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When each cell of a grid is subject to a recursive partition, resulting in a "series of discrete global grids with progressively finer resolution", [2] forming a hierarchical grid, it is called a hierarchical DGG (sometimes "global hierarchical tessellation" [3] or "DGG system"). Discrete global grids are used as the geometric basis for the ...
C-squares (acronym for the Concise Spatial QUery And REpresentation System) is a system of spatially unique, location-based identifiers for areas on the surface of the earth, represented as cells from a latitude- and longitude-based Discrete Global Grid at a hierarchical set of resolution steps, obtained by progressively subdividing 10×10 degree World Meteorological Organization squares; the ...
Triangulated irregular network TIN overlaid with contour lines. In computer graphics, a triangulated irregular network (TIN) [1] is a representation of a continuous surface consisting entirely of triangular facets (a triangle mesh), used mainly as Discrete Global Grid in primary elevation modeling.
This is an example of a "space-driven" or data independent method, as opposed to "data-driven" or data dependent method, as discussed further in Rigaux et al. (2002)). [3] A grid-based spatial index has the advantage that the structure of the index can be created first, and data added on an ongoing basis without requiring any change to the ...
Tessellation refer to a finite number of objects/cells that cover the surface as discrete partitions while Lattice refer to ordered sets of points that cover the surface in continuous vector space. The mathematical frame for a digital Earth reference model is a tessellation while the mathematical frame for an analog Earth reference is a lattice.
A "global DEM" refers to a discrete global grid. DEMs are used often in geographic information systems (GIS), and are the most common basis for digitally produced relief maps. A digital terrain model (DTM) represents specifically the ground surface while DEM and DSM may represent tree top canopy or building roofs.
Such a grid does not have a straightforward relationship to latitude and longitude, but conforms to many of the main criteria for a statistically valid discrete global grid. [9] Primarily, the cells' area and shape are generally similar, especially near the poles where many other spatial grids have singularities or heavy distortion.
The Snake Projection algorithm converts between geographical and grid coordinates, however the method of technical implementation can vary. One method of implementing a Snake Projection is to define using an NTv2 geodetic transformation coupled with a standard parameterised map projection (such as Transverse Mercator ); this is increasing in ...