Digital Raster Graphics (DRG's)
Contents:
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24K DRG subset image (Annapolis MD) |
Description
A Digital Raster Graphic (DRG) is a scanned image of a USGS standard series
topographic map, including all map collar information. 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. The map is
scanned at a minimum resolution of 250 dots per inch.
DRGs have been made for most of the quadrangles in the USGS standard topographic
map series for the United States, its territories and trusts.
Source maps include:
* 7.5-minute maps of the conterminous United States, Hawaii, and limited areas of Alaska at 1:24,000- and 1:25,000-scale.
* 7.5 x 15-minute maps in limited areas of the conterminous United States at 1:25,000-scale.
* Pacific Island maps at 1:20,000-, 1:24,000-, and 1:25,000-scales.
* Puerto Rico and the Virgin Islands at 1:20,000-scale.
* Culebra, its adjacent islands, and the Island of Vieques at 1:30,000-scale.
* Alaska at 1:63,360-scale.
* 30 x 60-minute maps of the conterminous United States at 1:100,000-scale.
* 1 x 2-degree maps of the United States at 1:250,000-scale.
The source data consist of the original USGS DRG's, but have been made available
as a collarless seamless product. To see the areas where the seamless product is available, at the map interface,
open the Layer Index group, then click on the DRG 24K Coverage, 100K, or 250K Coverage Index.
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Specifications
24K, 100K, 250K Digital Raster Graphics (DRG's)
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Scale
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24K, 100K, 250K
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Projection
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UTM
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Horizontal Datum
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NAD83
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Format Information
TIFF with world file, includes a projection file.
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Download Information
24K, 100K, 250K Digital Raster Graphics (DRG's)
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Delivery
Options |
Cost |
Format |
Availability |
Free Download up to 250 MB increments |
No
Charge |
TIFF with world file |
Conterminous U.S. (see The National Map Seamless Server for current coverage)
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