NAPP = National Aerial Photography Program 1:40,000 Scale: 1987 - 2007

The National Aerial Photography Program (NAPP) was coordinated by the USGS as an interagency project to acquire cloud-free aerial photographs at an altitude of 20,000 feet above mean terrain elevation. The photographs were taken with a 6-inch focal length lens and are at a scale of 1:40,000. Coverage over the conterminous United States includes both black-and-white (BW) and color infrared (CIR) aerial photographs. Film type and extent of coverage were determined by available funds and operational requirements. The NAPP program, which was operational from 1987 to 2007, consists of more than 1.3 million images. Photographs were acquired on 9-inch film and were centered over quarters of USGS 7.5-minute quadrangles.

Photographs are available as medium resolution digital images in Tagged Image File Format (TIFF). Medium resolution digital products were created with a digital single-lens reflex camera at a resolution of 63 microns, or 400 dots per inch (dpi).

国家航空摄影计划（National Aerial Photography Program, NAPP）由美国地质调查局（United States Geological Survey, USGS）牵头协调，作为跨部门合作项目，旨在获取平均地形高程以上20000英尺高度处的无云航空影像。该影像采用6英寸焦距镜头拍摄，比例尺为1:40000。覆盖美国本土的影像包含黑白（black-and-white, BW）与彩色红外（color infrared, CIR）航空摄影影像。胶片类型与覆盖范围由可用经费及作业需求决定。该项目运行周期为1987年至2007年，总计包含超过130万幅影像。航空影像采用9英寸胶片拍摄，中心对齐美国地质调查局7.5分地形图幅的四分区块。
影像以中等分辨率数字影像形式提供，格式为标签图像文件格式（Tagged Image File Format, TIFF）。中等分辨率数字产品由数码单反相机生成，分辨率为63微米，或每英寸400点（dots per inch, dpi）。