DRG’s – Digital Raster Graphics, Maine

Coverage Name and Path: /gis/me/drg/24k/<tile-name> and /gis/me/drg/24kgrey/<tile-name>

Image Catalog: /gis/me/drg/DRG24k.dbf or DRG_24k_grey.dbf conveniently displays photos in your view extent.

Geographic Extent: Maine (708 quads)

Scale: 1:24,000

Automation Date: 1999

Automation Agency: USGS/MEOGIS

Source of Data: 1:24,000 scale topo quad sheets. See drg_meta.dbf in this directory for date of each file.(Metadata for drg_meta.dbf.)

Description: DRGs are collarless digital raster graphics (DRGs), produced from 1:24,000 USGS DRGs covering Maine. These are .TIFF format images of US Geological Survey (USGS) 7.5 minute series topographic maps, clipped from USGS Digital Raster Graphics (DRGs) for Maine. DRGs do not include map collar information. Each image represents the area, of a USGS DRG, inside the map neatline and is georeferenced to the surface of the Earth. DRGs retain, from the USGS DRG source, the associated .tfw files and the GeoTIFF 0.2 specifications that define a set of TIFF tags. The tags describe all cartographic information associated with the source file. This GeoTIFF information now contains the UTM projection and the NAD83 datum. DRGs retain the 8-bit color image of the USGS DRGs. USGS DRGs employ a standardized color palette to ensure uniform colors throughout.

GOMP has created grey versions of these DRGs that work nicely as backgrounds for maps. The grey versions retain the blue color of hydrology but change other colors to a light shade of grey.

Image catalogs are available at /gis/me/drg for both of these sets of DRGs. Load drg24k for regular color DRGs and drg24k_grey for the grey version. Once loaded, the appropriate DRGs will automatically appear in your view as you zoom in.

General metadata by MEGIS is available.

Data Restrictions: May be redistributed to conservation partners. Credit MEOGIS when using. Reference or attach metadata.

Status: Complete

Projection: UTM Zone 19, meters, NAD83

File Type/Format: Geo-referenced tiff image.

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keywords: drg, digital raster graphic, topographic quadrangle, topo quad, map, USGS, Maine, 24K, 1:24,000