Pub Date : 2015-08-20DOI: 10.1109/RAST.2015.7208314
D. Micheli, R. Pastore, A. Vricella, M. Marchetti
This research is focused on simulation, manufacturing and measuring of shell radar absorbing structure of missiles. The novelty of the work is the study of a curved radar absorbing structure. The enhancement of electromagnetic wave absorption is obtained by using carbon nanotube filler in different weight ratio with respect to the epoxy-resin adopted in shell manufacturing. The structural resistance is granted by the use of conventional fiberglass. A radar absorbing prototype of an half shell, having the section of 15 cm radius has been built and characterized. The thickness of the shell is around 6.5 mm and is made of two different loaded layers. The measurements of electromagnetic reflection coefficient has been performed for two different incidence angles of 0° and 45°. The reflection coefficient show values down to -18 dB around 3 GHz and -10 dB around 11 GHz for 0° incidence angle, and -6 dB around 3 GHz and -10 dB around 12 GHz for 45° incidence angle. An electromagnetic simulation of a flat structure having the same layering configuration of the shell shows values of reflection coefficient very similar to the measured one for 0° incidence angle.
{"title":"Shell absorbing nanostructure for low radar observable missile","authors":"D. Micheli, R. Pastore, A. Vricella, M. Marchetti","doi":"10.1109/RAST.2015.7208314","DOIUrl":"https://doi.org/10.1109/RAST.2015.7208314","url":null,"abstract":"This research is focused on simulation, manufacturing and measuring of shell radar absorbing structure of missiles. The novelty of the work is the study of a curved radar absorbing structure. The enhancement of electromagnetic wave absorption is obtained by using carbon nanotube filler in different weight ratio with respect to the epoxy-resin adopted in shell manufacturing. The structural resistance is granted by the use of conventional fiberglass. A radar absorbing prototype of an half shell, having the section of 15 cm radius has been built and characterized. The thickness of the shell is around 6.5 mm and is made of two different loaded layers. The measurements of electromagnetic reflection coefficient has been performed for two different incidence angles of 0° and 45°. The reflection coefficient show values down to -18 dB around 3 GHz and -10 dB around 11 GHz for 0° incidence angle, and -6 dB around 3 GHz and -10 dB around 12 GHz for 45° incidence angle. An electromagnetic simulation of a flat structure having the same layering configuration of the shell shows values of reflection coefficient very similar to the measured one for 0° incidence angle.","PeriodicalId":282476,"journal":{"name":"2015 7th International Conference on Recent Advances in Space Technologies (RAST)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132373614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-08-20DOI: 10.1109/RAST.2015.7208341
H. Yaşar, Rıdvan Safa Hatipoğlu, M. Ceylan
The obtaining of the aerial images got easy thanks to technological developments in the field of unmanned aerial vehicles and these images were began to be used frequently in the field of image processing. Automatic changes detection from aerial images is among the most important study fields. An automatic system for changes detection has been proposed by using contourlet transform and artificial neural network (ANN) in this study. The contourlet transform is applied to the reference image in the first phase of the system consisting of two phases. Mean, variance, standard deviation and skewness values were calculated from the obtained sub-image matrix and seven image feature vectors are formed by using these statistical values and combinations. The numerical equivalents of the reference image were obtained by using the feature vectors by ANN. The same procedures were applied to the image that its exchange will be examined in the second phase of the system. The change between numerical provisions of the reference image and the image to be examined compared to the threshold value set by the user and automatic changes detection was performed. It was found that the changes in numerical results obtained at the end of the study overlap with the changes in aerial images.
