Papers (Scientific Conferences) by Çetin Mekik
Özellikle Türkiye gibi gelişmekte olan ülkelerde ve bölgelerde genel ve yerel yönetimlerin çalışm... more Özellikle Türkiye gibi gelişmekte olan ülkelerde ve bölgelerde genel ve yerel yönetimlerin çalışmalarının çok önemli bir bölümünün, imar, ulaştırma, su ve su içerikli yapı ve tesisler ile ilgili projelerin ve uygulamaların olduğu bilinmektedir. Bu tür arazi içerikli projeler, planlama ve uygulama hizmetleri için de güncel ve güvenilir coğrafi tabanlı bilgiler ve belgeler ilk öncelikli ihtiyaç olmaktadır. Bu kapsamdaki ihtiyaçların başında da proje ve planlama uygulamalarına konu coğrafi bölgelerin büyük ölçekli güncel temel planları (halihazır haritaları) gelmektedir. Bursa Metropolitan alanı gibi ekonomik ve sosyal gelişmelerin fazla ve hızlı olduğu coğrafi bölgelerde, gerek mevcut coğrafi bilgi ve belgelerdeki değişimler gerekse coğrafi tabanlı projelere ve planlamalara olan ihtiyaç daha fazla olmaktadır. Bildiride, Bursa Su ve Kanalizasyon İşleri (BUSKİ) Genel Müdürlüğü tarafından Bülent Ecevit Üniversitesi Mühendislik Fakültesi Geomatik Mühendisliği Bölümünün Müşavirliğinde ve denetiminde gerçekleştirilmekte olan Bursa Metropolitan alanı Sayısal Fotogrametrik Temel Planlarının Yapılması (M5) Projesi tanıtılmaktadır. Planlanan yaklaşık 12000 km2 alanda proje ile ilgili yapılmakta ve yapılacak olan Jeodezik ve Fotogrametrik çalışmalar hakkında detaylı bilgiler verilmektedir.
Papers by Çetin Mekik
Annales Geophysicae, Mar 15, 2019
Many scientists from different disciplines have studied earthquakes for many years. As a result o... more Many scientists from different disciplines have studied earthquakes for many years. As a result of these studies, it has been proposed that some changes take place in the ionosphere layer before, during or after earthquakes, and that the ionosphere should be monitored in earthquake prediction studies. This study investigates the changes in the ionosphere created by the earthquake with a magnitude of M w = 7.2 in the northwest of Lake Erçek, which is located to the north of the province of Van in Turkey on 23 October 2011 and at 13:41 local time (−3 UT) with the epicenter of 38.75 • N, 43.36 • E using the TEC values obtained by the global ionosphere models (GIMs) created by IONOLAB-TEC and CODE. In order to see whether the ionospheric changes obtained by the study in question were caused by the earthquake or not, the ionospheric conditions were studied by utilizing indices providing information on solar and geomagnetic activities (F10.7 cm, Kp, Dst). One of the results of the statistical test of the TEC values obtained from both models is positive and negative anomalies obtained for the times before, on the day of and after the earthquake, and the reasons for these anomalies are discussed in detail in the last section of the study. As the ionospheric conditions on the analyzed days were highly variable, it was thought that the anomalies were caused by geomagnetic effects, solar activity and the earthquake.
Several scientists from different disciplines have studied earthquakes for many years. As a resul... more Several scientists from different disciplines have studied earthquakes for many years. As a result of these studies, it has been proposed that some changes take place in the ionosphere layer before, during or after earthquakes, and the ionosphere should be monitored in earthquake prediction studies. This study investigates the changes in the ionosphere created by the earthquake with magnitude of Mw=7.2 in the northwest of the Lake Erçek which is located to the north of the province of Van in Turkey on 23 October 2011 and at 1.41 pm local time (-3 UT) with the epicenter of 38.758° N, 43.360° E using the TEC values obtained by the Global Ionosphere Models (GIM) created by IONOLAB-TEC and CODE. In order to see whether the ionospheric changes obtained by the study in question were caused by the earthquake or not, the ionospheric conditions were studied by utilizing indices providing information on solar and geomagnetic activities (F10.7 cm, Kp, Dst). As a result of the statistical test on the TEC values obtained from the both models, positive and negative anomalies were obtained for the times before, on the day of and after the earthquake, and the reasons for these anomalies are discussed in detail in the last section of the study. As the ionospheric conditions in the analyzed days were highly vibrant, it was thought that the anomalies were caused by geomagnetic effects, solar activity and the earthquake. The authors believe that interdisciplinary studies are needed to distinguish the earthquake-related part of the anomalies in question.
