DIGITAL RASTER GRAPHICS (1:100,000 SCALE)
ABSTRACT: The Digital Raster Graphic (DRG) is a raster image of a scanned US Geological Survey topographic map including the collar information, georeferenced to the Universal Transverse Mercator (UTM) grid.
PURPOSE: A DRG is useful as a source or background layer in a GIS, as a means to perform quality assurance on other digital products, and as a source for the collection and revision of DLG data. DRG's can also be merged with other digital data, e.g. Digital Elevation Models (DEM's) or Digital Orthophoto quadrangles (DOQ's), to produce a hybrid digital file.
PURPOSE: A DRG is useful as a source or background layer in a GIS, as a means to perform quality assurance on other digital products, and as a source for the collection and revision of DLG data. DRG's can also be merged with other digital data, e.g. Digital Elevation Models (DEM's) or Digital Orthophoto quadrangles (DOQ's), to produce a hybrid digital file.