TY - CHAP A1 - Wosniok, Aleksander ED - Werneck, M.M. ED - da Silva Barros Allil, R.C T1 - POF Sensors for Structural Health Monitoring N2 - The ever more ambitious strategic goals of meeting the requirements in ensuring technical safety and security of civil structures have resulted in flourishing development of innovative structural health monitoring (SHM) technologies for early damage diagnosis and prognosis. At the same time, implementing SHM systems provides tangible economic benefits derived from lower life-cycle costs associated with reduction in the maintenance, repair and insurance expenses. Due to the large size and harsh environmental conditions common to most civil structures, the broad range of favorable physical-mechanical properties of POFs allow for customized monitoring solutions for a wide variety of applications. In addition to common SHM-related advantages of optical fibers including their electromagnetic immunity, small size, lightweight as well as spark-free and non-conductive characteristics, POFs offer better bending and fracture resistance then their glass-counterparts. Particularly, the improved robustness of POFs, their ease of handling, low Young’s Modulus and high elastic limit of 10% compared to 1% in silica glass [1] are relevant to practical applications. Depending on the composition, dopants, drawing process and geometry [2], strain measurement up to 45% [3] or even above 100% [4,5] has been demonstrated with standard POFs. Therefore, the dominant market expected for POF sensors includes monitoring of high-strain-rate deformations in earthwork structures, crack detection in concrete and masonry structures [6] or overstressing in high-rise steel structures exposed to moisture, corrosion, leakage, fatigue, vibration, fire, overflow, earthquake and intentional damage. For fracture monitoring within concrete structures, the sensory usage of POFs becomes especially favorable since the extremely alkaline environment of concrete mixtures is well known to be corrosive to standard silica glass optical fibers (GOFs) [1,7]. Most of advanced distributed sensing techniques are commonly based on Rayleigh backscatter reflectometry using commercially available multimode (MM) POFs. Such typical MM POFs range from a step-index (SI) poly(methyl methacrylate) (PMMA) POF having a core diameter of 1 mm to a low-loss graded-index (GI) perfluorinated (PF) POF based on poly(perfluorobutenyl-vinylether) also known as CYTOP [8] with a 50 µm core diameter. The relatively low optical attenuation value of 30 dB/km at 1.3 µm [9,10] makes PFGI POFs also interesting for distributed Brillouin sensing [11-14]. Compared to GOFs, PFGI POFs offer better potential for temperature measurement and have comparably low theoretical attenuation limit [15]. Therefore, POF-based distributed Brillouin sensing is expected to play an important role in the future of SHM, especially at high-strain ranges. The significance of the Brillouin measurment technique can be also enhanced by further development of the single-mode (SM) POFs which are still subject of research and are used for coherent detection techniques [6]. Furthermore, SM PMMA POFs have been characterized in a Mach-Zehnder interferometer setup for strain values up to 15.8% [16,17]. The current development of SM perfluorinated and microstructured POFs (mPOFs) represents an immense promise for quasi-distributed dynamic measurement at high strain levels based on fiber Bragg grating (FBG) technology. While SM mPOFs with optical losses of about 1 dB/m can be fabricated [6], the SM PF POFs presented by Zhou et al. feature low attenuation of even less than 0.2 dB/m in the wavelength range of 1.41 µm to 1.55 µm [18]. At the same time, the SM PF POFs have the potential for improved thermal stability compared to their PMMA counterparts [19]. This whole chapter provides a comprehensive overview on current POF-based sensing principles and SHM technologies, highlighting their diverse applications in civil engineering structures. In the application-related context, close attention is paid to the development of smart sensor-based geotextiles and geogrids. Such geosynthetics-integrated distributed POF sensors have proven to be a promising solution for two- or even tree-dimensional monitoring of critical high mechanical deformations in both geotechnical