Aerial Photography

Minnesota Department of Natural Resources - Forestry Resource Assessment Program
As an aid to forest resource management efforts, the Minnesota Department of Natural Resources Forestry Resource Assessment Program distributes color infrared aerial photography for the forested areas of northern, central, and southeastern Minnesota.  These air photos are acquired on a rotating basis, covering each of these counties about once every 8 years.  The photos are taken from 7900 feet above the ground and each 9"x9" print covers an area about 2.25 square miles at a scale of approximately 1:15,840.  They are taken in stereoscopic overlap for three-dimensional viewing.  The photos in their original form are highly detailed, showing individual trees, buildings, and vehicles.  All are available for purchase at the original size of 9"x9", and as enlargements up to 36"x36".  For more information, contact the DNR's Grand Rapids office at 218-327-4449 (ext. 0) or point your browser to MN DNR's Forestry Resource Assessment.  The Air Photos Online application allows users to access (browse/download/order) DNR aerial photography holdings for selected portions of the state.  Currently, there are more than 11,000 photos available for 25 counties.  Many more will be added, with complete coverage of the forested areas of the state to be available by summer 1999. 

National Aerial Photography Program (NAPP)
The National Aerial Photography Program (NAPP) has produced photographs of Minnesota for two recent time periods.  NAPP coverage is complete for the spring 1991-92 flight, offering both color infrared and black and white images.  The latter were used to produce the statewide Digital Orthophoto Quadrangle (DOQ) coverage.  A more recent flight started in summer 1996 and is about 90 percent complete.  The remaining flights will be attempted in summer 1998.  This coverage is black and white only, with no plans to produce digital orthophotos.  The original images from both flights are 9"x9" and cover about 25 square miles at a scale of 1:40,000.  Enlargements up to 36" can also be ordered.  See Base Maps for the 1990s to view flight status maps, documentation, frequently asked questions, pricing information, detailed ordering information, and sample photography.  Products may be ordered by contacting either of the two federal air photo processing centers: 1) the EROS Data Center (EDC) in Sioux Falls, South Dakota, 605-594-6151 or 1-800-252-GLIS, or 2) the USDA, Farm Service Agency, Aerial Photography Field Office: Aerial Photography Field Office (APFO); USDA, Farm Service Agency (FSA); 2222 West 2300 South; Salt Lake City, Utah; 84119;  801-975-3503. 

The U.S. Geological Survey (USGS) has added two new tools, Map Finder and Photo Finder, to the Global Land Information System for use in identifying and ordering USGS 7.5-minute quadrangles and NAPP photos.  Searches can be conducted by entering the name of a populated place or zip code, or by clicking on a map.  The results of each search are displayed graphically.  Map search results include the selected and surrounding quadrangles.  Photo search results show the NAPP flight line and can also display the coverage area of each photograph.  Examples of NAPP photographs and a link to the NAPP status graphic are included in Photo Finder.  A list of maps and photographs identified by the search can be generated.  Orders for maps and photographs can be placed directly through Map Finder and Photo Finder.  Ordering information, prices, and methods of payment accepted are included on the web site. 

U.S. Geological Survey (USGS) Digital Orthophoto Quadrangles (DOQs)
More recently, natural resource specialists have been using U.S. Geological Survey (USGS) Digital Orthophoto Quadrangles (DOQs) for these types of applications.  DOQs are computer readable black and white aerial photographs that have been digitally processed to remove distortion caused by topography and camera angle.  Thus, DOQs combine the image characteristics of a photograph with the geometric qualities of a map.  Each data file of a USGS DOQ covers one quarter the area of a standard 1:24,000-scale, USGS 7.5-minute quadrangle map.  Cell resolution is 1 meter.  Collections of files are formatted on CD-ROM by county and distributed through the USGS.  As of 7/25/98, DOQ data sets are available for all of Minnesota's 87 counties.  County DOQ CDs are available from the Rolla-Earth Science Information Center (ESIC), 573-308-3500 or 1-888-ASK-USGS.  County CD-ROMs must be ordered by using each county's FIPS code number.  The cost is $32 per disk, plus a $3.50 handling fee for each order shipped.  Most Minnesota counties are on one disk.  Larger, northern counties are on multiple disks.  The cost for multiple-disk counties is $32 for the first disk and $10 for each additional disk.  Thus, the St. Louis County five-disk set is $72, plus the $3.50 handling fee for each order shipped.  For more information about DOQs, refer to: Base Maps for the 1990s - DOQs. 

Metadata:
Digital Orthophoto Quadrangles (DOQs) - Standard 1-meter resolution USGS Digital Orthophoto Quadrangles (DOQs) 

Digital Orthophoto Quadrangles, 10 Meter Resolution County Files - The Minnesota Land Management Information Center (LMIC) has taken the original 1-meter resolution USGS DOQs, resampled them to 10-meter resolution and joined them into county files. 

Metropolitan Council DOQs
The Metropolitan Council contracted aerial photography of the seven-county Twin Cities metropolitan area in 1997, using NAPP photography specifications and following 1991-92 USGS DOQ flight lines.  Blueline prints are available by contacting the council's Regional Data Center or call 651-602-1140.  DOQs are currently being created from this photography.  For DOQ status information contact Tanya Mayer or call 651-602-1604.

1997 Digital Orthophotos for the Seven County Twin Cities (Minneapolis and St. Paul) Metropolitan Area in Minnesota - This data set contains 265 digital, black and white orthophoto quarter-quadrangles (DOQs), 3.75' x 3.75', covering the 7 county Twin Cities (Minneapolis and St. Paul) Metropolitan Area in Minnesota. Each image is approximately 120Mb, with a .6 meter image pixel, and available in TIFF format.