scholarly journals An Improved Ball Pivot Algorithm-Based Ground Filtering Mechanism for LiDAR Data

2019 ◽  
Vol 11 (10) ◽  
pp. 1179 ◽  
Author(s):  
Wei Ma ◽  
Qingquan Li
Keyword(s):  
Spatial Relationship ◽  
Single Layer ◽  
Experimental Results ◽  
Lidar Data ◽  
Initial Surface ◽  
Seed Point ◽  
Pivot Algorithm ◽  
Group Iii ◽  
Digital Elevation ◽  
Elevation Model

Automatic ground filtering is an essential step for Digital Elevation Model (DEM) generation, which has significant application value. However, extraction and classification of ground points from the Light Detection and Ranging (LiDAR) data, especially in multitudinous terrain situations, is a challenging task because it is difficult to determine the set of optimal parameters for removing various non-ground features. In this paper, a new ground filtering technique based on an improved Ball Pivot Algorithm (BPA) is proposed. At the beginning, the LiDAR point cloud dataset was divided into different subsets based on the 2D regular grid. The lowest point in each grid was selected as the seed point to build a single-layer surface. After that, the improved BPA was executed to remove points on the higher location. Then, the rest of the points were calculated and selected as a new seed point according to the spatial relationship with the initial surface. Finally, non-ground points were filtered by means of improved BPA traversing all the grids. Our experimental results on the Benchmark dataset provided by the International Society for Photogrammetry and Remote Sensing (ISPRS) Working Group III/3 showed high accuracy (with a mean kappa coefficient over 80%) in terms of completeness, correctness, and quality for DEM generation. The experimental results demonstrated the proposed method is robust to various terrain situations, as it is more effective and feasible for ground filtering.

scholarly journals MAT: GIS-Based Morphometry Assessment Tools for Concave Landforms

2021 ◽  
Vol 13 (14) ◽  
pp. 2810
Author(s):  
Joanna Gudowicz ◽  
Renata Paluszkiewicz
Keyword(s):  
Rapid Development ◽  
Assessment Tools ◽  
Lidar Data ◽  
Automatic Extraction ◽  
Sensing Technology ◽  
Digital Elevation ◽  
Elevation Data ◽  
Elevation Model ◽  
Morphometric Assessment ◽  
Morphometric Evaluation

The rapid development of remote sensing technology for obtaining high-resolution digital elevation models (DEMs) in recent years has made them more and more widely available and has allowed them to be used for morphometric assessment of concave landforms, such as valleys, gullies, glacial cirques, sinkholes, craters, and others. The aim of this study was to develop a geographic information systems (GIS) toolbox for the automatic extraction of 26 morphometric characteristics, which include the geometry, hypsometry, and volume of concave landforms. The Morphometry Assessment Tools (MAT) toolbox in the ArcGIS software was developed. The required input data are a digital elevation model and the form boundary as a vector layer. The method was successfully tested on an example of 21 erosion-denudation valleys located in the young glacial area of northwest Poland. Calculations were based on elevation data collected in the field and LiDAR data. The results obtained with the tool showed differences in the assessment of the volume parameter at the average level of 12%, when comparing the field data and LiDAR data. The algorithm can also be applied to other types of concave forms, as well as being based on other DEM data sources, which makes it a universal tool for morphometric evaluation.

scholarly journals Reconstructing Pre-Industrial Long Distance Roads in a Hilly Region in Germany, Based on Historical and Archaeological Data

2017 ◽  
Vol 1 (2) ◽  
pp. 642-660 ◽  
Author(s):  
Irmela Herzog
Keyword(s):  
Cross Sections ◽  
Lidar Data ◽  
Long Distance ◽  
Early 19Th Century ◽  
Digital Elevation ◽  
Hilly Region ◽  
Local Accuracy ◽  
Cost Paths ◽  
Elevation Model ◽  
The One

