Study of the level of total electron content disturbance in the middle-latitude

Study of the level of total
electron content disturbance in
the middle-latitude
and Arctic regions by GPS data
Natalia P. Perevalova (1), Ilya K. Edemskiy (1), Olga V. Timofeeva (1, 2),
Darya D. Katashevtseva (1, 2), Anna S. Polyakova (1)
(1) Institute of Solar-Terrestrial Physics, SB RAS
(2) Irkutsk State University
Bolshie Koty, Russia
Total Electron Content (TEC)
The total electron content I is the
electron density Ne integrated along a
beam:
𝑺𝒕𝒐𝒑
𝑰=
𝑵𝒆 𝒅𝒔
𝑺𝒃𝒐𝒕
TEC calculation using the phase measurements at two GNSS frequencies:
𝟏
𝒇𝟏 𝟐 𝒇𝟐 𝟐
𝑰=
𝑳𝟏 𝝀𝟏 − 𝑳𝟐 𝝀𝟐 + 𝒄𝒐𝒏𝒔𝒕𝟏,𝟐 + 𝝈𝑳
𝟒𝟎. 𝟑𝟎𝟖 𝒇𝟏 𝟐 − 𝒇𝟐 𝟐
where 𝑳𝟏 𝝀𝟏 и 𝑳𝟐 𝝀𝟐 is the phase path increments of the radio signals; 𝑳𝟏 =
𝜟𝝋
𝜟𝝋
𝟐𝝅
and
𝑳𝟐 = 𝟐𝝅 , phase measurements by GNSS-receiver made at frequencies of f1 and f2 ;
𝒄𝒐𝒏𝒔𝒕𝟏,𝟐 , ambiguity of phase measurements; 𝝈𝑳, phase measurement error.
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WTEC index
 GPS/GLONASS station
exercises control of TEC
variations in a radius of 5001000 km;
 The time observation of a
GPS satellite at the station is
about 2-6 hours.
WTEC is multi-day series of averaged TEC disturbance
[Berngardt O.I., Voeykov S.V., Ratovsky K.G. Using a single GPS/GLONASS receiver for estimating the level of
ionospheric disturbance // XXXI URSI General Assembly and Scientific Symposium. Beijing, China. August 16-23,
2014: abstracts. 2014. GP2.31]
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Measurement data for 2013
Filtration period:
01-10 minutes medium-scale ionospheric
disturbances;
01-40 minuteslarge-scale ionospheric
disturbances.
Planetary geomagnetic indexes:
AE characterizes high latitudes; Dst, low latitudes;
Kp, middle latitudes.
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WTEC variations in March and June, 2013
middle-latitudes
high-latitudes
geomagnetic indexes
The WTEC variations for two ranges of periods (01-10 min, 01-40 min) at the NRIL,
MOND, ORDA stations and behavior of Dst, Kp, AE geomagnetic indexes. The vertical
dashed lines indicate sudden storm commencements.
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Diurnal-seasonal WTEC variations
The Diurnal-seasonal WTEC variations for ranges of periods of 01-10 min (a, c) and 01-40
min (b, d) at the NRIL (a, b) and MOND (c, d) stations. The black lines mark sunrise time at
100 km (solid) and 300 km (dashed). ST stands for the solar terminator.
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CONCLUSIONS
In Arctic region
 The minimal level of disturbance intensity does not depend on the
season.
 WTEC behavior correlates well with the variations in AE index and
does less with the behavior of the Dst index.
 WTEC variations caused by the solar terminator are absent.
In middle latitudes
 Diurnal WTEC variations are particularly pronounced over the year
and have also some seasonal features.
 The minimal level of disturbance intensity in summer is higher than in
winter.
 The solar terminator generates intense large-scale ionospheric
disturbances, but does not cause medium-scale ones.
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THANK YOU FOR YOUR
ATTENTION!
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nT
Time (t)
Day of the year (UT)
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LT, h
Solar terminator
2013, days
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Solar terminator
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Радиосигналы в ГНСС GPS и ГЛОНАСС
Все спутники GPS передают сигналы на двух одинаковых частотах:
f1 = 1575.42МГц и f2= 1227.60МГц
Спутники ГЛОНАСС передают сигналы на разных частотах в двух диапазонах.
Первый диапазон имеет центральную частоту f01= 1602 МГц,
частота передачи спутников определяется по формуле:
f1k=f01+k*Δf1
где Δf1=0,5625 МГц, k - номер частотного канала (k=-7,-6,-5,...0,...).
Второй диапазон имеет центральную частоту f02 = 1246 МГц,
частота передачи спутников определяется по формуле:
f2k=f02+k* Δf2
где Δf2=0.4375 МГц, k - номер частотного канала (k=-7,-6,-5,...0,...).
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