TUSAGA-Aktif Noktaları Kullanılarak Bölgesel TEC Değerinin Belirlenmesi

Yıl 2020, Cilt: 20 Sayı: 2, 250 - 266, 20.05.2020

Sercan Bülbül

https://doi.org/10.35414/akufemubid.646324

Öz

GNSS (Global Navigation Satellite Systems - Küresel Navigasyon Uydu Sistemleri) sinyalleri alıcıya ulaşıncaya kadar birçok tabakadan geçmektedir. Bu tabakalardan iyonosfer, günün saatine, mevsimlere, coğrafi konuma ve güneşteki patlamalara bağlı olarak sürekli değişim halindedir. İyonosferin karakteristik özelliği TEC (Total electron content - Toplam Elektron Yoğunluğu) ile belirlenmektedir. TEC, GNSS ölçülerini direk olarak etkilemez fakat üretilen kombinasyonlarla kestirilebilir. Bu çalışmada Türkiye’ nin kuzey doğusunda bulunan 13 TUSAGA-AKTİF istasyonu ile 12 IGS (The International GNSS Service- Uluslararası GNSS Servisi) istasyonunun bulunduğu toplam 25 istasyon seçilmiş ve değerlendirilmiştir. Değerlendirmede Bernese v5.2 Bilimsel GNSS yazılımı kullanılmıştır. 2009 yılından 2015 yılına kadar TEC değerleri ikişer saat aralıklarla hesaplanmıştır. Tek Tabaka Modelinin kullanıldığı çalışmada GNSS ölçülerinden elde edilen TEC değerleri, CODE(The Centre for Orbit Determination in Europe -Avrupa yörünge belirleme merkezi), ESA (The European Space Agency -Avrupa Uzay Ajansı), Jet Propulsion Laboratory (JPL) tarafından yayınlanan global iyonosfer haritası (GIM-TEC) ve uluslararası iyonosfer referans modeli programından elde edilen TEC (IRI TEC) değerleriyle karşılaştırılmıştır. Karşılaştırma sonucunda bölgesel (RIM) TEC değerleri ile gobal (CODE, ESA, JPL) TEC değerleri arasında büyük oranda benzerlik olduğu ve aralarındaki farkın en fazla 2,58 TECU olduğu görülmektedir. IRI’ den elde edilen TEC değerleri bu dört değere nazaran daha düşüktür ve bölgesel TEC (RIM) değerleri ile aralarındaki fark 15.67 TECU (TEC unit)' ya kadar ulaşmaktadır.

Anahtar Kelimeler

Bernese, GNSS, TEC, TUSAGA-Aktif, GIM, İyonosfer

Determination of Regional TEC Values using CORS-Tr Stations

Öz

GNSS(Global Navigation Satellite Systems) signals pass through various layers of atmosphere until they reach the receiver on earth. the ionosphere, one of these layers, is constantly changing depending on the time of day, seasons, geographical location and explosions in the sun. One of the most important parameters expressing the ionosphere is TEC (Total electron content). GNSS signals affected by the variable structure of the ionosphere are proportional to TEC. The determination of TEC exchange is important for the modeling of the ionosphere. The TEC value cannot be obtained directly from GNSS measurements, but can be estimated by the combinations produced. 13 CORS-Tr stations which are located at northeast of Turkey and 12 IGS stations were used. At process, Bernese GNSS software was used. From 2009 to 2015, TEC values were calculated in two hour intervals. The TEC values obtained from GNSS measurements were compared with Global Ionesphere Maps published by CODE, ESA, JPL and IRI -2012. As a result of the comparison, RIM-TEC values and CODE, ESA, JPL TEC values are similar and there is a maximum difference of 2.58 TECU. TEC values obtained from IRI-2012 are lower than these four values and the difference between RIM-TEC values and IRI-2012 TEC values are up to 15.67 TECU.

