![](http://ac.namu.la/20230427sac/d38cc104daa9c883cd23acc5738219be648c379db7d098c596d8c4b7344c4d97.png?expires=1719795600&key=VBwcLc9P650LU8U8E-1new)
KA-80 (U-2/SR-71/Apollo) | (U-2/SR-71) | (KH-9) | ||
---|---|---|---|---|
Focal length | 610 mm (24 inches) | 760 mm (30 inches) | 1524 mm (60 inches) | |
Aperture | 174 mm (f/3.5) | 218 mm (f/3.5?) | 508 mm (f/3.0) | |
Cross-track Field of View | 108 degrees | 140 degrees | 120 degrees | |
Film width | 127 mm (5 inches) | 127 mm (5 inches) | 168 mm (6.6 inches) | |
Film length | 2005 m (6500 feet) | 3200 m (10500 feet) | 70,000 m (230,000 feet) | |
Format | 114 x 1073 mm | 114 x 1857 mm | 155 x 3190 mm | |
Film resolution | 3.7 micron | 3.7 micron | 1000:1 contrast: 3.7 micron 1.6:1 contrast: 7.4 microns | |
Depth of focus | +/- 13 microns | +/- 13 microns | +/- 11 microns | |
Format resolution | 31k x 290k = 9 Gpix | 31k x 502k = 15 Gpix | 42k x 862k = 36 Gpix | |
Frames | 1650 | 1640 | 21,000 | |
Nominal Altitude | 24.4 km (80k feet) | 24.4 km (80k feet) | 152 km (82 nm) | |
Center ground resolution | 14.8 cm | 11.9 cm | 37 cm | |
Swath | 67 km | 134 km | 555 km | |
In-track field of view, center | 4.55 km | 3.66 km | 15 km | |
Nominal overlap | 55% | 55% | 10% (each camera) | |
Area collected | 226k km2 | 362k km2 | 2x 80m km2 | |
Nominal ground velocity | 1000 m/s | 1000 m/s | 7,800 m/s | |
Cycle time | 2 sec | 1.65 sec | 1.73 sec | |
Film velocity at slit | 1.9 m/s | 2.9 m/s | 5.5 m/s | |
Maximum slit size | 7.62 mm | 12? mm | 22? mm | |
Max exposure time | 4 ms | 4? ms | 4? ms |