and masonry structures. Moreover, geosynthetics in the form of nonwoven geotextiles as well as polymer-based geogrids used as carrier materials for POF sensors enable optimized load transfer from the monitored structure to the measuring fiber without losing their original functionality. In other words, smart geosynthetics provide a cost-efficient dual solution for, on the one hand, well-established increase of structure stability and decrease of erosion effects, on the other hand, early-warning and detection capabilities in the prevention and elimination of potential hazards and lasting damages. KW - Plastic Optical Fiber Sensor KW - OTDR KW - Brillouin Sensing KW - Interferometric Sensor KW - FBG KW - Long Period Grating KW - Smart Geosynthetics PY - 2020 SN - 978-1-13829-853-8 SP - 267 EP - 283 PB - CRC Press Taylor & Francis Group CY - Boca Raton, FL, USA AN - OPUS4-50561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Multifunktionale Geokunststoffe - nachhaltige Zustandsüberwachung durch ortsaufgelöste faseroptische Sensoren N2 - Vorstellung von Entwicklungsarbeiten zum Thema sensorbasierte Geokunststoffe mit integrierten faseroptischen Sensoren. T2 - 14. Bautextilien-Symposium BAUTEX 2020 CY - Chemnitz, Germany DA - 29.01.2020 KW - Intelligente Geokunststoffe KW - Sensorbasierte Geokunststoffe KW - Faseroptischer Sensor KW - Ortsverteilter Sensor PY - 2020 AN - OPUS4-50321 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Perk, M. A1 - Großwig, S. A1 - Pfeiffer, T. A1 - Rembe, M. A1 - den Hartogh, M. A1 - Weege, S. A1 - Krebber, Katerina A1 - Dijk, H. L. T1 - Faseroptische Leckage-Ortung zum Nachweis von Undichtheiten in Bohrlochkomplettierungen N2 - Im Rahmen der Integritätsbe­wertung einer zementierten 13 3/8" Rohrtour einer Sole-Produktionsbohrung wurden erstmals 2018 zeitgleich faserop­tische Temperaturmessungen (DTS) und faseroptische Akustikmessungen (DAS) durchgeführt und ausgewertet. Dazu wurde die Bohrung zeitweise mit Stick­stoff bespannt und wieder entlastet. T2 - DGMK/ÖGEW-Frühjahrstagung 2020 CY - Celle, Germany DA - 15.​04.​2020 KW - Kavernenspeicher KW - Verteilte faseroptische akustische Sensorik KW - Wasserstoffspeicher PY - 2020 N1 - Die DGMK/ÖGEW Frühjahrstagung 2020 wurde abgesagt, der Tagungsband aber trotzdem veröffentlicht. - The DGMK/ÖGEW Frühjahrstagung 2020 was cancelled, the proceedings were published nevertheless. VL - 136 IS - 4 SP - 25 EP - 26 PB - DVV Media Group CY - Hamburg AN - OPUS4-50783 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kowarik, Stefan A1 - Hussels, Maria-Teresa A1 - Chruscicki, Sebastian A1 - Münzenberger, Sven A1 - Lämmerhirt, A. A1 - Pohl, P. A1 - Schubert, M. T1 - Fiber Optic Train Monitoring with Distributed Acoustic Sensing: Conventional and Neural Network Data Analysis N2 - Distributed acoustic sensing (DAS) over tens of kilometers of fiber optic cables is well-suited for monitoring extended railway infrastructures. As DAS produces large, noisy datasets, it is important to optimize algorithms for precise tracking of train position, speed, and the number of train cars, The purpose of this study is to compare different data analysis strategies and the resulting parameter uncertainties. We present data of an ICE 4 train of the Deutsche Bahn AG, which was recorded with a commercial DAS system. We localize the train signal in the data either along the temporal or spatial direction, and a similar velocity standard deviation of less than 5 km/h for a train moving at 160 km/h is found for both analysis methods, The data can be further enhanced by peak finding as well as faster and more flexible neural network algorithms. Then, individual noise peaks due to bogie clusters become visible and individual train cars can be counted. From the time between bogie signals, the velocity can also be determined with a lower standard deviation of 0.8 km/h, The analysis methods presented here will help to establish routines for near real-time Train tracking and train integrity analysis. KW - Artificial neural networks KW - Distributed fiber optic sensing KW - Distributed acoustic sensing KW - Train tracking PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-502872 DO - https://doi.org/10.3390/s20020450 VL - 20 IS - 2 SP - 450 PB - MDPI CY - Basel, Switzerland AN - OPUS4-50287 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kowarik, Stefan