UNIVERSITY PARK, Pa. — Throughout most of the 20th century, aerial photography formed the building blocks of large-scale mapping activities across the country. Photos have historically been captured on large-format physical film that is now preserved in academic libraries, government archives and private collections nationwide. However, their inaccessibility often limits their usefulness, said Nathan Piekielek, head of the Donald W. Hamer Center for Maps and Geospatial Information at Penn State University Libraries and associate professor of geography.
“They are often undigitized, lack spatial reference — such as where they were captured and how they fit together — and even in digital form do not meet contemporary geospatial data standards,” Piekielek said.
Digitization of historic aerial photography has been ongoing for decades, but only recently have technological advances, including structure from motion photogrammetry and computer vision, increased the possibilities for using these archival documents both in research and for other purposes. In 2018, Piekielek began developing, testing and refining an efficient computer workflow to convert digitized archival aerial photography into geospatial data that is compatible with modern mapping and research tools. The results, he said, are not only “of comparable quality to modern datasets” but also applicable to many areas of research and public interest, such as climate change, urban expansion, golf course management, wetland and farmland preservation, cold-case crime investigation, family genealogy and others.
“This new workflow shows promise in increasing the accessibility of archival aerial photography,” he said. The workflow is being applied to historic imagery layers from Pennsylvania, and results will be posted to the Hamer Center’s ArcGIS Hub site as they become available.
Piekielek’s work is one example of research faculty conduct as part of the University Libraries, which recently announced 10 University-approved faculty librarian sabbaticals on a wide range of research topics for the 2025-26 academic year. They range from the use of artificial intelligence (AI) to create open educational resources, to the history and effects of book bans, to ways to improve upon and more widely disseminate information literacy instruction.