Kerem Halicioglu

• PhD
• Bundesanstalt für Geowissenschaften und Rohstoffe

Observations carried out to obtain astrogeodetic deflections of the vertical components in Türkiye began in 1942 with classical optical-mechanical astrogeodetic instruments. Thanks to digital astrogeodetic systems developed in parallel with the advancement of technology, astrogeodetic observation times have been shortened, the precision of observed...

Eşpotansiyel yüzeylerin belirlenmesine ilişkin geleneksel yöntemler gravite ve yükseklik ölçmelerine dayanmaktadır. Bu yaklaşımlar yola bağımlı olarak biriken hatalar barındırırken, yüzey bilgisinin farklı veri kombinasyonları ile dolaylı olarak elde edilmesi de hata birikimini artırmaktadır. Konvansiyonel yöntemlerin önemli sorunları arasında araz...

Turkey, as a developing country, is designing and performing massive construction projects around Istanbul. Beginning from the 1960s, rapid urbanization has been taking place due to industrialization, which brings an increase in the population. Yet, construction projects have been accelerated especially during the last decade, and many new projects...

We present the first high-precision astrogeodetic vertical deflection (VD) observations collected in Istanbul, Turkey, using a novel lightweight total station integrated with a charge-coupled device (CCD) camera, the QDaedalus system. The observed VDs are unique in that, they were measured for the first time in Istanbul, and they form Turkey's firs...

The Istanbul GPS Triangulation Network (IGTN) and the Istanbul Levelling Network (ILN), established in 2006, provide data for the determination of a local GNSS/levelling geoid model. These networks' measurements were done separately on both the Asian and European sides of the Bosphorus Strait in the vicinity of Istanbul. To connect these regions fo...

Genel Görelilik teorisinin bir sonucu olarak, kütleçkimsel alanlar gözlemci zaman akışını etkilemektedir. Zaman akışının aynı hıza sahip olduğu yüzeyler, Newton potansiyeli ile tariflenen eşpotansiyel yüzey kavramı ile aynı yüzeyleri tarif etmektedir. Eşpotansiyel yüzeyler klasik anlamda uzun yıllardır gravite ve yükseklik ölçmelerine bağlı olarak...

The Digital Zenith Camera Systems (DZCSs) are dedicated astrogeodetic instruments used to obtain highly accurate astrogeodetic vertical deflection (VD) data. The first Turkish DZCS, the Astrogeodetic Camera System (ACSYS), was developed in Istanbul, Turkey in 2015. The ACSYS was capable of determining astrogeodetic VDs with an accuracy of ~0.3 arcs...

We present the first astrogeodetic vertical deflections (VDs) observations using the QDaedalus systems in Istanbul. To establish the Istanbul astrogeodetic network, we selected 30 homogeneously distributed existing geodetic benchmarks, often located in coastal and mountainous settings. A total of three measurement campaigns were carried out from Fe...

The geoid is the equipotential surface of the Earth. Modeling the geoid with high accuracy is one of the critical issues in Geodesy. Development of geoid modeling is based on geodetic, gravimetric and astrogeodetic techniques. In order to reach the intended accuracy, deflection of the vertical (VD) components, which is obtained by the astrogeodetic...

Geoid is the fundamental geodetic infrastructure for rational use of Global Navigation Satellite System (GNSS) technology. For this reason, definition a ”cm geoid” is an actual subject in all countries. Development of geoid modelling is based on geodetic, gravimetric and astrogeodetic techniques, which are maintained using the geopotential models p...

National and local geoid models that are required to transform ellipsoidal heights from GNSS technique to practical (orthometric) heights are developed using data collected by different techniques. Development of geoid modelling is based on geodetic, gravimetric and astrogeodetic techniques, which are maintained using the geopotential models produc...

North Anatolian Fault bifurcates as northern and southern branches in the eastern Marmara region. Despite the fact that there are so many scientific studies on the northern part, there are limited studies on the southern strand. Having more than 150 km length, strike-slip structure south strand has a series of segments as Geyve, Iznik and Gemlik fa...

Astro-geodetic deflections of the vertical components provide accurate and valuable information of Earth’s gravity filed. Conventional methods require considerable effort and time whereas new methods, namely digital zenith camera systems (DZCS), have been designed to eliminate drawbacks of the conventional methods, such as observer dependent errors...

This study introduces the new results of a novel low-cost digital zenith camera system operated in Turkey that uses astronomical and geodetic instrumentation. Currently, it is possible to determine deflections of the vertical (DoV) components by using a vast amount of information gathered from geo-referenced star images, tilt measurements, and Glob...

GNSS observations on the western part of the North Anatolian Fault Zone (NAFZ) have been carrying out since the beginning of 1990s. August 17, 1999, Izmit earthquake (Mw= 7.4) excited more scientific attention on this area. Bogazici University Kandilli Observatory and Earthquake Research Institute (KOERI), Geodesy Department has been continually co...

Many great and important engineering projects have been realised in the city of Istanbul, which is one of the largest metropolises in the world. Fundamental geodetic infrastructure created for the diverse nature of these projects is of vital importance. Determination of a geoid model with high accuracy through the use of GNSS technology and levelli...

http://meetingorganizer.copernicus.org/EGU2016/EGU2016-9874.pdf

The East Anatolian Fault System (EAFS) is the second major fault system in Turkey, following the North Anatolian Fault System (NAFS). Unlike the NAFS, which produced 11 large earthquakes in the last ∼75 years, the EAFS has been relatively quiet during the same period of time. While historical records show that the EAFS has the potential to produce...

Astro-geodetic deflections of the vertical are crucial measurements in geoid determination studies and density investigations. Digital Zenith Camera Systems (DZCS) have been developed since the 2000s, which have been equipped with precise electronic tiltmeters, GPS receivers and CCD technology. After the first studies on DZCS in Germany, Switzerlan...

http://adsabs.harvard.edu/abs/2013AGUFM.G51A0881H

There are several current investigations on gravity field of the earth in Geodesy and Geophysics. Earth sciences and space researches are also interested in gravity studies. Geoid, which approximately has an equal potential to the potential of mean sea level, is the main datum for height systems and is used for coordinate transformation , reduction...

Both seismological and geodynamic research emphasize that the Aegean Region, which comprises the Hellenic Arc, the Greek mainland, and Western Turkey is the most seismically active region in Western Eurasia. The convergence of the Eurasian and African lithospheric plates forces a westward motion on the Anatolian plate relative to the Eurasian one....

During the last few years, the development of CCD image sensors at a reasonable price made the instruments of astrogeodetic observation possible to use for local high-precision astrogeodetic geoid and gravity field determination. Generally, the geoids of most European countries are in centimeter level accuracy except in mountainous regions. Turkish...

Both seismological and geodynamic research emphasize that the Aegean Region, which comprises the Hellenic Arc, the Greek mainland and Western Turkey is the most seismically active region in Western Eurasia. The convergence of the Eurasian and African lithospheric plates forces a westward motion on the Anatolian plate relative to the Eurasian one. W...

FAULT PARAMETERS AND DESIGN OF CONTROL NETWORKS Micro­geodetic networks are widely used in determination of crustal movements. High­precision geodetic techniques that are used to determine the crustal movements produce important inputs to geological and geophysical studies. Geophysics and geology have to contribute during the design process of geod...