Diagnostics of plasma in the ionospheric D-region: detection and study of different ionospheric disturbance types*
1 Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
2 Astronomical Observatory, Volgina 7, 11060 Belgrade, Serbia
Received: 30 November 2016
Received in final form: 20 March 2017
Published online: 11 July 2017
Here we discuss our recent investigations of the ionospheric plasma by using very low and low frequency (VLF/LF) radio waves. We give a review of how to detect different low ionospheric reactions (sudden ionospheric disturbances) to various terrestrial and extra-terrestrial events, show their classification according to intensity and time duration, and present some methods for their detections in time and frequency domains. Investigations of detection in time domain are carried out for intensive long-lasting perturbations induced by solar X-ray flares and for short-lasting perturbations caused by gamma ray bursts. We also analyze time variations of signals used in the low ionospheric monitoring after earthquake events. In addition, we describe a procedure for the detection of acoustic and gravity waves from the VLF/LF signal analysis in frequency domain. The research of the low ionospheric plasma is based on data collected by the VLF/LF receivers located in Belgrade, Serbia.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2017