Speaker
Description
In-ice radio experiments such as the Askaryan Radio Array at the South Pole and the Radio Neutrino Observatory in Greenland rely on an accurate understanding of radio-wave propagation through polar ice. In particular, the density and corresponding index-of-refraction profile of the near-surface firn affect the propagation of upward-going and reflected radio signals, as well as radio signals generated by cosmic-ray air showers, including the evolution of the shower cores that propagate into the ice.
The Center for Remote Sensing and Integrated Systems (CReSIS) at the University of Kansas has collected a large set of airborne radar data over Antarctica and Greenland. We are analyzing CReSIS echograms to identify radar reflections from subsurface layers to estimate their absolute reflectivity from the measured return power.
At the IPA Symposium, we present the methodology and preliminary results from our analysis of CReSIS radar data. We find that the absolute reflectivity of internal layers is approximately -60 dB, indicating that radio backgrounds from impacting air shower cores, which are upward reflected from below typical radio arrays, should be negligible.