Validation of theα-μModel of the Power Spectral Density of GPS Ionospheric Amplitude Scintillation

Abstract

Theα-μmodel has become widely used in statistical analyses of radio channels, due to the flexibility provided by its two degrees of freedom. Among several applications, it has been used in the characterization of low-latitude amplitude scintillation, which frequently occurs during the nighttime of particular seasons of high solar flux years, affecting radio signals that propagate through the ionosphere. Depending on temporal and spatial distributions, ionospheric scintillation may cause availability and precision problems to users of global navigation satellite systems. The present work initially stresses the importance of the flexibility provided byα-μmodel in comparison with the limitations of a single-parameter distribution for the representation of first-order statistics of amplitude scintillation. Next, it focuses on the statistical evaluation of the power spectral density of ionospheric amplitude scintillation. The formulation based on theα-μmodel is developed and validated using experimental data obtained in São José dos Campos (23.1°S; 45.8°W; dip latitude 17.3°S), Brazil, located near the southern crest of the ionospheric equatorial ionization anomaly. These data were collected between December 2001 and January 2002, a period of high solar flux conditions. The results show that the proposed model fits power spectral densities estimated from field data quite well.

Climatology and modeling of ionospheric scintillations and irregularity zonal drifts at the equatorial anomaly crest region

“…It can also be interpreted from Table 4 that for a given scintillation index S 4 , the α − µ model may describe different patterns of scintillation during different solar activity levels. This is an advantage of the α − µ model against the popular Nakagami-m distribution, as also addressed by Oliveira et al (2014).…”

“…Examples of the variability in the decorrelation time as computed from GPS L1 amplitude scintillation measurements can be found in Fig. 2 of the work of Oliveira et al (2014). Additionally to the fading rate, the τ 0 parameter may be used to characterize the turbulent ionospheric medium (Carrano et al, 2012) and to predict GPS receiver cycle slipping rates (Humphreys et al, 2010).…”

“…Therefore, the increased α coefficient for the same S 4 value represents a harsher scenario for propagation, with a higher chance of the occurrence of deep fades. More details about the fit capability and approximations for theoretical work can be found in Moraes et al (2012) and Oliveira et al (2014). For a more complete scenario and using the data sets of cases listed in Table 2, Fig.…”

GPS navigation data bit decoding error during strong equatorial scintillation

“…In recent years, the availability of massive scintillation measurement data has led to numerous studies focused on the temporal and spectral characteristics of the scintillation signal amplitude and phase (Seo et al 2009(Seo et al , 2011Oliveira et al 2014;Jiao et al 2016). This work will focus on the navigation message bit decoding error (BDE) during strong equatorial scintillation.…”