. The results proved that the application of DSM could make considerable improvement in the efficiency of obstacle clearance surveying of aerodrome.

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Assessment of Changes in a Viewshed in the Western Carpathians Landscape as a Result of Reforestation

Land ◽

10.3390/land9110430 ◽

2020 ◽

Vol 9 (11) ◽

pp. 430

Author(s):

Michał Sobala ◽

Urszula Myga-Piątek ◽

Bartłomiej Szypuła

Keyword(s):

Digital Elevation Model ◽

Forest Succession ◽

Western Carpathians ◽

Surface Model ◽

Digital Surface Model ◽

Mountainous Areas ◽

Viewshed Analysis ◽

Digital Elevation ◽

Elevation Model ◽

The Impact

A viewshed analysis is of great importance in mountainous areas characterized by high landscape values. The aim of this research was to determine the impact of reforestation occurring on former pasturelands on changes in the viewshed, and to quantify changes in the surface of glades. We combine a horizontal and a vertical approach to landscape analysis. The changes in non-forest areas and the viewshed from viewpoints located in glades were calculated using historical cartographic materials and a more recent Digital Elevation Model and Digital Surface Model. An analysis was conducted using a Visibility tool in ArcGIS. The non-forest areas decreased in the period 1848–2015. The viewshed in the majority of viewpoints also decreased in the period 1848–2015. In the majority of cases, the maximal viewsheds were calculated in 1879/1885 and 1933 (43.8% of the analyzed cases), whereas the minimal ones were calculated in 2015 (almost 57.5% of analyzed cases). Changes in the viewshed range from 0.2 to 23.5 km2 with half the cases analyzed being no more than 1.4 km2. The results indicate that forest succession on abandoned glades does not always cause a decline in the viewshed. Deforestation in neighboring areas may be another factor that has an influence on the decline.

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Digital Elevation Model and Digital Surface Model

International Encyclopedia of Geography: People, the Earth, Environment and Technology ◽

10.1002/9781118786352.wbieg0768 ◽

2017 ◽

pp. 1-17 ◽

Cited By ~ 2

Author(s):

Qiming Zhou

Keyword(s):

Digital Elevation Model ◽

Surface Model ◽

Digital Surface Model ◽

Digital Elevation ◽

Elevation Model

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Landform classification from a digital elevation model and satellite imagery

Geomorphology ◽

10.1016/j.geomorph.2008.01.011 ◽

2008 ◽

Vol 100 (3-4) ◽

pp. 453-464 ◽

Cited By ~ 57

Author(s):

Hossein Saadat ◽

Robert Bonnell ◽

Forood Sharifi ◽

Guy Mehuys ◽

Mohammad Namdar ◽

...

Keyword(s):

Digital Elevation Model ◽

Satellite Imagery ◽

Landform Classification ◽

Digital Elevation ◽

Elevation Model

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Urban Feature Extraction from Merged Airborne LiDAR Data and Digital Camera Data

Geoplanning Journal of Geomatics and Planning ◽

10.14710/geoplanning.7.2.57-74 ◽

2021 ◽

Vol 7 (2) ◽

pp. 57-74

Author(s):

Lamyaa Gamal EL-Deen Taha ◽

A. I. Ramzi ◽

A. Syarawi ◽

A. Bekheet

Keyword(s):

Neural Network ◽

Digital Camera ◽

Point Clouds ◽

Airborne Lidar ◽

Surface Model ◽

Digital Surface Model ◽

3D Point Clouds ◽

Digital Elevation ◽

Surface Models ◽

Elevation Model

Until recently, the most highly accurate digital surface models were obtained from airborne lidar. With the development of a new generation of large format digital photogrammetric aerial camera, a fully digital photogrammetric workflow became possible. Digital airborne images are sources for elevation extraction and orthophoto generation. This research concerned with the generation of digital surface models and orthophotos as applications from high-resolution images. In this research, the following steps were performed. A Benchmark data of LIDAR and digital aerial camera have been used. Firstly, image orientation, AT have been performed. Then the automatic digital surface model DSM generation has been produced from the digital aerial camera. Thirdly true digital ortho has been generated from the digital aerial camera also orthoimage will be generated using LIDAR digital elevation model (DSM). Leica Photogrammetric Suite (LPS) module of Erdsa Imagine 2014 software was utilized for processing. Then the resulted orthoimages from both techniques were mosaicked. The results show that automatic digital surface model DSM that been produced from digital aerial camera method has very high dense photogrammetric 3D point clouds compared to the LIDAR 3D point clouds. It was found that the true orthoimage produced from the second approach is better than the true orthoimage produced from the first approach. The five approaches were tested for classification of the best-orthorectified image mosaic using subpixel based (neural network) and pixel-based ( minimum distance and maximum likelihood).Multicues were extracted such as texture(entropy-mean),Digital elevation model, Digital surface model ,normalized digital surface model (nDSM) and intensity image. The contributions of the individual cues used in the classification have been evaluated. It was found that the best cue integration is intensity (pan) +nDSM+ entropy followed by intensity (pan) +nDSM+mean then intensity image +mean+ entropy after that DSM )image and two texture measures (mean and entropy) followed by the colour image. The integration with height data increases the accuracy. Also, it was found that the integration with entropy texture increases the accuracy. Resulted in fifteen cases of classification it was found that maximum likelihood classifier is the best followed by minimum distance then neural network classifier. We attribute this to the fine resolution of the digital camera image. Subpixel classifier (neural network) is not suitable for classifying aerial digital camera images.

