Broadband electromagnetic measurement of lightning discharges

The SLAVIA sensors (Shielded Loop Antenna with a Versatile Integrated Amplifier) detect horizontal components of the magnetic field fluctuations in a frequency interval from 5 kHz to 90 MHz. The loop surface is 0.23 m², the maximum amplifier gain is 47 dB. The maximum sensitivity of the recording system is 6 nT/s/√Hz, corresponding to 1 fT/√Hz at 1 MHz. Four sensors are used for interferometry measurements.

Multidimensional ELV/VLF analyzer ELMAVAN-G (up to 25 kHz) is a clone of the ELMAVAN instrument which is being prepared by the Institute of Atmospheric Physics for the Resonance spacecraft project. We use an 10-cm spherical electric antenna located 2 m above ground (channel 0) and two 12-turn magnetic loop antennas of 4 m² with preamplifiears ( E-W and S-N components, channels 1 and 2, respectively).

Our data are completed by measurements of the vertical atmospheric electric field using a commercial field mill device (Boltek EFM-100 Atmospheric Electric Field Mill).