State Orthoquad Sites
NAIP (National Agricultural Inventory Program) is a state-federal collaboration to acquire aerial images. A plane equipted with digital cameras flies at an elevation 20,000 feet above the land. The cameras acquire images that can be manipulated in a computer so that there is no lens distortion on the margins of each image, and so that the edge of each image overlaps the edge of the adjoining images. Some states, such as Florida, joined the program early while others, such as Oregon joined late. The more recent images have a higher color resolution than do the earlier images. Some images are in black and white, some in infra-red, some in color. Some states provide imagery at no cost, others charge a fee. Some of the NAIP imagery is used by Google Earth. The following sites are correctly linked as of 31 Dec 09. Some sites refer to NAIP data as DOQQ or orthoquads. Some site provide much more than orthoquad data. Some sites are easy to use. Some are not.
Please report errors to jjackson@pdx.edu
Alabama
http://www.aces.edu/waterquality/gis_data/
Alaska
Arizona
Arkansas
http://www.cast.uark.edu/home/research/data-distribution-and-discovery.html
California
Colorado
http://coloradogis.nsm.du.edu/Portal/
Connecticut
http://www.ct.gov/dep/cwp/view.asp?a=2698&q=323342&depNav_GID=1707&depNav=|
Delaware
http://www.udel.edu/FREC/spatlab/
Florida
http://ufdcweb1.uflib.ufl.edu/ufdc/?c=flap
Georgia
Hawaii
Idaho
Illinois
http://www.isgs.uiuc.edu/nsdihome/webdocs/doqs/launchims.html
Indiana
http://inmap.indiana.edu/viewer.htm
Iowa
I have not found a site for Iowa.
Kansas
http://www.kansasgis.org/catalog/catalog.cfm
Kentucky
http://ogi.ky.gov/data/doi.htm
Louisana
Maine
Maryland
http://www.msgic.state.md.us/index.asp
Massachusetts
http://www.mass.gov/mgis/massgis.htm
Michigan
Minnesota
http://www.dnr.state.mn.us/airphotos/index.html
Mississippi
http://www.maris.state.ms.us/home.htm
Missouri
Montana
http://nris.state.mt.us/nsdi/orthophotos/
Nebraska
http://www.dnr.state.ne.us/databank/doqall.html
Nevada
http://www.nbmg.unr.edu/geoinfo/geoinfo.htm
New Hampshire
New Jersey
http://www.state.nj.us/dep/gis/index.html
New Mexico
New York
http://www.nysgis.state.ny.us/
North Carolina
North Dakota
https://www.dmr.nd.gov/ndgs/gis/GISnew.asp
Ohio
http://ogrip.oit.ohio.gov/ServicesData/GISSupportCenter.aspx
Oklahoma
http://www.okmaps.onenet.net/GIS_data.htm
Oregon
http://gis.oregon.gov/DAS/EISPD/GEO/sdlibrary.shtml
Pennsylvania
http://www.dcnr.state.pa.us/topogeo/gismaps/maps.aspx
Rhode Island
South Carolina
http://www.dnr.sc.gov/GIS/gisdownload.html
South Dakota
Tennessee
Texas
Utah
http://agrc.utah.gov/agrc_sgid/sgidintro.html
Virginia
http://www.dof.virginia.gov/gis/index.shtml
Washington
http://fortress.wa.gov/dnr/app1/dataweb/dmmatrix.html
Vermont
West Virginia
Wisconsin
http://www.dnr.state.wi.us/maps/
Wyoming