Detecting of Quasi-Periodic Oscillations in the Ionosphere within rhe Acoustic Gravity Waves Range

Abstract

A technique for estimating parameters of quasi-periodic oscillations (wave trains) in time series of Doppler shifts acquired by HF Doppler radar at vertical incidence is presented. The oscillations were extracted from the mixed signal and background noise by employing a bandpass filter together with spectral analysis. The efficiency of extracting oscillations has been shown for both acoustic and internal gravity waves. The technique has been used for extracting oscillations generated by the dawn terminator. The terminator has been demonstrated to be associated with oscillations of electron density with 6-7 and 20-min periods and amplitudes of 0.2 and 2 %, respectively.