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Visual tools for wind farms development
Published in Corrado F Ratto, Giovanni Solari, Wind Energy and Landscape, 2020
A grid file produces a contour map, a two dimensional representation of three dimensional data. Contours define lines of constant Z, or in other words, lines of constant elevation or value, across the extent of the map. Contour lines are drawn as straight line segments between the grid lines in the grid file. The point where a contour line intersects a grid line is based on an interpolation between the Z values at the neighboring grid nodes. The smoothness of contours on a contour map is partially a function of the number of X and Y lines in the grid file: reduction of the number of lines in the X and Y directions can result in more angular contours on the contour map.
Geologic database management
Published in Martin Lloyd Smith, Geologic and Mine Modelling using Techbase and Lynx, 2020
Topographic data is the most common form of map data in which 2D features called contours are used to represent a line of constant elevation in plan view. But map data is not limited to the horizontal or to 2D data: the map plane is defined by a lower left origin, an azimuth and an inclination so that the plane to which the map data is referenced can be in any position. Features which are part of the map can be points, lines or contours which are defined by their xy position on the plane or features such as survey traverses which are defined both by their xy positions and by offsets taken normal to the plane. Since a map can take any orientation in Lynx (unlike Techbase), maps are extremely useful for working with underground structures such as veins, faults or stopes. There will be ample opportunities to manipulate map data in later exercises.
Interactive Visual Data Analysis
Published in Christian Tominski, Heidrun Schumann, Interactive Visual Data Analysis, 2020
Christian Tominski, Heidrun Schumann
The geographic space is three-dimensional. A position in geographic space is typically defined by three coordinates: latitude, longitude, and elevation. The latitude is the angle between the equator and the poles. The latitude is 0∘ at the equator, +90∘ at the north pole, and −90∘ at the south pole. The longitude is the angle with respect to the prime meridian in Greenwich. Eastward angles have a positive sign, whereas westward angles are negative. The maximum absolute value of the longitude is 180∘. Because the surface of the Earth is not perfectly planar, elevation is used to measure the distance of a geographic position above or below the sea level.
Mining large-gradient subsidence monitoring using D-InSAR optimized by GNSS
Published in The Imaging Science Journal, 2021
Haodi Fan, Xugang Lian, Wenfu Yang, Linlin Ge, Haifeng Hu, Zheyuan Du
The conventional monitoring method is to measure the subsidence by means of angle measurement, edge measurement, levelling and other technologies. It has the following advantages: providing the overall deformation state of the deformation body, checking the results in the form of an observation network, and great flexibility [2]. In practical applications, elevation measurement is generally obtained by geometric levelling or trigonometric levelling. Angle measurement is mainly obtained by theodolite and total station. Since the 1970s, various new types of precision photoelectric rangefinders have been widely used in deformation monitoring, but long-distance ranging needs to solve the problem of atmospheric refraction. After the 1990s, due to the wide application of GNSS, long-distance rangefinders were replaced by GNSS [7]. Compared with traditional surveying and mapping operations and methods GNSS has excellent performance and wide adaptability. On a local scale, China has used GNSS technology to monitor the deformation of a large number of mining areas and achieved a series of results [8–10]. However, these methods have obvious disadvantages: small monitoring range, long time span, low work efficiency, and large manpower and material consumption [11]. Therefore, with the progress of science, deformation monitoring technologies such as UAV remote sensing [12–14] and InSAR [15–17] have gradually emerged.
Vertical accuracy evaluation of freely available latest high-resolution (30 m) global digital elevation models over Cameroon (Central Africa) with GPS/leveling ground control points.
Published in International Journal of Digital Earth, 2019
Loudi Yap, Ludovic Houetchak Kandé, Robert Nouayou, Joseph Kamguia, Nasser Abdou Ngouh, Marie Brigitte Makuate
Finally, the DEM’s vertical accuracy is also evaluated in function of topography roughness which is one of the major influencing factors of vertical accuracy of DEMs. GCPs were segmenting in classes for slope (0° to 2°, 2° to 5°, 5° to 10°, >10°). Slope is a terrain attribute that represents the magnitude of the terrain inclination and is a measure of the change of elevation over a horizontal distance (Varga and Bašić 2015). Slope maps were calculated for all tested global DEMs using the spatial analyst tool within ArcGIS 9.3 software. From the slope maps, slope values were bilinearly interpolated for all the GCPs.
Is environment destiny? Spatial analysis of the relationship between geographic factors and obesity in Türkiye
Published in International Journal of Environmental Health Research, 2023
Hacı Ömer Yılmaz, Mehmet Akif Günen
The term “elevation” describes the elevation at which a point is in relation to sea level. Typically, elevation is expressed in a length unit, such as the meter. Levelling, aircraft or drones can also measure elevation to determine the heights of things on the ground. The elevation map used in this study was created by using the elevation information obtained from the official governorship website of the provinces with “gov” extension.