DIRBE instrument lightpath
Diffuse Infrared Background Experiment (DIRBE) was an experiment on NASA's COBE mission, to survey the diffuse infrared sky. The DIRBE instrument was an absolute radiometer with an off-axis folded-Gregorian reflecting telescope, with 19 cm diameter aperture. The goal was to obtain brightness maps of the universe at ten frequency bands ranging from the near to far infrared (1.25 to 240 micrometer). Also, linear polarization was measured at 1.25, 2.2, and 3.5 micrometers. During the mission, the instrument could sample half the celestial sphere each day.
See also 
Other infrared surveys 
External links 
||This article needs additional citations for verification. (July 2009)