A1 - Hicke, Konstantin A1 - Chruscicki, Sebastian A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Lämmerhirt, A. A1 - Pohl, P. A1 - Schubert, M. ED - Cranch, G. ED - Wang, A. ED - Digonnet, M. ED - Dragic, P. T1 - Train monitoring using distributed fiber optic acoustic sensing N2 - We use distributed acoustic sensing to determine the velocity of trains from train vibration patterns using artificial neural network and conventional algorithms. The velocity uncertainty depends on track conditions, train type and velocity. T2 - 27th International Conference on Optical Fiber Sensors (OFS) CY - Meeting was canceled DA - 08.06.2020 KW - Train monitoring KW - Distributed acoustic sensing KW - DAS KW - Distributed fiber optic sensing PY - 2020 SN - 978-1-55752-307-5 DO - https://doi.org/10.1364/OFS.2020.T3.25 SP - 1 EP - 4 PB - The Optical Society (Optical Society of America) CY - Washington D.C., USA AN - OPUS4-50758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Schreier, Andy T1 - Distributed Brillouin sensor in polymer optical fibers utilizing BOFDA N2 - In this thesis, a distributed Brillouin sensor in perfluorinated polymer optical fibers utilizing BOFDA is presented. These commercially available polymer fibers offer beneficial characteristics for sensing applications such as higher break down strain up to 100 %, minimal bending radii below 2 mm, higher sensitivity to temperature and lower sensitivity to strain compared to their silica equivalent. The chosen wavelength of operation at 1319 nm corresponds to lower fiber propagation loss (< 37 dB/km) compared to other approaches at 1550 nm (150 - 250 dB/km). A 86 m PFGI-POF was successfully measured by BOFDA with spatial resolution of 3.4 m. The findings related to humidity influences can serve as a basis for future distributed humidity sensors not only limited to stimulated Brillouin backscattering. KW - BOFDA KW - Polymer optical fiber KW - POF KW - Brillouin sensor KW - Distributed sensor PY - 2020 SN - 978-3-7369-7146-2 SP - 1 EP - 116 PB - Cuvillier Verlag Göttingen CY - Göttingen AN - OPUS4-51041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Longobucco, M. A1 - Stajanca, Pavol A1 - Curilla, L. A1 - Buczynski, R. A1 - Bugar, I. T1 - Applicable ultrafast all-optical switching by soliton self-trapping in high index contrast dual-core fibre N2 - The improvement potential of ultrafast all-optical switching by soliton self-trapping, using all-solid dual-core fibres with high index contrast, was analyzed numerically. The study of the femtosecond nonlinear propagation was performed based on coupled generalised nonlinear Schrödinger equations considering three fibre architectures: homogeneous cladding all-solid, photonic crystal air-glass, and photonic crystal all-solid. The structural geometries of all three architectures were optimised in order to support high-contrast switching performance in the C-band, considering pulse widths at the 100 fs level. Comparing the three structural alternatives, the lowest switching energies at common excitation parameters (1700 nm and 70 fs pulses) were predicted for the homogeneous cladding dual-core structure. Further optimization of the excitation wavelength and pulse width resulted in lower switching energies and simultaneous improvement of the switching contrasts at the combination of 1500 nm, 75 fs pulses and a fibre length of 43 mm. The spectral aspect in this optimised case expresses a broadband and uniform switching character with a span of over 200 nm and a contrast exceeding 30 dB at more frequency channels. KW - Ultrafast nonlinear propagation KW - All-optical switching KW - Dispersion tailoring of optical fibres KW - Generalised nonlinear Schrödinger equation KW - Dual-core optical fibres KW - Nonlinear directional coupler KW - Soft-glass optical fibres PY - 2020 DO - https://doi.org/10.1088/1612-202X/ab63d8 VL - 17 IS - 2 SP - 025102 PB - Astro Ltd. AN - OPUS4-51042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Infrastruktur- und Anlagenmonitoring mit verteilter faseroptischer akustischer Sensorik N2 - Anwendungsfelder von verteilter faseroptischer akustischer Sensorik (DAS) werden anhand von früheren, gegenwärtigen und zukünftigen Projekten an der BAM vorgestellt und die Leistungsfähigkeit von DAS demonstriert. Die dargestellten Anwendungen sind