Though cataloged within the USS Petrof Bay (CVE-80) collection, this item is a technical reference chart used to train aerial reconnaissance personnel, illustrating the ground coverage achieved by K-17, K-18, and F-56 aerial cameras at varying altitudes and focal lengths. Documents like this supported the vital work of photographic interpretation during World War II, helping planners select the right camera and altitude combination for a given reconnaissance mission. Project: 218459