Web tabanlı açık kaynak kodlu bir platform geliştirilerek jeodezik çalışmalarla kabuk deformasyonlarının statik modelle belirlenmesinin incelenmesi
Examining the determination of crustal deformationsby static model with geodetic studies by developing aweb-based open-source code platform
Yazar: MEHMET BAK
Danışman: PROF. DR. RAHMİ NURHAN ÇELİK
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Geomatik Mühendisliği Ana Bilim Dalı / Geomatik Mühendisliği Bilim Dalı
Derece: Doktora, 2024
Konu: Jeodezi ve Fotogrametri = Geodesy and Photogrammetry

Özet:
Deformasyon analizi, jeodezinin temel araştırma alanlarından biridir ve insan güvenliği için büyük bir öneme sahiptir. Yerkabuğu, çeşitli etmenlerin etkisi altında sürekli bir deformasyona uğrar. Bu etmenler arasında tektonik levha hareketleri, levha içi deformasyonlar, heyelanlar, depremler, volkanik patlamalar, karasal gel-git, yeryuvarının dönmesi ve kutup gezinmesi gibi faktörler bulunmaktadır. Yerkabuğundaki deformasyonlar, depremlere ve heyelanlara neden olabilir; ayrıca büyük mühendislik yapılarında, örneğin köprülerde, barajlarda, yollarda, binalarda, limanlarda ve bu yapıların çevresinde ciddi zararlara yol açabilir. Bu durum aynı zamanda çevrede önemli değişikliklere ve topoğrafyada derin izlere neden olabilir. Yerkabuğu hareketlerinin neden olduğu yatay ve düşey konum değişimleri ile deformasyonların tespiti, olası felaketlere karşı önleyici tedbirlerin alınması açısından son derece kritiktir. Kabuk deformasyon çalışmalarının belirlenmesi, bilim insanları için karşılaştıkları en önemli problemlerden biri olarak kabul edilir. Bu zorlukla başa çıkmak için bilim insanları büyük çaba harcamak zorunda kalırlar. Bununla birlikte, son yıllarda yerkabuğu hareketlerine olan ilginin artması ve teknolojideki hızlı gelişmeler, deformasyon analizi için yeni yazılımların kullanılmasını zorunlu kılmıştır. Bu analizler genellikle kolayca erişilemeyen akademik programlar veya maliyetli ticari yazılımlar kullanılarak gerçekleştirilmektedir.
Bu çalışmada jeodezik GNSS (Global Navigation Satellite System) ağlarındaki deformasyonların hızlı ve kolay tespitine yönelik alternatif bir çözüm oluşturmak ve bu sayede deformasyonların ve hareketlerin izlenmesi, belirlenmesi ve analiz edilmesine ilgi duyan uzman mühendislerin analizlerini daha kolay gerçekleştirmeleri için statik deformasyon analizi odaklı açık kaynak kodlu yazılımlar kullanılarak geliştirilmiş bir web tabanlı açık kaynaklı "Web-NDefA platformu ('Web'-based 'N'etwork 'Def'ormation 'A'nalysis)" oluşturulmuştur."
Web-NDefA, univaryant jeodezik ağlardaki önemli yer değiştirmeleri incelemek için S-Dönüşüm tekniğini kullanarak 3 boyutlu istatistiksel analiz gerçekleştiren bir deformasyon analiz platformudur. Bu platform sayesinde, 3 boyutlu deformasyon analizi üzerine çalışmalar yürüten her kişi veya kurum jeodezik verilerini değerlendirecek ve buradan elde edilecek sonuçlara eksiksiz, doğru ve hızlı bir şekilde ulaşacaktır.
Bu platform istemci taraflı programlama dillerinden olan JavaScript ile geliştirilmiştir. Platformunun oluşturulması için öncelikle HTML ve CSS uygulamaları gerçekleştirilmiştir. Platformu kullanmak için önce deformasyon çalışması için izlenen bir bölgede gerçekleştirilen GPS (Global Positioning System) kampanyasındaki veriler bir GNSS veri işleme yazılımına aktarılır ve değerlendirilir. Buradan baz vektörlerinin çözümlerini içeren ASCII veya Metin dosyası elde edilir ve akabinde Web-NDefA platformuna aktarılır. Burada karşılaştırılacak periyotlar seçilir ve 3 boyutlu statik deformasyon analizi gerçekleştirilir.
Bu çalışmanın sonucunda, geliştirilen web uygulamasının teknik altyapısı detaylı bir şekilde açıklanacak ve uygulamalar üzerinde gerçekleştirilen analizler sunulacaktır. Bu sayede, deformasyon analizi alanındaki platformlara yeni bir boyut eklenmiş olacak ve kullanıcılar, ihtiyaç duyabilecekleri statik deformasyon analizi sonuçlarına görsel olarak erişebileceklerdir.

Abstract:
Earthquake, landslide, rockfall, flood, etc. are natural disasters that cause great damage and changes to structures such as bridges, dams, roads, buildings, harbours and the surroundings of these structures. Events such as earthquakes, tsunamis, storms and floods can cause  loss of life. Many people can be injured in disasters. Injuries can occur, for example, when buildings collapse, trees fall or flood waters carry them away. Homes, businesses and infrastructure (roads, bridges, power lines, etc.) can be severely damaged. This can lead to billions of dollars in financial losses. It can cause people to leave their homes and migrate. This can lead to internal refugee problems and affect population movements in some regions. Disasters that leave deep scars in the topography can cause severe damage to a region's economy. Economic losses may occur due to reasons such as the destruction of agricultural products, the closure of businesses and the decrease in tourism. Thus, the economies of countries can be affected directly or indirectly.
