field

(or surface) A field is a representation in data of a phenomenon that could, in principle, be measured at all locations. The most obvious example is earth's elevation. Usually, it is assumed that there is only one attribute value at each spatial location, although this is a simplification with regard to actual fields (think of caves or overhanging cliffs, when there are two or more elevation values at a location). Fields may be stored as a digital elevation model (DEM), as a set of control points, as a triangulated irregular network (TIN), or as a mathematical equation relating spatial location to attribute values. Any field can be visualized as a surface. See also object.