Comparison of the effect of high‐latitude and equatorial ionospheric scintillation on GPS signals during the maximum of solar cycle 24

Abstract

Radio signal scintillation caused by electron density irregularities in the ionosphere affects the accuracy and integrity of Global Navigation Satellite Systems, especially in the equatorial and high-latitude regions during solar maxima. Scintillation in these two regions, nevertheless, is usually influenced by different factors and thus has different characteristics that cause different effects on GNSS signals. This paper compares the characteristics of high-latitude and equatorial scintillation using multifrequency GPS scintillation data collected at Gakona, Alaska, Jicamarca, Peru, and Ascension Island during the 24th solar maximum. Several statistical distributions are established based on the data to characterize the intensity, duration, and occurrence frequency of scintillation. Results show that scintillation in the equatorial region is generally more severe and longer lasting, while high-latitude scintillation is, in general, more moderate and usually dominated by phase fluctuations. Results also reveal the different impacts of solar activity, geomagnetic activity, and seasons on scintillation in different geographic locations.

Feasibility of precise navigation in high and low latitude regions under scintillation conditions

“…This is a consequence of the refractive nature of the scintillation and, because of this, the L IF combination is almost unaffected by scintillation, as can be seen on its s f . This agrees with the high correlation found in Jiao & Morton (2015) between the s f values at high latitude (a proportionality factor of 1.32). Moreover, there is a good equivalence between the s f computed at 50 Hz (output from the ISMR, in blue circles) and the s f values computed from 1 Hz data (in black stars).…”

“…From the s f values one can see events of strong scintillation as it was already reported by previous works during the St. Patrick's day storm. However, as it can be seen in the top panel in red, the amplitude scintillation, from the maximum S4 values, is very low, as it is expected for high latitude (see, for instance, Jiao & Morton, 2015) and, equivalently the s IF (see Juan et al, 2017), which is depicted in black, is just of few centimetres under these severe phase scintillation conditions. In the same bottom panel of the figure the number of satellites (divided by 10) used for computing the navigation solution is depicted by a black line.…”

“…On the other hand, the ionospheric activity for the low latitude receivers is characterized in the bottom panel by means of the AATR. As it is well known (see for instance Béniguel et al, 2009;Sanz et al, 2014or Jiao & Morton, 2015 the ionospheric activity at low latitudes appears linked to equatorial plasma bubbles, which start after the sunset hours, regardless the DST (which is defined in a global context). The solar flux during this period of 2014 is maintained around 150 SFU.…”

Space Weather Quarterly Volume 14, Issue 2, 2017

“…Each of the above observing and data systems alone constitutes a significant diagnostic capability for advancing the science of space weather. When these distributed measurements are combined and integrated (and coordinated with other important observing networks and instruments, some of which are described in the commentary by Cassak et al [2017]), whole new diagnostic capabilities become possible. The electrical conductivity of the ionosphere is one of the most important variables in geospace, and a viable method for imaging it is just beginning to emerge.…”

“…The Super Dual Auroral Radar Network (SuperDARN), an international scientific network consisting of 35 high-frequency (HF) radars located in the Northern and Southern Hemispheres (NH radars in Figure 1), images the circulation pattern at polar, high and mid latitudes every 1-2 minutes (cf. Greenwald [2017] for a historical perspective on the development of SuperDARN). SuperDARN uses the Doppler effect to infer line-of-sight velocities from radar signals coherently scattered by ionospheric density irregularities embedded in the moving plasma.…”