276 research outputs found

    Effect of noise on bathymetric side scan profiling sonar system resolution.

    Get PDF
    LD:D49067/84 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

    3d Seafloor Model Determination And Change Detection With Multitemporal Multi Beam Echo Sounder Bathymetry

    Get PDF
    Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2017Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2017Topografya yeryüzü üzerinde ve altında bulunan çeşitli yer şekillerini detayları ile inceleyen çalışmaların tanımlanmasıdır. Yeryüzündeki hareketlerin anlaşılması için detaylı topografik bilgiye ihtiyaç vardır. Okyanuslarda deniz tabanının yapısı, taban yüzeyinin özellikleri ile doğal oluşumlar ve insan yapılarını içeren coğrafi nitelikler topoğrafyanın kapsamına girmektedir. Bu kapsamda detaylı deniz haritalarının hazırlanması, fiziksel oşinografi, biyoloji, deniz jeolojisi ve jeofiziği gibi bilimler açısından önem arz etmektedir. Bunun yanında seyir haritalarının oluşturulması, deniz ulaşımı açısından da kritik öneme sahiptir. Bu ise hidrografik ölçümlerin ve ölçüm sistemlerinin gerekliliğini vurgulamaktadır. Deniz tabanının haritalanması için birçok teknik geliştirilmiştir. En ilkel tekniklerden birisi olan bir ipin ucuna bağlanmış ağırlığın suya daldırılması yoluyla yapılan el iskandili yönteminden, uydu tabanlı altimetrik sistemlere kadar birçok yöntem kullanılmıştır. Elektronik ve bilgisayar teknolojilerinin gelişmesi ile birlikte, modern ölçüm sistemleri daha hassas ve etkin hale gelmiştir. Günümüzde deniz ölçümleri için etkin kullanılan optik ve sonar sistemler bulunmaktadır. Optik sistemler içerisinde teknolojisi hızla gelişen Lidar sistemleri yeşil lazer ışını kullanarak su içerisine gönderdiği sinyallerin saçılımlarını derinlik verisi olarak değerlendirir. Görünebilirliğin yüksek olduğu sığ sularda etkin çalışan bu sistem, derinlik arttıkça ve görünürlük azaldıkça hassasiyetini ve etkinliğini kaybeder. İskandil sistemi ‘su yüksekliği’ olarak adlandırılan derinlik verisini üretebilmek için ses dalgasını kullanan modern tekniklerden birdir. Ses dalgası ile ölçüm yapan sistemler basitçe sesin suda gidiş ve dönüş hızını hesaplayarak derinlik verisi elde ederler. İskandiller bir seferde ölçebildikleri derinlik verisi sayısına göre sınıflandırılmıştır. Tek bimli iskandil (TBİ) sistemi bir seferde aletin nadiri doğrultusunda tek bir derinlik verisi üretir. Bunun yanında, çok bimli iskandil (ÇBİ), bir seferde yüzlerce derinlik ölçümü sağlayarak deniz tabanında %100 kaplama sağlamaktadır. Deniz haritası üretimi için çok bimli iskandil sistemleri kullanan hidrografi kurumları/şirketler hidrografik ölçüm standartlarına uygun olarak ölçüm yapmalıdırlar. Bu standartlar genellikle Uluslararası Hidrografi Örgütü (IHO) standartları ile uyumludur. Bazı örgütler doğrudan bu standartları kullanırken, bazıları ise bu standartlardan daha sıkı olan standartlar geliştirilmiştir. Çok bimli iskandil sistemleri; iskandil, konumlandırma sistemi ve hareket sensörü gibi senkronize bir şekilde çalışması gereken birçok ölçüm aletini içermektedir. Bundan dolayı sistem elemanlarının iyi bir kurulum ile tekneye monteleri gerçekleştirilmeli ve ölçüm teknesinin 3B uzayı içerisinde birbiriyle olan ilişkileri tanımlanmalıdır. Ölçümler öncesinde ‘patch testi’ olarak adlandırılan kalibrasyon prosedürü, kurulum ve aletlerin senkronizasyonundan kaynaklanan hataların giderilmesi için gerekmektedir. Bu test kapsamında, sinyal gecikmesi testi (latency), Y ekseni dönüklüğü (roll), X ekseni dönüklüğü (pitch) ve Z ekseni dönüklüğü (yaw) hataları hesaplanmıştır. Bunlarla birlikte, özellikle zamansal veri analizi ve 3B yüzey modellemesi için su kolonu boyunca gerçekleştirilen ses hızı ölçümleri ve su seviyesi değişimleri göz önünde bulundurulmuştur. Bu tezde göz önüne alınan çalışma bölgesi KKTC (Kuzey Kıbrıs Türk Cumhuriyeti) ‘Su Temini Projesi’ içerisinde yer alan, Anamur – KKTC ishale boru hattı güzergâhını kapsayan alandır. Bu proje, Türkiye’den Kuzey Kıbrıs Türk Cumhuriyeti’ne, Akdeniz’de deniz altından boru hatları ile içme ve sulama suyu temini amacı ile gerçekleştirilmiş olup, özellikleri bakımından dünyada benzeri bulunmayan uluslararası bir su iletim hattı projesidir. Proje 4 bölümden oluşmaktadır. Bu bölümlerden birincisi Anamur Alaköprü Barajı’ndan, Ören kasabasına kadar olan iletim hattı, ikincisi boru hatlarının kazı gemisi tarafından oluşturulmuş kanal içerisinde deniz ile buluştuğu bölüm, üçüncüsü projeyi bu boyutlarda yapılmış tek proje özelliğini kazandıran Akdeniz geçiş kısmı ve dördüncüsü ise KKTC kıyılarından Geçitköy barajına su taşınması kısmıdır. Akdeniz geçiş kısmını önemli yapan özelliği ise 500m uzunluğundaki yekpare boruların su seviyesinin 250m kadar altında askıda kalıp, çelik halatlar ile deniz tabanına monte edilmiş olmasıdır.Topography is the term that indicates the study of various landforms that exist on or below the Earth and a detailed knowledge of topography is required to understand the most Earth processes. In the oceans, sea floor topography refers the geographic features of the sea floor including the configuration of a surface and the position of its natural and man-made features; and detailed nautical charts are fundamental for many sciences such as physical oceanography, biology and marine geology. Besides, it is significant for navigational requirement. This revealed the necessity of hydrographic measurements and measurement systems. For this purpose, many techniques developed and used to create the map of the seafloor. From the first primitive technique which involved lowering a weighted line into the water to satellite derived altimetry many systems used for determination of seafloor. After the development of electronic and computer technology, the modern systems become more accurate and effective. An echo sounder system is one of the modern techniques that use the sound waves to determine the depth which is also called ‘sounding’. Echo sounders are classified with the capability of producing sounding in one time. Single beam echo sounder (SBES) system can produce single sounding in each measurement. Besides, multi beam echo sounder (MBES) system can produce hundreds of sounding in each measurement sets and provide 100% seafloor coverage. The hydrographic offices, which use the Multi Beam Echo Sounder (MBES) system for the establishment of nautical charts, have their own set of accuracy standards for hydrographic surveys, which generally comply with the standards defined by the International Hydrographic Organization (IHO). MBES systems include multiple measurement systems such as sonar head, positioning system, motion sensor that work in a synchronized manner. Therefore, the system components are installed and established to each other in 3D space of vessel. Before the measurements, the ‘Patch Test’ is required to eliminate the systematic errors due to instrumental synchronization and installation. In this test, signal delay test (latency), Y-axis rotation (roll), X-axis rotation (pitch), Z-axis rotation (yaw) errors are calculated. Besides, the effects of the sound velocity measurement through water column and the sea level changes need to be taken into consideration especially in the multi-temporal data analysis and 3D modeling. In this thesis, the seafloor of the Anamur -TRNC Drinking Water Pipeline route in the ‘Northern Cyprus Water Project’ is selected as a study area. This project, a unique in the world, is an international water diversion project designed to supply water for drinking and irrigation from southern Turkey to Northern Cyprus via pipeline under Mediterranean Sea. The dredged channels for pipe laying in the Anamur and TRNC shores are considered in this study and two MBES surveys are conducted in different periods to determine the surface differences. Multi temporal multi beam echo sounder measurements are used in the change analysis and surface modeling and the efficiency of this system is outlined together with its limitations.Yüksek LisansM.Sc