Geomatik, 2020
İyonosfer tabakası yapısı gereği güneş aktivitesi, mevsimsel değişim, gece-gündüz, konum, jeomany... more İyonosfer tabakası yapısı gereği güneş aktivitesi, mevsimsel değişim, gece-gündüz, konum, jeomanyetik aktivite, deprem gibi etmenlere bağlı olarak değişim göstermektedir. Bu tabakada meydana gelen değişim çoğunlukla güneş kaynaklı olsa da sözü edilen diğer etkiler iyonosfer modellemesi için göz önünde bulundurulmalıdır. Günümüzün en büyük doğal afetlerinden biri olan deprem dünya genelinde çok sayıda can ve mal kaybına sebep olmaktadır. Depremle ilgili geçmişten bugüne çok sayıda bilim insanı çalışma yapmıştır. Yapılan çalışmalar sonucunda; deprem öncesi, anı veya sonrasında iyonosfer tabakasında bazı değişimler meydana geldiği, bu sebeple deprem tahmini çalışmalarında iyonosfer tabakasının incelenmesi gerekliliği ortaya koyulmuştur. Bu çalışma kapsamında deprem kaynaklı iyonosferik anomalilerin belirlenebilmesi için deprem öncesi, anı ve sonrasını kapsayacak şekilde toplam 60 günlük TEC verisi kullanılmıştır. Alt sınır (LB) ve üst sınır (UB) değerlerinin hassas şekilde belirleneb...
Annales Geophysicae Discussions, 2018
Many scientists from different disciplines have studied earthquakes for many years. As a result o... more Many scientists from different disciplines have studied earthquakes for many years. As a result of these studies, it has been proposed that some changes take place in the ionosphere layer before, during or after earthquakes, and the ionosphere should be monitored in earthquake prediction studies. This study investigates the changes in the ionosphere created by the earthquake with magnitude of Mw=7.2 in the northwest of the Lake Erçek which is located to the north of the province of Van in Turkey on 23 October 2011 and at 1.41 pm local time (-3 UT) with the epicenter of 38.75° N, 43.36° E using the TEC values obtained by the Global Ionosphere Models (GIM) created by IONOLAB-TEC and CODE. In order to see whether the ionospheric changes obtained by the study in question were caused by the earthquake or not, the ionospheric conditions were studied by utilizing indices providing information on solar and geomagnetic activities (F10.7 cm, Kp, Dst). One of the results of the statistical test on the TEC values obtained from the both models, positive and negative anomalies were obtained for the times before, on the day of and after the earthquake, and the reasons for these anomalies are discussed in detail in the last section of the study. As the ionospheric conditions in the analyzed days were highly variable, it was thought that the anomalies were caused by geomagnetic effects, solar activity and the earthquake.
Annales Geophysicae, 2017
The ionosphere is a dynamic layer which generally changes according to radiation emitted by the s... more The ionosphere is a dynamic layer which generally changes according to radiation emitted by the sun, the movement of the earth around the sun, and sunspot activity. Variations can generally be categorized as regular or irregular variations. Both types of variation have a huge effect on radio wave propagation. In this study, we have focused on the seasonal variation effect, which is one of the regular forms of variation in terms of the ionosphere. We examined the seasonal variation over the ZONG station in Turkey for the year 2014. Our analysis results and IRI-2012 present different ideas about ionospheric activity. According to our analysed results, the standard deviation reached a maximum value in April 2014. However, the maximum standard deviation obtained from IRI-2012 was seen in February 2014. Furthermore, it is clear that IRI-2012 underestimated the VTEC values when compared to our results for all the months analysed. The main source of difference between the two models is the IRI-2012 topside ionospheric representation. IRI-2012 VTEC has been produced as a result of the integration of an electron density profile within altitudinal limits of 60-2000 km. In other words, the main problem with regard to the IRI-2012 VTEC representation is not being situated in the plasmaspheric part of the ionosphere. Therefore we propose that the plasmaspheric part should be taken into account to calculate the correct TEC values in midlatitude regions, and we note that IRI-2012 does not supply precise TEC values for use in ionospheric studies.