The aim of this contribution is on the one hand to map pre-industrial long distance roads located in a hilly region east of Cologne, Germany, as exactly as possible and on the other hand to assess the accuracy of least-cost approaches that are increasingly applied by archaeologists for prehistoric road reconstruction. Probably the earliest map covering the study area east of Cologne dates back to 1575. The map is distorted so that rectification is difficult. But it is possible to assess the local accuracy of the map and to transfer the approximate routes to a modern map manually. Most of the area covered by the 1575 map is also depicted on a set of more accurate maps created in the early 19th century and a somewhat later historical map set (ca. 1842 AD). The historical roads on these rectified historical maps close to the approximate roads were digitized and compared to the outcomes of least-cost analysis, specifically least-cost paths and accessibility maps. Based on these route reconstructions with limited accuracy, Lidar data is checked to identify remains of these roads. Several approaches for visualizing Lidar data are tested to identify appropriate methods for detecting sunken roads. Possible sunken roads detected on the Lidar images were validated by checking cross sections in the digital elevation model and in the field.

scholarly journals CREATING DIGITAL ELEVATION MODEL USING A MOBILE DEVICE

2017 ◽  
Vol IV-4/W4 ◽  
pp. 203-207 ◽  
Author(s):  
A. İ. Durmaz
Keyword(s):  
Mobile Devices ◽  
Digital Elevation Model ◽  
Mobile Device ◽  
Point Clouds ◽  
Lidar Data ◽  
Government Agencies ◽  
Gps Data ◽  
Digital Elevation ◽  
The World ◽  
Elevation Model

DEM (Digital Elevation Models) is the best way to interpret topography on the ground. In recent years, lidar technology allows to create more accurate elevation models. However, the problem is this technology is not common all over the world. Also if Lidar data are not provided by government agencies freely, people have to pay lots of money to reach these point clouds. In this article, we will discuss how we can create digital elevation model from less accurate mobile devices’ GPS data. Moreover, we will evaluate these data on the same mobile device which we collected data to reduce cost of this modeling.

scholarly journals Distribución espacial y temporal de glaciares, glaciares cubiertos y glaciares rocosos durante la última deglaciación en el valle de La Bonaigua (Pirineo Central)

2020 ◽  
Vol 46 (2) ◽  
pp. 413-446
Author(s):  
J. Ventura-Roca
Keyword(s):  
High Resolution ◽  
Little Ice Age ◽  
Ice Age ◽  
Lidar Data ◽  
Forest Environment ◽  
Digital Elevation ◽  
Rock Glaciers ◽  
Elevation Model ◽  
Glacial Landforms ◽  
Central Pyrenees

The application of the paleogeographic method to the study of glacial landforms and rock glaciers allows their morphometric and sedimentological characterization, the establishment of a detailed morphostratigraphic sequence and a chronological proposal for the identified glacial phases. This study analyzes 86 landforms (57 glacial deposits, 21 rock glaciers and 8 protalus ramparts) in the Bonaigua Valley (Noguera Pallaresa Basin, Central Pyrenees), with special attention to the differentiation between debris-covered glaciers and rock glaciers. Other subjects studied concerning rock glaciers are: distinguish its glacial or periglacial origin; the possible current activity of some landforms, and the detection of rock glaciers located at low altitudes (in the current forest environment) through the use of high-resolution digital elevation model (2x2 m) from LIDAR data. The chronological hypothesis elaborated by correlation with other high Pyrenean valleys (with absolute ages available) includes 7 phases (6 glacial phases and 1 periglacial phase) in which co-exist and/or evolve, in a paraglacial dynamic, glaciers, debris-covered glaciers and rock glaciers, and that we temporarily place between the end of the Oldest Dryas and the Little Ice Age.

Topographic Map Update of Esan Central LGA, Edo State, Nigeria, Using SPOT-5 and ASTER LiDAR Data

2014 ◽  
Vol 1 (1) ◽  
pp. 52-69
Author(s):  
S.O. Ogedegbe
Keyword(s):  
Spatial Data ◽  
Digital Terrain Model ◽  
Topographic Maps ◽  
Lidar Data ◽  
Topographic Map ◽  
Terrain Model ◽  
Digital Elevation ◽  
Système D’Information ◽  
Elevation Model ◽  
Spot 5

