Measurements of the anisotropy of the cosmic background radiation and diffuse galactic emission at millimeter and submillimeter wavelengths

Results from six balloon flights using multichannel differential radiometers are reported. The results include the following. 1. A new determination of the dipole anisotropy of the cosmic background radiation (CBR) with 3.40 +/- 0.42 mK toward α = 12.1 +/- 0.24 hr, δ = -23 +/- 5^deg^ in a 1.2 to 8 cm^-1^ band and 4.7 +/- 1.4 mK toward α = 9.9^+1.7^_-1.1_ hr, δ = -38 +/- 21^deg^ between 5 and 18 cm^-1^, where the amplitudes are listed as thermodynamic temperatures. Combining these results with prior measurements of the dipole moment of the CBR at lower frequencies gives new estimates of the absolute temperature in these two bands as 2.86 +/- 0.26 K and 3.01 +/- 0.31 K under the assumption that the CBR has a Planck spectrum. Our data do not confirm a reported rise in the brightness of the CBR at short wavelengths. 2. The diffuse Galactic emission has been fitted by a secant distribution in Galactic latitude yielding Galactic pole antenna temperatures of 30 +/- 16 microK_RJ_, ν <= 8 cm^-1^, 22 +/- 8 microK_RJ_, ν <= 18 cm^-1^, 39 +/- 7 microK_RJ_, ν <= 31 cm^-1^, and 30 +/- 8 microK_RJ_, ν <= 44 cm^-1^. The Galactic emission is more complex than a simple secant distribution exhibiting a longitudinal dependence. Further, the Galactic plane at low Galactic longitude appears broadened at low frequencies ν <= 8 cm^-1^. 3. We have made maps of the brightness of the sky that show the Galactic plane as well as some previously unknown sources off the plane. 4. The emission by dust in the zodiacal plane has been measured to be -44 +/- 82 microK_RJ_ at these frequencies. This null result is consistent with extrapolations of IRAS measurements. 5. Spatial variations in atmospheric emission at altitudes of 30 to 40 km attained by balloons are reported. These measurements are useful for further planning of submillimeter measurements using balloon-borne platforms.