APSRS state-base graphics

The National Cartographic Information Center (NCIC) is the information branch of the U.S. Geological Survey's National Mapping Division. In order to organize and distribute information about U.S. aerial photography coverage and to help eliminate aerial mapping duplication by tracking individual aerial projects, NCIC developed the Aerial Photography Summary Record System (APSRS). APSRS's principal products are State-Base Graphics (SBG), graphic indexes that show the coverage of conventional aerial photography projects over each State.