scholarly journals Digital Elevation Models: Terminology and Definitions

2021 ◽  
Vol 13 (18) ◽  
pp. 3581
Author(s):  
Peter L. Guth ◽  
Adriaan Van Niekerk ◽  
Carlos H. Grohmann ◽  
Jan-Peter Muller ◽  
Laurence Hawker ◽  
...  
Keyword(s):  
Near Infrared ◽  
Digital Elevation Models ◽  
Three Dimensional ◽  
Digital Terrain Model ◽  
General Term ◽  
Surface Model ◽  
Infrared Sensors ◽  
Terrain Model ◽  
Digital Elevation ◽  
Wide Range

Digital elevation models (DEMs) provide fundamental depictions of the three-dimensional shape of the Earth’s surface and are useful to a wide range of disciplines. Ideally, DEMs record the interface between the atmosphere and the lithosphere using a discrete two-dimensional grid, with complexities introduced by the intervening hydrosphere, cryosphere, biosphere, and anthroposphere. The treatment of DEM surfaces, affected by these intervening spheres, depends on their intended use, and the characteristics of the sensors that were used to create them. DEM is a general term, and more specific terms such as digital surface model (DSM) or digital terrain model (DTM) record the treatment of the intermediate surfaces. Several global DEMs generated with optical (visible and near-infrared) sensors and synthetic aperture radar (SAR), as well as single/multi-beam sonars and products of satellite altimetry, share the common characteristic of a georectified, gridded storage structure. Nevertheless, not all DEMs share the same vertical datum, not all use the same convention for the area on the ground represented by each pixel in the DEM, and some of them have variable data spacings depending on the latitude. This paper highlights the importance of knowing, understanding and reflecting on the sensor and DEM characteristics and consolidates terminology and definitions of key concepts to facilitate a common understanding among the growing community of DEM users, who do not necessarily share the same background.

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 Comparison of Digital Elevation Models by Visibility Analysis in Landscape

2016 ◽  
Vol 19 (2) ◽  
pp. 28-31
Author(s):  
Jozef Sedláček ◽  
Ondřej Šesták ◽  
Miroslava Sliacka
Keyword(s):  
Field Survey ◽  
Reference Model ◽  
Digital Terrain Model ◽  
Surface Model ◽  
Digital Surface Model ◽  
Visibility Analysis ◽  
Terrain Model ◽  
Digital Terrain ◽  
Model Average ◽  
Digital Elevation

Abstract The paper investigates suitability of digital surface model for visibility analysis in GIS. In experiment there were analysed viewsheds from 14 observer points calculated on digital surface model, digital terrain model and its comparison to field survey. Data sources for the investigated models were LiDAR digital terrain model and LiDAR digital surface model with vegetation distributed by the Czech Administration for Land Surveying and Cadastre. The overlay method was used for comparing accuracy of models and the reference model was LiDAR digital surface model. Average equalities in comparison with LiDAR digital terrain model, ZABAGED model and field survey were 15.5 %, 17.3% and 20.9%, respectively.

scholarly journals WORLDDEM – A NOVEL GLOBAL FOUNDATION LAYER

2015 ◽  
Vol XL-3/W2 ◽  
pp. 183-187 ◽  
Author(s):  
G. Riegler ◽  
S. D. Hennig ◽  
M. Weber
Keyword(s):  
Digital Terrain Model ◽  
Current Status ◽  
Disruptive Technology ◽  
Surface Model ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Elevation Data ◽  
Elevation Model ◽  
German Aerospace

Airbus Defence and Space’s WorldDEM™ provides a global Digital Elevation Model of unprecedented quality, accuracy, and coverage. The product will feature a vertical accuracy of 2m (relative) and better than 6m (absolute) in a 12m x 12m raster. The accuracy will surpass that of any global satellite-based elevation model available. WorldDEM is a game-changing disruptive technology and will define a new standard in global elevation models. <br><br> The German radar satellites TerraSAR-X and TanDEM-X form a high-precision radar interferometer in space and acquire the data basis for the WorldDEM. This mission is performed jointly with the German Aerospace Center (DLR). Airbus DS refines the Digital Surface Model (e.g. editing of acquisition, processing artefacts and water surfaces) or generates a Digital Terrain Model. Three product levels are offered: WorldDEMcore (output of the processing, no editing is applied), WorldDEM™ (guarantees a void-free terrain description and hydrological consistency) and WorldDEM DTM (represents bare Earth elevation). <br><br> Precise elevation data is the initial foundation of any accurate geospatial product, particularly when the integration of multi-source imagery and data is performed based upon it. Fused data provides for improved reliability, increased confidence and reduced ambiguity. This paper will present the current status of product development activities including methodologies and tool to generate these, like terrain and water bodies editing and DTM generation. In addition, the studies on verification & validation of the WorldDEM products will be presented.