Anahtar Kelimeler

Bernese, GIM, GNSS, TEC, CORS-Tr, Ionesphere

Kaynakça

• Abdullah, M., Strangeways, H. J. ve Walsh, D. M., 2009, Improving ambiguity resolution rate with an accurate ionospheric differential correction, Journal of Navigation, 62 (01), 151-166.
• Afraimovich, E. L., Chernukhov V.V. ve Demyanov, V. V., 2000a, The Updated Ionospheric Delay Model to Improve the Performance of GPS Single-Frequency Receivers, Radio Science, 35 (1), 257-262.
• Alcay, S., Yigit, C. O., Seemala, G., Ceylan, A., 2014. “GPS-Based Ionosphere Modeling: A Brief Review”, Fresenius Environmental Bulletin, 23(3a), 815-824.
• Arıkan, F., Erol, C. ve Arıkan, O., 2003, Regularized estimation of vertical total electron content from Global Positioning System data, Journal of Geophysical Research: Space Physics, 108 (A12), 1469-1480.
• Arslan, N., 2004, GPS ile İyonosfer Toplam Elektron Yoğunluğu Değişimlerinin Koordinatlara Etkilerinin Araştırılması, Doktora Tezi, Yıldız Teknik Üniversitesi Fen Bilimleri Enstitüsü, İstanbul.
• Arslan, N., 2010, İyonosferdeki Değişimlerin TEQC Yazılımı İle İzlenmesi, 5. Ulusal Mühendislik Ölçmeleri Sempozyumu, Zonguldak Karaelmas Üniversitesi Merkez Kampüsü, Zonguldak.
• Ateş, H. B., 2011, TUSAGA-AKTİF GPS Ağ Verileri İle Bölgesel İyonosferik Modelin Oluşturulması, Yüksek Lisans Tezi, Gebze Yüksek Teknoloji Enstitüsü Mühendislik Ve Fen Bilimleri Enstitüsü, Gebze.
• Aysezen, M. Ş., 2008, Türkiye İçin IONOLAB-TEC Kullanılarak GPS Tabanlı TEİ Ve Alıcı Yanlılığı Veri Tabanı Hazırlanması, Yüksek Lisans Tezi, Zonguldak Karaelmas Üniversitesi Fen Bilimleri Enstitüsü, Zonguldak.
• Başçiftçi, F., 2017, GNSS Verileri Kullanılarak İyonosfer Modelinin Oluşturulması ve Global Modellerle Karşılaştırılması, Doktora Tezi, Selçuk Üniversitesi Fen Bilimleri Enstitüsü, Harita Mühendisliği Ana Bilim Dalı, Konya.
• Başçiftçi, F., İnal, C., Yıldırım, Ö. ve Bülbül, S., 2017a, Determination of Regional TEC Values by GNSS Measurements, A Case Study: Central Anatolia Sample, Turkey. Surveying the world of tomorrow – From digitalisation to augmented reality, FIG Working Week 2017. Helsinki/Finland.
• Başçiftçi, F., Inal, C., Yıldırım, Ö., Bülbül, S., 2017, Determining Regional Ionospheric Model and Comparing With Global Models, Geodetski Vestnik, 61 (3), 427-440. DOI:10.15292/geodetski-vestnik.2017.03.427-440, ISSN:0351-0271.
• Başçiftçi, F., Inal, C., Yıldırım, Ö., Bülbül, S.,2018. Comparisonof Regional and Global TEC Values: Turkey Model, International Journal of Engineering and Geosciences, 3 (2), 61-72. DOI: 10.26833/ijeg.382604, e-ISSN: 2548-0960
• Başpınar, S., 2012, CORS-TR Verileriyle İyonosfer Modellerinin İncelenmesi, Doktora Tezi, İstanbul Kültür Üniversitesi Fen Bilimleri Enstitüsü, İstanbul.
• Bilitza, D., Altadil, D., Zhang, Y., Mertens, C., Truhlink, V., Richards, P., McKinnell, L., Reinish, B. (2014). The International Reference Ionosphere 2012-a model of international collaboration. Journal of Space Weather and Space Climate, 4, A107, http://dx.doi.org/10.1051/swsc/2014004.
• Calais, E. ve Minster, J. B., 1998, GPS, earthquakes, the ionosphere, and the Space Shuttle, Physics of the Earth and Planetary Interiors, 105 (3), 167-181.
• Chakraborty, M., Kumar, S., De, B. K. ve Guha, A., 2014, Latitudinal characteristics of GPS derived ionospheric TEC: a comparative study with IRI 2012 model, Annals of geophysics, 57 (5).
• Dach, R., Lutz, S., Walser, P. ve Fridez, P., 2015, Bernese GNSS Software Version 5.2, Switzerland, Astronomical Institute, University of Bern, p.
• Danilov, A. ve Lastovicka, J., 2001, Effects of geomagnetic storms on the ionosphere and atmosphere, International Journal of Geomagnetism and Aeronomy, 2 (3), 209-224.
• Davies, K. ve Hartmann, G., 1997, Studying The Ionosphere With The Global Positioning System, Radio Science, 32 (4), 1695-1703.
