Automatic Data Downloading Program (DDP) in Determining Regional Ionosphere Model

Yıl 2018, Cilt: 7 Sayı: 1, 17 - 28, 20.04.2018

Fuat Başçiftçi Cevat İnal Ömer Yıldırım Sercan Bülbül

Öz

GNSS (Global Navigation Satellite System) signals pass
through various layers of the atmosphere until they reach the receiver on the
Earth. One of these layers is the Ionosphere. Ionosphere may be defined as the
atmospheric layer that consists of the gasses that are ionized with sunrays
located 60 and 1100 km above the ground level with important effects on the
signals used by satellite-based positioning, short-wave communication, and
other communication systems. One of the important parameters that express the
characteristics of the Ionosphere is the Total Electron Content (TEC), which is
a function of the electron density that shows variations with the radiation of
the Sun. The TEC value cannot be obtained directly from GNSS
measurements; however, it may be predicted with the combinations produced.
In the scope of the present study, the Bernese v5.2 GNSS scientific Software
that was developed by the Swiss Bern University Astronomy Institute (AIUB) was
used in the determination of the TEC values for the Regional Ionosphere model.
Before the stage in which the TEC values are determined with the Bernese v5.2
GNSS Software, some files must be downloaded from the Internet in the Bernese
format according to GPS day/week and year/the day of year values and copies to
the DATAPOOL folder, which is created with the use of the software. For this
purpose, it has been ensured that the files in the Bernese format are obtained
from the relevant Internet addresses in an automatic manner by using a series
of commands with the name Data Downloading Program (DDP) in the MATLAB for the
purpose of facilitating the manual data collection process and eliminating
other possible difficulties that might appear. The Regional TEC values are
computed with the Bernese v5.2 GNSS Software by using the downloaded files.

