Digital_raster_graphic Knowpia

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.

External links edit

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 Archived 2005-05-21 at the Wayback Machine
- Earth Explorer (GeoTIFFs)
- Map Locator (GeoPDFs)
Kentucky Raster Graphics Image Download Center Archived 2006-09-25 at the Wayback Machine
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)^{[permanent dead link]}
FTP site, DRGs for New York (free)^{[permanent dead link]}
FTP site, DRGs for Virginia (free)^{[permanent dead link]}
FTP site, DRGs for Maryland (free)^{[permanent dead link]}
FTP site, DRGs for Washington DC (free)^{[permanent dead link]}
FTP site, DRGs for Delaware (free)^{[permanent dead link]}
FTP site, DRGs for North Carolina (free)^{[permanent dead link]}
Texas Natural Resources Information System
- DRGs without collars organized by county

Summary

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