The Northern Forest Historical Atlas Project will bring to life the University of Maine’s Sewall Archive of over 700,000 historical aerial photographs covering the Northern Forest region dating back to the 1940’s. While over 99% of the archive remains un-digitized and inaccessible to researchers and the broader public, these film photographs–remarkable for their detail, age, and geographic extent–provide a sweeping historical record of the Northern Forest. At native pixel resolutions of 2032 dots per inch (dpi), most photos provide 40 cm spatial detail of the historical landscape. However, given the time and labor intensity of manually digitizing large format film at high resolutions, automation of the scanning process is essential for digitization at archival scale. GeoDyn scanners are the only scanners on the market globally with automated film drive capacity, scanning photos 250 times faster than manual digitization using an otherwise state-of-the-art photo scanner.

 During the 3 month scanner lease period, 180,000 photos will be digitized, prioritizing imagery that is oldest, most spatially contiguous, and covering Areas of Interest to our Research Users. Using modern photogrammetry software, photos will be stitched together into high accuracy orthomosaics and Digital Surface Models (DSMs) to analyze long-term forest change, extending the remote sensing record of the Northern Forest by decades. Using unprecedented historical data, the goal of the Historical Atlas Project is to explore landscape-scale changes across the Northern Forest and make the Sewall Archive accessible to the research community, land managers, educators and the broader public.