USGS EROS Archive - Aerial Photography - Digital Orthophoto Quadrangle (DOQs)

Science Center Objects

Digital images of aerial photos which combine the image characteristics of the photo with the georeferenced qualities of a map. (1987 - 2006)

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Quarter Quad of Digital Orthophoto Quadrangle (DOQs) Black and White

3.75-minute B/W DOQ, Washington, DC
(Public domain)

A Digital Orthophoto Quadrangle (DOQ) is a computer-generated image of an aerial photograph in which the image displacement caused by terrain relief and camera tilt has been removed. The DOQ combines the image characteristics of the original photograph with the georeferenced qualities of a map.

DOQs are black and white (B/W), natural color, or color-infrared (CIR) images with 1-meter ground resolution.

The USGS produces two types of DOQs:

3.75-minute (quarter-quad) DOQs cover an area measuring 3.75-minutes longitude by 3.75-minutes latitude. Full coverage of the U.S. was completed in 2004. Quarter-quad DOQs are available in both Native and GeoTIFF formats. Native format consists of an ASCII keyword header followed by a series of 8-bit binary image lines for B/W and 24-bit band-interleaved-by-pixel (BIP) for color. DOQs in native format are cast to the Universal Transverse Mercator (UTM) projection and referenced to either the North American Datum (NAD) of 1927 (NAD27) or the NAD of 1983 (NAD83). GeoTIFF  format consists of a georeferenced Tagged Image File Format (TIFF), with all geographic referencing information embedded within the .tif file. DOQs in GeoTIFF format are cast to the UTM projection and referenced to NAD83. The average file size of a B/W quarter quad is 40-45 megabytes, and a color file is generally 140-150 megabytes. All DOQs are distributed thru EarthExplorer as compressed files (.tgz).

Quarter Quad of Digital Orthophoto Quadrangle (DOQs) Color

3.75-minute CIR DOQ, Washington, DC
(Public domain)

 

7.5-minute (full-quad) DOQs cover an area measuring 7.5-minutes longitude by 7.5-minutes latitude. Full-quad DOQs are mostly available for Oregon, Washington, and Alaska. Limited coverage may also be available for other states. Full-quad DOQs are available in both Native and GeoTIFF formats. Native is formatted with an ASCII keyword header followed by a series of 8-bit binary image lines for B/W. DOQs in native format are cast to the UTM projection and referenced to either NAD27 or NAD83. GeoTIFF is a georeferenced Tagged Image File Format with referencing information embedded within the .tif file. DOQs in GeoTIFF format are cast to the UTM projection and referenced to NAD83. The average file size of a B/W full quad is 140-150 megabytes. All DOQs are  distributed thru EarthExplorer as compressed files (.tgz).

Coverage Maps

Coverage Maps indicating the availability of DOQ products are available for download.

Additional Information

Access Data

EarthExplorer and USGS Global Visualization Viewer (GloVis) can be used to search, preview, and download Digital Orthophoto Quadrangle (DOQs). In EarthExplorer the collection are located under the Aerial Imagery category.