Abstract:
The various manifestations of TID in ionograms received with minute periodicity by Kazan (55°N, 48°E) ionosonde during winter time are considered. Besides a U-shaped TID trace traditionally observable in ionogram and corresponding intensive inhomogeneities are revealed focusing TID which corresponding low-intensity inhomogeneities. The focusing TID detection became possible owing to a gain choice which excludes restriction of amplitude of the reflected signal. Use of a three-dimensional array of amplitudes of F-region echoes has allowed to determine a basic parameters of TID such as periodicity and descent time. © 2011 IEEE.