    EM 2000 Microbathymetric and HYDROSWEEP DS-2 Bathymetric Surveying – a Comparison of Seafloor Topography at Porcupine Bank, west of Ireland

    Get PDF
    One of the latest discoveries in the world oceans are carbonate structures in the North-East Atlantic. In the frameworks of several European projects, the research vessel POLARSTERN and underwater robot VICTOR 6000 were engaged to explore these areas. The data described in this thesis were collected during the expedition ARK XIX/3 between 16 - 19th June 2003. Bathymetric and microbathymetric data in parts of the Pelagia Province, located on the northern Porcupine Bank, west of Ireland, were measured with two multibeam sonar systems deployed at different distances from the bottom. The four compared models come from a KONGSBERG SIMRAD EM 2000 multibeam sonar system and an ATLAS ELEKTRONIK HYDROSWEEP DS-2 multibeam sonar system. After necessary corrections of the data, digital terrain models were created, subtracted and correlated using appropriate software. This thesis begins with a description of the historical background of bathymetry, followed by a description of the principles of navigation and underwater navigation, inertial navigation systems, and the calibration of these systems. Systematic errors will be pointed out. It examines the measurement principles of the echo sounders used on the ARK XIX/3a expedition and accompanying necessary procedures, such as CTD measurements. A discussion of how the data are processed from raw data to edited results, and the effects of the errors, follows. One chapter is dedicated to a comparison and interpretation of the data. Sidescan, mosaic and PARASOUND data from the Hedge and Scarp Mounds are introduced as complementary information