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2015
Ionosphere has been studied by a number of scientists in recent years. Since GPS observations can... more Ionosphere has been studied by a number of scientists in recent years. Since GPS observations cannot provide TEC value directly, it can be estimated from combination of observations. In this study TEC values derived from GPS observations were produced variations with two hours increments from the eighth day to fifteenth day in months just after beginning of each season, namely January, April, July and October in 2014 for ZONG TUSAGA-Aktif station and 41 other stations (TUSAGA-Aktif, EUREF, IGS). TEC values computed by the Bernese 5.0 software were compared with the Global Ionosphere Model (GIM) TEC values regularly published by Center for Orbit Determination in Europe (CODE) and International Reference Ionosphere (IRI-2012) TEC values. As a result of this study, with the comparison of GPS TEC values to GIM TEC values, it has become obvious that GPS TEC values are quite similar to the GIM TEC values. The differences of TEC values derived from GPS TEC and GIM TEC change from 0.91 TECU...
Natural Hazards, 2017
Kozlu is a mining town only 5 km away from the main city of Zonguldak and initially was not favor... more Kozlu is a mining town only 5 km away from the main city of Zonguldak and initially was not favored for settlement due to its rugged and hilly topography. However, along with hard coal production in large quantities throughout the years came the industrialization at its full speed with plenty job opportunities which then gave rise to intense population in the region where there were only a few sheds and slums just a century ago. Workers migrating to Kozlu in thousands needed dwellings to live in, but the law, so-called the Coal Basin Restrictions Law which came in effect in 1910, hindered the implementation of zoning plans. Planned housing was not possible in the region not until the abolishment of the law in 1986. During these 76 years, the settlement in the area mostly by the mining and industry workers was carried out without proper zoning plans, usually on demand basis. Today because of this unplanned housing and harsh topography, the Kozlu settlement area (KSA) has a history of being attraction point for many natural and manmade disasters which can be summarized as are topography, geological and carstic & Deniz Arca
Global Navigation Satellite Systems (GNSS) have recently proved to be one of the crucial tools fo... more Global Navigation Satellite Systems (GNSS) have recently proved to be one of the crucial tools for determining continuous and precise precipitable water vapor (GNSS-MET networks). GNSS, especially CORS networks such as CORS-TR (the Turkish Network-RTK), provide high temporal and spatial accuracy for the wet tropospheric zenith delays which are then converted to the precipitable water vapor due to the fact that they can operate in all weather conditions continuously and economically.
Harita Teknolojileri Elektronik Dergisi, 2014
GPS alicilari tasinabilir, ekonomik ve hava kosullarindan etkilenmeden olcum yapabildiginden, hav... more GPS alicilari tasinabilir, ekonomik ve hava kosullarindan etkilenmeden olcum yapabildiginden, hava tahmini icin onem tasiyan yogusabilir (yagisa donusebilir) su buhari miktari (PWV) ve toplam zenit gecikmesi (ZTD) belirlemede kullanilan degerli bir yontemdir. GPS gozlemleriyle, radyosonda verilerinde oldugu gibi nem profili cikartilamaz. Bununla birlikte, radyosondalar ile gunde sadece iki kez olcum yapilabilirken, GPS ile surekli ve otomatik olarak gozlem yapilabilmesi bir ustunluk kabul edilebilir. Bu sebeple GPS sinyalleri ile yogusabilir su buhari miktari belirlenmesinde kullanilan troposferik gecikme modelleme yontemleri surekli olarak gelistirilmektedir. Troposferik modellerde oldugu gibi Global Izdusum fonksiyonu (GMF) ve Vienna Izdusum Fonksiyonu [1] (VMF1) gibi izdusum fonksiyonlarinda da atmosferik parametrelere ihtiyac duyulmaktadir. Gunumuzde en yuksek dogruluklu zenit gecikmeleri bu iki izdusum fonksiyonu ile hesaplanabilmektedir. GMF ve VMF1 izdusum fonksiyonlarinin yani sira Niell Izdusum Fonksiyonu da akademik calismalarda sik sik kullanilmaktadir. Gecmis calismalarda radyosonda analiz algoritmasina dayanan ve toplam sekiz radyosonda istasyonundan altisina ait veriler degerlendirilerek Turkiye icin yuzey sicakligi, agirlikli ortalama sicaklik