  The Diffuse InfraRed Background Experiment on COBE measured the total
infrared signal seen from space at a distance of 1 astronomical unit from the
Sun. Using time variations as the Earth orbits the Sun, it is possible to
remove most of the foreground signal produced by the interplanetary dust cloud
[zodiacal light]. By correlating the DIRBE signal with the column density of
atomic hydrogen measured using the 21 cm line, it is possible to remove most of
the foreground signal produced by interstellar dust, although one must still be
concerned by dust associated with H_2 (molecular gas) and H II (the warm
ionized medium). DIRBE was not able to determine the CIRB in the 5-60 micron
wavelength range, but did detect both a far infrared background and a near
infrared background. The far infrared background has an integrated intensity of
about 34 nW/m^2/sr, while the near infrared and optical extragalactic
background has about 59 nW/m^2/sr. The Far InfraRed Absolute Spectrophotometer
(FIRAS) on COBE has been used to constrain the long wavelength tail of the far
infrared background but a wide range of intensities at 850 microns are
compatible with the FIRAS data. Thus the fraction of the CIRB produced by SCUBA
sources has large uncertainties in both the numerator and the denominator.
