Seçil Karatay | Kastamonu University (original) (raw)
Papers by Seçil Karatay
Journal of Polytechnic, Dec 30, 2023
In this study, the relation between Total Electron Content (TEC) estimates obtained from GPS and ... more In this study, the relation between Total Electron Content (TEC) estimates obtained from GPS and the earthquakes is examined. Five earthquakes between 2003-2008 occured in Japan with different properties and China earthquake in May 2008 are chosen for the purpose. The 15-days period before and after the registered earthquakes are considered for the basis of this investigation. Also the TEC in computed for each GPS station for the time periods including Ionosphere quiet and disturbed days not without any serious earthquake in the region. For the statistical analysis, the cross correlation function (CC) which is used in the literature before, and the Kullback-Leibler Divergence (KLD) with L2-Norm (L2N) methods which are used for the first time in this context, are applied to the data sets. The computed values for CC, KLD and L2N are compared for both between different GPS stations where available and between consecutive days for the time periods in the data set. With CC analysis, the anomalies existed in the earthquake time intervals are also observed for the quiet days data set. For the earthquakes with scale larger than 6, the possibilities of generating an alarm signal is more likely with a future detailed comperative study of the estimated TEC nearby GPS station estimates in space and time. 1. Giri�
Geodesy and Geodynamics, May 1, 2020
43rd COSPAR Scientific Assembly. Held 28 January - 4 February, 2021
Advances in Space Research, May 1, 2020
Advances in Space Research, Nov 1, 2017
Journal of geodesy, Aug 31, 2020
One of the more common methods of observation of variability of the Earth’s ionosphere is based o... more One of the more common methods of observation of variability of the Earth’s ionosphere is based on total electron content (TEC) estimated from ground-based dual-frequency Global Positioning System (GPS) receivers. Variations in solar, geomagnetic and seismic activity cause depletions or enhancements in the ionospheric electron concentrations that can be detected as disturbances. Some of these disturbances have wave-like characteristics, where frequency of oscillation can be used to identify and classify the disturbance. In this study, the frequency of such periodic disturbances is estimated using a fast Fourier transform (FFT)-based method, namely IONOLAB-FFT, in the spectral domain. IONOLAB-FFT, which was initially developed to be used on slant TEC (STEC), is modified to be applied to TEC in the local zenith direction of the receiver. The algorithm is tested using literature data on disturbances generated by a geomagnetic activity, a solar flare, a medium-scale traveling ionospheric disturbance (MSTID), a large-scale TID (LSTID) and an earthquake. An accordance with these known disturbances is observed in running IONOLAB-FFT, and the main frequencies and durations of the disturbances are estimated. IONOLAB-FFT method is applied to TEC computed from Turkish Permanent GPS Network (TNPGN-Active) which lies in mid-latitude region to detect the any wave-like oscillations, sudden disturbances and other irregularities during December, March, June and September months for 2010, 2011 and 2012 years. It is observed that a large number of the estimated frequencies are accumulated between 0.08 and 0.14 MHz corresponding to periods of 3.5 h to 2 h. The significant frequencies are grouped less than 0.28 MHz. A large number of the durations of the oscillations are between 425 and 550 min in 2010, 300 and 550 min in 2011 and 350 and 400 min in 2012. The longest duration (around 800 min: 13.33 h) is observed in December months, and the shortest duration (around 2 h) is observed in September months.
Turkish Journal of Science and Technology
In recent years, forest fires can be brought under control in line with the information obtained ... more In recent years, forest fires can be brought under control in line with the information obtained from Unmanned Aerial Vehicles (UAVs), which play an important role in determining the progression of fires, detecting heat points and determining intervention locations. In this study, if the UAV detects the fire by autonomously positioning in the area where the fire is located, the point where the fire reaches the most intense temperature is determined with the help of the thermal camera, and it is ensured that the fireball is dropped to the target with a 100% success rate. The requirements of the UAV, which will be produced in order to realize this task, such as fast, load-carrying and stable flight are also taken into consideration. In addition to being economical and long-lasting of the materials inside, it will be able to fly efficiently in most weather conditions (foggy, dark, etc.). In the construction of the UAV, a domestic Electronic Speed Controller (ESC) with a unique design i...
