Author:
Maltseva Olga
Affiliation:
Southern Federal University, Russian Federation
Keyword(s):
GPS, Total electron content TEC, Ionospheric models, Radio wave propagation, Geomagnetic disturbances.
Abstract:
Conditions of radio-wave propagation in the ionosphere, influencing functioning of the modern navigation
and communication systems, are defined by the critical frequency foF2 and an electron density distribution
termed the N(h)- profile. In the given paper, the experimental values of the total electron content TEC(obs)
are used for their determination. It is shown that the median of the equivalent slab thickness of the
ionosphere is the good calibration factor, allowing to obtain values of foF2 from TEC(obs) of any global
map though in most cases values of foF2, the closest to foF2(obs), are provided with the JPL map. For
coordination of the N(h)-profile with values of TEC(obs), coefficient K(PL), modifying a plasmaspheric
part of a profile, is entered (up to heights of navigation and geostationary satellites). In this case, the CODE
map is the best one. It is necessary to have models of the ТЕС parameter to support navigation system
operation. It is shown that the big progress in mo
deling of this parameter is reached during the last years:
appearance of various models allows us to compare and use them at forecast ТЕС for any level of solar
activity. It is especially important, because values of solar spots and the F10.7 parameter and also
geomagnetic indexes of Kp, Dst, АЕ are well enough predicted.
(More)