• Feltens, J. ve Schaer, S., 1998, IGS Products for the Ionosphere, Proceedings of the 1998 IGS Analysis Center Workshop Darmstadt, Germany.
• Fedrizzi, M., Langley, R. B., Komjathy, A., Santos, M. C., de Paula, E. R. ve Kantor, I. J., 2001, The Low-Latitude Ionosphere: Monitoring Its Behavior With GPS, Proceedings of ION GPS, Salt Lake City, Utah, USA.
• Gao, Y. ve Liu, Z. Z., 2002, Precise ionosphere modelling using regional GPS network data, Journal of Global Positioning Systems, 1, No. 1: 18-24.
• Gizawy, M. L., 2003, Development of an ionosphere monitoring technique using GPS measurements for high latitude GPS users, Ph.D. Thesis, University of Calgary, Italy.
• Gümrükcü, O., 2009, GPS Sinyalleri İle Konum Belirlemede İyonosferik Etkilerin İncelenmesi,, Yüksek Lisans Tezi, Yıldız Teknik Üniversitesi Fen Bilimleri Enstitüsü, İstanbul.
• Hawarey, M. ve Ayan, T., 2004, Uzay mekiği tırmanışı, deprem, ve füze fırlatılışından kaynaklanan TEC değişimlerinin GPS ile belirlenmesi, İTÜ Dergisi, 3 (2-3-4-5).
• Hernández-Pajares, M., Juan, J. M., Sanz, J., Orus, R.,Garcia-Rigo, A., Feltens, J., ... & Krankowski, A. (2009). The IGS VTECmaps: a reliable source of ionospheric information since 1998. Journalof Geodesy, 83(3), 263-275. DOI: 10.1007/s00190-008-0266-1
• Hugentobler, U., Schaer, S., Pridez, F., Beutler, G., Bock, H. (2001). Bernese GPS Software Version 4.2. Astronomical Institute University of Bern, Switzerland.
• Hunsucker, R.D., Hargreaves, J.K., (2003), “The High-Latitude Ionosphere and its Effects on the Radio Propogation”, Cambridge University Press 2003
• İnyurt, S., 2015, İyonosferdeki Toplam Elektron Miktarı (TEC) Ve Kod Yanlılık Değerlerinin (DCB) GNSS Ölçümleriyle Belirlenmesi, Yüksek Lisans Tezi, Bülent Ecevit Üniversitesi Fen Bilimleri Enstitüsü, Zonguldak.
• Komjathy, A. ve Langley, R., 1996, An assessment of predicted and measured ionospheric total electron content using a regional GPS network, Proceedings of the national technical meeting of the Institute of Navigation, 615-624.
• Komjathy, A., 1997, Global Ionospheric Total Electron Content Mapping Using the Global Positioning System, Ph. D. Thesis, University of New Brunswick Department of Geodesy and Geomatics Engineering, Canada, 248p.
• Langley, R. B., 2002, Monitoring the Ionosphere and Neutral Atmosphere with GPS, Viewgraphs of invited presentation to the Canadian Association of Physicists Division of Atmospheric and Space Physics Workshop, Fredericton, N.B.
• Leong, S. K., Musa, T. A., Omar, K., Subari, M. D., Pathy, N. B., Asillam, M. F. (2015). Assessment of ionosphere models at Banting: Performance of IRI-2007, IRI-2012 and NeQuick 2 models during the ascending phase of Solar Cycle 24. Advances in Space Research, 55 (8), 1928–1940.
• Liu, Z., Skone, S., Gao, Y. ve Komjathy, A., 2005, Ionospheric modeling using GPS data, Gps Solutions, 9 (1), 63-66.
• Liu, J.-Y., Chen, Y., Chen, C.-H., Liu, C., Chen, C., Nishihashi, M., Li, J., Xia, Y., Oyama, K. ve Hattori, K., 2009, Seismoionospheric GPS total electron content anomalies observed before the 12 May 2008 Mw7. 9 Wenchuan earthquake, Journal of Geophysical Research: Space Physics, 114 (A4).
• Liu, M., Luo, G. ve Wang, H., 2014, The 2013 Lushan earthquake in China tests hazard assessments, Seismological Research Letters, 85 (1), 40-43.
• Mao, T., Wan, W., Yue, X., Sun, L., Zhao, B., & Guo, J.(2008). An empirical orthogonal function model of total electron content overChina. Radio Science, 43(2), doi:10.1029/2007RS003629..
• Memarzadeh, Y., 2009, Ionospheric modeling for precise GNSS applications, Ph.D. Thesis, Delft University of Technology, Netherlands.
• Namgaladze, A. A., Zolotov, O. V., Karpov, M. I. ve Romanovskaya, Y. V., 2012, Manifestations of the earthquake preparations in the ionosphere total electron content variations, Natural Science, 4 (11), 848-855.
