Analytic Calculation of Radio Emission from Extensive Air Showers   subjected to Atmospheric Electric Fields
  We have developed a code that semi-analytically calculates the radio footprint (intensity and polarization) of an extensive air shower subject to atmospheric electric fields. This can be used to reconstruct the height dependence of atmospheric electric field from the measured radio footprint. The various parameterizations of the spatial extent of the induced currents are based on the results of Monte-Carlo shower simulations. The calculated radio footprints agree well with microscopic CoREAS simulations. 
Olaf Scholten, Gia Trinh, Krijn D. de Vries and Lucas van Sloten
astro-ph.HE