In the last few decades, new developments in science and technology have emerged to meet the increasing needs of society. Today these developments in technology have affected the lives of people as well as scientific studies and research. It has now become easier to determine intercontinental displacements and to monitor the movements of the earth's crust. One of the factors that has facilitated this improvement is the development of geodetic deformation measurement and analysis methods. In the deformation studies carried out, geodetic measurements are used to determine the magnitude, direction and location of the earth's crust movements that cause stresses, compression and severe rupture in the earth's crust. Geodesy undertakes the task of determining the horizontal and vertical movements in three dimensions, monitoring any deformations, separating the displacement vectors from biased errors and interpreting the results in its study area.
Geodetic studies play an important role in the field of deformation analysis. They are an important technique to monitor and understand the effects of natural disasters, structural changes, and environmental deformations. Geodetic surveying methods can be used to accurately track the displacements of specific points. Such monitoring can be done, especially after earthquakes or to assess the impact of construction projects. It determines the displacements and deformations that occur during or after an earthquake. This is important for earthquake predictions and monitoring in earthquake-prone areas. In addition, geodetic data are used to determine surface deformations (especially to monitor the effects of natural events such as landslides, landslides, and land collapses). Geodetic surveys can provide early detection of structural problems such as building collapse or bridge deformation. In this way, the deformation of structures and infrastructure can be monitored.
Monitoring the changes and movements in the earth's crust and large engineered structures (dams, bridges, skyscrapers, underground tunnels, etc.) is essential to reduce the severity of disasters with preventive measures and keep the loss of life and property to a minimum. The earth's crust and large engineered structures are always affected by physical force. Monitoring the reactions of these structures to forces is important not only to understand their behaviour but also to take some precautions before any possible damage occurs. Geodetic studies can provide sufficient accuracy and sensitivity to overcome this problem. Therefore, geodetic methods are indispensable for crustal and structural deformation studies.
A series of GNSS stations can be created for geodetic deformation analysis. These stations form a geodetic control network that is used to monitor surface deformations more accurately. Deformation analysis generally deals with small deformation amounts within the measurement error limits. In order to make correct decisions about the acceptability of the deformation model, very careful and accurate analysis and statistical testing of the results are required. Model accuracy is important to determine the causes, rates and directions of deformation of the Earth's surface. Surface deformations and displacements are analysed by combining GNSS data and deformation models. This analysis aims to detect deformations caused by subsurface rocks, plate movements, earthquakes or human intervention.
The determination of current crustal movements and deformations has been investigated by scientists who are interested in these issues. Software's used for geodetic deformation analysis is designed to process precise geodetic measurement data, analyse deformations and visualize the results. They are used by researchers, engineers and other experts to monitor changes in the earth's surface. Each software has specific features and capabilities.
Many commercial, academic and online web-based services are used to process the data obtained from GNSS observations and to compute the baseline solutions of the stations in the geodetic network. However, there are few alternatives for analysing deformations using baseline solutions. This type of analysis is usually done with academic programs that are not easily accessible or with expensive commercial software. 
Considering the many areas in which open source software is used, it can be said to currently hold a leading role in the development of information technologies. Most commercial software has open source alternatives. In the last 2 decades, open source software has been adopted widely by many companies due to its significant advantages over patented alternatives. Many companies use open source software because it helps them get their products to the market much more easily and its development costs are low. Thus, they create business services and products. The global community contributes to the study and development of open source software. In this way, such software is considered reliable and safe. Web standards (e.g. HTML, CSS and JavaScript) can be used to build a client-side open source web application. These standards control numerical computations, user interface and visual output within the browser.
This study provides information about "Web-NDefA ('Web'-based 'N'etwork 'Def'ormation 'A'nalysis)", a web-based, user-friendly, unlimited and open-source platform developed as an alternative solution for easy determination of deformations in univariant geodetic networks periodically monitored with GNSS observations using the static deformation model and S-transformation method, and compares observations from 2016, 2019 and 2020.
The Web-NDefA platform has been developed in the internet environment for easier access to information and can be used by any individual or institution who wants to organise geodetic data within the scope of deformation analysis and to access the results to be obtained from these data quickly, accurately and completely when necessary. The platform has been developed for the determination of deformations in geodetic networks with univariant design periodically monitored by GNSS with a static model. After a period of user-defined GNSS baseline solution files (ASCII, TXT format) are uploaded to the platform, the free adjustment, reliability criteria, deformation analysis, coordinate differences of the points in the compared periods, displacement vectors and error ellipses of these vectors can be performed.
The advantage of the Web-NDefA is that it analyses the baseline solution files extracted by a post-processing software that evaluates the data obtained from any geodetic GNSS network by putting them into a suitable format by the user. It is the user-defined ASCII or TXT format of the data uploaded to the platform for analysis. Thus, easily perform static deformation analysis visually. The ASCII or TXT file contains numeric expressions for a GNSS network as shown in the figure below (Figure 1). Numerical expressions include contains approximate coordinate information of reference and rover station points, ∆X, ∆Y, ∆Z coordinate differences, mean square error (a posteriori value) (m0), GNSS baseline cofactor matrices information. The web-based static deformation analysis platform processes and analyses this data and makes it possible to obtain the desired deformation analysis results quickly and easily. File upload, free adjustment, deformation analysis and displacement vectors are displayed on the Web-NDefA platform and deformations can be followed visually.
Thus, practitioners from all over the world who want to determine the current crustal movement in any region will be able to access the Web-NDefA web page in seconds and make their analysis visually. In this way, a new dimension will be added to the applications used in deformation analysis calculation by making use of technological developments.