2006 Minnesota Aerial Photography
In fall 2006, new aerial photography was acquired over 40 Minnesota counties to validate or collect road centerline data in support of the U.S. Census Bureau MAF/TIGER Accuracy Improvement Project (MTAIP). The Census Bureau worked through their prime contractor, The Harris Corporation, to verify that all local street centerline GIS files meet or exceed the spatial accuracy requirement of 7.6 meters. The Harris Corporation contracted with MacDonald, Dettwiler & Associates (MDA) of British Columbia to acquire aerial photography to be used in the evaluation/data development process for selected counties. Depending on funding, these photos may be available to the public in future (see last paragraph below).
MDA flew the areas at a flight height of 27,000 feet with a Zeiss Top 15 camera. The film was scanned at a resolution of 14 microns to yield a ground sample distance of 1 meter pixel resolution on the resulting digital imagery. The digital imagery was processed in DOQQ (3.75’ X 3.75’) format with overedge coverage. The accuracy of the digital orthoimagery is 5 meters at CE95 (95% Circular Error). The data is available in GeoTIF format, NAD 83, UTM coordinates. The photography was flown between August and November with natural color film. The coverage in Minnesota is approximately 45,081 square miles. A graphic below illustrates the coverage of the photography (Editor’s Note: a legend for the colors used on the graphic was not available).
Negotiations for Public Domain Availability
MDA owns all of the imagery and has licensed it to Harris, but it is not in the public domain. However, the vendor is willing to negotiate the release of the data to the public domain. MDA made a similar offer with Arizona at a nominal cost of $2 per square mile. There is currently an effort underway to solicit potential partners to fund the acquisition of all of the Minnesota imagery. If you or your agency are interested in helping to fund the purchase of the aerial photography, please contact Chris Cialek at firstname.lastname@example.org or 651-201-2481.