  The ARIANNA detector aims to detect neutrinos with energies above
\SI{e16}{eV} by instrumenting 0.5 Teratons of ice with a surface array of a
thousand independent radio detector stations in Antarctica. The Antarctic ice
is transparent to the radio signals caused by the Askaryan effect which allows
for a cost-effective instrumentation of large volumes. Several pilot stations
are currently operating successfully at the Moore's Bay site (Ross Ice Shelf)
and at the South Pole. As the ARIANNA detector stations are positioned at the
surface, the more abundant cosmic-ray air showers are also measured and serve
as a direct way to prove the capabilities of the detector. We will present
measured cosmic rays and will show how the incoming direction, polarization and
electric field of the cosmic-ray pulse can be reconstructed from single
detector stations comprising 4 upward and 4 downward facing LPDA antennas.
