National aerial photography program as a geographic information system resource
The National Aerial Photography Program (NAPP) is jointly funded by Federal agencies and States that choose to participate in a 50-50 cost sharing cooperative arrangement. The NAPP is designed to acquire black-and-white (B&W) or color infrared (CIR) photography at a scale of 1:40,000. The status of NAPP flying, now going into the first year of its second 5-year cycle, is reviewed to inform the user community of NAPP's coverage. The resolution, geometric quality and flight parameters are used to estimate the system's cartographic potential to produce orthophotoquads, digital elevation models, topographic maps and digital information to meet national map accuracy standards at 1:12,000 and 1:24,000-scale and serve as a geographic information system resource. Also, a technique is presented to compute the optimum scanning spot size (15 ??m) and storage required for converting the B&W or CIR photography to digital, machine-readable pixel form. The resulting digital NAPP data are suitable for a wide variety of new applications, including use in geographic information systems.