Near-field effects of Cherenkov radiation induced by ultra high energy cosmic neutrinos

► An alternative approach to calculating Cherenkov radiation is presented. ► This approach based on FDTD method calculates near-field radiation efficiently. ► We show near-field Cherenkov pulse is a bipolar asymmetric waveform. ► Such feature is general regardless of multi-peak structure of LPM-extended showers. ► Such feature would be prevalent for ground-based neutrino detectors such as ARA.