Sammendrag
This paper discusses the phase scintillation decorrelation as observed between dual and triple frequency civil GNSS signals. Comparisons are made between the characteristics of data collected in Norway during events of strong and persistent phase activity versus data collected in Hanoi during periods of vigorous amplitude and phase scintillation. Under both types of scintillation activity a degree of decorrelation is observed between the multiple carriers which is not attributable to nominal ionospheric behavior, and in turn the assumption that the ionosphere-free combination is for all intents and purposes free of the influence of the ionosphere is violated.