  We present a partial-sky survey of the radio continuum at 2.3 GHz within the
scope of the Galactic Emission Mapping (GEM) project, an observational program
conceived and developed to reveal the large-scale properties of Galactic
synchrotron radiation through a set of self-consistent surveys of the radio
continuum between 408 MHz and 10 GHz. The GEM experiment uses a portable and
double-shielded 5.5-m radiotelescope in altazimuthal configuration to map
60-degree-wide declination bands from different observational sites by
circularly scanning the sky at zenithal angles of 30 deg from a constantly
rotating platform. The observations were accomplished with a total power
receiver, whose front-end High Electron Mobility Transistor (HEMT) amplifier
was matched directly to a cylindrical horn at the prime focus of the parabolic
reflector. The Moon was used to calibrate the antenna temperature scale and the
preparation of the map required direct subtraction and destriping algorithms to
remove ground contamination as the most significant source of systematic error.
We used 484 hours of total intensity observations from two locations in
Colombia and Brazil to yield 66% sky coverage from DEC = -51.73 deg to DEC =
+34.78 deg. The zero-level uncertainty of the combined survey is 103 mK with a
temperature scale error of 5% after direct correlation with the Rhodes/HartRAO
survey at 2326 MHz on a T-T plot. The sky brightness distribution into regions
of low and high emission in the GEM survey is consistent with the appearance of
a transition region as seen in the Haslam 408 MHz and WMAP K-band surveys.
Preliminary results also show that the temperature spectral index between 408
MHz and the 2.3 GHz band of the GEM survey has a weak spatial correlation with
these regions; but it steepens significantly from high to low emission regions
with respect to the WMAP K-band survey.
