Browsing by Subject "GPS network"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
Item Open Access Investigation of ionospheric trend over Turkey using sliding window statistical analysis method(IEEE, 2013) Deviren, M. N.; Arikan, F.; Arıkan, OrhanIn this paper, variability of trend over Turkey is investigated statistically by Sliding Window Statistical Analysis (SWSA) method. First and second moment of the variability of ionospheric trend is calculated by SWSA method in a period of several years. Variance bounds are also obtained. This method is applied to Total Electron Content (TEC) estimates which are obtained from Turkish National Permanent GPS Network (TNPGNActive) between 2009 and 2012. The Wide Sense Stationarity (WSS) period of ionospheric trend over Turkey is determined for the first time. © 2013 IEEE.Item Open Access Investigation on the reliability of earthquake prediction based on ionospheric electron content variation(ISIF, 2013-07) Akyol, Ali Alp; Arıkan, Orhan; Arıkan F.; Deviren, M. N.Due to lack of statistical reliability analysis of earthquake precursors, earthquake prediction from ionospheric parameters is considered to be controversial. In this study, reliability of earthquake prediction is investigated using dense TEC data estimated from the Turkish National Permanent GPS Network (TNPGN- Active). © 2013 ISIF ( Intl Society of Information Fusi.Item Open Access İyonosfer TEİ verilerinin uzay-zamansal aradeğerlemesi(IEEE, 2011-04) Yıldız, Aykut; Arıkan, Orhan; Arıkan, F.GPS sinyalleri iyonosferdeki elektron yoğunluğunun kestirilmesi için önemli bir bilgi kaynağıdır. Ancak, GPS alıcılarında sinyallerin kaydedilemediği durumlar olmaktadır. Bu kesinti sırasında iyonosfer elektron içeriğinin kestiriminin yapılabilmesi için kesinti sureleri içinde kalan verilerin aradeğerleme ile kestirimi gereklidir. Bu çalışmada, bir GPS ağındaki ölçümlerin uzay-zamansal ilintileri kullanılarak yeni bir aradeğerleme tekniği geliştirilmiştir. Gerçek veriye dayalı sonuçlar, geliştirilen tekniğin yüksek başarımlı kestirimler ürettiğini göstermiştir. GPS signals are crucial, because they are used to estimate the electron density in the ionosphere. However, sometimes GPS receivers can not receive signals. In order to estimate ionospheric electron density during this cutoff, the interpolation of the data is necessary. In this paper, a new interpolation scheme that uses spatio-temporal correlation in the GPS network is proposed. The simulation results on real data show that the proposed technique produces promising results. © 2011 IEEE.Item Open Access Space weather activities of IONOLAB group using TNPGN GPS Network(IEEE, 2011) Aktug, B.; Lenk O.; Kurt, M.; Parmaksiz, E.; Ozdemir, S.; Arikan F.; Sezen, U.; Toker, C.; Arıkan, OrhanCharacterization and constant monitoring of variability of the ionosphere is of utmost importance for the performance improvement of HF communication, Satellite communication, navigation and guidance systems, Low Earth Orbit (LEO) satellite systems, Space Craft exit and entry into the atmosphere and space weather. Turkish National Permanent GPS Network (TNPGN) is the Reference Station Network of 146 continuously-operating GNSS stations of which are distributed uniformly across Turkey and North Cyprus Turkish Republic since May 2009. IONOLAB group is currently investigating new techniques for space-time interpolation, and automatic mapping of TEC through a TUBITAK research grant. It is utmost importance to develop regional stochastic models for correction of ionospheric delay in geodetic systems and also form a scientific basis for communication link characterization. This study is a brief summary of the efforts of IONOLAB group in monitoring of space weather, and correction of geodetic positioning errors due to ionosphere using TNPGN. © 2011 IEEE.Item Open Access Space-time interpolation and automatic mapping of TEC using TNPGN-active(2011-08) Arıkan, F.; Arıkan, Orhan; Sezen, U.; Toker, C.; Aktug, B.; Lenk, O.; Kurt ,M.; Parmaksız, E.Turkish National Permanent GPS Network (TNPGN) is the Reference Station Network of 146 continuously-operating GNSS stations o which are distributed uniformly across Turkey and North Cyprus Turkish Republic since May 2009. IONOLAB group, formed by researchers and students in Hacettepe University, Bilkent University and General Command of Mapping is currently investigating new techniques for space-time interpolation, and automatic mapping of TEC through a TUBITAK research grant. This study presents the developments in monitoring of space weather, and correction of geodetic positioning errors due to ionosphere using TNPGN. © 2011 IEEE.