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Improving the Accuracy of Open Source Digital Elevation Models with Multi-Scale Fusion and a Slope Position-Based Linear Regression Method

Remote Sensing ◽

10.3390/rs10121861 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1861 ◽

Cited By ~ 1

Author(s):

Yu Tian ◽

Shaogang Lei ◽

Zhengfu Bian ◽

Jie Lu ◽

Shubi Zhang ◽

...

Keyword(s):

Linear Regression ◽

Data Fusion ◽

Digital Elevation Model ◽

Regression Method ◽

Slope Position ◽

Surface Model ◽

Linear Regression Method ◽

Multi Scale ◽

Digital Elevation ◽

Elevation Model

The growing need to monitor changes in the surface of the Earth requires a high-quality, accessible Digital Elevation Model (DEM) dataset, whose development has become a challenge in the field of Earth-related research. The purpose of this paper is to improve the overall accuracy of public domain DEMs by data fusion. Multi-scale decomposition is an important analytical method in data fusion. Three multi-scale decomposition methods—the wavelet transform (WT), bidimensional empirical mode decomposition (BEMD), and nonlinear adaptive multi-scale decomposition (N-AMD)—are applied to the 1-arc-second Shuttle Radar Topography Mission Global digital elevation model (SRTM-1 DEM) and the Advanced Land Observing Satellite World 3D—30 m digital surface model (AW3D30 DSM) in China. Of these, the WT and BEMD are popular image fusion methods. A new approach for DEM fusion is developed using N-AMD (which is originally invented to remove the cycle from sunspots). Subsequently, a window-based rule is proposed for the fusion of corresponding frequency components obtained by these methods. Quantitative results show that N-AMD is more suitable for multi-scale fusion of multi-source DEMs, taking the Ice Cloud and Land Elevation Satellite (ICESat) global land surface altimetry data as a reference. The fused DEMs offer significant improvements of 29.6% and 19.3% in RMSE at a mountainous site, and 27.4% and 15.5% over a low-relief region, compared to the SRTM-1 and AW3D30, respectively. Furthermore, a slope position-based linear regression method is developed to calibrate the fused DEM for different slope position classes, by investigating the distribution of the fused DEM error with topography. The results indicate that the accuracy of the DEM calibrated by this method is improved by 16% and 13.6%, compared to the fused DEM in the mountainous region and low-relief region, respectively, proving that it is a practical and simple means of further increasing the accuracy of the fused DEM.

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The Maras Triple Junction (southern Turkey) based on digital elevation model and satellite imagery interpretation

Journal of Geophysical Research Atmospheres ◽

10.1029/94jb00321 ◽

1994 ◽

Vol 99 (B10) ◽

pp. 20225-20242 ◽

Cited By ~ 35

Author(s):

Jean Chorowicz ◽

Pascal Luxey ◽

Nikos Lyberis ◽

José Carvalho ◽

Jean-François Parrot ◽

...

Keyword(s):

Digital Elevation Model ◽

Satellite Imagery ◽

Triple Junction ◽

Digital Elevation ◽

Southern Turkey ◽

Elevation Model

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Accuracy assessment of TanDEM-X IDEM using airborne LiDAR on the area of Poland

Geodesy and Cartography ◽

10.1515/geocart-2017-0007 ◽

2017 ◽

Vol 66 (1) ◽

pp. 137-148 ◽

Cited By ~ 3

Author(s):

Małgorzata Woroszkiewicz ◽

Ireneusz Ewiak ◽

Paulina Lulkowska

Keyword(s):

Digital Elevation Model ◽

Laser Scanning ◽

Accuracy Assessment ◽

Shuttle Radar Topography Mission ◽

Reference Points ◽

Airborne Lidar ◽

Surface Model ◽

Digital Elevation ◽

Elevation Model ◽

German Aerospace

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.

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