Monitoring von Rohrleitungen, von Unterseekabeln, von Zügen und Gleisen, von Brücken, von Strassen und Verkehr, von Erdbebenauswirkungen in urbanen Gebieten, von Bohrlöchern im Kontext Erdgasspeicher und für Exploration und Monitoring von Untergründen für Geothermie-Anwendungen. T2 - Sitzung des VDI/VDE-GMA FA 2.17 CY - Online meeting DA - 24.09.2020 KW - Verteilte faseroptische Sensorik KW - Verteilte faseroptische akustische Sensorik KW - DAS KW - Infrastrukturmonitoring KW - Zustandsüberwachung PY - 2020 AN - OPUS4-51304 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Faseroptische akustische Sensorik zur Infrastrukturüberwachung N2 - Die Eigenschaften von optischen Fasern und faseroptischen Sensoren werden beschrieben und die Funktionsweise von verteilter faseroptischer akustischer Sensorik (DAS) erklärt. Die Verwendung von DAS für Zustandsmonitoring vor allem von Infrastruktur und Anlagen wird motiviert. Im Folgenden wird die Einsetzbarkeit von DAS für verschiedenste Anwendungen anhand einiger Beispiele (vergangene und gegenwärtige Projekte der BAM zum Thema DAS für Infrastrukturmonitoring) gezeigt. Diese betreffen das Monitoring von Rohrleitungen/Pipelines, von Energiekabeln, von Gleisanlagen und Zügen, von Brücken und von Strassen und Strassenverkehr. T2 - 419. Sitzung des AK Berlin der DGZfP CY - Online meeting DA - 15.09.2020 KW - Verteilte faseroptische Sensorik KW - DAS KW - Verteilte akustische Sensorik KW - Infrastrukturmonitoring KW - Zustandsüberwachung PY - 2020 AN - OPUS4-51249 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gräf, T. A1 - Hicke, Konstantin A1 - Heidmann, G. A1 - Kölling, M. A1 - Menge, M. A1 - Vaterrodt, K. T1 - Integrierte lokale und verteilte faseroptische Sensorik zum flächende-ckenden Online-Monitoring von Kabelanlagen und Betriebsmitteln N2 - Faseroptische Sensorsysteme bieten heute die Möglichkeit des Online-Monitorings von sensiblen, für die Energieversorgung wichtigen Betriebsmitteln. Insbesondere Hochenergiekabel, wie diese sowohl im Offshore- als auch im Onshorebereich eingesetzt werden, sind prädestiniert für eine zustandsorientierte Überwachung. Gerade Hochspannungshochenergiekabel sind Betriebsmittel, die im Falle eines Ausfalls durch Schäden mit hohen Reparatur- und Folgekosten verbunden sind. Mit dem Einsatz von faseroptischen Sensoren sind mechanische Einflüsse wie Vibrationen z. B. verursacht durch Ankerfall, Temperaturhotspots oder auch Teilentladungsaktivitäten an dezidierten vulnerablen Stellen wie Kabelendverschlüssen oder –muffen über längere Kabelstrecken detektierbar. Der Einsatz von im Rahmen des Verbundprojekts Monalisa entwickelter faseroptischer Diagnosetechnik in Verbindung mit faseroptischen Sensoren wird hier aufgezeigt. T2 - VDE Fachtagung Hochspannungstechnik CY - Online-Meeting DA - 09.11.2020 KW - Verteilte faseroptische Sensorik KW - Energiekabel KW - Zustandsüberwachung KW - Infrastrukturmonitoring KW - Eingebettete Sensorik PY - 2020 SN - 978-3-8007-5353-6 SN - 0341-3934 VL - 2020 SP - 1 EP - 6 PB - VDE Verlag GmbH CY - Berlin AN - OPUS4-51559 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Münzenberger, Sven A1 - Borchardt, Christopher T1 - Long-distance fiber optic vibration sensing using convolutional neural networks as real-time denoisers N2 - A long distance range over tens of kilometers is a prerequisite for a wide range of distributed fiber optic vibration sensing applications. We significantly extend the attenuation-limited distance range by making use of the multidimensionality of distributed Rayleigh backscatter data: Using the wavelength-scanning coherent optical time domain reflectometry (WS-COTDR) technique, backscatter data is measured along the distance and optical frequency dimensions. In this work, we develop, train, and test deep convolutional neural networks (CNNs) for fast denoising of these two-dimensional backscattering results. The very compact and efficient CNN denoiser “DnOTDR” outperforms state-of-the-art image denoising algorithms for this task and enables denoising data rates of 1.2 GB/s in real time. We demonstrate that, using the CNN denoiser, the quantitative strain measurement with nm/m resolution can be conducted with up to 100 km distance without the use of backscatter-enhanced fibers or distributed Raman or Brillouin amplification. KW - Neural networks KW - Fiber optic KW - Vibration sensing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518694 DO - https://doi.org/10.1364/OE.402789 VL - 28 IS - 26 SP - 39325 AN - OPUS4-51869 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Krebber, Katerina T1 - Direct detection based φOTDR using the Kramers-Kronig receiver N2 - A Kramers-Kronig (KK) receiver is applied to a phase-sensitive optical time domain reflectometry based on direct detection. An imbalanced Mach-Zehnder interferometer with a 2× 2 coupler is used in sensing system to encode the phase information into optical intensity. The directly obtained signal is treated as the in-phase component, and the KK receiver provides the quadrature component by Hilbert transform of the obtained signal, so that the optical phase can be retrieved by IQ demodulation. The working principle is well explained, and the obtained phase variance is theoretically analyzed. The experiment demonstrates the functionality of the sensor and validates the theoretical analysis. KW - Kramers-Kronig detector KW - Distributed fiber sensing KW - Acoustic sensing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516803 UR - https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-28-24-37058&id=442839 DO - https://doi.org/10.1364/OE.405723 VL - 28 IS - 24 SP - 37058 EP - 37068 PB - Optical Society of America AN - OPUS4-51680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos T1 - Machine learning for strain and temperature discrimination in Brillouin distributed sensing N2 - Short presentation of the PhD project in machine learning based Brillouin distributed sensing. Machine learning can be used to enhance the performance of BOFDA and reduce considerably the measurement time. Apart from this, ML can also be used to extract more information from the Brillouin gain spectrum in order to render the temperature and strain discrimination possible T2 - PhD Day 2020 CY - Online meeting DA - 15.09.2020 KW - Fiber optics sensors KW - Machine learning PY - 2020 AN - OPUS4-51689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Perk, M. A1 - Großwig, S. A1 - Pfeiffer, T. A1 - Rembe, M. A1 - den Hartogh, M. A1 - Weege, S. A1 - Krebber, Katerina A1 - Dijk, H. L. T1 - Faseroptische Leckage-Ortung zum Nachweis von Undichtheiten in Bohrlochkomplettierungen N2 - Im Rahmen der Integritätsbewertung einer zementierten 13 3/8" Rohrtour einer Sole-Produktionsbohrung wurden erstmals 2018 zeitgleich faseroptische Temperaturmessungen (DTS, Distributed Temperature Sensing) und faseroptische Akustikmessungen (DAS, Distributed Acoustic Sensing) durchgeführt und ausgewertet. Dazu wurde die Bohrung zeitweise mit Stickstoff bespannt und wieder entlastet. Durch die Bespannung der Bohrung mit Stickstoff in Kombination mit dem Herunterdrücken des Stickstoff-Sole-Spiegels unter den Rohrschuh der 13 3/8" Rohrtour, konnte Stickstoff aus der Kavernenbohrung durch eine Leckagestelle in die Zementation übertreten und dort ein Stickstoff-Reservoir bilden. Bei der anschließenden Stickstoffentlastung erfolgte der Wiederanstieg des Stickstoff-Sole-Spiegels deutlich schneller als die Entleerung des in der Zementation angelegten Stickstoff-Reservoirs. Der dadurch entstandene Druckgradient hatte zur Folge, dass an der Leckagestelle der Stickstoff aus der Zementation in die aufsteigende Sole in Form von Bläschen eingetreten und dort aufgestiegen ist. Dieser Übertritt der Stickstoffbläschen war sowohl mit der Entstehung eines akustischen Geräusches als auch mit einer Temperaturänderung verbunden, welche mit der DAS- und DTS-Technik nachgewiesen werden konnten. Um die Ergebnisse bzgl. ihres physikalischen Hintergrundes zu überprüfen und basierend auf einer mathematisch-physikalischen Grundlage eine nachvollziehbare Interpretation der Messergebnisse zu ermöglichen, wurde ein numerisches Simulationsmodell der gekoppelten Festkörper- und Druckakustik für die Bohrung aufgebaut. Das Modell berücksichtigt die Geologie und die Komplettierung der Kavernenbohrung. Nach Identifikation der Schallquelle konnte mit dem Modell die Ausbreitung des Schalldrucks in der Bohrung erfolgreich nachgestellt werden. Um dieses Verfahren einer simultanen DAS-DTS-Messung in eine feldtaugliche Version zu überführen, läuft seit November 2019 ein breit angelegtes und vom BMWi gefördertes ZIM-Kooperationsprojekt zwischen der