This study examines the effectiveness and accuracy of SPOT-5 and ASTER LiDAR data satellite images, Global Pos1t1on1ng System (GPS), Digital Terrain Model (DTM), and Geographic Information System (GIS) in carrying out a revision of Nigerian topographic maps at the scale of 1:50,000. The data for the study were collected by extraction of relevant spatial data from the 1964 topographic map, delineation and interpretation of 2009 SPOT-5 data, and field surveys. The landscape changes extracted from SPOT- 5 were used to update the topographic base map and to determine the nature and direction of changes that have taken place in the study area. The findings revealed that changes have occurred in both cultural and relief features over time. The coefficient of correlation and t-test was calculated to show that changes in point, linear and areal features are significant. Also significant were the planh11etric and height accuracies of the revised map. The study shows that satellite data especially SPOT-5 is useful for the revision of topographic maps at scales of 1:50,000 and even larger. And, high-resolution remote sensing at Sm and ASTER data (30m) with GPS (±1.9m) can be used to c.reate a digital elevation model (DEM) on the map which is an essential dataset for complete revision. Cette étude examine l'efficacité et la précision des images satellites de données SPOT-5 et ASTER LiDAR, du système de positionnement global (GPS), du modèle numérique de terrain (MNT) et du système d'information géographique (SIG) pour effectuer une révision des cartes topographiques nigérianes au échelle de 1:50 000. Les données de l'étude ont été recueillies par extraction de données spatiales pertinentes à partir de la carte topographique de 1964, délimitation et interprétation des données SPOT-5 de 2009 et relevés de terrain. Les changements de paysage extraits de SPOT-5 ont été utilisés pour mettre à jour le fond de carte topographique et pour déterminer la nature et la direction des changements qui ont eu lieu dans la zone d'étude. Les résultats ont révélé que des changements se sont produits dans les caractéristiques culturelles et du relief au fil du temps. Le coefficient de corrélation et le test t ont été calculés pour montrer que les changements dans les caractéristiques ponctuelles, linéaires et aréales sont significatifs. Les précisions planimétriques et altimétriques de la carte révisée étaient également importantes. L'étude montre que les données satellitaires, en particulier SPOT-5, sont utiles pour la révision des cartes topographiques à des échelles de 1:50 000 et même plus. De plus, la télédétection haute résolution aux données Sm et ASTER (30 m) avec GPS (± 1,9 m) peut être utilisée pour créer un modèle d'élévation numérique (DEM) sur la carte qui est un ensemble de données essentiel pour une révision complète.

A new high-resolution bathymetry model for the Terre Adélie and George V continental margin, East Antarctica

2010 ◽  
Vol 23 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Robin J. Beaman ◽  
Philip E. O’Brien ◽  
Alexandra L. Post ◽  
Laura De Santis
Keyword(s):  
High Resolution ◽  
Digital Elevation Model ◽  
Continental Margin ◽  
Regional Scale ◽  
Spatial Relationship ◽  
East Antarctica ◽  
Digital Elevation ◽  
Terre Adélie ◽  
Elevation Model ◽  
High Resolution Bathymetry

AbstractThe Collaborative East Antarctic Marine Census (CEAMARC) surveys to the Terre Adélie and George V continental margin highlight the requirement for a revised high-resolution bathymetry model that can be used as a spatial tool for improving information on the physical environment of the region. We have combined shiptrack singlebeam and multibeam bathymetry, coastline data, and land and ice sheet topographic data to develop a new regional-scale bathymetry grid, called GVdem (short for George V digital elevation model). The GVdem grid spans an area between 138–148°E and 63–69°S, with a cell pixel size of 0.001-arcdegree (c. 100 m). The revised digital elevation model is a large improvement over previously available regional-scale grids from the area, and highlights seabed physiographic detail not formerly observed in this part of East Antarctica. In particular, the extent and complexity of the rugged inner-shelf valleys are revealed, and their spatial relationship with large shelf basins and adjacent flat-topped banks. The new grid also reveals further insight into the spatial distribution of the submarine canyons found on the continental slope.

scholarly journals Mapeamento das áreas de armazenamento de água em depressão, usando dados LIDAR: Estudo de caso avenida Caxangá

2021 ◽  
Vol 14 (1) ◽  
pp. 058
Author(s):  
Camila Gardenea de Almeida Bandim ◽  
Josiclêda Domiciano Galvíncio
Keyword(s):  
Water Storage ◽  
Light Detection And Ranging ◽  
Lidar Data ◽  
Urban Drainage ◽  
Lidar System ◽  
Light Detection ◽  
Urban Flood ◽  
Digital Elevation ◽  
Elevation Model

