  We report the first measurements of anisotropy in the cosmic microwave
background (CMB) radiation with the Arcminute Cosmology Bolometer Array
Receiver (ACBAR). The instrument was installed on the 2.1m Viper telescope at
the South Pole in January 2001; the data presented here are the product of
observations up to and including July 2002. The two deep fields presented here,
have had offsets removed by subtracting lead and trail observations and cover
approximately 24 deg^2 of sky selected for low dust contrast. These results
represent the highest signal to noise observations of CMB anisotropy to date;
in the deepest 150GHz band map, we reached an RMS of 8.0\mu K per 5' beam. The
3 degree extent of the maps, and small beamsize of the experiment allow the
measurement of the CMB anisotropy power spectrum over the range \ell = 150-3000
with resolution of \Delta \ell=150. The contributions of galactic dust and
radio sources to the observed anisotropy are negligible and are removed in the
analysis. The resulting power spectrum is found to be consistent with the
primary anisotropy expected in a concordance \Lambda CDM Universe.