Bundesanstalt für Materialforschung und -prüfung (BAM), der IAB Weimar gGmbH, der GESO GmbH & Co. Projekt KG, der DEEP.KBB GmbH sowie der Rembe Consulting PartG mbB. Durch die Messdatenkopplung und den Wegfall der bewegungsbedingten Nachteile einer Messsonde werden präzisere Ergebnisse zur Bewertung der Bohrlochintegrität erwartet. Das Ziel ist, mit Hilfe der noch zu entwickelnden einfachen und robusten Technik, quantitative Aussagen über die Zustände im verrohrten Bohrloch direkt am Messplatz treffen zu können, wobei ein Fokus auf Detektierung und Quantifizierung von Kleinstleckagen liegt. Im Rahmen dieses Forschungsprojektes kommt neben numerischen Berechnungen auch ein geplanter Bohrlochsimulator zum Einsatz, mit dem umfangreiche Untersuchungen zur Ermittlung der Grenzparameter und Detektionsschwellen durchgeführt werden sollen. T2 - DGMK/ÖGEW-Frühjahrstagung 2020 CY - Celle, Germany DA - 15.​04.​2020 KW - Kavernenspeicher KW - Verteilte faseroptische akustische Sensorik KW - Wasserstoffspeicher PY - 2020 UR - https://dgmk.egnyte.com/fl/k3KJMqKMSb#folder-link/ SN - 978-3-947716-04-3 SN - 1433-9013 N1 - Die DGMK/ÖGEW Frühjahrstagung 2020 wurde abgesagt, der Tagungsband aber trotzdem veröffentlicht. - The DGMK/ÖGEW Frühjahrstagung 2020 was cancelled, the proceedings were published nevertheless. VL - DGMK-Tagungsbericht 2020-1 SP - 106 EP - 121 PB - DGMK - Deutsche Wissenschaftliche Gesellschaft für Erdöl, Erdgas und Kohle CY - Hamburg AN - OPUS4-52159 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Fiber optic distributed acoustic and vibration sensing for condition monitoring of infrastructure and hazard monitoring applications N2 - Fiber optic Distributed Acoustic Sensing (DAS) is an emerging method for many different monitoring purposes, enabling a spatially and temporally resolved collection of acoustic and vibration information over many kilometers. DAS, thus being a "dynamic" sensing technique, allows for online condition monitoring and the detection and localization of threats or hazards in real time via characteristic acoustic/vibration states and their changes or via occurring anomalous signals, respectively. At BAM, we have employed this technology for a number of different applications of monitoring of large infrastructures, e.g., bridges, pipelines, submarine power cables or railway tracks. Currently, we are investigating the use of DAS for further innovative uses, which aim at facilitating the energy transition, enabling "smart" infrastructure and providing the basis for comprehensive hazard monitoring and warning systems, respectively. Our research fields include fiber optic borehole monitoring in the context of hydrogen storage caverns, traffic and road monitoring, using DAS for earthquake monitoring in urban areas for disaster management and long-term monitoring of large-scale subsidence caused by mining activities. Another new topic is structural health monitoring in concrete structures in the framework of the FSP Security. In this talk, we will first briefly present the basics and capabilities of DAS. Then, we will portray our previous and current works related to this technology and show some attractive results. Finally, we will discuss our upcoming projects on exciting new applications of DAS. T2 - Abteilungsseminar 8. CY - Online meeting DA - 24.02.2021 KW - Distributed fiber optic sensing KW - Distributed acoustic sensing KW - DAS KW - Infrastructure monitoring KW - Hazard monitoring PY - 2021 AN - OPUS4-52160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Jansen, R. A1 - Cheng, L. A1 - Chruscicki, Sebastian T1 - Ortsaufgelöste Zustandsüberwachung von Brückenbauwerken mittels faseroptischer Sensoren N2 - In der vorliegenden Studie wurde der Einfluss der statischen Verkehrsbelastung auf die geringen Durchbiegungseffekte in der Betonkonstruktion einer bestehenden Brücke mittels ortsauflösender faseroptischer Sensoren untersucht. Dabei tragen die Ergebnisse der an der Amsterdamer Brücke 705 durchgeführten Belastungstests wesentlich zum Verständnis des Strukturverhaltens bei. Das Konzept der statischen Belastung basierte auf dem Einsatz von zwei 36-Tonnen-Lastwagen, die an mehreren vorbestimmten Stellen auf der Brücke anhielten. Die auf diese Weise aufgebrachte Last führte zu ortsabhängigen kleinen Durchbiegungseffekten, die als lokale Längsdehnung der an