O objetivo deste estudo consiste em avaliar as áreas inundáveis em Recife, com especial atenção à avenida Caxangá.  Iniciando uma análise sobre a drenagem convencional utilizando a tecnologia LIDAR (Light Detection And Ranging). Os dados empregados neste trabalho foram captados pelo sistema LIDAR e possuem 50 cm de resolução, sendo um total de 12 quadrículas xyz para a constituição do mosaico Modelo Digital de Elevação (MDE) da avenida Caxangá, com destaque para as quadrículas 81_50-05 e 81_60-05, partindo dessas foram geradas as direções e acúmulos de fluxo. Os resultados obtidos enfatizam a alta resolução através da nítida visualização de elementos naturais e artificiais, e ainda o nivelamento do terreno. Em seguida, observa-se o acúmulo de fluxo que exibe as diferentes direções e acúmulos do escoamento superficial, ainda se percebe a influência na drenagem urbana das construções antrópicas e da vegetação em locais pontuais da avenida Caxangá. Em conclusão os dados do sistema LIDAR responderam positivamente, tanto na captação na modelagem do terreno e topografia artificial, como também para as gerações de direções e acúmulo de fluxos apresentando maiores valores para áreas depressivas naturais e antropizadas. Sendo destaque neste estudo as áreas antropizadas por provocarem problemas de desastres naturais. Conclui-se que as áreas antropizadas exercem um importante papel na drenagem urbana.  Mapping water storage areas in depression, using LIDAR data: Caxangá Avenida case study A B S T R A C TThe objective of this study is to evaluate the floodable areas in Recife, with special attention to Avenida Caxangá. Starting an analysis on conventional drainage using LIDAR (Light Detection And Ranging) technology. The data used in this work were captured by the LIDAR system and have 50 cm of resolution, with a total of 12 xyz squares for the constitution of the Digital Elevation Model (MDE) mosaic on Avenida Caxangá, with emphasis on the squares 81_50-05 and 81_60 -05, from these directions and flow accumulations were generated. The results obtained emphasize the high resolution through the clear visualization of natural and artificial elements, as well as the leveling of the terrain. Then, there is the accumulation of flow that shows the different directions and accumulations of runoff, the influence on the urban drainage of anthropic buildings and vegetation in specific places on Avenida Caxangá is still perceived. In conclusion, the data from the LIDAR system responded positively, both in capturing terrain modeling and artificial topography, as well as for generations of directions and accumulation of flows, presenting higher values for natural and anthropized depressive areas. Being highlighted in this study the areas anthropized because they cause problems of natural disasters. It is concluded that anthropized areas play an important role in urban drainage.Keywords: Geoprocessing. Remote sensing. Urbanization. Urban flood. drainage

scholarly journals PERFORMANCE EVALUATION OF DIFFERENT GROUND FILTERING ALGORITHMS FOR UAV-BASED POINT CLOUDS

2016 ◽  
Vol XLI-B1 ◽  
pp. 245-251 ◽  
Author(s):  
C. Serifoglu ◽  
O. Gungor ◽  
V. Yilmaz
Keyword(s):  
Point Cloud ◽  
Point Clouds ◽  
Good Alternative ◽  
Lidar Data ◽  
Filtering Algorithms ◽  
Aerial Photos ◽  
Digital Elevation ◽  
Aerial Vehicle ◽  
Elevation Model ◽  
Uav Images

Digital Elevation Model (DEM) generation is one of the leading application areas in geomatics. Since a DEM represents the bare earth surface, the very first step of generating a DEM is to separate the ground and non-ground points, which is called ground filtering. Once the point cloud is filtered, the ground points are interpolated to generate the DEM. LiDAR (Light Detection and Ranging) point clouds have been used in many applications thanks to their success in representing the objects they belong to. Hence, in the literature, various ground filtering algorithms have been reported to filter the LiDAR data. Since the LiDAR data acquisition is still a costly process, using point clouds generated from the UAV images to produce DEMs is a reasonable alternative. In this study, point clouds with three different densities were generated from the aerial photos taken from a UAV (Unmanned Aerial Vehicle) to examine the effect of point density on filtering performance. The point clouds were then filtered by means of five different ground filtering algorithms as Progressive Morphological 1D (PM1D), Progressive Morphological 2D (PM2D), Maximum Local Slope (MLS), Elevation Threshold with Expand Window (ETEW) and Adaptive TIN (ATIN). The filtering performance of each algorithm was investigated qualitatively and quantitatively. The results indicated that the ATIN and PM2D algorithms showed the best overall ground filtering performances. The MLS and ETEW algorithms were found as the least successful ones. It was concluded that the point clouds generated from the UAVs can be a good alternative for LiDAR data.

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