Aerial Photography - State Sources

Department of Natural Resources

• Color-infrared (CIR) photography:  The Minnesota Department of Natural Resources' Forestry Resource Assessment Unit obtains and distributes CIR aerial photography for the forested eastern half of Minnesota. In recent years, selected full or partial counties have been flown in the fall, when leaves are changing color; this timing allows maximum cover type differentiation. Print coverage at 10" x 10" is approximately 2.25 miles x 2.25 miles at a scale of approximately 1:15,840.
  
  From DNR's Photos Online website, you can view the photos at low- and medium-resolution, order a high-resolution digital version and order prints and enlargements. Alternatively, contact the DNR's Grand Rapids office at 218-327-4449.
  
  CIR orthophotos:  The Resource Assessment Unit is creating 1-meter orthophotos from the color-infrared photography. The staff scans prints at 400 pixels per inch and uses OrthoBase software to create the final product. All photos flown since 2001 are done. New projects are rectified as soon as possible after the flight; older photos are being rectified as time is available. Contact DNR's Grand Rapids office to place an order. The default format is MrSID, and the photos are packaged as ESRI image catalogs to facilitate access. Prices are determined by the size of the area covered:
  • 1-5 square miles @ $12.00 per square mile
  • 6-9 square miles @ $8.80 per square mile
  • 20-199 square miles @ $7.20 per square mile
  • 200+ square miles @ $6.80 per square mile
     
• Historic air photos:  View or download historic air photos from MnDNR's LandView website. Two majors sources are 1938-39 U.S. Department of Agriculture photos, and 1950s U.S. Geological Survey photos used to support production of USGS 1:24,000-scale maps. There are also some photos from the 1940s, and the 1960s through the 1990s. DNR has scanned the hardcopy photos as gray-scale images; each photo covers about ten square miles. Note that the photos are not georeferenced. The project is ongoing -- to see the status of which areas are covered, go to the LandView site, check the box(es) for one or more decades under "Historic Air Photos" and then click the "refresh" button (two arrows in a circle).  To retrieve a photo, click on the "info" button (an "i" with an arrow) and then on a colored dot showing a photo center location.  For more help using the site, click on "how to use" at the top left of the LandView screen.
   

Department of Transportation

If your area of interest is within a quarter- or a half-mile of a state highway, chances are good that the Minnesota Department of Transportation will have photo coverage. Mn/DOT's photos are usually taken at low altitude to be detailed enough for engineering purposes. The typical scale is 1" = 250'; other scales include 1" = 500' and 1" = 800'. Minnesota airports also have photo coverage at a a scale of 1" = 1200'. The photos may be taken either spring or fall.

Mn/DOT's archives contain some film dating back to the late 1950s and some prints dating back to the 1930s. Prints can be ordered at the standard 9" x 9" size or up to 4 times enlargement. Indexes of all Mn/DOT photos can be viewed at Mn/DOT's Air Photo Library, Photogrammetrics Unit, 7th Floor Transportation Building, 395 John Ireland Blvd., St. Paul 55155.

For more information, including cost and ordering procedure, call 651-366-5000 or (toll free) 1-888-234-1247. Mn/DOT's Photogrammetrics staff are listed on their website.
 

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