Total electron content driven data products of SIMuRG

2020 ◽  
Author(s):  
Artem Vesnin ◽  
Yury Yasyukevich ◽  
Boris Maletckii ◽  
Alexander Kiselev ◽  
Ilya Zhivetiev ◽  
...  
Keyword(s):  
Total Electron Content ◽  
Large Scale ◽  
Reference Level ◽  
Electron Content ◽  
Russian Science ◽  
Total Electron ◽  
Is Implementation ◽  
Data Product ◽  
Ionospheric Variability ◽  
Data Products

<p>System for the Ionosphere Monitoring and Researching from GNSS (SIMuRG, see <em>https://simurg.iszf.irk.ru</em>) has been developed in ISTP SB RAS. The system servers as proxy for the RINEX data of global GNSS receivers network. SIMuRG automatically downloads, process and visualize GNSS data. Despite of the system takes routine processing task from the researches, which is valuable by itself, it provides newly developed and improved data products. All data products are based on total electron content (TEC) calculated from RINEX and global ionospheric maps GIM. The first data product is ionospheric variations (TEC variations). The variations are widely used for ionospheric studies, but SIMuRG performs calculation using the filtration that suits TEC data the best way. Before new filtration technique was applied major unphysical artifacts were detected in the data. The artifacts could even prevent from correct interpretation of processing results. The variations together with widely used ROTI index which is also implemented in the system helps to study ionospheric variability. The second data product is newly developed “adjusted TEC”. For that we use GIM to force all TEC series from different site-satellite line-of-sights have one reference level. While the reference level is the same, adjusted TEC leaves all the peculiarities exhibited in different TEC series unaffected. Adjusted TEC broaden ionospheric maps capability near the GNSS stations improving time resolution up to 30 seconds and giving better space resolution. The third data product is implementation of D1 method which calculates ionospheric irregularities motion velocity. D1 shows velocity vector while variations show only amplitude of the irregularity (deviation from the background). D1 calculation is designed in the way that it possible to choose scale of the disturbance to study. It makes possible to study the disturbances of different physical origin. D1 is able to show global ionospheric dynamics and can help detect traveling ionospheric disturbances of various scales. The data described above are attribute by the interactive experimental geometry plots, which might consider as one more data product. The geometry plots might be useful since the TEC data cover area of several thousands kilometers across. The fourth data product is global and regional electron content (GEC and REC), see <em>https://simurg.iszf.irk.ru/gec</em> for reference. SIMuRG provides interactive plots of the GEC and REC. While TEC shows the number of electrons in a given direction (surface density), GEC and REC show amount of a plasma in a volume. GEC is weighted sum of the TEC around the globe, REC – in some geographical region. GEC and REC suits for large scale long-living ionospheric variations studies. Using REC we detect after-storm plasma density change in equatorial ionosphere. There is an option to choose region for REC using geographic and geomagnetic coordinates. We also developed the interface for ionospheric events tracking and submission. We hope to use the events database for machine learning purpose. We hope all above newly developed and improved TEC based data products find application among researches.</p><p>This work was performed under the Russian Science Foundation Grant No. 17-77-20005.</p>

scholarly journals Ionospheric response to magnetar flare: signature of SGR J1550–5418 on coherent ionospheric Doppler radar

2017 ◽  
Vol 35 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Ayman Mahrous
Keyword(s):  
Total Electron Content ◽  
Large Scale ◽  
Doppler Radar ◽  
Ionospheric Disturbance ◽  
Eastern Mediterranean ◽  
Small Scale ◽  
Electron Content ◽  
Total Electron ◽  
Ionospheric Perturbations ◽  
Onset Phase

Abstract. This paper presents observational evidence of frequent ionospheric perturbations caused by the magnetar flare of the source SGR J1550–5418, which took place on 22 January 2009. These ionospheric perturbations are observed in the relative change of the total electron content (ΔTEC/Δt) measurements from the coherent ionospheric Doppler radar (CIDR). The CIDR system makes high-precision measurements of the total electron content (TEC) change along ray-paths from ground receivers to low Earth-orbiting (LEO) beacon spacecraft. These measurements can be integrated along the orbital track of the beacon satellite to construct the relative spatial, not temporal, TEC profiles that are useful for determining the large-scale plasma distribution. The observed spatial TEC changes reveal many interesting features of the magnetar signatures in the ionosphere. The onset phase of the magnetar flare was during the CIDR's nighttime satellite passage. The nighttime small-scale perturbations detected by CIDR, with ΔTEC/Δt  ≥  0.05 TECU s−1, over the eastern Mediterranean on 22 January 2009 were synchronized with the onset phase of the magnetar flare and consistent with the emission of hundreds of bursts detected from the source. The maximum daytime large-scale perturbation measured by CIDR over northern Africa and the eastern Mediterranean was detected after ∼ 6 h from the main phase of the magnetar flare, with ΔTEC/Δt  ≤  0.10 TECU s−1. These ionospheric perturbations resembled an unusual poleward traveling ionospheric disturbance (TID) caused by the extraterrestrial source. The TID's estimated virtual velocity is 385.8 m s−1, with ΔTEC/Δt  ≤  0.10 TECU s−1.

scholarly journals Annual and semiannual variations of vertical total electron content during high solar activity based on GPS observations

2011 ◽  
Vol 29 (5) ◽  
pp. 865-873 ◽  
Author(s):  
M. P. Natali ◽  
A. Meza
Keyword(s):  
Solar Activity ◽  
Total Electron Content ◽  
Principal Component ◽  
High Solar Activity ◽  
Electron Content ◽  
Vertical Total Electron Content ◽  
Total Electron ◽  
Ionospheric Variability ◽  
Low Latitudes ◽  
Sudden Decrease

