Space weather studies of IONOLAB group

Arıkan, Feza; Sezen, Umut; Toker, Cenk; Artuner, Harun; Bulu, Gurhan; Demir, Uygar; Erdem, Esra; Arıkan, Orhan; Tuna, Hakan; Gulyaeva, T.L.; Karatay, Secil; Mošna, Zbyšek

doi:10.1109/ursiap-rasc.2016.7601365

Cited by 10 publications

(9 citation statements)

References 16 publications

(25 reference statements)

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“…GPS-TEC can be obtained from a directory or given as an input. Before the augmentation of the GPS network with GIM-TEC, the values are checked and possible erroneous values are corrected using the methods given in [2,12,24]. For the purpose of reducing instabilities in kriging that occur in the inverse operation [19,20], GPS-TEC is augmented with corrected GIM-TEC.…”

Section: Resultsmentioning

confidence: 99%

“…A neural network is a powerful method when extrapolation is considered. However, this method has high computational complexity [5,12]. The TEC mapping technique, on the basis of a Kalman filter data assimilation scheme, suffers from similar drawbacks, and small-scale variability of the ionosphere can be missed due to its low temporal resolution [13].…”

Section: Introductionmentioning

confidence: 99%

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IONOLAB-MAP: An automatic spatial interpolation algorithm for total electron content

Deviren¹,

Arıkan²

2018

Turk J Elec Eng & Comp Sci

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Investigation of the variability of total electron content (TEC) is one of the most important parameters of the observation and monitoring of space weather, which is the main cause of signal disturbance in space-based communication, positioning, and navigation systems. TEC is defined as the total number of electrons on a ray path.The Global Positioning System (GPS) provides a cost-effective solution for the estimation of TEC. Due to various physical and operational disturbances, TEC may have temporal and spatial domain gaps. Global ionospheric maps (GIMs) provide worldwide TEC with 1-to 2-h temporal resolution and 2.5 • ×5 • spatial resolution in latitude and longitude, respectively.The GIM-TEC with the highest possible accuracy can be obtained 10 days after the recording of the signals. Therefore, a high-resolution and accurate interpolation of TEC is necessary to image and monitor the regional distribution of TEC in near-real time. In this study, a novel spatiotemporal interpolation algorithm with automatic gridding is developed for 2-D TEC imaging by data fusion of GPS-TEC and GIM-TEC. The algorithm automatically implements optimum spatial resolution and desired temporal resolution with universal kriging with linear trend for midlatitude regions and ordinary kriging for other regions. The theoretical semivariogram function is estimated from GPS network data using a Matern family, whose parameters are determined with a particle swarm optimization algorithm. The developed algorithm is applied to the Turkish National Permanent GPS Network (TNPGN-Active), a dense midlatitude GPS network. For the first time in the literature, high spatial resolution TEC maps are obtained between May 2009 and May 2012 with a 2.5min temporal update period. These TEC maps will be used to investigate the spatiotemporal variability of the ionosphere over the diurnal and annual trend structure, including seasonal anomalies and geomagnetic and seismic disturbances over ionosphere.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

IONOLAB-MAP: An automatic spatial interpolation algorithm for total electron content

Deviren¹,

Arıkan²

2018

Turk J Elec Eng & Comp Sci

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“…To this purpose, we use the TEC estimates provided by IONOLAB (http://www.ionolab.org) (Arikan et al, 2009) for five mid latitude GPS stations of EUREF network, which cover epicentral distances of 359.08-2,327.29 km and for the period 07/11/2018-05/01/2019. The selected GPS stations are at about the same latitude and, therefore, it is expected to be affected equally from the Equatorial Anomaly as well as from Auroral storms.…”

Section: Observational Datamentioning

confidence: 99%

“…The IONOLAB TEC estimation system uses a single station receiver bias estimation algorithm, IONOLAB-BIAS, to obtain daily and monthly averages of receiver bias and is successfully applied to both, quiet and disturbed days of the ionosphere, for station position at any latitude. In addition, TEC estimations with high resolution are also feasible (Arikan et al, 2009).…”