scholarly journals Solving the problem of region creation on the TIN model with DCEL structure

2019 ◽  
Vol 60 (4) ◽  
pp. 22-30
Author(s):  
Lê Quang Hùng ◽  
Trần Thùy Dương ◽  
Vũ Quang Hiếu ◽  
Lê Hữu Huệ
Keyword(s):  
Data Management ◽  
Data Model ◽  
Fundamental Problem ◽  
Modern Science ◽  
Digital Terrain Model ◽  
Surface Model ◽  
Terrain Model ◽  
Cadastral Maps ◽  
Digital Elevation ◽  
Elevation Model

With the advances in modern science and technology, we are able to collect and integrate data about earth surfaces to a centralized data model for the purpose of creating topographic maps and cadastral maps. In reality, when it comes to TIN models in geodesy and cartography, TIN model is used to build Digital Elevation Model (DEM), Digital Terrain Model (DTM), or Digital Surface Model (DSM). When applying the TIN model to solve cadastral problems, Topology is a fundamental problem in data processing and data management. The purpose of this paper is to study and to create Topology of land plots on cadastral maps by two methods: traditional “Vector” and “Rasterizing” on TIN model. DCEL structure, which has the advantage of managing independent half edges flexibly in updating data’s changes, is determined to be the data structure in this study. Research results in creating Topo model for land plots can confirm that it is possible to apply TIN model in cadastral data management. Simultaneously, it is also confirmed that the problem of processing combined terrains and cadastral data on a centralized data model has high practical meaning.

scholarly journals Konversi DSM Menjadi DTM Menggunakan Filter Berbasis Kelerengan Untuk Pemetaan Genangan Banjir Rob Di Kecamatan Tirto

2020 ◽  
Author(s):  
Trida Ridho Fariz ◽  
Nur Rokhayati
Keyword(s):  
Digital Terrain Model ◽  
Surface Model ◽  
Digital Surface Model ◽  
Model Data ◽  
Alos Palsar ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Elevation Model ◽  
Digital Elevation Model Data

Salah satu data penginderaan jauh yang penting adalah DEM (Digital Elevation Model). Data DEM memberikan informasi ketinggian suatu permukaan bumi dimana dikelompokkan menjadi 2 yaitu DSM (Digital Surface Model) yang menyajikan informasi ketinggian permukaan tutupan lahan dan DTM (Digital Terrain Model) yang menyajikan informasi ketinggian tanah. Pemetaan banjir rob secara umum menggunakan data DTM. Tetapi untuk mendapatkan data DTM sangatlah sulit. Salah satu data DEM yang tersedia secara gratis adalah data DEM terkoreksi hasil ekstraksi dari ALOS PALSAR yang memiliki resolusi spasial 12,5 meter, tidak terlalu bagus untuk digunakan sebagai data untuk pemetaan genangan banjir rob mengingat itu hanyalah DSM. Sedangkan menggunakan data titik ketinggian yang di interpolasi tidak terlalu merepresentatifkan kondisi ketinggian medan suatu wilayah kecuali jika jumlah titiknya banyak. Penelitian ini menggunakan metode slope based filtering untuk mengkonversi data DEM dari ALOS PALSAR menjadi DTM.Hasil dari metode ini dilakukan uji statistik berupa korelasi dengan data titik ketinggian dan mempunyai nilai korelasi yang sangat tinggi yaitu sebesar 0,80 dan nilai RMSE sebesar 1,402. Selanjutnya dibuat pemodalan spasial genangan banjir rob dari DTM. Hasil pemodelan spasial genanngan banjir rob kemudin diuji akurasi dengan uji statistik korelasi dan penghitungan RMSE dengan data hasil survey lapangan. Hasil pemodelan memiliki korelasi sebesar 0,78 dengan nilai RMSE tinggi genangan banjir rob sebesar 0,763. Yang berarti bahwa rata-rata selisih nilai ketinggian genangan banjir rob dari peta dan dilapangan adalah sebesar 0,763m. Wilayah genangan banjir rob meliputi Desa Jeruksari, Desa Tegaldowo, Desa Mulyorejo dan Desa Karangjompo.