Abstract. Annual, semiannual and seasonal variations of the Vertical Total Electron Content (VTEC) have been investigated during high solar activity in 2000. In this work we use Global IGS VTEC maps and Principal Component Analysis to study spatial and temporal ionospheric variability. The behavior of VTEC variations at two-hour periods, at noon and at night is analyzed. Particular characteristics associated with each period and the geomagnetic regions are highlighted. The variations at night are smaller than those obtained at noon. At noon it is possible to see patterns of the seasonal variation at high latitude, and patterns of the semiannual anomaly at low latitudes with a slow decrease towards mid latitudes. At night there is no evidence of seasonal or annual anomaly for any region, but it was possible to see the semiannual anomaly at low latitudes with a sudden decrease towards mid latitudes. In general, the semiannual behavior shows March–April equinox at least 40 % higher than September one. Similarities and differences are analyzed also with regard to the same analysis done for a period of low solar activity.

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.

scholarly journals Spatial gradient of total electron content (TEC) between two nearby stations as indicator of occurrence of ionospheric irregularity

2018 ◽  
Author(s):  
Teshome Dugassa ◽  
John Bosco Habarulema ◽  
Melessew Nigussie
Keyword(s):  
Total Electron Content ◽  
Large Scale ◽  
Equatorial Region ◽  
Ionospheric Irregularity ◽  
Rate Of Change ◽  
Ionospheric Irregularities ◽  
Spatial Gradient ◽  
Electron Content ◽  
Total Electron ◽  
Pass Through

Abstract. The relation between the occurrence of ionospheric irregularity and spatial gradient of total electron content (TEC) during the post-sunset hours over the equatorial region is studied. The ionospheric irregularities could pose serious challenges to satellite-based navigation and positioning applications when trans-ionospheric signals pass through them. Different instruments and techniques have been applied to study the behavior of these ionospheric irregularities. In this study, the Global positioning system (GPS) based derived total electron content (TEC) was used to investigate the spatial gradient of TEC between two nearby stations as an indicator of the occurrence of ionospheric irregularity over the East African sector. The gradient of TEC between the two stations (ASAB: 4:34° N, 114:39° E and DEBK: 3:71° N, 109:34° E, geomagnetic) located within the equatorial region of Africa were considered in this study during the year 2014. The rate of change of TEC based derived index (ROTIave) is also used to observe the correlation between the spatial gradient of TEC and the occurrence of ionospheric irregularities. The result obtained shows that most of the maximum positive/depletions in the spatial gradient of TEC observed in March and September equinoxes are more pronounced between 19:00 LT–24:00 LT as the large-scale ionospheric irregularities do. Moreover, the observed spatial gradient of TEC shows two peaks (in March and September) and they exhibit equinoctial asymmetry where the March equinox is greater than September equinox. The enhancement in the spatial gradient of TEC and ROTIave during the 15 evening time period also show similar trends but lag 1–2 hrs from the equatorial electric field (EEF). The spatial gradient of TEC between the two nearby stations could be used as an indicator of the occurrence of ionospheric irregularities.

scholarly journals Study of GPS derived Total Electron Content and Scintillation Index variations over Indian Arctic and Antarctic stations

2013 ◽  
Vol 5 (2) ◽  
pp. 255-264 ◽  
Author(s):  
P. Bhawre ◽  
A. K. Gwal ◽  
A. A. Mansoori ◽  
P. A. Khan
Keyword(s):  
Total Electron Content ◽  
Winter Season ◽  
Scintillation Index ◽  
Activity Period ◽  
Electron Content ◽  
Gps Receiver ◽  
Dual Frequency ◽  
Total Electron ◽  
Ionospheric Variability ◽  
Solar Activity Period

In the present study we have investigated the monthly and seasonal variability of total electron content (TEC) and amplitude scintillation index (S4) over two Indian polar stations Maitri (Antarctic) and Ny-Alesund (Arctic), during the low solar activity period 2008. We have used the Novatel’s dual frequency GPS receiver GSV4004A to accomplish this study. From our analysis we observed that TEC achieves its highest values during the months of November and December while during the month of May and June the lowest values of TEC were recorded at Maitri station. Similarly during summer season the highest values of TEC are recorded while in winter season lowest values of TEC are observed. The scintillations that occurred during the year 2008 at Maitri as well as at Ny-Alesund were generally found to be of weak type (S4?0.1), although few cases of moderate (S4?0.3) and strong (S4?0.5) scintillation were also observed. The occurrence characteristics of scintillations showed that maximum scintillations at Maitri occur during the month of July and August while least scintillations occur during the month of January and February. This type of ionospheric variability can be explained on the basis of solar irradiance at Polar Regions.Keywords: Total electron content; Scintillation index; Polar ionosphere.© 2013 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v5i2.12724        J. Sci. Res. 5 (2), 255-264 (2013)

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

2016 ◽  
Vol 2 (1) ◽  
pp. 50-60
Author(s):  
Наталья Перевалова ◽  
Natalia Perevalova ◽  
Илья Едемский ◽  
Ilya Edemsky ◽  
Ольга Тимофеева ◽  
...  
Keyword(s):  
Total Electron Content ◽  
Large Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Minimum Level ◽  
Total Electron ◽  
Middle Latitudes ◽  
The Arctic Region

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

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