Rosetta's OSIRIS camera instrument

The Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) is the main imaging system of the Rosetta mission. It consists of two cameras, one narrow-angle and one wide-angle. The narrow-angle camera (NAC) is intended for high-resolution mapping of the nucleus of comet Churyumov-Gerasimenko, while the wide-angle camera (WAC) is optimized for mapping the gas and dust in space in the vicinity of the comet. When it is at the comet, OSIRIS NAC will be able to capture photos with resolutions as high as two centimeters per pixel! To capture images in a wide variety of ranges, the NAC has focusing plates that enable it to do both far-focus (2 km to infinity) and near-focus (1 to 2 km) imaging.

The information onthis page came from Keller et al. 2007, "OSIRIS - The Scientific Camera System Onboard Rosetta" (PDF)

Credit for OSIRIS data should go to "ESA / OSIRIS Team MPS / UPD / LAM / IAA / RSSD / INTA / UPM / DASP / IDA" but one could be forgiven for writing "ESA / MPS / OSIRIS Team."

Note: OSIRIS image data usually needs to be mirror-flipped. Check the orientation of the images carefully!

Camera	Narrow-angle	Wide-angle
Specifications
Field of view	2.20 x 2.22° (38.4 x 38.7 mrad)	11.35°(y) x 12.11°(x) (198 x 211 mrad)
Spectral filters	12 on 2 wheels mostly medium-band	14 on 2 wheels mostly narrow-band
Spectral range	250-1000	240-720
Pixel size (mrad)	average 0.0186	0.0965 (y) x 0.101-0.106 (x) average 0.101
Detector size (pixels)	2048 x 2048	2048 x 2048

Naming conventions for images include the date, time in hours and minutes, and a spacecraft clock count. The last two digits in the file name identify the filters used. There are two overlapping filter wheels on each camera. For true-color NAC images, look for RGB combinations made with images ending with 12/13/14 or 82/83/84.

Name	Central Wavelength (nm)	Bandwidth (nm)	Purpose
Filters: Narrow-Angle Camera
8x Neutral	640	520	Passes only 5% of light (neutral density filter)
3x NFP-Vis	600	>600	Refocusing lens for near-field imaging
2x FFP-Vis	600	600	Refocusing lens for near-field imaging
1x FFP-UV	600	>600	Clear filter for far-field imaging with wheel 2 filters
x1 FFP-IR	600	>600	Clear filter for far-field imaging with wheel 1 filters
x5 Far-UV	269.3	53.6	Surface spectral reflectance
x6 Near-UV	360.0	51.1	Surface spectral reflectance
x4 Blue	480.7	74.9	Surface spectral reflectance
x3 Green	535.7	62.4	Surface spectral reflectance
x2 Orange	649.2	84.5	Surface spectral reflectance
x7 Hydra	701.2	22.2	Water of hydration band
x8 Red	743.7	64.1	Surface spectral reflectance
5x Ortho	805.3	40.5	Orthopyroxene
4x Near-IR	882.1	65.9	Surface spectral reflectance
6x Fe2O3	931.9	34.9	Iron-bearing minerals
7x IR	989.3	38.2	IR surface reflectance

The wide-angle camera is designed mostly for studying gas emission. There are medium-band red and green filters (12 and 21, respectively), but they are not often used, and there is no blue filter. The combination of narrowband filters that is closest to the RGB combinations in the narrow-angle camera is OI/NH2/CN (17/15/14), but proceed with caution.

Name	Central Wavelength (nm)	Bandwidth (nm)	Purpose
Filters: Wide-Angle Camera
1x Empty	--	--	Empty position for use with wheel 2
x1 Empty	--	--	Empty position for use with wheel 1
3x UV245	246.2	14.1	Continuum surface spectral reflectance
4x CS	259.0	5.6	CS gas emission
5x UV295	295.9	10.9	Continuum for OH
6x OH-WAC	309.7	4.1	OH emission near nucleus
7x UV325	325.8	10.7	Continuum for OH, surface spectral reflectance
8x NH	335.9	4.1	NH gas emission
x3 UV375	375.6	9.8	Continuum for CN, surface spectral reflectance
x4 CN	388.4	5.2	CN gas emission
2x Green	537.2	63.7	Dust continuum
x5 NH2	572.1	11.5	NH2 gas emission
x6 Na	590.7	4.7	Sodium gas emission
x8 VIS610	612.6	9.8	Continuum for OI, surface spectral reflectance
x7 OI	631.6	4.0	O gas emission for dissociation of H2O
x2 Red	629.8	156.8	Broadband filter for nucleus and asteroid detection and redundancy with NAC