{"title":"An automatic system of detecting changes in aerial images using ANN based contourlet transform","authors":"H. Yaşar, Rıdvan Safa Hatipoğlu, M. Ceylan","doi":"10.1109/RAST.2015.7208341","DOIUrl":"https://doi.org/10.1109/RAST.2015.7208341","url":null,"abstract":"The obtaining of the aerial images got easy thanks to technological developments in the field of unmanned aerial vehicles and these images were began to be used frequently in the field of image processing. Automatic changes detection from aerial images is among the most important study fields. An automatic system for changes detection has been proposed by using contourlet transform and artificial neural network (ANN) in this study. The contourlet transform is applied to the reference image in the first phase of the system consisting of two phases. Mean, variance, standard deviation and skewness values were calculated from the obtained sub-image matrix and seven image feature vectors are formed by using these statistical values and combinations. The numerical equivalents of the reference image were obtained by using the feature vectors by ANN. The same procedures were applied to the image that its exchange will be examined in the second phase of the system. The change between numerical provisions of the reference image and the image to be examined compared to the threshold value set by the user and automatic changes detection was performed. It was found that the changes in numerical results obtained at the end of the study overlap with the changes in aerial images.","PeriodicalId":282476,"journal":{"name":"2015 7th International Conference on Recent Advances in Space Technologies (RAST)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114933265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-08-20DOI: 10.1109/RAST.2015.7208438
A. Cepe, A. Golovan
GNSS based attitude determination algorithms require highly accurate data about the geometry of receiver's antennas. Due to a variety of factors, such as heating and gravity, somewhat mechanical distortions occur in the baselines' configuration. In order to improve the performance of attitude estimation algorithm, it is of importance to determine the baseline biases arising from these distortions. However, notably in real-time applications computation of full-order models which include baseline biases may lead to a significant computational burden to the filter, resulting in a decrease in performance of algorithms. In this paper we've performed an analysis of the attitude estimation algorithm for the reduced-order models. Based on stochastic measure of observability we've examined the performance of the Kalman filter.
{"title":"Stochastic analysis of reduced order GNSS based attitude determination algorithm","authors":"A. Cepe, A. Golovan","doi":"10.1109/RAST.2015.7208438","DOIUrl":"https://doi.org/10.1109/RAST.2015.7208438","url":null,"abstract":"GNSS based attitude determination algorithms require highly accurate data about the geometry of receiver's antennas. Due to a variety of factors, such as heating and gravity, somewhat mechanical distortions occur in the baselines' configuration. In order to improve the performance of attitude estimation algorithm, it is of importance to determine the baseline biases arising from these distortions. However, notably in real-time applications computation of full-order models which include baseline biases may lead to a significant computational burden to the filter, resulting in a decrease in performance of algorithms. In this paper we've performed an analysis of the attitude estimation algorithm for the reduced-order models. Based on stochastic measure of observability we've examined the performance of the Kalman filter.","PeriodicalId":282476,"journal":{"name":"2015 7th International Conference on Recent Advances in Space Technologies (RAST)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126794956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-08-20DOI: 10.1109/RAST.2015.7208452
Mohamed Abo-Arais, Mohamed Elfeki, Abdullah Mohammed, Mahmoud El-Mohr, Belal Abdelmoteleb, A. Hatem, Abo-Bakr Mohamed, Ahmed Ramy, Khaled Walid, M. El-Fiky, Ahmed Darwish, Mostafa Abd Al-Kareem, Walid El-Ajmi, Mohamed Gaber, M. Salah, A. Sobhy
Conquest of the space spreads with small educational projects that aim to explore the capabilities and the potentials that the mankind have. This paper concludes our experiments that led to launching the second Can-Sat form Alexandria, Egypt under affiliation of Space and Technology Program in Bibliotecha Alexandrina. Here we presents our satellite system and the communication system that connects the ground station to the flying system, as well it represents the launching procedure, and some of the problems we overboard during our project duration.
