Особенности описания ионосферных неоднородностей высоких широт с помощью ROTI индекса по данным навигационных систем GPS и Transit/Парус

Abstract

The paper compares the possibilities for describing high latitude ionospheric irregularities with characteristic horizontal scales of several tens of kilometers with ROTI index, based on the reception of GPS and Parus/Transit signals. It is shown that in the case of GPS, the maximum ROTI values are observed in the regions of the auroral oval and polar cap, while for Parus/Transit there is an additional region associated with the field aligned enhancement of phase and TEC fluctuations for observations in the direction of the magnetic zenith. Such differences are associated with the inclinations of the orbits of low-orbit (Parus/Transit) and medium-orbit (GPS) satellites, the latter of which does not effectively scan the magnetic zenith region for receivers located at high latitudes. In addition, there are significant, up to 2 times, differences in the ROTI index values according to GPS and Parus/Transit data, which is associated with different speeds of movement of satellite ionospheric piercing points and their mutual orientation with the plasma drift speed in high latitudes, which can lead to a mismatch in the characteristic horizontal scales of irregularities to which the ROTI index demonstrates maximum sensitivity.