Politeknik Dergisi
The ionosphere is an important layer that provides radio communication in the upper atmosphere. T... more The ionosphere is an important layer that provides radio communication in the upper atmosphere. The ionosphere is located between 50 km and 1000 km above the atmosphere. Electron density, which is the most important parameter of the ionosphere, changes depending on location, time, seasons, altitude, solar, geomagnetic and seismic activity. A significant measurable amount of electron density is Total Electron Content (TEC), which is used to probe the structure of the ionosphere and upper atmosphere. The Global Positioning System (GPS), which has a low cost and widespread receiver network is prominent used in TEC estimation. The IONOLAB-TEC data estimated from GPS is used in this study. Prediction of TEC is important phenomenon to operate and to plan the Earth-space and satellite-to-satellite communication systems, to generate the earthquake precursor signals using TEC and to detect of anomalies in the ionosphere. In this study, IONOLAB-TEC data obtained from GPS is estimated using re...
European Journal of Science and Technology
Black Sea Journal of Agriculture
With the development of technology, today, the use of technology in the field of agriculture has ... more With the development of technology, today, the use of technology in the field of agriculture has become widespread. In order to meet the increasing demand for agricultural products, automation techniques should be used in agricultural areas in order to make the production of agricultural products simpler and more efficient. In this study, an automation system is designed by making use of technology against problems such as irrigation problem and water shortage, which have become an important problem in agricultural areas. The data coming from the humidity sensor placed in the soil is processed to the controller. According to these processed data, when the soil is dry and the plant needs water, the water-pumping set automatically activates and meets the water needs of the plant. Optimum use of irrigation water to be used in agriculture is prevented unnecessary agricultural irrigation, reducing excessive water waste and providing a very high level of energy savings. At the same time, ...
43rd COSPAR Scientific Assembly. Held 28 January - 4 February, 2021
41st COSPAR Scientific Assembly, Jul 1, 2016
Ionosphere is a time varying, inhomogeneous, anisotropic and spatio-temporally dispersive medium ... more Ionosphere is a time varying, inhomogeneous, anisotropic and spatio-temporally dispersive medium whose descriptive properties can be estimated using indirect measurements. The variability of ionosphere can result from solar, geomagnetic, gravitational or seismic activities. This complex spatiotemporal variability is very difficult to be identified due to extensive scales in amplitude, duration, period and frequency of disturbances. The random field model of ionosphere, which is made up of a trend component and a variability component, can be related to various solar and geomagnetic indices such as Sun Spot Number (SSN), F10.7 solar flux, Disturbance storm time (Dst), Auroral Electrojet (AE), Kp and W-index. Since most of these indices are estimated or predicted to indicate the ionospheric activity at different parts of the Earth or they indicate global disturbance, it is highly complicated to identify and classify regional disturbances.
Yer’in iyonkuresi, uzay-havasi incelemelerinde onemli bir etkendir ve bu nedenle iyonkurenin degi... more Yer’in iyonkuresi, uzay-havasi incelemelerinde onemli bir etkendir ve bu nedenle iyonkurenin degiskenliginin incelenmesi, basta iyonkure fizigi ve radyo iletisimi olmak uzere bircok alanda onemlidir. Iyonkureyi karakterize eden temel parametreler, yukseklik, enlem, boylam, jeomanyetik isleklik, gunes islekligi ve sismik hareketlilikle degisimler gosteren elektron yogunlugudur. Iyonkureyi karakterize eden bir diger parametre ise atmosferde bir yol boyunca hesaplanan serbest elektronlarin miktarina esit olan Toplam Elektron Icerigidir (TEI). TEI olcumleri, uzay havasindaki degisimleri ve sismik hareketliligin iyonkurede yarattigi etkileri sergilemeye olanak saglar. Bu calismada, Turkiye’de konumlanmis Turkiye Ulusal Sabit GPS Istasyonlari Agindaki (TUSAGAAktif) on bir Yerkuresel Konumlama Sistemi (YKS) istasyonlarindan elde edilen TEI verileri, Capraz Ilinti Katsayisi (CIK), Simetrik Kullback-Leibler Mesafesi (KLD), L2-Normu (L2N) kullanilarak iyonkurenin sakin gunlerini, siddetli jeo...
