GPS and ionospheric scintillations

Ionospheric scintillations are one of the earliest known effects of space weather. Caused by ionization density irregularities, scintillating signals change phase unexpectedly and vary rapidly in amplitude. GPS signals are vulnerable to ionospheric irregularities and scintillate with amplitude variations exceeding 20 dB. GPS is a weak signal system and scintillations can interrupt or degrade GPS receiver operation. For individual signals, interruption is caused by fading of the in‐phase and quadrature signals, making the determination of phase by a tracking loop impossible. Degradation occurs when phase scintillations introduce ranging errors or when loss of tracking and failure to acquire signals increases…