Emine Tanir Kayikci

Karadeniz Technical University · Department of Geomatics Engineering

Dünya’nın yerçekimi alanı, mevcut kütle dağılımına bağlı olarak değişmektedir. İklimsel değişimler, buzul hareketleri, deniz seviyesindeki değişimler yerçekimi alanındaki değişimleri tetiklemektedir. Yerçekimi alanındaki değişime yüzey üstü ve altı sular, buzul kütleleri, okyanuslardaki hareketler sebep olmaktadır. Su kaynaklarındaki değişimin yerç...

Günümüzde iklim değişikliğine bağlı olarak atmosferdeki sera gazı miktarında ortaya çıkan artış, sıcaklıklar gittikçe artmakta ve artan sıcaklıklar ise deniz ve okyanus sularının genleşmesine, buzulların erimesine ve düzensiz ekstrem yağışlara sebep olmaktadır. Dünya nüfusunun büyük bir kısmının kıyı yerleşim alanlarında yaşıyor olması sebebiyle de...

İnsanlık tarihi boyunca meydana gelen doğal afetler can ve mal kaybına sebep olmakla beraber sosyo-ekonomik yaşamı da etkilemektedir. Türkiye, küresel iklim değişikliği kaynaklı oluşabilecek etkiler bakımından risk grubundaki ülkeler arasında değerlendirilmektedir. Ülkemizde meteorolojik ve hidrolojik birçok afet olmakta ve ciddi zararlara yol açma...

Günümüzde su kaynaklarının miktarı ve değişiminin araştırılması ve toprak nemi, yağış, sıcaklık vb. iklimsel parametrelerin su kaynaklarındaki değişimine etkisinin incelenmesi önemli araştırma konularındandır. 17 Mart 2002 tarihinde uzaya gönderilen GRACE (Gravity Recovery and Climate Experiment) uydusunun temel bilim hedefi Dünya’nın yerçekimi ala...

In this study, the relationships between possible ionospheric total electron content (TEC) anomalies and earthquake focal depths and fault types were investigated using 3,099 global earthquakes with Mw ≥ 6.0 between 2000 and 2020.

Küresel Navigasyon Uydu Sistemleri İnterferometrik Reflektometri (GNSS-IR), yansıyan sinyalleri kullanarak deniz seviyesinin belirlenmesine olanak sağlamaktadır. Bu nedenle, geleneksel mareograf ölçümlerine alternatif bir teknik olarak düşünülmektedir. Bu çalışmada; GNSS-IR tekniğinin gelgit bileşenlerinin belirlenmesine katkısı araştırılmıştır. Ça...

Artan deniz seviyesinin özellikle kıyı alanlarında çevresel, ekonomik ve sosyal açıdan önemli bir etkiye sahip olduğu bilinmektedir. Bu nedenle, deniz seviyesinde zaman içerisinde meydana gelen değişimin etkili ve doğru bir şekilde gözlemlenmesi ve değişime neden olan faktörlerin belirlenmesi önemlidir. Küresel Navigasyon Uydu Sistemleri İnterferom...

Sea level is a key component of climate change and plays an important role in the hydrological cycle. Rising sea levels have significant impacts such as environmental, social, and economic along with coastal areas. Global Navigation Satellite System Interferometric Reflectometry (GNSS-IR) enables to retrieve sea level heights using the reflected si...

Global Navigation Satellite System Reflectometry (GNSS-R) can be used to measure sea level heights based on reflected signals recorded as oscillations in signal-to-noise ratio (SNR) data. This study utilizes the SNR data from an existing MERS, located in Erdemli, Mersin on the Mediterranean coast of Turkey over a one-year time period. The dominant...

İklim senaryolarında önemli bir parametre olan deniz seviyesi değişimleri farklı konumlarda farklı oranlarda meydana gelmektedir. Bu nedenle, bölgesel ölçekte deniz seviyesinde meydana gelen değişimin belirlenmesi son derece önemlidir. Mareograf istasyonları yardımıyla deniz seviyesi gözlemlerinin elde edilmesi geleneksel bir yöntemdir. Ancak bu şe...

