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The Imagery_FilmCameraPhotoCenter feature class records the center point locations of single frame aerial photography exposures collected by the USDA Forest Service. This aerial photography was collected to support various planning, monitoring and inventory efforts in support of the agency mission and public projects across the nation.The aerial photo center points have been derived from flight line indexes (line indexes, mosaic indexes or spot indexes); the Structure from Motion (SfM) process; or by individual photo placement. When available, flightline index maps were scanned and georeferenced, the flightlines digitized, and the photo center locations estimated by assuming uniform placement of the aerial photos along the appropriate flightlines. The Structure from Motion process was used when flightline index maps were not available: The film was scanned, the SfM software was used to create a low-resolution photo mosaic, the mosaic was georeferenced, and the SfM software used to estimate the center point location for each aerial photo in the mosaic. When these methods could not be used, individual photos were scanned, georeferenced, and the photo center location determined.The aerial photos cataloged in this index were collected to provide stereoscopic resource photography for large areas such as entire national forests or to support specific projects such as timber sales, archeology, campground renovation or road construction activities.This catalog does not include the actual images but contains information for locating or ordering digital copies of images from the US Department of Agriculture (USDA), Farm Service Agency (FSA), Aerial Photography Field Office (AFPO) in Salt Lake City, Utah.Most Forest Service film acquired after 1954 is stored at APFO, where it is being scanned and converted to digital copies. Forest Service film older than 1955 is located at the National Archive and Records Administration (NARA). By 2028, all Forest Service film will be sent to NARA for permanent storage. Some of the film sources in the Forest Service collection are affected by vinegar syndrome and other forms of degradation, which threaten the long-term accessibility of the original film.The Imagery_FilmCameraPhotoCenter feature class is a component part of a catalog of images produced from scanning of analog aerial photos acquired with film cameras by the US Forest Service. The feature class Imagery_FilmCameraMission records the boundaries of the project areas in which the aerial photos were collected and general characteristics of the photos collected for each mission. |