scholarly journals Spatial Analysis Using Temporal Point Clouds in Advanced GIS: Methods for Ground Elevation Extraction in Slant Areas and Building Classifications

2019 ◽  
Vol 8 (3) ◽  
pp. 120 ◽  
Author(s):  
Sara Shirowzhan ◽  
Samad Sepasgozar
Keyword(s):  
Digital Elevation Model ◽  
Urban Growth ◽  
Urban Areas ◽  
Future Directions ◽  
3D Data ◽  
Contour Lines ◽  
Digital Elevation ◽  
The Future ◽  
Elevation Model ◽  
Skewness And Kurtosis

Deriving 3D urban development patterns is necessary for urban planners to control the future directions of 3D urban growth considering the availability of infrastructure or being prepared for fundamental infrastructure. Urban metrics have been used so far for quantification of landscape and land-use change. However, these studies focus on the horizontal development of urban form. Therefore, questions remain about 3D growth patterns. Both 3D data and appropriate 3D metrics are fundamentally required for vertical development pattern extraction. Airborne light detection and ranging (Lidar) as an advanced remote-sensing technology provides 3D data required for such studies. Processing of airborne lidar to extract buildings’ heights above a footprint is a major task and current automatic algorithms fail to extract such information on vast urban areas especially in hilly sites. This research focuses on proposing new methods of extraction of ground points in hilly urban areas using autocorrelation-based algorithms. The ground points then would be used for digital elevation model generation and elimination of ground elevation from classified buildings points elevation. Technical novelties in our experimentation lie in choosing a different window direction and also contour lines for the slant area, and applying moving windows and iterating non-ground extraction. The results are validated through calculation of skewness and kurtosis values. The results show that changing the shape of windows and their direction to be narrow long squares parallel to the ground contour lines, respectively, improves the results of classification in slant areas. Four parameters, namely window size, window shape, window direction and cell size are empirically chosen in order to improve initial digital elevation model (DEM) creation, enhancement of the initial DEM, classification of non-ground points and final creation of a normalised digital surface model (NDSM). The results of these enhanced algorithms are robust for generating reliable DEMs and separation of ground and non-ground points in slant urban scenes as evidenced by the results of skewness and kurtosis. Offering the possibility of monitoring urban growth over time with higher accuracy and more reliable information, this work could contribute in drawing the future directions of 3D urban growth for a smarter urban growth in the Smart Cities paradigm.

Study on the Utilization of Digital Elevation Model for Calculation Method of Reservoir Capacity

2012 ◽  
Vol 472-475 ◽  
pp. 1627-1631
Author(s):  
Li Fang Lai ◽  
Yu Fen Zhang
Keyword(s):  
Digital Elevation Model ◽  
Calculation Method ◽  
Reservoir Capacity ◽  
Contour Lines ◽  
Digital Elevation ◽  
Capacity Calculation ◽  
Elevation Model

Reservoir capacity is a very important parameter for reservoir. This paper discusses the use of contour lines to establish digital elevation model (DEM) of reservoir, and to calculate reservoir capacity to improve the accuracy of the capacity calculation through the method that uses digital elevation model.

Determination of actual snow-covered area using Landsat TM and digital elevation model data in Glacier National Park, Montana

Polar Record ◽  
1995 ◽  
Vol 31 (177) ◽  
pp. 191-198 ◽  
Author(s):  
Dorothy K. Hall ◽  
James L. Foster ◽  
Janet Y.L. Chien ◽  
George A. Riggs
Keyword(s):  
Snow Cover ◽  
Digital Elevation Model ◽  
National Park ◽  
Glacier National Park ◽  
Modis Data ◽  
Snow Covered Area ◽  
Covered Area ◽  
Digital Elevation ◽  
The Future ◽  
Elevation Model

AbstractIn the future, data from the moderate resolution imaging spectroradiometer (MODIS) will be employed to map snow in an automated environment at a resolution of 250 m to 1 km. Using Landsat thematic mapper (TM) data, an algorithm, SNOMAP, has been developed to map snow-covered area. This algorithm will be used, with appropriate modification, with MODIS data following the launch of the first Earth Observing System (EOS) platform in 1998. SNOMAP has been shown to be successful in mapping snow in a variety of areas using TM data. However, significant errors may be present in mountainous areas due to effects of topography. To increase the accuracy of mapping global snow-covered area in the future using MODIS data, digital elevation model (DEM) data have been registered to TM data for parts of Glacier National Park, Montana, so that snow cover on mountain slopes can be mapped. This paper shows that the use of DEM data registered to TM data increases the accuracy of mapping snow-covered area. Using SNOMAP on a subscene within the 14 March 1991 TM scene of northwestern Montana, 215 km2 of snow is mapped when TM data are used alone to map the snow cover. We show that about 1062 km2 of snow are actually present as measured when the TM and DEM data are registered. Approximately five times more snow is present when the effects of topography are considered for this subscene, which is in a rugged area in Glacier National Park. A simple model has been developed to determine the relationship between terrain relief and the amount of correction that must be applied to map actual snow-covered area in Glacier National Park using satellite data alone.

scholarly journals DIGITAL ELEVATION MODEL INTERPOLATION BY FUSION OF MORPHOLOGICAL RECONSTRUCTION AND DISTANCE TRANSFORMATION

2017 ◽  
Vol XLII-2/W7 ◽  
pp. 881-885
Author(s):  
J. Shen ◽  
W. L. Han ◽  
J. Ge ◽  
L. B. Zhang ◽  
H. Tan
Keyword(s):  
Digital Elevation Model ◽  
Flow Line ◽  
Interpolation Method ◽  
Linear Interpolation ◽  
Morphological Reconstruction ◽  
Distance Transformation ◽  
Spatial Point ◽  
Contour Lines ◽  
Digital Elevation ◽  
Elevation Model

