Digital orthophoto quadrangle explained
A digital orthophoto quadrangle[1] (DOQ) is aerial photography or satellite imagery that has been corrected so that its pixels are aligned with longitude and latitude lines, and have a narrowly defined region of coverage. This is a widely used format introduced by United States Geological Survey (USGS). The correction technique is called image rectification and is a large part of photogrammetry.[2]
DOQs produced by the USGS cover an area measuring 7.5-minutes longitude by 7.5-minutes latitude (the same area covered by a USGS 1:24,000-scale topographic map, also known as a 7.5-minute quadrangle) or 3.75-minutes by 3.75-minutes. The second format is also known as a digital orthophoto quarter quadrangle (DOQQ) because each covers one quarter of a quadrangle (four 1:12,000-scale DOQQs display the same area as one 1:24,000-scale DOQ).[3] [4] [5]
See also
References
- Web site: USGS GeoData Digital Orthophoto Quadrangles . USGS Fact Sheet 057-01 . United States Geological Survey . May 2001 . dead . https://web.archive.org/web/20100527103950/http://edc2.usgs.gov/pubslists/factsheets/fs05701.pdf . 2010-05-27 .
- Web site: Introduction to Photogrammetry . The Aerial Archive . . dead . https://web.archive.org/web/20060924194938/http://www.univie.ac.at/Luftbildarchiv/wgv/intro.htm . 2006-09-24 .
- Web site: USGS DOQ History . United States Geological Survey: Western Region . April 24, 2012 .
- Web site: USGS 7.5-minute maps . United States Geological Survey: Eastern Geographic Science Center . April 24, 2012 . March 29, 2014 . https://web.archive.org/web/20140329131119/http://egsc.usgs.gov/isb//pubs/booklets/usgsmaps/usgsmaps.html#7.5-minute . dead .
- Web site: DOQHEAD Toolkit . United States Geological Survey: Rocky Mountain Mapping Center . June 22, 1998 . dead . https://web.archive.org/web/20111018011505/http://rockyweb.cr.usgs.gov/software/doqhead/readme.doq . 2011-10-18 .
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