    Hatton-Rockall geophysical survey RRS discovery cruise D273 BGS project 03/01 operations report

    Get PDF
    This report describes the operation of Discovery Cruise D273, BGS Project 03/01, a regional geophysical survey of the UK Continental Shelf in the Hatton–Rockall area, carried out from 13th to 28th August 2003. Due to ongoing difficulties with the Discovery winch replacement programme, the duration of the cruise was cut, initially from 21 to 17 days and then by a further two days shortly before the start. Since the programme was planned for 21 days operations it was always going to be impossible to complete it. The vessel proved to be excellent for the work and the survey was very successful, with the above caveat. A total of 1677km of good quality data were collected. The survey was a part of the BGS Offshore Mapping and Modelling Project (E1281S73) and was allocated Discovery Station Number 15232

    RRS Discovery Cruise 223, 28 Sep-19 Nov 1996. VIVALDI '96

    Get PDF
    RRS Discovery Cruise 22, VIVALDI '96, was a contribution to the UK WOCE Community Research Programme. The pattern of SeaSoar sections was designed to enable the upper ocean circulation in the Subpolar gyre of the North Atlantic to be mapped and in particular the course of the North Atlantic and Irminger Currents within the region to be determined. The sparse deep CTD survey was required to complement the upper ocean survey and provide estimates of total mass transport and an 'oceanographic opinion poll' of water mass properties, including CFCs. The cruise commenced by repeating the well-established Rockall Trough CTD Section from Barra Head to Rockall Island. This was then extended north to Lousy Bank from where a CTD section measured before by Saunders across the Iceland Basin was repeated. From then onwards the cruise consisted principally of SeaSoar/ADCP sections interspersed with deep CTD casts (see track plot, Fig.1). These were placed on the 'Vivaldi Grid' (round 3° of latitude and multiples of 300km west of 20°W) where possible, though the complex topography was taken into account. East of Greenland a more intense CTD section of stations (12995-13001) was made along 60°N to cut the East Greenland Current. In addition, 7 profiling floats were deployed in the Irminger Basin

    The development and testing of a parametric SONAR system for use in sediment classification and the detection of buried objects

    Get PDF
    This thesis describes the work carried out in the development and testing of parametric sonar systems for application in the fields of seabed sediment characterisation and classification, and the detection of seabed embedded objects. Parametric sonar systems offer a number of advantages over conventional sonar systems. This is especially true of the conflicting requirements of both seabed delineation and penetration required for a practical sub-seabed profiling system. Echoes from sub-bottom layers vary in strength dependent on both the boundary acoustic reflectivity and the absorption characteristics of the layer above. Absorption effects are usually frequency dependent, allowing better penetration to lower frequency signals. [Continues.

    Sustainable seabed mining: guidelines and a new concept for Atlantis II Deep

    No full text
    The feasibility of exploiting seabed resources is subject to the engineering solutions, and economic prospects. Due to rising metal prices, predicted mineral scarcities and unequal allocations of resources in the world, vast research programmes on the exploration and exploitation of seabed minerals are presented in 1970s. Very few studies have been published after the 1980s, when predictions were not fulfilled. The attention grew back in the last decade with marine mineral mining being in research and commercial focus again and the first seabed mining license for massive sulphides being granted in Papua New Guinea’s Exclusive Economic Zone.Research on seabed exploitation and seabed mining is a complex transdisciplinary field that demands for further attention and development. Since the field links engineering, economics, environmental, legal and supply chain research, it demands for research from a systems point of view. This implies the application of a holistic sustainability framework of to analyse the feasibility of engineering systems. The research at hand aims to close this gap by developing such a framework and providing a review of seabed resources. Based on this review it identifies a significant potential for massive sulphides in inactive hydrothermal vents and sediments to solve global resource scarcities. The research aims to provide background on seabed exploitation and to apply a holistic systems engineering approach to develop general guidelines for sustainable seabed mining of polymetallic sulphides and a new concept and solutions for the Atlantis II Deep deposit in the Red Sea.The research methodology will start with acquiring a broader academic and industrial view on sustainable seabed mining through an online survey and expert interviews on seabed mining. In addition, the Nautilus Minerals case is reviewed for lessons learned and identification of challenges. Thereafter, a new concept for Atlantis II Deep is developed that based on a site specific assessment.The research undertaken in this study provides a new perspective regarding sustainable seabed mining. The main contributions of this research are the development of extensive guidelines for key issues in sustainable seabed mining as well as a new concept for seabed mining involving engineering systems, environmental risk mitigation, economic feasibility, logistics and legal aspects
    corecore