{"title":"Approaching a nano-satellite using CAN-SAT systems","authors":"Mohamed Abo-Arais, Mohamed Elfeki, Abdullah Mohammed, Mahmoud El-Mohr, Belal Abdelmoteleb, A. Hatem, Abo-Bakr Mohamed, Ahmed Ramy, Khaled Walid, M. El-Fiky, Ahmed Darwish, Mostafa Abd Al-Kareem, Walid El-Ajmi, Mohamed Gaber, M. Salah, A. Sobhy","doi":"10.1109/RAST.2015.7208452","DOIUrl":"https://doi.org/10.1109/RAST.2015.7208452","url":null,"abstract":"Conquest of the space spreads with small educational projects that aim to explore the capabilities and the potentials that the mankind have. This paper concludes our experiments that led to launching the second Can-Sat form Alexandria, Egypt under affiliation of Space and Technology Program in Bibliotecha Alexandrina. Here we presents our satellite system and the communication system that connects the ground station to the flying system, as well it represents the launching procedure, and some of the problems we overboard during our project duration.","PeriodicalId":282476,"journal":{"name":"2015 7th International Conference on Recent Advances in Space Technologies (RAST)","volume":"416 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134467322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-06-16DOI: 10.1109/RAST.2015.7208429
S. Gao, F. Qin, C. Mao, A. Patyuchenko, M. Younis, G. Krieger, S. Glisic, W. Debski, L. Boccia, G. Amendola, E. Arnieri, M. Krstic, A. Koczor, P. Penkala, E. Celton
A Ka/X-band digital beamforming (DBF) spaceborne Synthetic Aperture Radar (SAR) is presented in this paper. To overcome the performance limitations of current SAR systems while reducing the cost, size, mass and power consumption, it employs a multi-static passive radar concept using DBF, highly integrated analogue and digital circuits and shared-aperture Ka/X band dual-polarization antennas. Compact modular architecture of the proposed system enables the realization of various configurations of spaceborne SAR missions. The radar concept is introduced, followed by some results of antennas, analogue and digital circuits as well as the MMIC technologies.
{"title":"A Ka/X-band digital beamforming synthetic aperture radar for earth observation","authors":"S. Gao, F. Qin, C. Mao, A. Patyuchenko, M. Younis, G. Krieger, S. Glisic, W. Debski, L. Boccia, G. Amendola, E. Arnieri, M. Krstic, A. Koczor, P. Penkala, E. Celton","doi":"10.1109/RAST.2015.7208429","DOIUrl":"https://doi.org/10.1109/RAST.2015.7208429","url":null,"abstract":"A Ka/X-band digital beamforming (DBF) spaceborne Synthetic Aperture Radar (SAR) is presented in this paper. To overcome the performance limitations of current SAR systems while reducing the cost, size, mass and power consumption, it employs a multi-static passive radar concept using DBF, highly integrated analogue and digital circuits and shared-aperture Ka/X band dual-polarization antennas. Compact modular architecture of the proposed system enables the realization of various configurations of spaceborne SAR missions. The radar concept is introduced, followed by some results of antennas, analogue and digital circuits as well as the MMIC technologies.","PeriodicalId":282476,"journal":{"name":"2015 7th International Conference on Recent Advances in Space Technologies (RAST)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125264285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-06-16DOI: 10.1109/RAST.2015.7208307
H. Fekrmandi, Rafael Gonzalez Sebastian Rojas, I. Tansel, David Meiller, Kyle Lindsay
In this study surface response to excitation (SuRE) method with a neural network was used for structural health monitoring of an aluminum beam. SuRE method excited and monitored the elastic guided waves on the structure. The frequency-transfer function was captured over a range of high frequencies (20-200 kHz) using a low cost Digital Signal Processor (DSP) system. For magnitude estimation, the amplitude of the received signal for each frequency value is calculated. With the magnitude estimation, the frequency domain spectrum response is calculated. Using an aluminum plate as the experimental surface, load in different points of the beam were applied and the response signals organized in a database. With the experimental data, a neural network is trained with the Levenberg-Marquardt algorithm and then trained with the scaled conjugated gradient algorithm. The study indicated that the SuRE method may be used as a low cost alternative to detect surface changes.
