Glossary for Geospatial Science

overlay: (vector, CAD, TIN) A transparent layer placed on an underlying image.� The overlay is where symbols, annotations, or image traces can be created or displayed without changing the underlying image.� A TNTmips symbol overlay is a vector object with symbol shapes assigned to its nodes so that the symbols line up with features of interest on the underlying image.� For example, a duck symbol might overlay a duck habitat feature and be linked to a database record with site specifics.