Proxy Index Derived From All Sky Imagers for Space Weather Impact on GPS

Abstract

Global Positioning System (GPS) signals passing through the auroral ionosphere, which exhibits multiscreen electron density structuring, maybe scintillated causing observation and possibly positioning errors. It is advantageous to determine the magnitude of GPS signal scintillation associated with a given level of auroral brightness observed around the signal's ionospheric pierce point (IPP). Such information would enable the exploitation of auroral image observations in space weather monitoring and help in assessment of impact on infrastructure/services reliant on GNSS. Studies have observed a general positive correlation between auroral brightness and GPS phase scintillation but not a definite one-to-one relationship. In this study a correlation coefficient of 0.38 is observed between the phase scintillation and the level of auroral arc brightness around the GPS signal's raypath for a data set of 292 events in the Canadian sector. Alternatively, a new pseudo-scintillation index, Rate of change of Brightness index, is introduced in this study which is derived from the changing auroral brightness around the satellite's IPP. This Rate of change of Brightness index is highly positively correlated (correlation coefficient: 0.75) with GPS phase scintillation. Spatial and spectral relationships between auroral brightness around the satellite's IPP and phase scintillation were also analyzed. It is observed that probability of GPS signals experiencing phase scintillation is high when the auroral brightness around the satellite's IPP has dominant fluctuations in the frequency band~0.06 to 0.16 Hz. These results indicate that GPS signal scintillation is related to the dynamics of the brightness around the satellite's IPP as the satellite signal propagates through the aurora.

Nightside High‐Latitude Phase and Amplitude Scintillation During a Substorm Using 1‐Second Scintillation Indices

“…Polar cap arcs are also associated with scintillation (Jayachandran et al., 2017; Wang et al., 2021). The scintillation tends to occur on the leading and trailing edges of auroral forms, suggesting that density irregularities develop at density gradients that are created by particle precipitation (Loucks et al., 2017; Mrak et al., 2018; Mushini et al., 2018; Semeter et al., 2017; van der Meeren et al., 2015).…”

GPS Scintillations and TEC Variations in Association With a Polar Cap Arc

“…Zhang et al (2017) defined the polar cap hot patch and suggested it may associate with polar cap arcs and stronger scintillations. Furthermore, the positive relations of auroral emissions and phase scintillations have been statistically established, generally higher values of emission intensity correspond to stronger phase scintillation (Kinrade et al, 2013;Mushini et al, 2018). Additionally, Kintner et al (2002) and Jayachandran et al (2009) reported TEC variations due to an auroral arc, but there were no analysis on scintillations.…”

“…At high latitudes, the effects of scintillations associated with a variety of ionospheric irregularities have been investigated in many studies (e.g., Jayachandran et al, 2017;Jin et al, 2014Jin et al, , 2015Jin et al, , 2016Moen et al, 2013;Mushini et al, 2018;Oksavik et al, 2015;van der Meeren et al, 2014van der Meeren et al, , 2015Wang et al, 2016;and references therein). In this study, we are focusing on the polar cap arc, which is an aurora arc in the polar cap region that is primarily formed during northward interplanetary magnetic field (IMF) and under a quiet geomagnetic condition (e.g., Fear et al, 2014;Kullen, 2012;Xing et al, 2018;Zhu et al, 1997).…”