Anahtar Kelimeler

GNSS, Bernese, MATLAB, Total Electron Content (TEC), Ionosphere

Kaynakça

• Afraimovich, E. L., Astafyeva, E. I., 2008. TEC anomalies—Local TEC changes prior to earthquakes or TEC response to solar and geomagnetic activity changes?. Earth, planets and space, 60(9), 961-966.
• Alizadeh, M. M., Schuh, H., Todorova, S., Schmidt, M., 2011. Global ionosphere maps of VTEC from GNSS, satellite altimetry, and formosat-3/COSMIC data. J Geod, 85(12):975-987, https://doi.org/10.1007/s00190-011-0449-z.
• 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.
• Aysezen, M. Ş., 2008. Preparation of GPS based TEC and receiver bias database for Turkey using IONOLAB-TEC. M.Sc. Thesis, Zonguldak Karaelmas University, Graduate School of Natural and Applied Sciences, Department of Geodesy and Photogrammetry Engineering Zonguldak-Turkey (in Turkish).
• Başçiftçi, F., 2017. The Creation of Ionosphere Model Using GNSS Data and Its Comparison With Global Models. Ph. D. Thesis, Selcuk University, Graduate School of Natural and Applied Sciences, Department of Geomatics Engineering Konya-Turkey (in Turkish).
• Başpınar, S., 2012. Examine Ionoshphere Models with CORS-TR Data. Ph.D. Thesis, Istanbul Kultur University, Graduate School of Natural and Applied Sciences, Department of Civil Engineering Istanbul-Turkey (in Turkish).
• Chakraborty, M., Kumar, S., De, B. K., Guha, A., 2014. Latitudinal characteristics of GPS derived ionospheric TEC: a comparative study with IRI 2012 model. Ann. Geophys., 57, A0539, https://doi.org/10.4401/ag-6438.
• Coley, W. R., Stoneback, R. A., Heelis, R. A., Hairston, M. R., 2014. Topside equatorial zonal ion velocities measured by C/NOFS during rising solar activity. Ann. Geophys., 32, 69–75, https://doi.org/10.5194/angeo-32-69-2014.
• Dach, R., Lutz, S., Walser, P., Fridez, P., 2015. Bernese GNSS Software Version 5.2. Astronomical Institute, University of Bern, Switzerland, DOI: 10.7892/boris.72297.
• Hawarey, M., Ayan, T., 2004. GPS detection of ionospheric perturbations excited by space shuttle ascent, earthquake, and missile launch. itüdergisi/d, vol.3, 2-3-4-5, pp.45-56.
• Inyurt, S., Yildirim, O., Mekik, C., 2017. Comparison between IRI-2012 and GPS-TEC observations over the western Black Sea. Ann. Geophys., 35, 817–824, https://doi.org/10.5194/angeo-35-817-2017.
• Liu, J.-Y., Chen, Y., Chen, C.-H., Liu, C., Chen, C., Nishihashi, M., Li, J., Xia, Y., Oyama, K., 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), doi:10.1029/2008JA013698.
• Namgaladze, A. A., Zolotov, O. V., Karpov, M. I., Romanovskaya, Y. V., 2012. Manifestations of the Earthquake Preparations in the Ionosphere Total Electron Content Variations, Natural Science, Vol.4, No.11, 848-855.
• Pajares, M. H., Juan, J. M., Sanz, J., Angel, A. A., Rigo, A. G., Salazar, D., Escudero, M., 2011. The Ionosphere: Effects, GPS Modeling and the Benefits for Space Geodetic Techniques. J Geod, doi: 10.1007/s00190-011-0508-5.
• Parkinson, B. W. ve Spilker, J. J., 1996. Global Positioning System: Theory and Applications.
• 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. Surv Geophys 32:197–253.
• Rama Rao, P. V. S., Niranjan, K., Prasad, D. S. V. V. D., Gopi Krishna, S., Uma, G., 2006. On the validity of the ionospheric pierce point (IPP) altitude of 350 km in the Indian equatorial and low-latitude sector. Ann. Geophys., 24, 2159–2168, https://doi.org/10.5194/angeo-24-2159-2006.
• Schaer, S., 1999. Mapping and Predicting the Earth’s Ionosphere Using the Global Positioning System, Ph.D Thesis. University of Bern, Bern.
• Schmidt, M., Bilitza, D., Shum, C. K., Zeilhofer, C., 2008. Regional 4-D modeling of the ionospheric electron density. Adv. Space Res., 42, 782–790.
• Turel, N., Aktas, E., Arikan, F., 2007. TEC Statistics and Correlogram Applications. IEEE 15th Signal Processing and Communications Applications, pp.1-4, Eskisehir, doi: 10.1109/SIU.2007.4298639.
• Wild, U., 1994. Ionosphere and geodetic satellite systems: permanent GPS tracking data for modelling and monitoring. Geod.-Geophys. Arb. Schweiz, Vol. 48, 48.
• Withers, P., and Mendillo, M., 2005. Response of peak electron densities in the Martian ionosphere to day-to-day changes in solar flux due to solar rotation. Planetary and Space Science, 53(14), 1401-1418.
• Yildirim, O., Inyurt, S., Mekik, Ç., 2016. “Review of variations in M w< 7 earthquake motions on position and TEC (M w= 6.5 Aegean Sea earthquake sample). Natural Hazards and Earth System Sciences, 16(2), 543-557.
• URL 1, 2016. ftp://ftp.unibe.ch/aiub/CODE/yyyy (yyyy=yıl)
• URL 2, 2016. ftp://cddis.gsfc.nasa.gov/gps/products/wwww
• URL 3, 2016. ftp://cddis.gsfc.nasa.gov/pub/glonass/products/wwww
• URL 4, 2016. ftp://ftp.unibe.ch/aiub/BSWUSER52/GEN
• URL 5, 2016. ftp://ftp.unibe.ch/aiub/BSWUSER52/STA
• URL 6, 2016. ftp://cddis.gsfc.nasa.gov/gps/data/daily
• URL 7, 2016. ftp://igs.bkg.bund.de/EUREF/obs
• URL 8, 2016. Bernese GNSS Software website, Available: http://www.bernese.unibe.ch
• URL 9, 2016. ftp://cddis.gsfc.nasa.gov/gps/products/ionex
• URL 10, 2015. International Reference Ionosphere - IRI-2012 website, http://omniweb.gsfc.nasa.gov/vitmo/iri2012_vitmo.html
• URL 11, 2015. Tusaga-Aktif website, http://rinex.tusaga-aktif.gov.tr
• URL 12, 2015. ftp://igs.bkg.bund.de/IGS/obs