scholarly journals Research on colorized physical terrain modeling for intelligent vehicle navigation

2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878741
Author(s):  
Jingbin Hao ◽  
Hansong Ji ◽  
Hao Liu ◽  
Zhongkai Li ◽  
Haifeng Yang
Keyword(s):  
Digital Elevation Model ◽  
Land Use Planning ◽  
Three Dimensional ◽  
Aerial Images ◽  
Surface Model ◽  
File Format ◽  
Terrain Model ◽  
Digital Elevation ◽  
Model File ◽  
Elevation Model

Colorized physical terrain models are needed in many applications, such as intelligent navigation, military strategy planning, landscape architecting, and land-use planning. However, current terrain elevation information is stored as digital elevation model file format, and terrain color information is generally stored in aerial images. A method is presented to directly convert the digital elevation model file and aerial images of a given terrain to the colorized virtual three-dimensional terrain model, which can be processed and fabricated by color three-dimensional printers. First, the elevation data and color data were registered and fused. Second, the colorized terrain surface model was created by using the virtual reality makeup language file format. Third, the colorized three-dimensional terrain model was built by adding a base and four walls. Finally, the colorized terrain physical model was fabricated by using a color three-dimensional printer. A terrain sample with typical topographic features was selected for analysis, and the results demonstrated that the colorized virtual three-dimensional terrain model can be constructed efficiently and the colorized physical terrain model can be fabricated precisely, which makes it easier for users to understand and make full use of the given terrain.

scholarly journals VEGETATION REMOVAL FROM UAV DERIVED DSMS, USING COMBINATION OF RGB AND NIR IMAGERY

2018 ◽  
Vol IV-2 ◽  
pp. 255-262 ◽  
Author(s):  
D. Skarlatos ◽  
M. Vlachos
Keyword(s):  
Near Infrared ◽  
Digital Terrain Model ◽  
Reference Points ◽  
Surface Model ◽  
Terrain Model ◽  
Vegetation Removal ◽  
Whole Process ◽  
Digital Terrain ◽  
Ndvi Index ◽  
Small Uav

Current advancements on photogrammetric software along with affordability and wide spreading of Unmanned Aerial Vehicles (UAV), allow for rapid, timely and accurate 3D modelling and mapping of small to medium sized areas. Although the importance and applications of large format aerial overlaps cameras and photographs in Digital Surface Model (DSM) production and LIDAR data is well documented in literature, this is not the case for UAV photography. Additionally, the main disadvantage of photogrammetry is the inability to map the dead ground (terrain), when we deal with areas that include vegetation. This paper assesses the use of near-infrared imagery captured by small UAV platforms to automatically remove vegetation from Digital Surface Models (DSMs) and obtain a Digital Terrain Model (DTM). Two areas were tested, based on the availability of ground reference points, both under trees and among vegetation, as well as on terrain. In addition, RGB and near-infrared UAV photography was captured and processed using Structure from Motion (SfM) and Multi View Stereo (MVS) algorithms to generate DSMs and corresponding colour and NIR orthoimages with 0.2&amp;thinsp;m and 0.25&amp;thinsp;m as pixel size respectively for the two test sites. Moreover, orthophotos were used to eliminate the vegetation from the DSMs using NDVI index, thresholding and masking. Following that, different interpolation algorithms, according to the test sites, were applied to fill in the gaps and created DTMs. Finally, a statistic analysis was made using reference terrain points captured on field, both on dead ground and under vegetation to evaluate the accuracy of the whole process and assess the overall accuracy of the derived DTMs in contrast with the DSMs.

scholarly journals Automatic LIDAR building segmentation based on DGCNN and euclidean clustering

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Ahmad Gamal ◽  
Ari Wibisono ◽  
Satrio Bagus Wicaksono ◽  
Muhammad Alvin Abyan ◽  
Nur Hamid ◽  
...  
Keyword(s):  
Digital Terrain Model ◽  
Primary Source ◽  
Surface Model ◽  
Lidar Data ◽  
Dynamic Graph ◽  
Urban And Regional Planning ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Elevation Model

