  A surface array of radio antennas will enhance the performance of the IceTop
array and enable new, complementary science goals. First, the accuracy for
cosmic-ray air showers will be increased since the radio array provides a
calorimetric measurement of the electromagnetic component and is sensitive to
the position of the shower maximum. This enhanced accuracy can be used to
better measure the mass composition, to search for possible mass-dependent
anisotropies in the arrival directions of cosmic rays, and for more thorough
tests of hadronic interaction models. Second, the sensitivity of the radio
array to inclined showers will increase the sky coverage for cosmic-ray
measurements. Third, the radio array can be used to search for PeV photons from
the Galactic Center. Since IceTop is planned to be enhanced by a scintillator
array in the near future, a radio extension sharing the same infrastructure can
be installed with minimal additional effort and excellent scientific prospects.
The combination of ice-Cherenkov, scintillation, and radio detectors at IceCube
will provide unprecedented accuracy for the study of highenergy Galactic cosmic
rays.

Instrumentation and Methods for Astrophysics;High Energy Astrophysical Phenomena