Digital Raster Graphic

A Digital Raster Graphic (DRG) is a digital image (scanned version) of the USGS topographic map. DRGs are produced from USGS 1:24,000-, 1:24,000/1:25,000-, 1:63,360- (Alaska), 1:100,000-, and 1:250,000-scale topographic map series. The image inside the map neatline is georeferenced to the surface of the Earth and fit to the Universal Transverse Mercator (UTM) projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map.

A DRG may be used as a source or background layer in a geographic information system (GIS) to collect, review, and revise other digital data. A DRG can be combined with a DEM and a DOQ to produce an image with additional visual information for the extraction and revision of base cartographic information.

To learn more about DRGs, check out the DRG page at the Crater Lake Data Clearinghouse Web site.

Data Download

The San Francisquito Creek project covers six USGS 7.5-minute quadrangles. These six quads have been mosaicked together for your convenience of viewing and analyzing the information throughout the area. Data are reprojected to one standard projection (UTM NAD27 zone 10 meters). Click on the following link to download the data:

drg100k.zip (4 MB uncompressed) -- DRG with world file in TIFF format.

drg24k_gray.zip (74 MB uncompressed) -- DRG with world file in TIFF format.

drg24k.zip (20 MB uncompressed) -- DRG with world file in Mr. SID format.

Metadata

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Introduction Study Area

Framework GIS Project

Digital Data Issues

Contacts Links

U.S. Department of the Interior || U.S. Geological Survey || National Mapping Information || Western Regional Geography URL: http://geography.wr.usgs.gov/sfcreek/drg.html Designer and Maintainer: Connie Hoong, choong@usgs.gov Webmaster: Gary Sullivan, gsullivan@usgs.gov Last Modified: Friday, 07-Feb-2003 22:42:49 EST (cmh) Privacy Statement || Disclaimer || FOIA || Accessibility || Search