Georectification:
[Archaeologist Peter] Gavette explains that a great deal of work is now being done to georectify old maps and aerial imagery on top of new maps to see if changes over time might be identified. Georectification is a process by which images, including aerial and satellite photographs, geophysics data, or scanned maps, are coordinated in order to determine the exact location of structures or landscape features. The technique is especially helpful for visualizing how places change over time, particularly when building remains are absent or overgrown, or when the topography of an area itself has shifted due to human intervention or natural events. “We’re lucky to have a wealth of cartography for the island because of its military history, so we are able to look at it through multiple layers and levels,” Gavette says. [“Letter from Alcatraz,” Matthew Brunwasser, Archaeology (September/October 2020), p. 6 of the link]