Küresel ve bölgesel ölçekte deniz seviyesinde meydana gelen değişimin belirlenmesi ve değişimin nedenlerinin anlaşılması iklim değişikliği çalışmalarında önemlidir. Küresel Navigasyon Uydu Sistemleri (GNSS) sinyalleri, uzaktan algılama uygulamaları için kullanılabilecek bazı ayırt edici özelliklere sahiptir. GNSS tabanlı deniz seviyesinin belirlenm...

Monitoring of sea level variation is one of the most important parameters in climate change scenarios. Therefore, realizing and determining sea level variations both on a regional and global scale are of great importance. Conventionally, the sea level variations are determined using a tide gauge. However, the tide gauge records are also impressed b...

Forecasting future sea levels is of great importance in terms of the conservation of coastal areas, monitoring and forecasting coastal ecosystems, and the maintenance and planning of coastal structures. In addition, highly accurate sea level forecasts allow adequate water management policies and coastal infrastructures to be developed. Today, many...

Very Long Baseline Interferometry (VLBI) plays an indispensable role in the realization of global terrestrial and celestial reference frames and in the determination of the full set of the Earth Orientation Parameters (EOP). The main goal of this research is to assess the quality of the VLBI observations based on the sensitivity and robustness crit...

The mean sea level has been continuously increasing since the end of the 19th century and will continue to increase in the 21st century. The Intergovernmental Panel on Climate Change (IPCC) states that the sea level will rise by 40-60 cm until 2100. This situation will lead to social and economic problems, especially in coastal areas. For this reas...

Nowadays, it is known that for many reasons such as climate change, the sea level has globally increased. Sea level rises affect coastal ecosystems and threaten coastal settlements. From a geodetic point of view, long term sea level observations are important in terms of determining the datum of vertical control networks. Copula functions, which ar...

Global Navigation Satellite System (GNSS) observations play an important role in climate studies because of the advantages they provide. An analysis of the GNSS observations can be used to obtain the zenith total delay (ZTD) parameter, which represents the effect of weather conditions. In this study, the trends of the time series of IGS (Internatio...

Günümüzde iklim değişikliği başta olmak üzere birçok nedenden dolayı deniz seviyesinin global ölçekte arttığı bilinmektedir. Deniz seviyesinde meydana gelen bu artışlar kıyı ekosistemlerini etkilemekte ve kıyı yerleşimlerini tehdit etmektedir. Jeodezik açıdan ise uzun dönemli deniz seviyesi gözlemleri düşey kontrol ağlarının datumunun güncellenmesi...

GNSS gözlemlerinin analizinden elde edilen toplam zenit gecikmesi (ZTD) hava şartlarının belirlenmesinde önemli bir parametre olması sebebiyle GNSS tekniğinin iklimsel çalışmalarda da önemli bir yeri vardır. ZTD verilerinden oluşturulan zaman serilerinin trend analizi ile, uzun dönemlerde veride meydana gelen değişimler incelenebilmektedir. Bu çalı...

Global sea level has increased about 19 cm since the last century. This increase is expected to continue in the next century. Sea level increases threaten both coastal settlements and coastal habitats. In addition, the sea level is used as the datum of vertical control networks. High rise-rates of sea level geodetically brings the problem of updati...

Bu çalışmada, Ege Denizi’ nde bulunan 8 mareograf istasyonunda (Thessaloniki, Alexandroupolis, Khilos, Mentes, Bodrum 2, Leros, Siros, Khalkis North) (Şekil 1) 1990 – 2008 yılları arasında kaydedilen aylık ortalama deniz seviyesi verileri ile Ege Denizi’ nin uzun dönemli deniz seviyesi değiĢimleri ve bu değişimlerin deniz yüzey sıcaklığı anomaliler...

In recent years, Global Navigation Satellite Systems (GNSS) have gained great importance in terms of the benefi ts it provides such as precise geodetic point positioning, determining crustal deformations, navigation, vehicle monitoring systems and meteorological applications etc. As in Turkey, for this purpose, each country has set up its own GNSS...