{"title":"Automation of the interpretation of surface response to excitation (SuRE) method by using neural networks","authors":"H. Fekrmandi, Rafael Gonzalez Sebastian Rojas, I. Tansel, David Meiller, Kyle Lindsay","doi":"10.1109/RAST.2015.7208307","DOIUrl":"https://doi.org/10.1109/RAST.2015.7208307","url":null,"abstract":"In this study surface response to excitation (SuRE) method with a neural network was used for structural health monitoring of an aluminum beam. SuRE method excited and monitored the elastic guided waves on the structure. The frequency-transfer function was captured over a range of high frequencies (20-200 kHz) using a low cost Digital Signal Processor (DSP) system. For magnitude estimation, the amplitude of the received signal for each frequency value is calculated. With the magnitude estimation, the frequency domain spectrum response is calculated. Using an aluminum plate as the experimental surface, load in different points of the beam were applied and the response signals organized in a database. With the experimental data, a neural network is trained with the Levenberg-Marquardt algorithm and then trained with the scaled conjugated gradient algorithm. The study indicated that the SuRE method may be used as a low cost alternative to detect surface changes.","PeriodicalId":282476,"journal":{"name":"2015 7th International Conference on Recent Advances in Space Technologies (RAST)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125345829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-06-16DOI: 10.1109/RAST.2015.7208362
Abdullah H. Ozcan, C. Unsalan
LiDAR data provides valuable information for various remote sensing applications. For these, one important and challenging problem is ground filtering. This operation separates the bare earth and object data. Researchers proposed several methods to solve this problem. However, the complexity of the data limit the usability of these methods for all terrain types. Besides, the performance obtained in ground filtering should be improved further. In this study, we focus on this problem and propose a novel ground filtering method using Empirical Mode Decomposition (EMD). We tested the proposed method on the standard ISPRS data set and evaluate its strengths and weaknesses. We also compared the proposed method with the ones in the literature to show the improvements obtained.
{"title":"Using empirical mode decomposition for ground filtering","authors":"Abdullah H. Ozcan, C. Unsalan","doi":"10.1109/RAST.2015.7208362","DOIUrl":"https://doi.org/10.1109/RAST.2015.7208362","url":null,"abstract":"LiDAR data provides valuable information for various remote sensing applications. For these, one important and challenging problem is ground filtering. This operation separates the bare earth and object data. Researchers proposed several methods to solve this problem. However, the complexity of the data limit the usability of these methods for all terrain types. Besides, the performance obtained in ground filtering should be improved further. In this study, we focus on this problem and propose a novel ground filtering method using Empirical Mode Decomposition (EMD). We tested the proposed method on the standard ISPRS data set and evaluate its strengths and weaknesses. We also compared the proposed method with the ones in the literature to show the improvements obtained.","PeriodicalId":282476,"journal":{"name":"2015 7th International Conference on Recent Advances in Space Technologies (RAST)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125397160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-06-16DOI: 10.1109/RAST.2015.7208310
C. Tola, M. Nikbay
The main focus of this study is to examine the effect of thickness, taper ratio and aspect ratio on the fin flutter speed of a model rocket using response surface method. The most effective geometric parameter on fin flutter is determined. Coupled effects of these parameters are also analyzed within the content of the study. Additionally, a response surface representing the flutter velocity behavior is also determined. Modal analysis of different fin geometries having the same planform area have been performed using a FEA solver and the variation of the natural frequencies under the suitable boundary conditions are examined. Then, flutter analysis are performed using an aeroelastic solver based on the results of the modal analysis. As a result, taking the advantage of response surface method, the effect of thickness, taper ratio, aspect ratio and also the combined effects of these parameters on flutter speed is presented.