Politeknik Dergisi, 2019
The ionosphere is an ionized layer that extends between 50 km and 1000 km altitudes in the atmosp... more The ionosphere is an ionized layer that extends between 50 km and 1000 km altitudes in the atmosphere. It plays an important role in atmospheric electricity. The ionosphere has the number of electrically charged particles and thus, it affects the propagation of the radio waves. In this study, magnitudes of impedance for different seasons and different geomagnetic activity periods in the ionospheric plasma are calculated using the real geometry of Earth. It is observed that the impedance of the ionospheric plasma in all directions generally has high values for all seasons. The diagonal components of the tensor of the impedance are greater than the other components. It is also observed that the ionospheric plasma, generally, has weak conductivity in all directions and seasons. Impedance varies inversely with electron density. Hence, geomagnetic activity periods which lead to an increase in electron density decreases the impedance. It is observed that the ionospheric plasma has a react...
Geomagnetism and Aeronomy, 2019
The ionosphere, a part of upper atmosphere, plays an important role on the propagation of radio w... more The ionosphere, a part of upper atmosphere, plays an important role on the propagation of radio waves. Hence, understanding, remote sensing and monitoring of the ionospheric phenomena can provide a compressive description to the physical process that are affected by the behavior of ionosphere. One of descriptive quantity of ionosphere is Total Electron Content (TEC). TEC is the total number of electrons integrated between two points and characterized by observing carrier phase delays of received radio signals transmitted from satellites located above the ionosphere, often using Global Positioning System (GPS) satellites. In this study, TEC is predicted from TEC estimates obtained from GPS network located in Turkey in space and time using an Adaptive Data Fusion Technique (ADF). It is observed that characteristic distributions of the predict TEC and original TEC values are similar with each other. Mean Square Errors are less than 4 TECU. ADF has a high performance for the spatio-temporal prediction when the results are compared with the techniques used in the related studies in the literature.
Geodesy and Geodynamics, 2020
Journal of Polytechnic, Dec 30, 2023
In this study, the relation between Total Electron Content (TEC) estimates obtained from GPS and ... more In this study, the relation between Total Electron Content (TEC) estimates obtained from GPS and the earthquakes is examined. Five earthquakes between 2003-2008 occured in Japan with different properties and China earthquake in May 2008 are chosen for the purpose. The 15-days period before and after the registered earthquakes are considered for the basis of this investigation. Also the TEC in computed for each GPS station for the time periods including Ionosphere quiet and disturbed days not without any serious earthquake in the region. For the statistical analysis, the cross correlation function (CC) which is used in the literature before, and the Kullback-Leibler Divergence (KLD) with L2-Norm (L2N) methods which are used for the first time in this context, are applied to the data sets. The computed values for CC, KLD and L2N are compared for both between different GPS stations where available and between consecutive days for the time periods in the data set. With CC analysis, the anomalies existed in the earthquake time intervals are also observed for the quiet days data set. For the earthquakes with scale larger than 6, the possibilities of generating an alarm signal is more likely with a future detailed comperative study of the estimated TEC nearby GPS station estimates in space and time. 1. Giri�
Geodesy and Geodynamics, May 1, 2020
43rd COSPAR Scientific Assembly. Held 28 January - 4 February, 2021
Advances in Space Research, May 1, 2020
Advances in Space Research, Nov 1, 2017
Journal of geodesy, Aug 31, 2020
One of the more common methods of observation of variability of the Earth’s ionosphere is based o... more One of the more common methods of observation of variability of the Earth’s ionosphere is based on total electron content (TEC) estimated from ground-based dual-frequency Global Positioning System (GPS) receivers. Variations in solar, geomagnetic and seismic activity cause depletions or enhancements in the ionospheric electron concentrations that can be detected as disturbances. Some of these disturbances have wave-like characteristics, where frequency of oscillation can be used to identify and classify the disturbance. In this study, the frequency of such periodic disturbances is estimated using a fast Fourier transform (FFT)-based