ve yogusabilir su buhari miktarini hesaplayan bir Tm modeli gelistirildi [2]. Bu calismada ise Ankara (GANM) ve Istanbul (GISM)’e kurulan surekli olcum yapan GPS alicilarindan elde edilen veriler Niell Izdusum Fonksiyonu kullanilarak BERNESE v5.0 [3] yazilimindan ve Global Basinc ve Sicaklik (GPT) ampirik modeli ile [4] tarafindan gelistirilen Tm modeli kullanan Gamit/GLOBK [5] yazilimi ile degerlendirilmistir. Bu degerler, radyosonda analiz algoritmasinin ve gelistirilmis Tm modelinin dogrulugunu, guvenilirligini gozlemlemek ve gelistirmek icin, radyosonda analiz algoritmasindan elde edilen degerler ve gercek radyosonda degerleri ile karsilastirilmistir. Sonuc olarak, bu calismada kullanilan tum degerlendirme yontemleriyle PWV degerleri radyosonda dogruluguna gore ±1-2 mm ile hesaplanmistir. Bu sebeple cogu Avrupa ulkesinde oldugu gibi Turkiye’de de PWV degerlerinin elde edilmesinde zamansal cozunurluk acisindan daha guclu olan GPS sisteminin kullanilmaya baslanmasi gerekmektedir. Algoritmanin ve Tm modelinin gelistirilmesi amaciyla degerlendirmeye katilmamis son iki radyosonda istasyonundan alinan veriler kullanilarak algoritma daha da guclendirilecektir. Anahtar Kelimeler: Radyosonda analiz algoritmasi, yogusabilir su buhari miktari, izdusum fonksiyonu, Bernese v5.0
Egu General Assembly Conference Abstracts, May 1, 2014
Continuously Operating GPS Networks are being used for meteorological and climate research. The w... more Continuously Operating GPS Networks are being used for meteorological and climate research. The wet tropospheric zenith delays derived from these networks are converted to the precipitable water vapour. Thus, an important data is produced for the development of numerical models of the tropospheric zenith delay and the precipitable water vapor for local, regional and global areas and for the meteorology and climate research. The radiosonde observation data and the results derived from them are taken as references for the determination of accurate and reliable transformation parameters between the wet tropospheric zenith delay and the precipitable water vapor.
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2015
Global Navigation Satellite System (GNSS) observations can precisely estimate the total zenith tr... more Global Navigation Satellite System (GNSS) observations can precisely estimate the total zenith tropospheric delay (ZTD) and precipitable water vapour (PWV) for weather prediction and atmospheric research as a continuous and all-weather technique. However, apart from GNSS technique itself, estimations of ZTD and PWV are subject to effects of geophysical models with large uncertainties, particularly imprecise ocean tide models in Turkey. In this paper, GNSS data from Jan. 1 st to Dec. 31 st of 2014 are processed at 4 co-located GNSS stations (GISM, DIYB, GANM, and ADAN) with radiosonde from Turkish Met-Office along with several nearby IGS stations. The GAMIT/GLOBK software has been used to process GNSS data of 30-second sample using the Vienna Mapping Function and 10° elevation cutoff angle. Also tidal and non-tidal atmospheric pressure loadings (ATML) at the observation level are also applied in GAMIT/GLOBK. Several widely used ocean tide models are used to evaluate their effects on GNSS-estimated ZTD and PWV estimation, such as IERS recommended FES2004, NAO99b from a barotropic hydrodynamic model, CSR4.0 obtained from TOPEX/Poseidon altimetry with the model FES94.1 as the reference model and GOT00 which is again long wavelength adjustments of FES94.1 using TOPEX/Poseidon data at 0.5 by 0.5 degree grid. The ZTD and PWV computed from radiosonde profile observations are regarded as reference values for the comparison and validation. In the processing phase, five different strategies are taken without ocean tide model and with four aforementioned ocean tide models, respectively, which are used to evaluate ocean tide models effects on GNSS-estimated ZTD and PWV estimation through comparing with co-located Radiosonde. Results showed that ocean tide models have greatly affected the estimation of the ZTD in centimeter level and thus the precipitable water vapour in millimeter level, respectively at stations near coasts. The ocean tide model FES2004 that is the product of assimilation of the altimetric data of ERS2, TOPEX/POSEIDON and the data of a global tide gauge network, gave the most accurate results when compared to radiosonde with ±1.
