the electron density environment and play an important role spreading radio signals
propagating through the ionosphere. A method combining spectral analysis and cross-
correlation is applied to time series of ionospheric characteristics (ie, MUF (3000) F2 or foF2)
using data of the networks of ionosondes in Europe and South Africa to estimate the period,
amplitude, velocity and direction of propagation of TIDs. The method is verified using …