Very Low Frequency radio signal amplitude from the Indian navigational transmitter VTX received at Kolkata (Calcutta University) from 2019-04-25 to 2019-05-07 during the Extremely Severe Cyclone Fani of May, 2019

Published: 09-04-2020| Version 2 | DOI: 10.17632/t86fp5d45w.2
Sujay Pal,
Subrata Midya


The ZIP file contains Very Low Frequency radio signal amplitude at frequency 18.2 kHz received at Kolkata before, during and after the extremely severe cyclone Fani of May 2019 over northeastern part of the Indian Ocean. The Vertical component of VLF electric field is captured using a 3.65 metre E-field whip antenna, which is then amplified by an OP-AMP amplifier circuit before feeding into the sound card of the computer for analog to digital conversion. SpectrumLab V2.9 software is used to record the amplitude of the VLF field at desired frequency at a sampling rate of 5 Hz. The data are helpful to understand the effects of the cyclonic storm on the lower ionosphere. The ZIP file contains 13 days data and details can also be found in each file. Purpose: These data were collected to study the effects of the tropical cyclone on the lower ionosphere. Atmospheric gravity waves from the cyclone can propagate upward up to the ionospheric heights and disturb the electrical conductivity in the ionosphere. Changes in ionospheric conductivity profiles can be extracted from the VLF received signal.