Nowadays, climate change is one of the most important environmental problems and there are many scientific studies on adaptation to climate change. Zenith Tropospheric Delay (ZTD) have a great importance in climate change studies. Analyzes of Global Navigation Satellite System (GNSS) observations can be used to obtain the ZTD parameter representing...

This report summarizes the activities of the KTU-GEOD IVS Analysis Center (AC) in 2013 and outlines the planned activities for the year 2014. Determination of optimal weights of constraints on VLBI auxiliary parameters as well as estimation interval lengths have been our specific interests in 2013.

IVS Analysis Centers apply various statistical methods, namely Least-Squares (LSQ) method, the Kalman Filter (KF) method, the Square-Root Information Filter (SRIF) and the Least-Squares Collocation (LSQC) method and consider the behaviour of stochastic parameters in different approaches. The majority of geodetic VLBI analysis softwares uses LSQ, e....

Günümüzde, iklim değişikliği en önemli çevre sorunlarından biridir ve iklim değişikliğine uyum konusunda pek çok bilimsel çalışma yapılmaktadır (Demircan vd.,2016). GNNS (Global Navigation Satellite System) gözlemleri sağladığı avantajlar dolayısıyla iklimsel çalışmalarda önemli bir rol oynamaktadır (Baldysz vd.,2016). GNSS gözlemlerinin analizleri...

The Project proposal “Using Regional GNSS Networks to Strengthen Severe Weather Prediction” has been selected by The Scientific and Research Council of Turkey to be funded under “1001 - Scientific and Technological Research Projects Funding Program”. The project received a three-year grant of 304.685,60 TL. The project team consist of one manager,...

Integrated water vapour (IWV) is calculated from processing of GNSS data and IWV time series are produced. IWV time series analysis is important to monitoring of climate changes. Inhomogeneities caused by earthquakes, changes in hardware or equipment etc., can affect actual trends and seasonal variability in time series. This work presents a methodo...

Integrated water vapour (IWV) is calculated from processing of GNSS data and IWV time series are produced. IWV time series analysis is important to monitoring of climate changes.Inhomogeneities caused by earthquakes, changes in hardware or equipment etc., can affect actual trends and seasonal variability in time series. This work presents non-parame...

Time series of any climatic variables, e.g., precipitation, may be affected by non-climatic factors, which may alter the climatic signals. Homogeneous climatic time series are important for climate change studies. Inhomogeneities caused by station relocation and instrumentation changes, etc., can mask actual trends and seasonal variability in time...

T his p ap er focuses on the performance o f tworegression-based and one Inverse Distance Weighted (IDW)and two combined versions of IDW methods for interpolationof daily mean temperature at the Black Sea Region of Turkey.Simple linear regression (SLR) and multiple linear regression(MLR) are used as regression-based methods. Combinationsof IDW with...

Son yıllarda, GNSS verilerin değerlendirilmesi veya yeniden değerlendirilmesi sırasında Zenit Troposferik Gecikmesi (Zenit Total Delay-ZTD) ve Entegre Su Buharı (Integrated Water Vapour-IWV) zaman serileri üretilmiştir. ZTD ve IWV zaman serilerinin en önemli avantajı iklim değişikliğinin takibi için kullanılmasıdır. Genelde iklimsel olmayan faktörl...

Son yıllarda, GNSS verilerin değerlendirilmesi veya yeniden değerlendirilmesi sırasında Zenit Troposferik Gecikmesi (Zenit Total Delay-ZTD) ve Entegre Su Buharı (Integrated Water Vapour-IWV) zaman serileri üretilmiştir. ZTD ve IWV zaman serilerinin en önemli avantajı iklim değişikliğinin takibi için kullanılmasıdır. Genelde iklimsel olmayan faktörl...