Interpolation methods have significant impacts on the accuracy of the digital elevation model (DEM) from contours which are one of frequently employed data sources. In this paper, an interpolation method is presented to build DEM from contour lines by fusion/integration of morphological reconstruction and distance transformation with obstacles. Particularly, morphological reconstruction is used to get the elevation values of the higher contour lines and the lower contour lines of any a spatial point between two contour lines, and distance transformation with obstacles is used to get the geodesic distances of the spatial point to the higher contour lines and the lower contour lines respectively. At last, linear interpolation along water flow line is used to get the elevation values of the pixels to be interpolated. The experiment demonstrates that feasibility of our proposed method.

scholarly journals Applied spatial analytic tools in orchards with special regard to agro-ecology

2011 ◽  
Vol 17 (1-2) ◽  
Author(s):  
T. Fórián ◽  
A. Nagy ◽  
J. Tamás ◽  
Z. Szabó ◽  
M. Soltész ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Digital Terrain Model ◽  
Analytical Techniques ◽  
Soil Surface ◽  
Terrain Model ◽  
Digital Terrain ◽  
Contour Lines ◽  
Digital Elevation ◽  
Elevation Model ◽  
Fruit Orchards

Our investigation was carried out in several orchards in Hungary. This study reviews applicability of the different spatial analytical techniques in orchard especially models based on surface relief, such as digital elevation model, digital terrain model, slope and aspect maps. In recent time, the generation of digital elevation model has become a popular examination method. However, the elevation models generated from contour lines or elevation points could be applied to evaluate agro- ecological potential of fruit orchards to some extent. The highest deficiency of these models is the fact that these show the altitude of soil surface only and do not demonstrate landmarks on the surface. Consequently, the calculation of the radiation value results data relating to soil surface. The terrain model generated and applied by our team demonstrates fine surface texture and the landmarks in the orchard, so it is suitable for further examination.

scholarly journals Using Photogrammetric UAV Measurements as Support for Classical Topographical Measurements in Order to Obtain the Topographic Plan for Urban Areas

2017 ◽  
Vol 74 (2) ◽  
pp. 197
Author(s):  
Elemer Emanuel SUBA ◽  
Tudor SĂLĂGEAN ◽  
Ioana POP ◽  
Florica MATEI ◽  
Jutka DEAK ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Urban Areas ◽  
Point Cloud ◽  
Ground Control ◽  
Control Points ◽  
Ground Control Points ◽  
Triangulation Network ◽  
Digital Elevation ◽  
Photogrammetric Method ◽  
Elevation Model

This article aims to highlight the benefits of UAV photogrammetric measurements in addition to classical ones. It will also deal with the processing and integration of the point cloud, respectively the digital elevation model in topo-cadastral works. The main purpose of this paper is to compare the results obtained using the UAV photogrammetric measurements with the results obtained by classical methods. It will briefly present the classical measurements made with the total station. In the present project, the closed-circuit traverse and the supported on the endings traverse were made using known coordinate points. Determining the coordinates of the points used for the traverses was done by GNSS methods. The area on which the measurements were made is 67942m2 and is covered by 31 determined station points. From these points, 13 were used as ground control points, respectively components of the aero-triangulation network and 17 points were used to control the obtained results by comparing their coordinates obtained by classical methods with those obtained by the UAV photogrammetric method. It was intended that the constraint points of the aero triangulation to be uniformly distributed on the studied surface.

STUDY OF THE LANDSLIDE MORPHOLOGY BASED ON GNSS DATA AND AIRBORNE SOUNDING (ON THE EXAMPLE OF A SECTION OF THE PROTVA RIVER VALLEY)

2018 ◽  
Vol 12 (5-6) ◽  
pp. 50-57 ◽  
Author(s):  
I. S. Voskresensky ◽  
A. A. Suchilin ◽  
L. A. Ushakova ◽  
V. M. Shaforostov ◽  
A. L. Entin ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Geodetic Network ◽  
Aerial Survey ◽  
River Valley ◽  
Ease Of Use ◽  
Digital Elevation ◽  
Loose Deposits ◽  
Positioning Method ◽  
Landslide Body ◽  
Elevation Model

To use unmanned aerial vehicles (UAVs) for obtaining digital elevation models (DEM) and digital terrain models (DTM) is currently actively practiced in scientific and practical purposes. This technology has many advantages: efficiency, ease of use, and the possibility of application on relatively small area. This allows us to perform qualitative and quantitative studies of the progress of dangerous relief-forming processes and to assess their consequences quickly. In this paper, we describe the process of obtaining a digital elevation model (DEM) of the relief of the slope located on the bank of the Protva River (Satino training site of the Faculty of Geography, Lomonosov Moscow State University). To obtain the digital elevation model, we created a temporary geodetic network. The coordinates of the points were measured by the satellite positioning method using a highprecision mobile complex. The aerial survey was carried out using an unmanned aerial vehicle from a low altitude (about 40–45 m). The processing of survey materials was performed via automatic photogrammetry (Structure-from-Motion method), and the digital elevation model of the landslide surface on the Protva River valley section was created. Remote sensing was supplemented by studying archival materials of aerial photography, as well as field survey conducted immediately after the landslide. The total amount of research results made it possible to establish the causes and character of the landslide process on the study site. According to the geomorphological conditions of formation, the landslide refers to a variety of landslideslides, which are formed when water is saturated with loose deposits. The landslide body was formed with the "collapse" of the blocks of turf and deluvial loams and their "destruction" as they shifted and accumulated at the foot of the slope.

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