-- Name -- Statistical grid cell -- Definition -- Unit for dissemination or use of statistical information that is represented as a grid cell. -- Description -- A statistical grid cell is associated with: - the unique statistical grid cell of its upper level (if any) it is covered by, - the statistical grid cells of its lower level (if any) it covers. NB Statistical grid cells are squares. EXAMPLE In a quadtree structure, some cells are associated with the four cells they are decomposed into.
-- Name -- Statistical grid -- Definition -- A grid composed of statistical cells. -- Description -- Such grid is associated with an upper grid, that has a bigger resolution, and a lower grid that has a lower resolution. Some statistical grids are organised into a hierarchy of grids with different resolutions. The cells composing two linked grids have to satisfy some topological constraints: each cell of the upper grid should be the aggregation of cells of the lower grid. EXAMPLE The hierarchical structure is a quadtree if the grids are composed of quadrilateral cells and each cell is composed of less than four cells of the lower level.
-- Name -- Statistical grid resolution -- Definition -- A statistical unit resolution value. -- Definition -- The resolution can be a distance or an angle.