İklim zamansal ve konumsal süreçlerde devamlı bir değişim içerisindedir. Bu değişim meydana getirdiği etkilerden dolayı günümüzde üzerinde yoğun olarak çalışılan önemli problemlerden biridir. İklimin ana elemanlarından biri olan sıcaklık ile ilgili bilgiler iklim değişimlerinin karakterlerinin belirlenmesinde büyük öneme sahiptir. Bu çalışmanın ama...

Meteorological and climate studies are enrichments with new observation technic and technology as well as secondary equipment’s such as Global Positioning System GPS/ Global Navigation Satellite System (GNSS). To determine the accurate data in GNSS, it is need to know Integrated Water Vapour (IWV) which cause to tropospheric zenith delay. Vice vers...

In this paper station coordinate time series from three space geodesy techniques that have contributed to the realization of the International Terrestrial Reference Frame 2014 (ITRF2014) are compared. In particular the height component time series extracted from official combined intra-technique solutions submitted for ITRF2014 by DORIS, VLBI and G...

In this study, the estimation of a local geoid model in the area of Trabzon by using geometric methods is presented. The geometric method used in this study interpolates Global Positioning System-derived ellipsoidal and orthometric heights by using the weighted average interpolation, polynomial surface regression, and multiquadratic interpolation....

Seasonal components in the ZTD (Zenith Tropospheric Delay) and IWV (Integrated Water Vapour) time series are important and provide information about weather conditions in a given region. The main purpose of this research is to analyze linear trends and seasonal components of ZTD’s and IWS’s in GPS reprocessing campaign at selected stations in Europ...

Spatial interpolation methods are frequently used to estimate values of meteorological data in locations where they are not measured. The correct determination of the spatial distribution of meteorological variables is as important as their measurement. Although there are several methods to perform this, it can be difficult to determine which one b...

Global Positioning System (GPS) satellites have been used as sensors with the development in space and satellite techniques. Total Electron Content (TEC) variations in the ionosphere before, during and after the earthquake can be identified by means of GPS observations. Thus, the effects of earthquakes over TEC variations can be monitored. In this...

In this work we have compared the Up component time series reprocessed in view of the new ITRF2014. The solutions that we have considered are the combinations of individual submissions of the Operational Analysis Centers (ACs) as official IVS, IGS and IDS products. We have modelled time series as discrete-time Marcov processes, we have detected and...

Evaluating the distribution patterns of surface temperature data at Very Long Baseline Interferometry (VLBI)/Global Positioning System (GPS) co-located sites w.r.t. normality is one of the most important issues in modeling surface temperature data over long periods. Such evaluation can generate algorithms for filling in missing data at measurement...

This report summarizes the activities of the KTU-GEOD IVS Analysis Center (AC) in 2014 and outlines the planned activities for 2015. Determination of optimal weights of constraints on VLBI auxiliary parameters as well as estimation intervals is our specific interest in 2015.

Very Long Baseline Interferometry (VLBI) is a primary space-geodetic technique for determining precise coordinates on the Earth, for monitoring the variable Earth rotation and orientation with highest precision, and for deriving many other parameters of the Earth system. The International VLBI Service for Geodesy and Astrometry (IVS, http://ivscc.g...

This report summarizes the activities of the KTU-GEOD IVS Analysis Center (AC) in 2013 and outlines the planned activities for the year 2014. Determination of optimal weights of constraints on VLBI auxiliary parameters as well as estimation interval lengths have been our specific interests in 2013.

Earth Orientation Parameters (EOP) provide the rotation from the ITRS to the GCRS as a function of time. When estimating a Celestial Reference Frame (CRF) usually a number of radio sources with a long history of observations and stable positions are included in the datum definition used to define the orientation of the frame. To estimate the Intern...

In a general parameter estimation model, a priori information is used to linearize the system of equations being solved so that just offsets to the a priori values need to be estimated. A priori information used in Very Long Baseline Interferometry (VLBI) data analysis is additionally needed for modeling and constraining the auxiliary parameters, i...

