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Location Awareness and Navigation in Location-Based Systems
Published in Krzysztof W. Kolodziej, Johan Hjelm, Local Positioning Systems, 2017
Krzysztof W. Kolodziej, Johan Hjelm
A coordinate system is a vector space spanned over a domain. It has an origin that is the subordinate-contained location or the system boundary. A position’s coordinates are an element of a coordinate system. Each singular coordinate is a component of this element. To give an example, the coordinates specifying the position of the location “Room 101” consist of the room number only. There may be additional coordinates, such as a room description, a room type, the measurements of the room, and so on. These coordinates identify the room uniquely within the associate coordinate system for rooms. The domain a coordinate system is spanned over consists of continuous or discrete values from various dimensions. These dimensions correspond to coordinate types; the values are valid coordinate values. They may be specified by an enumeration in case of discrete values or by setting a valid value range with suitable constraints. The coordinate system, the measurement precision, and the data structures supported by the indoor location infrastructure often differ from outdoor navigation. In general, a coordinate-based spatial reference system is defined by a representation (e.g., cartesian, polar, latitude–longitude coordinates) and a reference frame (e.g., the point of origin). In the outdoor case, there is one primary space to represent. An example of a coordinate system is a room coordinate system with the dimensions number, type, description, and measurements and with valid values for these dimensions. Its origin may be the contained location “Building 1,” containing the rooms of the coordinate system. It may also be the system boundary — that is, void — if subordinate locations are irrelevant to the application and there can be no ambiguities. Various coordinate systems may be used, but they typically have well-defined (standardized) transformations between them. There may also be several instances of any type of coordinate system.
A GIS-based simulation and visualization tool for the assessment of gully erosion processes
Published in Journal of Spatial Science, 2022
Adel Omran, Dietrich Schröder, Christian Sommer, Volker Hochschild, Michael Märker
Before starting the model processing steps, all relevant geo-data were projected in the spatial reference system UTM zone 35 South related to the geodetic datum WGS84. The flow lines have been extracted from the original DTM of the study area as shown in Figure 6. The resulting flow lines were evaluated visually by overlaying the RGB orthomosaic of the study area. The extracted main flow line coincides with the main path of the gully development. Therefore, this main flow line was selected to calculate the gully’s geometry. The model preparation step was run on the selected main flow line. This flow line was transformed into a sequence of point features. We assigned to each point the elevation of each soil or substrate layer, the flow accumulation and the coordinates of each point.