Data Layer: DIGITAL RASTER GRAPHIC
You are invited to read the definitions of terms used in this data standard.
||Digital Raster Graphic (DRG)|
||Digital maps created by the U.S. Geological Survey (USGS). These are scanned, georeferenced copies of the USGS topographic maps. They are available in the standard topographic map scales and are in a GeoTIFF format.|
EROS Data Center - DOQs are available for download from USGS Earth Explorer.
The National Map - DRGs Available Online.
|Historical Data||For information on past versions of this standard, contact the National Data Administrator, Branch of Data and Systems Services, Division of Information Resources and Technology Management|
Part 270, FW 6, Data Management and Standards, has been superceded by Part 274, FW 2, Establishing Service Data Standards.
Graphics (DRG) - DOQs are available for download from USGS Earth Explorer.
DRG Program Overview - history, description, georeferencing information, updates and product maintenance, and DRGs from non-USGS sources.
DRG Fact Sheet - General information on DRGs; very readable.
||The USGS DRGs are automated to strict standards. They are used frequently
as a locational backdrop, but also as a source for on-screen digitizing and updating
existing files. Any DRGs used by Service personnel should either be obtained from the USGS
or, at a minimum, have been scanned to meet USGS standards. Tools for utilizing these
data, converting the data to formats used by different GIS systems, and evaluating the
accuracy of DRGs created by offices other than the USGS are listed below.
The DRG files obtained from the USGS, rather than a re-seller, are generally in the UTM coordinate system.
||The USGS DRGs can be viewed with a variety of commercial software packages, as well as with a free USGS viewer, at http://earthexplorer.usgs.gov/ and http://nationalmap.gov/viewer.html|
||March 21, 2000|
||January 28, 2011|
||Chris Lett, National FWS GIS Coordinator, Branch of Data and System Services, Division of Information Resources and Technology Management.|