method, namely IONOLAB-FFT, in the spectral domain. IONOLAB-FFT, which was initially developed to be used on slant TEC (STEC), is modified to be applied to TEC in the local zenith direction of the receiver. The algorithm is tested using literature data on disturbances generated by a geomagnetic activity, a solar flare, a medium-scale traveling ionospheric disturbance (MSTID), a large-scale TID (LSTID) and an earthquake. An accordance with these known disturbances is observed in running IONOLAB-FFT, and the main frequencies and durations of the disturbances are estimated. IONOLAB-FFT method is applied to TEC computed from Turkish Permanent GPS Network (TNPGN-Active) which lies in mid-latitude region to detect the any wave-like oscillations, sudden disturbances and other irregularities during December, March, June and September months for 2010, 2011 and 2012 years. It is observed that a large number of the estimated frequencies are accumulated between 0.08 and 0.14 MHz corresponding to periods of 3.5 h to 2 h. The significant frequencies are grouped less than 0.28 MHz. A large number of the durations of the oscillations are between 425 and 550 min in 2010, 300 and 550 min in 2011 and 350 and 400 min in 2012. The longest duration (around 800 min: 13.33 h) is observed in December months, and the shortest duration (around 2 h) is observed in September months.
Turkish Journal of Science and Technology
In recent years, forest fires can be brought under control in line with the information obtained ... more In recent years, forest fires can be brought under control in line with the information obtained from Unmanned Aerial Vehicles (UAVs), which play an important role in determining the progression of fires, detecting heat points and determining intervention locations. In this study, if the UAV detects the fire by autonomously positioning in the area where the fire is located, the point where the fire reaches the most intense temperature is determined with the help of the thermal camera, and it is ensured that the fireball is dropped to the target with a 100% success rate. The requirements of the UAV, which will be produced in order to realize this task, such as fast, load-carrying and stable flight are also taken into consideration. In addition to being economical and long-lasting of the materials inside, it will be able to fly efficiently in most weather conditions (foggy, dark, etc.). In the construction of the UAV, a domestic Electronic Speed Controller (ESC) with a unique design i...
Politeknik Dergisi
The ionosphere is an important layer that provides radio communication in the upper atmosphere. T... more The ionosphere is an important layer that provides radio communication in the upper atmosphere. The ionosphere is located between 50 km and 1000 km above the atmosphere. Electron density, which is the most important parameter of the ionosphere, changes depending on location, time, seasons, altitude, solar, geomagnetic and seismic activity. A significant measurable amount of electron density is Total Electron Content (TEC), which is used to probe the structure of the ionosphere and upper atmosphere. The Global Positioning System (GPS), which has a low cost and widespread receiver network is prominent used in TEC estimation. The IONOLAB-TEC data estimated from GPS is used in this study. Prediction of TEC is important phenomenon to operate and to plan the Earth-space and satellite-to-satellite communication systems, to generate the earthquake precursor signals using TEC and to detect of anomalies in the ionosphere. In this study, IONOLAB-TEC data obtained from GPS is estimated using re...
European Journal of Science and Technology
Black Sea Journal of Agriculture
With the development of technology, today, the use of technology in the field of agriculture has ... more With the development of technology, today, the use of technology in the field of agriculture has become widespread. In order to meet the increasing demand for agricultural products, automation techniques should be used in agricultural areas in order to make the production of agricultural products simpler and more efficient. In this study, an automation system is designed by making use of technology against problems such as irrigation problem and water shortage, which have become an important problem in agricultural areas. The data coming from the humidity sensor placed in the soil is processed to the controller. According to these processed data, when the soil is dry and the plant needs water, the water-pumping set automatically activates and meets the water needs of the plant. Optimum use of irrigation water to be used in agriculture is prevented unnecessary agricultural irrigation, reducing excessive water waste and providing a very high level of energy savings. At the same time, ...
