  Extensive air showers are detectable by radio signals with a radio surface
detector. A promising theory of the dominant emission process is the coherent
synchrotron radiation emitted by e+ e- shower particles in the Earth's magnetic
field (geosynchrotron effect). A radio air shower detector can extend IceTop,
the air shower detector on top of IceCube. This could increase the sensitivity
of IceTop to higher shower energies and for inclined showers significantly.
Muons from air showers are a major part of the background of the neutrino
telescope IceCube. Thus a surface radio air shower detector could act as a veto
detector for this muonic background. Initial radio background measurements with
a single antenna in 2007 revealed a continuous electromagnetic background
promising a low energy threshold of radio air shower detection. However, short
pulsed radio interferences can mimic real signals and have to be identified in
the frequency range of interest. These properties of the electromagnetic
background was being measured at the South Pole during the Antarctic winter
2009 with two different types of surface antennas. In total four antennas are
placed at distances ranging up to 400m from each other. In 2010 a small eight
channel surface detector will test an amplitude threshold self trigger strategy
with large dipole antennas on the South Pole snow ground. The installation will
be described.