• Odijk, D., 2002, Fast precise GPS positioning in the presence of ionospheric delays, Ph.D. Thesis, Delft University of Technology, The Netherlands.
• Orús Pérez, R., 2005, Contributions on the improvement, assessment and application of the Global Ionospheric VTEC Maps computed with GPS data, Ph. D. dissertation, Universitat Politècnica de Catalunya, Barcelona, Spain.
• Orus, R., Hernández-Pajares, M., Juan, J. ve Sanz, J., 2005, Improvement of global ionospheric VTEC maps by using kriging interpolation technique, Journal of Atmospheric and Solar-Terrestrial Physics, 67 (16), 1598-1609.
• Parkinson, B. W. ve Spilker, J. J., 1996, Global Positioning System: Theory and Applications, p.
• Petrie, E. J., Hernández-Pajares, M., Spalla, P., Moore, P. ve King, M. A., 2011, A Review of Higher Order Ionospheric Refraction Effects on Dual Frequency GPS, Surveys in geophysics, 32 (3), 197-253.
• Schaer, S., Beutler, G., Mervart, L., Rothacher, M. ve Wild, U., 1995, Global and regional ionosphere models using the GPS double difference phase observable, IGS Workshop on Special Topics and New Directions, Germany.
• Schaer, S., Gurtner, W. ve Feltens, J., 1998, IONEX: The ionosphere map exchange format version 1, Proceedings of the IGS ESA/ESOC workshop Darmstadt, Germany.
• Schaer, S., 1999, Mapping and Predicting the Earth’s Ionosphere Using the Global Positioning System, Ph.D Thesis, Universitat Bern, Switzerland, 228p.
• Scharroo, R.,and Smith, W. H. F.,(2010). A global positioning system–based climatology for the total electroncontent in the ionosphere. Journal of Geophysical Research: SpacePhysics, 115, A10318, doi:10.1029/2009JA014719.
• Seeber, G., 2003, Satellite geodesy: foundations, methods, and applications, Walter de Gruyter, p.
• Skone, S. ve Cannon, M., 1999, Ionospheric effects on differential GPS applications during auroral substorm activity, ISPRS journal of photogrammetry and remote sensing, 54 (4), 279-288.
• Skone, S. ve Jong, M. D., 2000a, The Impact of Geomagnetic Substorms on GPS Receiver Performance, Earth Planets and Space, 52, 1067-1071.
• Todorova, S., Hobiger, T., Weber, R., Schuh, H., (2003), “Regıonal Ionosphere Modellıng With GPS And Comparison With Other Techniques”, Proceedings of the Symposium "Modern Technologies, Education and Professional Practice in the Globalizing World", November 06-07, Sofia.
• Turel, N., Aktas, E. ve Arikan, F., 2007, TEC Statistics and Correlogram Applications, Signal Processing and Communications Applications, 2007. SIU 2007. IEEE 15th, 1-4.
• Ulukavak, M. ve Yalçınkaya, M., 2014, Deprem Kaynaklı Toplam Elektron İçeriği Değişimlerinin Araştırılması: Ege Denizi Depremi (24.05. 2014 Mw: 6.5), Harita Teknolojileri Elektronik Dergisi, 6 (3), 10-21.
• Wan,W., Ding, F., Ren, Z., Zhang, M., Liu, L., & Ning, B. (2012). Modeling theglobal ionospheric total electron content with empirical orthogonal functionanalysis. Science China Technological Sciences, 55(5),1161-1168, doi: 10.1007/s11431-012-4823-8.
• Wild, U., 1994, Ionosphere and geodetic satellite systems: permanent GPS tracking data for modelling and monitoring, Geod.-Geophys. Arb. Schweiz, Vol. 48, 48.
• Ya'acob, N., Ismail, M. ve Abdullah, M., 2010, GPS total electron content (TEC) prediction at ionosphere layer over the Equatorial region, INTECH Open Access Publisher, p.
• Zou, Y., 2010, Ionospheric Anomalies Detected By GPS TEC Measurements During Two Strong Earthquakes In Indonesia, Environmental Science and Information Application Technology (ESIAT), 2010 International Conference on, Guilin University of Electronic Technology, China, 199-202.
• URL1, Ziyaret Tarihi: 13.03.2016, http://www.ionolab.org/index.php?page=ionosphere&language=tr,
• URL2. (2016). International GNSS Service (IGS) Server ftp://cddis.gsfc.nasa.gov/gps/products/ionex, accessed: 04 January, 2016.
• URL3. (2015). https://ccmc.gsfc.nasa.gov/modelweb/models/iri2016_vitmo.php, accessed: 10 December, 2015.