43rd COSPAR Scientific Assembly. Held 28 January - 4 February, 2021
41st COSPAR Scientific Assembly, Jul 1, 2016
Ionosphere is a time varying, inhomogeneous, anisotropic and spatio-temporally dispersive medium ... more Ionosphere is a time varying, inhomogeneous, anisotropic and spatio-temporally dispersive medium whose descriptive properties can be estimated using indirect measurements. The variability of ionosphere can result from solar, geomagnetic, gravitational or seismic activities. This complex spatiotemporal variability is very difficult to be identified due to extensive scales in amplitude, duration, period and frequency of disturbances. The random field model of ionosphere, which is made up of a trend component and a variability component, can be related to various solar and geomagnetic indices such as Sun Spot Number (SSN), F10.7 solar flux, Disturbance storm time (Dst), Auroral Electrojet (AE), Kp and W-index. Since most of these indices are estimated or predicted to indicate the ionospheric activity at different parts of the Earth or they indicate global disturbance, it is highly complicated to identify and classify regional disturbances.
Yer’in iyonkuresi, uzay-havasi incelemelerinde onemli bir etkendir ve bu nedenle iyonkurenin degi... more Yer’in iyonkuresi, uzay-havasi incelemelerinde onemli bir etkendir ve bu nedenle iyonkurenin degiskenliginin incelenmesi, basta iyonkure fizigi ve radyo iletisimi olmak uzere bircok alanda onemlidir. Iyonkureyi karakterize eden temel parametreler, yukseklik, enlem, boylam, jeomanyetik isleklik, gunes islekligi ve sismik hareketlilikle degisimler gosteren elektron yogunlugudur. Iyonkureyi karakterize eden bir diger parametre ise atmosferde bir yol boyunca hesaplanan serbest elektronlarin miktarina esit olan Toplam Elektron Icerigidir (TEI). TEI olcumleri, uzay havasindaki degisimleri ve sismik hareketliligin iyonkurede yarattigi etkileri sergilemeye olanak saglar. Bu calismada, Turkiye’de konumlanmis Turkiye Ulusal Sabit GPS Istasyonlari Agindaki (TUSAGAAktif) on bir Yerkuresel Konumlama Sistemi (YKS) istasyonlarindan elde edilen TEI verileri, Capraz Ilinti Katsayisi (CIK), Simetrik Kullback-Leibler Mesafesi (KLD), L2-Normu (L2N) kullanilarak iyonkurenin sakin gunlerini, siddetli jeo...
Politeknik Dergisi, 2019
The ionosphere is an ionized layer that extends between 50 km and 1000 km altitudes in the atmosp... more The ionosphere is an ionized layer that extends between 50 km and 1000 km altitudes in the atmosphere. It plays an important role in atmospheric electricity. The ionosphere has the number of electrically charged particles and thus, it affects the propagation of the radio waves. In this study, magnitudes of impedance for different seasons and different geomagnetic activity periods in the ionospheric plasma are calculated using the real geometry of Earth. It is observed that the impedance of the ionospheric plasma in all directions generally has high values for all seasons. The diagonal components of the tensor of the impedance are greater than the other components. It is also observed that the ionospheric plasma, generally, has weak conductivity in all directions and seasons. Impedance varies inversely with electron density. Hence, geomagnetic activity periods which lead to an increase in electron density decreases the impedance. It is observed that the ionospheric plasma has a react...
Geomagnetism and Aeronomy, 2019
The ionosphere, a part of upper atmosphere, plays an important role on the propagation of radio w... more The ionosphere, a part of upper atmosphere, plays an important role on the propagation of radio waves. Hence, understanding, remote sensing and monitoring of the ionospheric phenomena can provide a compressive description to the physical process that are affected by the behavior of ionosphere. One of descriptive quantity of ionosphere is Total Electron Content (TEC). TEC is the total number of electrons integrated between two points and characterized by observing carrier phase delays of received radio signals transmitted from satellites located above the ionosphere, often using Global Positioning System (GPS) satellites. In this study, TEC is predicted from TEC estimates obtained from GPS network located in Turkey in space and time using an Adaptive Data Fusion Technique (ADF). It is observed that characteristic distributions of the predict TEC and original TEC values are similar with each other. Mean Square Errors are less than 4 TECU. ADF has a high performance for the spatio-temporal prediction when the results are compared with the techniques used in the related studies in the literature.
Geodesy and Geodynamics, 2020