Limitations in GPS reciever tracking performance under ionospheric scintillation conditions

GPS receiver tracking performance can be degraded during periods of enhanced ionospheric activity when small-scale scintillation effects (phase and amplitude variations) may be observed in the high latitude auroral region and the low latitude equatorial anomaly region. During periods of intense scintillation the availability of carrier phase observations may be limited through loss of signal lock, with a significant impact on precise positioning applications. Such effects have a larger impact on the L2 tracking performance where codeless and semi-codeless technologies are employed to extract the encrypted L2 signal. The tracking performance of a given receiver depends not only on the magnitude of scintillation activity observed, but also on the receiver tracking capabilities. Tracking performance can vary significantly between receivers under identical scintillation conditions. In this paper the impact of scintillation effects on GPS receiver tracking performance is investigated in both the equatorial and high latitude aurora! regions. A comparison of receiver technologies is also conducted using both codeless and semi-codeless GPS receivers. Performance comparisons and tracking statistics are established and interpreted with respect to GPS network applications and the availability of GPS observations at solar maximum. (C) 2001 Elsevier Science Ltd. All rights reserved.