NAPL On-Line allows you to search and retrieve metadata for over 3 million air photos using several criteria, including official place name, geographical coordinate, National Topographic System map number, or Roll and Photo number. NAPL On-Line visually depicts the "footprint" of air photos on a seamless map background. After a search is completed, the air photos can be ordered from the National Air Photo Library.

While the National Air Photo Library endeavours to display the coverage of each air photo as accurately as possible within the NAPL On-Line application, the outline depicted is a theoretical "footprint" based on a number of variables such as aircraft altitude, camera focal length and ground elevation. Variations in the methods used to record flight line data as well as the process used to digitize this data will result in differences between the theoretical "footprint" and the actual air photo coverage. To enable you to select the proper photo for your requirements, please ensure that your area of interest lies well within the boundary of the "footprint", and carefully read the instructions for NAPL On-Line prior to ordering.