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Space applications
OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) will be the main scientific imaging system on the orbiter of ESA's Rosetta mission to comet P/Wirtanen.
OSIRIS consists of two camera systems, the wide angle camera (WAC) designed to image large parts of the inner coma and the dust and gas emission directly above the surface of the nucleus, and the narrow angle camera (NAC), designed to study the nucleus at high resolution. A common electronics box is shared by both cameras.
The wide-angle camera is a two-mirror off-axis F/5.6 system, the primary mirror is a convex oblate ellipsoid and the secondary is a concave oblate ellipsoid. A baffle and the off-axis design provide high straylight rejection. The image is focused onto a 2048 x 2048 CCD with 14 micron pixels. The CCD readout is passed to a 14-bit analog-to-digital converter and then to a data processing unit. The field-of-view is 12.1 by 12.1 degrees and the resolution is 100 microradians per pixel. The focal length is 140 mm and the framing rate is 3.5 s per image. The wavelength range of the camera is from 250 to 1000 nm, two filter wheels hold 14 filters covering appropriate gas emission lines.
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