grids.xsd Grid geometries A subset of implicit geometries Designed for use with GML Coverage schema, but maybe useful elsewhere as well. Copyright (c) 2002 OGC, All Rights Reserved. Implicitly defines an unrectified grid, which is a network composed of two or more sets of equally spaced parallel lines in which the members of each set intersect the members of the other sets at right angles. Provides grid coordinate values for the diametrically opposed corners of an envelope that bounds a section of grid. The value of a single coordinate is the number of offsets from the origin of the grid in the direction of a specific axis. A rectified grid has an origin and vectors that define its post locations.