The importance of geodetic deformation measurements and analysis has gradually increased in the last decade. The method which is commonly used to determine deformation is called the geodetic monitoring network method. The monitoring network consists of deformation control points (object points) which are established on the moving area and control p...

This report summarizes the activities of the KTU-GEOD IVS Analysis Center (AC) in 2012 and outlines planned activities for 2013. The analysis of the EUROPE sessions is one of our specific interests, and the combination of different AC solutions for continuous VLBI campaigns, e.g. CONT11, will be investigated.

This report summarizes the activities of the KTU-GEOD IVS Analysis Center (AC) in 2011 and outlines the planned activities for the year 2012. Analysis of the EUROPE sessions is one of our specific interests. Combination of different AC solutions for continuous VLBI sessions, e.g., CONT11 sessions, will be investigated.

This report summarizes the activities of the KTU-GEOD IVS Analysis Center (AC) in 2010 and outlines the planned activities for the year 2011. Analysis of the IVS EUROPE sessions is one of our specific interests.

Uluslararası Çok Uzun Baz Enterferometrisi Jeodezi ve Astrometri Servisi (International Very Long Baseline Interferometry for Geodesy and Astrometry, IVS) bünyesinde Avrupa’daki kabuk hareketlerini belirlemek ve Avrupa için sürdürülen duyarlığı yüksek ve stabil yer sabit referans çatısına (European Terrestrial Reference Frame, ETRF) katkı sağlamak...

This report summarizes the establishment process of the KTU-GEOD IVS Analysis Center (AC) and its foreseen scientific activities. Beginning from 23rd of March 2009, the date the IVS Directing Board approved our application for establishing an AC named as KTU-GEOD in Turkey, we equipped our office with two workstations, one server, and one printer. All...

In this study, we investigate the coordinate time series of the radio telescopes which regularly take part in IVS-R1 and-R4 sessions. Firstly, we determine the linear trend (velocity vectors of the antenna coordinates) due to e.g. plate tectonics. The trends of the coordinate time series are estimated by Least Squares (LS), fitting the coefficients...

Various important aspects should be taken into account in the combination of different space geodetic techniques. Consistency of models and standards, quality checks of solutions from individual Analysis Centers (AC), proper scaling of these solutions within the combination process, usage of rigorous combination methods and quality checks of the fi...

In order to investigate the deformations of an area or an object, geodetic observations are repeated at different time epochs and then these observations of each period are adjusted independently. From the coordinate differences between the epochs the input parameters of a deformation model are estimated. The decision about the deformation is given...

This paper presents the results of a case study analysis applied to the Very Long Baseline Interferometry (VLBI) session 021020XA in terms of datum deficiency. An analysis was performed to determine the num-ber of minimal conditions or constraints neces-sary to remove the datum deficiency (for various parameter combinations). The respective num-ber...

The IVS (International VLBI Service for Geodesy and Astrometry) Analysis Centers (BKG (Federal Agency for Cartography and Geodesy), NASA GSFC (Goddard Space Flight Center), DGFI (Deutsches Geodaetisches Forschungsinstitut), SHA (Shanghai Astronomical Observatory), USNO (U.S. Naval Observatory), MAO (Main Astronomical Observatory), AUS (Geoscience A...

Among other studies in 2006, the Institute of Geodesy and Geophysics (IGG) at the Vienna University of Technology has carried out Monte-Carlo simulations to assist the development of a new geodetic VLBI system (VLBI2010). These investigations are critical for the definition of the observing strategy and network configuration, and it has been shown...

Based on the recommendations given by the Global Geodetic Observing System (GGOS), common standards in modeling, parameterization (designation of unknowns) and analysis will be homogenized and improved across the various space geodetic techniques. In addition, there is the project VLBI2010 of the International VLBI Service for Geodesy and Astrometr...

The VLBI software packages for the data analysis which are used by different IVS (International VLBI Service for Geodesy and Astrometry) Analysis Centers applying various statistical methods. These statistical methods are the Least-Squares (LSQ) method, the Kalman filter (KF) method, the Square-Root Information Filter (SRIF) and the Least-Squares C...