Uzay esaslı konum belirleme tekniği olan GPS 'in ölçme ve jeodezi mesleğinde çığır açtığı bil... more Uzay esaslı konum belirleme tekniği olan GPS 'in ölçme ve jeodezi mesleğinde çığır açtığı bilinen bir gerçektir. Ülkemizde ve dünyada bilim adamları ve mühendisler, GPS'in kullanım alanlarını sistemi tasarlayanların bile hayal edemeyeceği yerlere kadar genişletmişlerdir. Ancak, yine de GPS sonsuz kullanım alanı olan bir sistem değildir; onun da kullanım alanları için sınırlar vardır. Örneğin, yeterli sayıda (dört) ya da hiç uydu sinyalinin alınmadığı şehir içleri, ormanlar, köprü altları, tüneller ve bina içleri gibi alanlar. Sinyal iletişiminin güç olduğu veya olmadığı alanlarda GPS'ten yararlanmak için "uydusallar" geliştirilmiştir. Uydusallar, jeodezi ve ölçme yanında navigasyon amaçları için de kullanılabilmektedir. Birkaç yıl içinde uydusalların GPS ile birlikte veya GPS'siz kullanımının yaygınlaşacağı ve hatta ileride elektronik takeometrelerin yerini alacağı düşünülmektedir. Bu yayında ülkemiz için yeni olan uydusallar kısaca anlatılmış ve uydusallar...
Özet GPS alıcıları taşınabilir, ekonomik ve hava koşullarından etkilenmeden ölçüm yapabildiğinden... more Özet GPS alıcıları taşınabilir, ekonomik ve hava koşullarından etkilenmeden ölçüm yapabildiğinden, hava tahmini için önem taşıyan yoğuşabilir (yağışa dönüşebilir) su buharı miktarı (PWV) ve toplam zenit gecikmesi (ZTD) belirlemede kullanılan değerli bir yöntemdir. GPS gözlemleriyle, radyosonda verilerinde olduğu gibi nem profili çıkartılamaz. Bununla birlikte, radyosondalar ile günde sadece iki kez ölçüm yapılabilirken, GPS ile sürekli ve otomatik olarak gözlem yapılabilmesi bir üstünlük kabul edilebilir. Bu sebeple GPS sinyalleri ile yoğuşabilir su buharı miktarı belirlenmesinde kullanılan troposferik gecikme modelleme yöntemleri sürekli olarak geliştirilmektedir. Troposferik modellerde olduğu gibi Global İzdüşüm fonksiyonu (GMF) ve Vienna İzdüşüm Fonksiyonu [1] (VMF1) gibi izdüşüm fonksiyonlarında da atmosferik parametrelere ihtiyaç duyulmaktadır. Günümüzde en yüksek doğruluklu zenit gecikmeleri bu iki izdüşüm fonksiyonu ile hesaplanabilmektedir. GMF ve VMF1 izdüşüm fonksiyonların...
Natural Hazards and Earth System Sciences Discussions, 2015
Turkey is a country located in Middle Latitude zone and in which tectonic activity is intensive. ... more Turkey is a country located in Middle Latitude zone and in which tectonic activity is intensive. Lastly, an earthquake of magnitude 6.5<i>M</i><sub>w</sub> occurred at Aegean Sea offshore on date 24 May 2014 at 12:25 UTC and it lasted approximately 40 s. The said earthquake was felt also in Greece, Romania and Bulgaria in addition to Turkey.…
Satellite Positioning - Methods, Models and Applications, 2015
Figure 10. Statistical description of the tide effects in GANM and GISM stations for the first 60... more Figure 10. Statistical description of the tide effects in GANM and GISM stations for the first 60 days of 2014 (Processing strategies are listed in the Table 1) Satellite Positioning-Methods, Models and Applications 126
Arabian Journal of Geosciences, 2021
Slope movements are commonly occurring natural disasters damaging the infrastructures, upper stru... more Slope movements are commonly occurring natural disasters damaging the infrastructures, upper structures, and nature. Among the slope movements, landslide is the most damaging and frequent natural disaster. This study investigates the previously occurring slope instability and runs a landslide susceptibility analysis for the Karabük-Yenice area in NW of Turkey. Types of slope movements in the area were mainly slide, flow, and fall type failures. The most frequent slope movements were slides and flows. Fall type of movement, however, was seen only in two locations in bedrock as rock falls. After the determination of the mass movements, landslide susceptibility analysis was performed for the study area. Four predisposing parameters, geology, slope, aspect, and distance to the river were used in the frequency ratio landslide susceptibility analysis. Geographical information system (GIS) and frequency ratio methods were used in landslide susceptibility analysis. GIS made it easy to prepare the required layers and to perform analysis for generating a landslide susceptibility map. The outcome of this study, the landslide susceptibility map, reveals the susceptibility in five classes, namely, very low, low, moderate, high, and very high. The locations of the previous landslides defined by the fieldwork were overlaid on the landslide susceptibility map to verify the validity of the susceptibility analysis and make evaluations and interpretations.
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Papers (Scientific Conferences) by Çetin Mekik
Papers by Çetin Mekik