The behavior features of main ionospheric parameters along a weakly oblique path

Abstract

Analysis of the behavior of main ionospheric parameters allows us to study the physical processes in the ionosphere and develop empirical and semi-empirical the ionosphere models (IRI) with applications to the various geo- and radio-physical problems. Vertical-incidence sounding ionosondes provide the key source of information about ionospheric parameters. The worldwide network of ionosondes includes over 120 stations. On the other hand, sounding techniques using chirp-signals (linear-frequency-modulated signals) are also under development mainly for oblique-incidence sounding paths. With a small receiver-transmitter separation on the order of 100 km, weakly oblique-incidence sounding is very similar in its information capabilities to vertical-incidence sounding. Furthermore, the constraint imposed on maximum duration is removed in the case of weakly oblique sounding thus making it possible to use chirp-signals with a long baseline and to signicantly improve the signal/noise ratio. It is therefore of interest to estimate the matching weakly oblique-incidence sounding data with vertical-incidence sound (VS) data acquired by sounders, such as digisonde DPS-4. This paper presents the results derived from comparing the weakly oblique-incidence sounding data with the main vertical-incidence ionospheric parameters obtained with digital ionosonde DPS-4. The comparisons are made for the ionosheric E- and F-regions, for both quiet and disturbed ionospheric conditions. Our study reported in this paper has shown that the recorded ionospheric parameters for the ionosondes of both types are similar in their values for both quiet and disturbed days.