der Unterseite der Brücke integrierten Sensorfaser aufgezeichnet wurden. Die reflektometrischen Messungen beruhten auf dem Prinzip genannt TW-COTDR (Tunable Wavelength Coherent Optical Time Domain Reflectometry). Die Messgenauigkeit lag im Bereich von 0,5 µm/m. T2 - DGZfP-Jahrestagung 2021 CY - Online meeting DA - 10.05.2021 KW - Frequenzbereichsreflektometrie KW - Ortsaufgelöste Fasersensorik KW - Rayleigh-Streuung PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-526752 UR - https://jahrestagung.dgzfp.de/Programm#P73 SP - 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-52675 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Krebber, Katerina T1 - Characterizing detection noise in phase-sensitive optical time domain reflectometry N2 - Phase-sensitive optical time domain reflectometry (φOTDR) is an excellent distributed fiber sensing technique and has been applied in various areas. Its noise is however never been comprehensively studied to the best of our knowledge. The different detection noise sources in such a sensing system are thoroughly investigated. The impacts of thermal noise, shot noise and the beat between signal and the amplified spontaneous emission from a pre-amplifier have been theoretically and experimentally demonstrated. Due to the random nature of the φOTDR signal, the detection noise demonstrates distinct features at different fiber positions in a single measurement. The theoretical analysis and the experimental result explicitly affirm most of the fiber sections, and the difference at some positions may be explained by ambient noise. KW - Noise analysis KW - Acoustic sensing KW - Distributed fiber sensing PY - 2021 DO - https://doi.org/https://doi.org/10.1364/OE.424410 SN - 1094-4087 VL - 29 IS - 12 SP - 18791 EP - 18806 PB - Optical Society of America CY - Washington, DC AN - OPUS4-52757 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Faseroptische Strahlungssensoren für kerntechnische Anwendungen N2 - Faseroptische Strahlungssensoren ermöglichen ein räumlich verteiltes Online-Monitoring entlang der gesamten Sensorfaser. Verschiedene Messverfahren nutzen überwiegend zwei durch die ionisierende Strahlung in optischen Fasern induzierte Effekte, d. h. die Erhöhung der optischen Dämpfung und die damit verbundene Veränderung des Brechungsindex des Fasermaterials. Die Sensitivität der Strahlungssensoren lässt sich je nach Anwendung durch die Wahl der Dotierstoffe im Glasfaserkern sowie der Art des Polymermaterials des POF-Sensors beeinflussen. Ferner ist die Sensitivität auch durch den Betrieb bei geeigneten Wellenlängen einstellbar. Bei dem sensorischen Einsatz von faseroptischen Sensoren muss auch die vorhandene Ausheilung des Sensors sowie die Abhängigkeit der erfassten Messsignale von der Temperatur und der Dosisleistung berücksichtigt werden. T2 - 2. Tage der Standortauswahl CY - Online meeting DA - 11.02.2021 KW - Faseroptischer Strahlungssensor KW - Ortsauflösende Fasersensorik KW - Strahlungsinduzierte optische Dämpfung PY - 2021 AN - OPUS4-52112 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Faseroptische Strahlungssensoren für kerntechnische Anwendungen N2 - Faseroptische Strahlungssensoren ermöglichen ein räumlich verteiltes Online-Monitoring entlang der gesamten Sensorfaser. Verschiedene Messverfahren nutzen überwiegend zwei durch die ionisierende Strahlung in optischen Fasern induzierte Effekte, d. h. die Erhöhung der optischen Dämpfung und die damit verbundene Veränderung des Brechungsindex des Fasermaterials. Die Sensitivität der Strahlungssensoren lässt sich je nach Anwendung durch die Wahl der Dotierstoffe im Glasfaserkern sowie der Art des Polymermaterials des POF-Sensors beeinflussen. Ferner ist die Sensitivität auch durch den Betrieb bei geeigneten Wellenlängen einstellbar. Bei dem sensorischen Einsatz von faseroptischen Sensoren muss auch die vorhandene Ausheilung des Sensors sowie die Abhängigkeit der erfassten Messsignale von der Temperatur und der Dosisleistung berücksichtigt werden. T2 - 2. Tage der Standortauswahl CY - Online meeting DA - 11.02.2021 KW - Faseroptischer Strahlungssensor KW - Ortsauflösende Fasersensorik KW - Strahlungsinduzierte optische Dämpfung PY - 2021 AN - OPUS4-52113 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Ortsaufgelöste Zustandsüberwachung von Brückenbauwerken mittels faseroptischer