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USGS › Geography › Earth Resources Observation and Science (EROS) Center |
The National High Altitude Photography (NHAP) program was in operation from 1980 to 1989. It was coordinated by the USGS to acquire aerial photography of the 48 conterminous states on a 5–7 year repeat cycle.
NHAP photography was acquired from an altitude of 40,000 feet. Two different camera systems were used to acquire simultaneous coverage at two different scales. A 6-inch focal length lens acquired black-and-white (B/W) film at an approximate scale of 1:80,000. B/W photos cover a ground area of 11 x 11 miles. An 8.25-inch lens acquired color-infrared (CIR) film at an approximate scale of 1:58,000. CIR photos cover a ground area of 8 x 8 miles.
High Resolution Scanned Product | |||
---|---|---|---|
Film Size | Micron Size | Black and white (B/W | Color-infrared (CIR) |
9 x 9 in | 21 Micron (1200 dpi) * | 117 MB | 350 MB |
14 Micron (1800 dpi) | 262 MB | 787 MB | |
7 Micron (3600 dpi) | 1.3 GB | Not Available** |
* Denotes the recommended micron size.
** Color/CIR film source is not available at a 7 micron spot size because the file size is too large and there are no advantages below the 14 micron spot size.
The above sizes may vary due to scanning more than just image data. The files are created in TIFF format. With our procedure of scanning the surrounding metadata and adding the USGS logo, the actual image size will generally be larger than the estimates above.
The file sizes are about 15 megabytes for black-and-white images and 40 megabytes for color images. The files are stored in TIFF format. The medium-resolution files are created at about 400 dpi.
All NHAP photography can be searched and ordered on EarthExplorer and GloVis.
All of the NHAP and NAPP images have been digitized. Products can be downloaded through EarthExplorer or GloVis. All NHAP medium resolution digitized images are downloadable at no cost.
NHAP photography may also be ordered through the USDA Aerial Photography Field Office (APFO) Businesses that can provide printed images from USGS digital data.
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