Lightning observations using broadband VHF interferometer and electric field measurements

Abstract

A broadband radio interferometer for locating lightning emissions was built and deployed at the high-altitude research station on Mount Aragats (Armenia). The instrument operates in the frequency range from 24 to 78 MHz and employs three identical broadband flat-plate antennas which are located in the horizontal plane and form two orthogonal baselines of 13 m length. The time differences of arrival of the signals at pairs of antennas determined from the peak of the cross-correlation function are used to measure the azimuth and elevation angles of the radiation source as a function of time. This paper describes the operation of the interferometer and reports observations of lightning flashes complemented by synchronous measurements of fast wideband electric field waveforms and changes in the near-surface electrostatic field. Combined analysis of these data makes it possible to identify the type of lightning discharge. The capability of the system to classify lightning types is demonstrated by example observations of an intracloud and a cloud-to-ground lightning flashes. K: Interferometry; Avalanche-induced secondary effects; Detector modelling and simulations II (electric fields, charge transport, multiplication and induction, pulse formation, electron emission, etc) 1Corresponding author.

Multi-messenger observations of thunderstorm-related bursts of cosmic rays

“…Thus, the fast waveform patterns are synchronized with particle fluxes and with slow (20 Hz) NSEF measurements. For the location of lightning discharges in Aragats, we use a short-baseline Very High Frequency (VHF) interferometer system [15]. The interferometer (frequency range from 24 to 78 MHz) employs three identical circular flat-plate antennas of 30 cm diameter, which are located in the horizontal plane and form two orthogonal baselines of 13 m in length each.…”