Glossary for Geospatial Science

symbol overlay:� A vector object can have symbol shapes assigned to some or all of its point features.� When this vector object is displayed over (or overlaid on) an image, you can also choose to display the symbols over the top of the features in the underlying image.� Such symbols may also be attached to database records and used to graphically retrieve such reference information.� For example, a symbol overlay that uses ducks to represent nesting sites could be shown over a habitat map.� A click on a particular duck symbol could retrieve a record from an associated database and display it on the text screen to provide such information as the date of first occupancy, number of eggs, number of fledglings, and so on.� (See also: overlay.)