Section: Observational Datamentioning

confidence: 99%

Lower Ionospheric Turbulence Variations During the Recent Activity of Etna’s Volcano, Sicily, in December 2018

2019

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In this paper, we present an investigation on the ionospheric turbulence from TEC observations before and during the recent activity of Etna’s Volcano. Mount Etna is located close to the eastern coast of Sicily. The last eruption of Etna volcano took place on 24 December 2018 while two days later (26 December, 02:19 UTC) an earthquake of M=5.0 occurred ~15 km to the ESE of the volcano, causing damage to the nearby city of Catania. The results of our investigation, on the occasion of the Etna’s Volcanic activity, indicate that the high-frequency limit fo of the ionospheric turbulence band content, is increasing with time to the volcano eruption while, at the same time, fo isdecreasing with distance from the volcano. We conclude that the LAIC mechanism through acoustic or gravity waves could explain this phenomenology, as it has happened in cases of earthquake activity. Our observations indicate that the effect of volcanic eruption on the band content of the ionospheric turbulence is insignificant at distances greater than 1000km (at the most), a fact that we must consider in our research on Ionospheric turbulence in relation to earthquake precursors research.

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“…IONOLAB group has been using IRI‐Plas as a background ionosphere model in the development of various HF communication (Sezen et al, ), High Frequency (HF) ray tracing and propagation (Erdem & Arikan, ), Computerized Ionospheric Tomography (Erturk et al, ; Tuna et al, ), and 1‐D and 2‐D imaging (Arikan et al, ; Arikan, Shukurov, et al, ; Tuna et al, ) algorithms. IRI‐Plas has also been offered as an online Space Weather service at http://www.ionolab.org with a user‐friendly interface (Arikan, Sezen, et al, ; Sezen et al, ).…”

Section: Introductionmentioning

confidence: 99%

Performance of Solar Proxy Options of IRI‐Plas Model for Equinox Seasons

2018

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International Reference Ionosphere (IRI) is the most acclaimed climatic model of the ionosphere. Since 2009, the range of the IRI model has been extended to the Global Positioning System (GPS) orbital height of 20,000 km in the plasmasphere. The new model, which is called IRI extended to Plasmasphere (IRI‐Plas), can input not only the ionosonde foF2 and hmF2 but also the GPS‐total electron content (TEC). IRI‐Plas has been provided at http://www.ionolab.org, where online computation of ionospheric parameters is accomplished through a user‐friendly interface. The solar proxies that are available in IRI‐Plas can be listed as sunspot number (SSN1), SSN2, F10.7, global electron content (GEC), TEC, IG, Mg II, Lyman‐α, and GEC_RZ. In this study, ionosonde foF2 data are compared with IRI‐Plas foF2 values with the Consultative Committee International Radio (CCIR) and International Union of Radio Science (URSI) model choices for each solar proxy, with or without the GPS‐TEC input for the equinox months of October 2011 and March 2015. It has been observed that the best fitting model choices in Root Mean Square (RMS) and Normalized RMS (NRMS) sense are the Jet Propulsion Laboratory global ionospheric maps‐TEC input with Lyman‐α solar proxy option for both months. The input of TEC definitely lowers the difference between the model and ionosonde foF2 values. The IG and Mg II solar proxies produce similar model foF2 values, and they usually are the second and third best fits to the ionosonde foF2 for the midlatitude ionosphere. In high‐latitude regions, Jet Propulsion Laboratory global ionospheric map‐TEC inputs to IRI‐Plas with Lyman‐α, GEC_RZ, and TEC solar proxies are the best choices. In equatorial region, the best fitting solar proxies are IG, Lyman‐α, and Mg II.

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Space weather studies of IONOLAB group

Cited by 10 publications

References 16 publications

IONOLAB-MAP: An automatic spatial interpolation algorithm for total electron content

IONOLAB-MAP: An automatic spatial interpolation algorithm for total electron content

Lower Ionospheric Turbulence Variations During the Recent Activity of Etna’s Volcano, Sicily, in December 2018

Performance of Solar Proxy Options of IRI‐Plas Model for Equinox Seasons

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