{"title":"Investigation of the effect of thickness, taper ratio and aspect ratio on fin flutter velocity of a model rocket using response surface method","authors":"C. Tola, M. Nikbay","doi":"10.1109/RAST.2015.7208310","DOIUrl":"https://doi.org/10.1109/RAST.2015.7208310","url":null,"abstract":"The main focus of this study is to examine the effect of thickness, taper ratio and aspect ratio on the fin flutter speed of a model rocket using response surface method. The most effective geometric parameter on fin flutter is determined. Coupled effects of these parameters are also analyzed within the content of the study. Additionally, a response surface representing the flutter velocity behavior is also determined. Modal analysis of different fin geometries having the same planform area have been performed using a FEA solver and the variation of the natural frequencies under the suitable boundary conditions are examined. Then, flutter analysis are performed using an aeroelastic solver based on the results of the modal analysis. As a result, taking the advantage of response surface method, the effect of thickness, taper ratio, aspect ratio and also the combined effects of these parameters on flutter speed is presented.","PeriodicalId":282476,"journal":{"name":"2015 7th International Conference on Recent Advances in Space Technologies (RAST)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125505875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-06-16DOI: 10.1109/RAST.2015.7208431
Demet Cilden, C. Hajiyev, H. Soken
Singular value decomposition (SVD) method and unscented Kalman filter (UKF) are integrated to estimate the attitude and attitude rates of a nanosatellite recursively. First the SVD method minimizes the Wahba's loss function to find the optimal solution for the attitude on the basis of magnetometer and sun sensor vector measurements. Then the UKF uses this attitude information as the measurements for providing more accurate attitude estimates even when the satellite is in eclipse. The “rotation angle error covariance matrix” calculated for the estimations of the SVD method are regarded as the measurement noise covariance for the UKF. Discussions for the UKF tuning are included specifically for the eclipse period where the SVD method fails and practically there is no measurements incoming to the filter.
{"title":"Attitude and attitude rate estimation for a nanosatellite using SVD and UKF","authors":"Demet Cilden, C. Hajiyev, H. Soken","doi":"10.1109/RAST.2015.7208431","DOIUrl":"https://doi.org/10.1109/RAST.2015.7208431","url":null,"abstract":"Singular value decomposition (SVD) method and unscented Kalman filter (UKF) are integrated to estimate the attitude and attitude rates of a nanosatellite recursively. First the SVD method minimizes the Wahba's loss function to find the optimal solution for the attitude on the basis of magnetometer and sun sensor vector measurements. Then the UKF uses this attitude information as the measurements for providing more accurate attitude estimates even when the satellite is in eclipse. The “rotation angle error covariance matrix” calculated for the estimations of the SVD method are regarded as the measurement noise covariance for the UKF. Discussions for the UKF tuning are included specifically for the eclipse period where the SVD method fails and practically there is no measurements incoming to the filter.","PeriodicalId":282476,"journal":{"name":"2015 7th International Conference on Recent Advances in Space Technologies (RAST)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114928543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-06-16DOI: 10.1109/RAST.2015.7208399
S. Shukurov, F. Arıkan, T. Gulyaeva
Ionosphere has importance for civilian and military Short Wave (SW) and satellite communications. Earthquakes, Solar Explosions and geomagnetic storms have effects on this layer. Electron density of ionosphere provides necessary information to investigate the ionospheric variability. In this study ionospheric variability over the Turkey are investigated using Cross Correlation Coefficient on IONOLAB-STEC data. The Slant Total Electron Content (STEC) data that are used are obtained from Turkish National Permanent GPS Network (TNPGN) stations.
{"title":"Observing ionosphere over Turkey using Correlation Coefficient for slant total electron content","authors":"S. Shukurov, F. Arıkan, T. Gulyaeva","doi":"10.1109/RAST.2015.7208399","DOIUrl":"https://doi.org/10.1109/RAST.2015.7208399","url":null,"abstract":"Ionosphere has importance for civilian and military Short Wave (SW) and satellite communications. Earthquakes, Solar Explosions and geomagnetic storms have effects on this layer. Electron density of ionosphere provides necessary information to investigate the ionospheric variability. In this study ionospheric variability over the Turkey are investigated using Cross Correlation Coefficient on IONOLAB-STEC data. The Slant Total Electron Content (STEC) data that are used are obtained from Turkish National Permanent GPS Network (TNPGN) stations.","PeriodicalId":282476,"journal":{"name":"2015 7th International Conference on Recent Advances in Space Technologies (RAST)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122072150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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