Search results
Results from the WOW.Com Content Network
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 ...
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 ...
There are several discrete fixed-point theorems, stating conditions under which a discrete function has a fixed point. For example, the Iimura-Murota-Tamura theorem states that (in particular) if f {\displaystyle f} is a function from a rectangle subset of Z d {\displaystyle \mathbb {Z} ^{d}} to itself, and f {\displaystyle f} is hypercubic ...
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 ...
The main idea of multigrid is to accelerate the convergence of a basic iterative method (known as relaxation, which generally reduces short-wavelength error) by a global correction of the fine grid solution approximation from time to time, accomplished by solving a coarse problem. The coarse problem, while cheaper to solve, is similar to the ...
Development of the quadrilateralized spherical cube projection on an Earth model [1] In mapmaking, a quadrilateralized spherical cube, or quad sphere for short, is an equal-area polyhedral map projection and discrete global grid scheme for data collected on a spherical surface (either that of the Earth or the celestial sphere).
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.