Observations of Ionospheric Scintillation on GPS Signals in Japan

Abstract

: Ionospheric scintillation is the rapid amplitude and phase fluctuation of transionosphere radio waves due to local irregularity of the ionosphere. At low magnetic latitudes, amplitude scintillation often occurs after sunset around equinox periods, especially in the maximum of solar activity. GPS signal fading due to scintillation can cause receiver loss of lock. To assess the effect of ionospheric scintillation on the MTSAT Satellite-based Augmentation System (MSAS), the Electronic Navigation Research Institute (ENRI) has conducted observations of ionospheric scintillation since March 1999. Strong scintillation has been observed, some of which continued over 10 min with an elevation mask of 15 deg. The number of satellites tracked by the receiver decreased distinctly by 1–4 for about 3 h when strong scintillation occurred. This result indicates that ionospheric scintillation has the potential to affect GPS and must be taken into account for satellite-based augmentation system (SBAS) operation in the area near the magnetic equator.