Digital Raster Graphic (DRG) |
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A Digital Raster Graphic (DRG) is a digital image (scanned version) of a 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. DRGs for Lake Tahoe are available here as TIFF and MrSID images of USGS 7.5-minute topographic maps, along with its associated world file in text. The world file can be used by some software to place the DRGs in digital space. DRGs in MrSID format can be viewed with MrSID viewers from LizardTech, which are available for free from their website. For more information about DRGs, please visit http://craterlake.wr.usgs.gov/drg_brief.html. DRG Download
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U.S. Department of the Interior
|| U.S. Geological Survey
|| National Mapping Information
|| Western Regional Geography URL: http://tahoe.usgs.gov/DRG.html Page Contact: T. Mathiasmeier, tmathias@usgs.gov Last Modified: Monday, 26-Apr-2004 16:25:40 EDT (tm) Privacy Statement || Disclaimer || FOIA || Accessibility || Web Team || Feedback || Search |