Show simple item record

dc.contributor.advisorÖzbay, Ekmel
dc.contributor.authorUyar, Faruk
dc.date.accessioned2018-09-28T12:33:50Z
dc.date.available2018-09-28T12:33:50Z
dc.date.copyright2018-09
dc.date.issued2018-09
dc.date.submitted2018-09-26
dc.identifier.urihttp://hdl.handle.net/11693/48031
dc.descriptionCataloged from PDF version of article.en_US
dc.descriptionThesis (M.S.): Bilkent University, Department of Electrical and Electronics Engineering, İhsan Doğramacı Bilkent University, 2018.en_US
dc.descriptionIncludes bibliographical references (leaves 84-90).en_US
dc.description.abstractPhase-sensitive optical time domain re ectometer (ø-OTDR) based distributed acoustic sensor (DAS) systems have attracted increasing attention in recent years due to their remarkable advantages in a wide range of industrial and military applications such as health monitoring and security of civil infrastructures, railways, oil and gas pipelines, borders, and so on. They measure vibrations and detect perturbations along a section of fiber. Different approaches have been adopted to realize the ø-OTDR systems and process the data from these sensors. In this thesis, a direct detection DAS based on ø-OTDR architecture with long sensing range and high signal-to-noise ratio (SNR) is demonstrated. Testing and characterization of critical system components is conducted before integrating them into the system. The results of laboratory tests are presented, in which the detected traces are successively analyzed in order to localize and investigate the perturbation events along the test fibers. The field tests are demonstrated with different external events such as digging, walking, and motor vibration. Considering the random nature of Rayleigh backscattered light and fading effect encountered in these tests, a new performance metric, which is Mean SNR, is proposed for assessing and comparing the system performances. Besides, statistical characteristics of the SNR of the vibration events in different distances for both laboratory tests and field tests is experimentally measured. The photon statistics of Rayleigh backscattered signal in a ø-OTDR based fiber sensor in the presence of amplified spontaneous emission noise is theoretically modeled and experimentally demonstrated, as well.en_US
dc.description.statementofresponsibilityby Faruk Uyar.en_US
dc.format.extentxiv, 90 leaves : charts (some color) ; 30 cm.en_US
dc.language.isoen_USen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectDistributed Acoustic Sensoren_US
dc.subjectOptical Time Domain Reflectometeren_US
dc.subjectø-OTDRen_US
dc.subjectRayleigh Scatteringen_US
dc.subjectFadingen_US
dc.subjectFiber Opticsen_US
dc.titleDevelopment and characterization of a direct detection fiber optic distributed acoustic sensoren_US
dc.title.alternativeDoğrudan algılama bir fiber optik dağıtık akustik sensörün geliştirilmesi ve karakterizasyonuen_US
dc.typeThesisen_US
dc.departmentDepartment of Electrical and Electronics Engineeringen_US
dc.publisherBilkent Universityen_US
dc.description.degreeM.S.en_US
dc.identifier.itemidB159034
dc.embargo.release2020-07-15


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record