| Abstract: | The results of experimental studies of the fine structure of a signal in the vicinity of the maximum observed frequency (MOF)
on the Khabarovsk—Nizhny Novgorod path of oblique chirp sounding (OCS) are presented. Additional tracks were observed in the
region between the high-angle and low-angle rays during magneto-ionospheric disturbances. Under strong disturbances the ionograms
were of a spreading type in the vicinity of the MOF. The observed effect was modelled in the presence of travelling ionospheric
disturbances (TID) with different parameters. It is shown that the stratification of the high-angle ray into several additional
tracks is a maximum for TID with vertical scales
km whose wave fronts make angles about 0–10° with the horizontal line. The possibilities of using the Pedersen mode as a
probing wave for diagnostics of the fine structure of the ionosphere in the vicinity of the F-layer maximum are discussed.
Radiophysical Research Institute, Nizhny Novgorod; State Technical University of Ioshkar-Ola, Mari Republic; Institute of
Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation, Russian Academy of Sciences, Troitsk, Moscow region, Russia.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 1, pp. 3–12, January, 1998. |
