New Results on Ionospheric Irregularity Drift Velocity
Estimation Using Multi-GNSS Spaced-Receiver
Array During High-Latitude Phase Scintillation
, Y. Jade Morton
, and Donald Hampton
Smead Aerospace Engineering Sciences Department, University of Colorado Boulder, Boulder, CO, USA,
Institute, University of Alaska Fairbanks, Fairbanks, AK, USA
The spaced-receiver technique using Global Navigation Satellite Systems (GNSS) receivers offers
an inexpensive approach for estimating ionospheric irregularity velocity during ionospheric scintillations. Our
previous work has demonstrated that correlative studies of the GNSS carrier phase variations can be used
to derive irregularity drift velocity at high latitudes. This study expanded upon our previous projects by
incorporating Global Navigation Satellite System (GLONASS) signals, investigation on ionospheric irregularity
height assumption, and all-sky imager measurements into the methodology. A case study is presented
based on Global Positioning System, Galileo, and GLONASS measurements during a geomagnetic storm event
on 20 December 2015, obtained from a closely spaced receiver array at Poker Flat Research Range near
Fairbanks, Alaska. The GNSS-estimated irregularity drift velocities are in general agreement with the
measurements from the Poker Flat Incoherent Scatter Radar and the Poker Flat all-sky imager. The study also
shows that the irregularity altitude assumption will not lead to signiﬁcant variations in the irregularity drift
velocity estimates, especially for satellites with relatively high elevations. The techniques presented in this
paper demonstrate that GNSS receiver arrays can be used as powerful means to monitor the ionospheric
plasma dynamics during space weather events.
Compact and inexpensive in nature, Global Navigation Satellite Systems (GNSS) receivers have gained popu-
larity as distributed sensors for space weather and ionosphere monitoring in recent years (Basu et al., 2002;
Van Dierendonck, 2005). In particular, researchers utilize the transionospheric GNSS radio signals to sense
plasma motion via spaced-receiver techniques during ionospheric scintillations (Ledvina et al., 2004; Spatz
et al., 1988; Vacchione et al., 1987). Historically, this technique has been focused on equatorial zonal drift velo-
city estimation using Global Positioning System (GPS) L1 signal intensity measurements during amplitude
scintillations (Basu et al., 1991; Kil et al., 2000, 2002; Kintner et al., 2004; Otsuka et al., 2006). But in high-
latitude regions, where phase scintillations are more prominent than amplitude scintillations, it is more
appropriate to use carrier phase signals for spaced-receiver studies (Aarons, 1997; Aquino et al., 2005;
Azeem et al., 2013; Doherty et al., 2003; Jiao et al., 2013; Jiao & Morton, 2015; Skone et al., 2008).
In our previous studies, ground work has been laid out for using both GPS and Galileo carrier phase signals to
estimate the ionospheric drift velocities based on a multi-GNSS spaced-receiver array (Wang & Morton, 2015,
2017). Following the same approach, this paper presents recent updates and new results on this topic, focus-
ing on three major aspects. First, GLONASS signals have been utilized in high-latitude GNSS spaced-receiver
studies for the ﬁrst time. Second, variation in estimated drift velocities caused by different ionospheric irre-
gularity altitude assumptions is addressed. This is a less discussed issue in the literature, as the irregularity
altitude is often empirically assumed to be near the nominal peak F region altitude. And lastly, all-sky imager
(ASI) data are employed to demonstrate the auroral emission during a geomagnetic storm and are eventually
used to perform cross comparison against the GNSS-estimated ionospheric irregularity drift velocities.
During a geomagnetic storm event on 20 December 2015, the drift velocities are estimated from GPS,
GLONASS, and Galileo satellites under a range of irregularity altitude assumptions. Following the comparison
scheme proposed in Wang and Morton (2017), a cross comparison is conducted against the measurements
provided by the colocated Poker Flat incoherent scatter radar (PFISR) and the results show general agree-
ment between the two approaches. In addition, the GNSS-estimated results are further cross-compared
against the continuous images from the ASI on-site.
WANG ET AL. 228
URSI General Assembly and
Scientiﬁc Symposium (2017)
• GLONASS signals are used to ﬁnd
high-latitude ionospheric irregularity
drift velocity using spaced-receiver
technique for the ﬁrst time
• Variations in the estimated drift
velocities caused by different
ionospheric irregularity altitude
assumptions have been accounted for
• Estimated ionospheric irregularity drift
velocities are compared favorably
against the ASI- and PFISR-measured
Wang, J., Morton, Y. J., & Hampton, D.
(2018). New results on ionospheric
irregularity drift velocity estimation
using multi-GNSS spaced-receiver array
during high-latitude phase scintillation.
Radio Science, 53, 228–240. https://doi.
Received 17 OCT 2017
Accepted 2 FEB 2018
Accepted article online 9 FEB 2018
Published online 24 FEB 2018
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