Digital raster graphic

File:Topographic map example.png

A small portion of a USGS DRG

A digital raster graphic (DRG) is a digital image resulting from scanning a paper USGS topographic map for use on a computer. DRGs created by USGS are typically scanned at 250 dpi and saved as a TIFF. The raster image usually includes the original border information, referred to as the "map collar". The map file is UTM projected and georeferenced to the surface of the Earth. DRG's are regularly used in GIS applications. DRGs were first produced in 1995.

See also

• GeoTIFF

External links

• Libre Map Project
  • All 50 States USGS Topographic Maps on the Internet Archive
  • USGS Topographic Maps of ALL 50 States
• USGS Sites
  • Digital Raster Graphics Template:Webarchive
  • Earth Explorer (GeoTIFFs)
  • Map Locator (GeoPDFs)
• Kentucky Raster Graphics Image Download Center Template:Webarchive
• Montana State Library Digital Raster Graphics download page
• Pennsylvania Spatial Data Access sites
  • Digital Raster Graphics for PA (free)
  • Digital raster graphics without collar info for PA (free)
• FTP site, DRGs for West Virginia (free)Template:Dead linkTemplate:Cbignore
• FTP site, DRGs for New York (free)Template:Dead linkTemplate:Cbignore
• FTP site, DRGs for Virginia (free)Template:Dead linkTemplate:Cbignore
• FTP site, DRGs for Maryland (free)Template:Dead linkTemplate:Cbignore
• FTP site, DRGs for Washington DC (free)Template:Dead linkTemplate:Cbignore
• FTP site, DRGs for Delaware (free)Template:Dead linkTemplate:Cbignore
• FTP site, DRGs for North Carolina (free)Template:Dead linkTemplate:Cbignore
• Texas Natural Resources Information System
  • DRGs without collars organized by county

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