scholarly journals A New Method to Determine the Optimal Thin Layer Ionospheric Height and its Application in the Polar Regions

2021 ◽  
Vol 13 (13) ◽  
pp. 2458
Author(s):  
Hu Jiang ◽  
Shuanggen Jin ◽  
Manuel Hernández-Pajares ◽  
Hui Xi ◽  
Jiachun An ◽  
...  
Keyword(s):  
Thin Layer ◽  
Correlation Coefficient ◽  
Total Electron Content ◽  
Mapping Function ◽  
The Arctic ◽  
Electron Content ◽  
Polar Regions ◽  
Total Electron ◽  
Ionospheric Height ◽  
The Antarctic

The conversion between the line-of-sight slant total electron content (STEC) and the vertical total electron content (VTEC) depends on the mapping function (MF) under the widely used thin layer ionospheric model. The thin layer ionospheric height (TLIH) is an essential parameter of the MF, which affects the accuracy of the conversion between the STEC and VTEC. Due to the influence of temporal and spatial variations of the ionosphere, the optimal TLIH is not constant over the globe, particularly in the polar regions. In this paper, a new method for determining the optimal TLIH is proposed, which compares the mapping function values (MFVs) from the MF at different given TLIHs with the “truth” mapping values from the UQRG global ionospheric maps (GIMs) and the differential TEC (dSTEC) method, namely the dSTEC- and GIM-based thin layer ionospheric height (dG-TLIH) techniques. The optimal TLIH is determined using the dG-TLIH method based on GNSS data over the Antarctic and Arctic. Furthermore, we analyze the relationship between the optimal TLIH derived from the dG-TLIH method and the height of maximum density of the F2 layer (hmF2) based on COSMIC data in the polar regions. According to the dG-TLIH method, the optimal TLIH is mainly distributed between 370 and 500 km over the Arctic and between 400 and 500 km over the Antarctic in a solar cycle. In the Arctic, the correlation coefficient between the hmF2 and optimal TLIH is 0.7, and the deviation between them is 162 km. Meanwhile, in the Antarctic, the correlation coefficient is 0.60, with a phase lag of ~3 months, with the hmF2 leading the optimal TLIH, and the deviation between them is 177 km.

scholarly journals Spatial and Temporal Variations of Polar Ionospheric Total Electron Content over Nearly Thirteen Years

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 540 ◽  
Author(s):  
Hui Xi ◽  
Hu Jiang ◽  
Jiachun An ◽  
Zemin Wang ◽  
Xueyong Xu ◽  
...  
Keyword(s):  
Solar Activity ◽  
Total Electron Content ◽  
Geomagnetic Storms ◽  
Weddell Sea ◽  
The Arctic ◽  
Electron Content ◽  
Spherical Cap ◽  
Total Electron ◽  
Ionospheric Total Electron Content ◽  
The Antarctic

It is of great significance for the global navigation satellite system (GNSS) service to detect the polar ionospheric total electron content (TEC) and its variations, particularly under disturbed ionosphere conditions, including different phases of solar activity, the polar day and night alternation, the Weddell Sea anomaly (WSA) as well as geomagnetic storms. In this paper, four different models are utilized to map the ionospheric TEC over the Arctic and Antarctic for about one solar cycle: the polynomial (POLY) model, the generalized trigonometric series function (GTSF) model, the spherical harmonic (SH) model, and the spherical cap harmonic (SCH) model. Compared to other models, the SCH model has the best performance with ±0.8 TECU of residual mean value and 1.5–3.5 TECU of root mean square error. The spatiotemporal distributions and variations of the polar ionospheric TEC are investigated and compared under different ionosphere conditions in the Arctic and Antarctic. The results show that the solar activity significantly affects the TEC variations. During polar days, the ionospheric TEC is more active than it is during polar nights. In polar days over the Antarctic, the maximum value of TEC always appears at night in the Antarctic Peninsula and Weddell Sea area affected by the WSA. In the same year, the ionospheric TEC of the Antarctic has a larger amplitude of annual variation than that of the TEC in the Arctic. In addition, the evolution of the ionization patch during a geomagnetic storm over the Antarctic can be clearly tracked employing the SCH model, which appears to be adequate for mapping the polar TEC, and provides a sound basis for further automatic identification of ionization patches.

scholarly journals Global Ionospheric Model Accuracy Analysis Using Shipborne Kinematic GPS Data in the Arctic Circle

2019 ◽  
Vol 11 (17) ◽  
pp. 2062
Author(s):  
Di Wang ◽  
Xiaowen Luo ◽  
Jinling Wang ◽  
Jinyao Gao ◽  
Tao Zhang ◽  
...  
Keyword(s):  
Total Electron Content ◽  
Satellite System ◽  
The Arctic ◽  
Electron Content ◽  
Ionospheric Model ◽  
International Gnss Service ◽  
Total Electron ◽  
Arctic Circle ◽  
Analysis And Evaluation ◽  
Ionospheric Models

The global ionospheric model built by the International Global Navigation Satellite System (GNSS) Service (IGS) using GNSS reference stations all over the world is currently the most widely used ionospheric product on a global scale. Therefore, analysis and evaluation of this ionospheric product’s accuracy and reliability are essential for the practical use of the product. In contrast to the traditional way of assessing global ionospheric models with ground-based static measurements, our study used shipborne kinematic global positioning system (GPS) measurements collected over 18 days to perform a preliminary analysis and evaluation of the accuracy of the global ionospheric models; our study took place in the Arctic Circle. The data from the International GNSS Service stations near the Arctic Circle were used to verify the ionospheric total electron contents derived from the kinematic data. The results suggested that the global ionospheric model had an approximate regional accuracy of 12 total electron content units (TECu) within the Arctic Circle and deviated from the actual ionospheric total electron content value by about 4 TECu.

