Gather, analyze and verify data to make sure maps are accurate.
Lays out and matches aerial photographs to form photographic mosaic of geographic area for subsequent use in photogrammetric activities, such as topographical mapping: Lays out photographic prints on table according to sequence in which photographs were taken during flightpath of aircraft. Examines prints to locate established landmarks and notes absence of normal overlap of adjacent prints indicating deflection of aircraft from prescribed flightpath. Locates and marks specified reference points, such as structures and highway or rail junctions. Computes and measures scaled distances between reference points to establish exact relative position of adjoining prints. Trims excess from edges of overlapping prints and glues prints to backing board, maintaining scaled distances between reference points and alignment of adjoining prints.