Abstract :
Scintillation of the transionospheric VHF/UHF signals caused by stochastic time-dependent variations of electron density of the ionosphere may significantly affect performance of GNSS and may be responsible for positioning degradation and even lead to the system failure. Two approaches are employed to study the effect of scintillation on the GNSS receivers. Firstly, the simulators of scintillating transionospheric signal can be used to generate the input for a receiver to investigate its behavior in various disturbed conditions, and secondly, some theoretical models of scintillating signal and a receiver tracking loop can be employed for estimating the effect (e.g. R. S. Conker et al., Radio Science, 38(1), 2003; A. O. Moraes et al., Radio Science, 49, 2014, pp. 315–329). The signal simulators can be empirically based (e.g. T. E. Humphreys et al., IEEE Journal of Selected Topics in Signal Processing, 3, 2009, pp. 707–715; T.E. Humphreys, IEEE Transactions on Aerospace and Electronic Systems, 46(4), 2010, pp. 1624–1637), or they are derived on physics, i.e., obtained as the solutions to appropriate equations of the theory of the high frequency wave propagation in the ionosphere with random local inhomogeneities of the electron density, e.g. the Hybrid Scintillation Propagation Model (HSPM) (V. E. Gherm et al., Radio Science, 40(1), 2005) or (N. N. Zernov and V. E. Gherm, Radio Science, 2014, in press).