scholarly journals Variations of f o F 2 and GPS total electron content over the Antarctic sector

2011 ◽  
Vol 63 (4) ◽  
pp. 327-333 ◽  
Author(s):  
M. Mosert ◽  
L. A. McKinnell ◽  
M. Gende ◽  
C. Brunini ◽  
J. Araujo ◽  
...  
Keyword(s):  
Total Electron Content ◽  
Electron Content ◽  
Total Electron ◽  
The Antarctic

scholarly journals Dynamics of disturbance level of total electron content at high and middle latitudes according to GPS data

2016 ◽  
Vol 2 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Наталья Перевалова ◽  
Natalia Perevalova ◽  
Илья Едемский ◽  
Ilya Edemsky ◽  
Ольга Тимофеева ◽  
...  
Keyword(s):  
Total Electron Content ◽  
Large Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Continuous Series ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Minimum Level ◽  
Total Electron ◽  
The Arctic Region

We study the level of total electron content (TEC) disturbance in ionospheric mid-latitude and high-latitude regions during 2013. TEC behavior is calculated using data from two GPS stations: MOND (Mondy) and NRIL (Norilsk). TEC variations are calculated from two-frequency phase measurements for all radio rays. We analyze the TEC variations in two time ranges: 10 and 40 min. These ranges correspond to middle- and large-scale ionospheric disturbances respectively. The TEC disturbance level is characterized using the special index WTEC. WTEC allows us to receive multi-day continuous series of average TEC variation intensity. We reveal that at high latitudes WTEC variations agree well with AE ones. The correlation between WTEC and Dst variations is much less. The minimum level of TEC disturbance is independent of the season in the Arctic region; diurnal WTEC variations are more pronounced for medium-scale ionospheric disturbances than for large-scale ones. At mid-latitudes, the WTEC behavior agrees well with the Dst and Kp variations only during strong magnetic storms. The minimum level of TEC disturbance is higher in summer than in winter. At mid-latitudes, the sunset terminator generates gravitational waves. In the Arctic region, terminator-generated waves are not observed.

SEASONAL FEATURES OF THE CORRELATION OF THE TOTAL ELECTRON CONTENT AT MAGNETICALLY CONJUGATE POINTS

2021 ◽  
Vol 44 ◽  
pp. 130-132
Author(s):  
A.V. Timchenko ◽  
◽  
F.S. Bessarab ◽  
A.V. Radievsky ◽  
◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Activity ◽  
Field Line ◽  
Correlation Coefficient ◽  
Total Electron Content ◽  
Electron Content ◽  
Geomagnetic Equator ◽  
Total Electron ◽  
Dipole Magnetic Field ◽  
Statistical Relationships

The paper presents the results of studies of the seasonal variability of statistical relationships between Magnetoconjugated Points (MCP) of the ionosphere. The analysis is based on the calculation of the correlation coefficients between the variations in the Total Electron Content (TEC) at points located on the same field line of the dipole magnetic field on both sides of the geomagnetic equator. Global TEC maps were used as initial data. For the four seasons of 2009 and 2015, the values of the Pearson’s correlation coefficient between the variations in the Total Electron Content in the MCP were calculated. For two levels of solar activity, we examined the seasonal features of statistical relationships between TEC variations at points located on the same field line of the dipole magnetic field on both sides of the geomagnetic equator. Pearson's correlation coefficient was calculated for the mean daily TEC variations. It was shown in the work that during the period of low solar activity, the correlation between the TEC variations in the MCP regions is weak or absent, except for autumn. In 2015, a significant correlation between magnetoconjugated regions is observed during all seasons, while in winter and summer they are localized at low latitudes and in spring and autumn at high and middle latitudes.

scholarly journals An Enhanced Mapping Function with Ionospheric Varying Height

2019 ◽  
Vol 11 (12) ◽  
pp. 1497 ◽  
Author(s):  
Yan Xiang ◽  
Yang Gao
Keyword(s):  
Total Electron Content ◽  
Mapping Function ◽  
Lower Latitude ◽  
Line Of Sight ◽  
Electron Content ◽  
Vertical Total Electron Content ◽  
Total Electron ◽  
Effective Height ◽  
Essential Parameter ◽  
Slant Total Electron Content

Mapping function (MF) converts the line-of-sight slant total electron content (STEC) into the vertical total electron content (VTEC), and vice versa. In an MF, an essential parameter is the ionospheric effective height. However, the inhomogeneous ionosphere makes this height vary spatially and temporally, meaning it is not a global constant. In the paper, we review several mapping functions and propose a mapping function that utilizes the ionospheric varying height (IVH). We investigate impacts of the IVH on mapping errors and on the ionospheric modeling, as well as on the satellite and receiver differential code biases (DCBs). Our analysis results indicate that the mapping errors using IVH are smaller than those from the fixed height of 450 km. The integral height achieves smaller mapping errors than using a fixed height of 450 km, an improvement of about 8% when compared with the fixed height of 450 km. And 35% smaller mapping errors were found using HmF2 at the lower latitude. Also, the effects of IVH on the satellite DCBs are about 0.1 ns, and larger impacts on the receiver DCBs at 1.0 ns.

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