This proposal seeks funding to refocus the former Radio Ice Cherenkov Experiment (RICE) mission into a Neutrino Array Radiofrequency Calibration platform, which will serve as a testbed for future development of an eventual large-scale neutrino radio-detection array. RICE has historically been calibrated using in-ice radio transmitters; however, these transmitters suffer additional drawbacks of having signal geometry distinctly different from the neutrino-induced air showers produced by ultra-high energy cosmic rays in the Earth's atmosphere. These extensive air showers (EAS) currently observable both via their particle flux at the South Pole surface with the IceCube Neutrino Observatory IceTop detectors, and also the flux of penetrating muons reaching IceCube 2-km below. Such air showers will also produce two radio wave signals ? one at long-wavelengths in-air due to the EAS charged particle flux undergoing geomagnetic separation, and the other in-ice produced when that particle flux impacts the surface, resulting in a Cherenkov signal identical to that expected for in-ice neutrinos. It is proposed to redirect the former RICE trigger scheme for both 'in-air' and 'in-ice' EAS, taking advantage of the existing air-shower detection capabilities offered by the combination of the IceCube and IceTop detectors. Coincident detection with the next-generation in-ice digital radio module hardware will allow complete tracking of air shower signals from several hundred meters above the ice surface to hundreds of meters below. This would establish the constant calibration beam upon which future in-ice radio detection devices can be further developed, and which must be quantified for proposed surface neutrino-detection arrays with no up-down discrimination, leaving them susceptible to fake signals from air showers. Continued reliance on students provides a broader impact to this proposed research and firmly grounds this effort in its educational mission.