AbstractThere has been growing demand for 3D modeling from earth observations, especially for purposes of urban and regional planning and management. The results of 3D observations has slowly become the primary source of data in terms of policy determination and infrastructure planning. In this research, we presented an automatic building segmentation method that directly uses LIDAR data. Previous works have utilized the CNN method to automatically segment buildings. However, the existing body of works have relied heavily on the conversion of LIDAR data into Digital Terrain Model (DTM), Digital Surface Model (DSM), or Digital Elevation Model (DEM) formats. Those formats required conversion of LIDAR data into raster images, which poses challenges to the evaluation of building volumes. In this paper, we collected LIDAR data with unmanned aerial vehicle and directly segmented buildings utilizing the said LIDAR data. We utilized a Dynamic Graph Convolutional Neural Network (DGCNN) algorithm to separate buildings and vegetation. We then utilized Euclidean Clustering to segment each building. We found that the combination of these methods are superior to prior works in the field, with accuracy up to 95.57% and an Intersection Over Union (IOU) score of 0.85.

Pembuatan Digital Terrain Model (DTM) dari Light Detection and Ranging (LiDAR) menggunakan Metode Morfologi Sederhana

Teknik ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 40
Author(s):  
Ayu Nur Safi'i ◽  
Prayudha Hartanto
Keyword(s):  
Digital Terrain Model ◽  
Light Detection And Ranging ◽  
Surface Model ◽  
Light Detection ◽  
Terrain Model ◽  
Digital Terrain ◽  
Digital Elevation ◽  
Morphological Filtering ◽  
Elevation Model ◽  
Data Surface

Pembuatan Peta RBI skala 1:5.000 membutuhkan waktu yang lama, khususnya untuk pembuatan layer kontur. Layer kontur bisa didapatkan dari data hasil ekstraksi foto udara dan data Light Detection and Ranging (LIDAR). Sekarang ini, teknologi LiDAR lebih diandalkan untuk membuat Data Surface Model (DSM). Dari DSM dilakukan proses ekstrasi data untuk mendapatkan data Digital Terrain Model (DTM) atau Digital Elevation Model (DEM) yang prosesnya lebih cepat dan membutuhkan biaya yang relatif rendah. Metode filtering yang digunakan adalah metode Simple Morphological Filtering (SMRF) dengan memasukkan nilai parameter cell size, slope, windows, elevation threshold dan scalling factor. Hasil Cohen’s kappa rata-rata menunjukkan indikator DTM dalam kondisi baik, yang artinya dengan menggunakan metode SMRF, nilai kappa berada diantara 0,4-0,7. Smoothing filter dilakukan untuk menghilangkan sel kosong/ sel tanpa data. DTM yang dihasilkan dibandingkan dengan data validasi lapangan. Root Mean Square Error (RMSE) yang diperoleh berkisar antara 0,621-0,930 dan nilai Linear Error 90% (LE90) yang diperoleh berkisar antara 1,025-1,605. Hasil penelitian ini menunjukkan nilai RMSE dan LE90 tersebut memenuhi ketelitian vertikal peta skala 1: 5.000 dan masuk dalam kelas 2 dan 3 sesuai Peraturan BIG No.6 Tahun 2018 mengenai perubahan atas Perka BIG No.15 Tahun 2014 tentang Pedoman Teknis Ketelitian Peta Dasar

Application of Bentley Power Rail Track Software in the BIM Railway Design

2014 ◽  
Vol 587-589 ◽  
pp. 1091-1094
Author(s):  
Xi Sheng ◽  
Hua Peng Luo ◽  
Ping Wang
Keyword(s):  
Cross Sections ◽  
High Efficiency ◽  
Three Dimensional ◽  
Digital Terrain Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Rail Track ◽  
Terrain Model ◽  
Digital Terrain ◽  
Design Software

Belonging to the Bentley Microstation series which work as one of the BIM platforms, the Bentley Power Rail Track shows huge advantages in the railway design for its visibility, high efficiency, advance, reliability and so on. This paper introduces the way to build the digital terrain model, alignments, cross sections, turnouts and to display the three-dimensional model of the railway for the Bentley Power Rail Track 3D railway design software. It provides application preparation for the BIM railway design and achieves the preliminary exploration of BIM applications. Bentley Power Rail Track proves capable of the BIM railway design.

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