Sensoren N2 - In der vorliegenden Studie wurde der Einfluss der statischen Verkehrsbelastung auf die geringen Durchbiegungseffekte in der Betonkonstruktion einer bestehenden Brücke mittels ortsauflösender faseroptischer Sensoren untersucht. Dabei tragen die Ergebnisse der an der Amsterdamer Brücke 705 durchgeführten Belastungstests wesentlich zum Verständnis des Strukturverhaltens bei. Das Konzept der statischen Belastung basierte auf dem Einsatz von zwei 36-Tonnen-Lastwagen, die an mehreren vorbestimmten Stellen auf der Brücke anhielten. Die auf diese Weise aufgebrachte Last führte zu ortsabhängigen kleinen Durchbiegungseffekten, die als lokale Längsdehnung der an der Unterseite der Brücke integrierten Sensorfaser aufgezeichnet wurden. Die reflektometrischen Messungen beruhten auf dem Prinzip genannt TW-COTDR (Tunable Wavelength Coherent Optical Time Domain Reflectometry). Die Messgenauigkeit lag im Bereich von 0,5 µm/m. T2 - DGZfP-Jahrestagung 2021 CY - Online meeting DA - 10.05.2021 KW - Ortsaufgelöste Fasersensorik KW - Frequenzbereichsreflektometrie KW - Rayleigh-Streuung PY - 2021 UR - https://jahrestagung.dgzfp.de/Programm#P73 AN - OPUS4-52632 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Faseroptische Strahlungssensoren für kerntechnische Anwendungen N2 - Der Anstieg der Vielfalt nuklearer Anwendungen weit über die Bereiche der kerntechnischen Stromerzeugung erhöht die Relevanz der Entwicklung und Anwendung neuer Technologien zur Strahlungsüberwachung. Auch die offenen Sicherheitsfragen bei der Entsorgung radioaktiver Abfälle einschließlich Zwischen- und Endlagerungsproblematik verstärkt die Nachfrage nach effizienten Monitoringsystemen zum Schutz von Mensch und Umwelt vor ionisierender Strahlung. Aufgrund ihrer messtechnisch vorteilhaften Materialeigenschaften stellen die faseroptischen Strahlungssensoren eine vielversprechende Alternative zu traditionellen Dosimetern dar. Bedingt durch ihre kleinen Abmessungen, elektromagnetische Unempfindlichkeit und ihr geringes Gewicht können faseroptische Sensoren in einer harschen Umgebung an schwer zugänglichen Stellen eingesetzt werden. Darüber hinaus bietet diese Art der Sensoren die Möglichkeit der ortsverteilten Messung entlang der gesamten Sensorfaser. Somit kann durch eine einzelne optische Faser eine Vielzahl an punktuell messenden Sensoren ersetzt werden. Dieser Beitrag beschreibt die in der BAM vorangetriebenen Entwicklungen unterschiedlicher Sensorprinzipien, -lösungen und -verfahren zur Detektion ionisierender Strahlung. T2 - 2. Tage der Standortauswahl CY - Online meeting DA - 11.02.2021 KW - Faseroptischer Strahlungssensor KW - Ortsauflösende Fasersensorik KW - Strahlungsinduzierte optische Dämpfung KW - Gammastrahlung KW - Rayleigh-Streuung KW - Brillouin-Streuung PY - 2021 SP - 43 AN - OPUS4-52211 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin A1 - Chruscicki, Sebastian A1 - Münzenberger, Sven T1 - Urban traffic monitoring using Distributed Acoustic Sensing along laid fiber optic cables N2 - The feasibility of traffic monitoring along a major urban road using Distributed Acoustic Sensing (DAS) is demonstrated. We present measurement results of conventional intensity-based DAS along a dark fiber in a tubed fiber optic cable buried roadside. With only minimal postprocessing different classes of traffic participants can be distinguished (cars, bikes, pedestrians). Different methods for pre-processing raw data are compared, especially with regard to providing suitable inputs for pattern recognition algorithms. Furthermore, the various challenges for automatized vehicle detection and classification related to varying sensitivity and inhomogeneous signal propagation are discussed. Sensitivity fluctuations and variations are in part inherent to the measurement technology and originate in part in ground conditions. The measurement quality and usefulness for traffic monitoring of intensity-based DAS is compared to that of state-of-the-art phase-resolved DAS, allowing quantitative evaluation of vibration signals. T2 - EAGE GeoTech 2021 Second EAGE Workshop on Distributed Fibre Optic Sensing CY - Online meeting DA - 01.03.2021 KW - Distributed fiber optic sensing KW - Distributed acoustic sensing KW - DAS KW - Traffic monitoring KW - Road condition monitoring PY - 2021 DO - https://doi.org/10.3997/2214-4609.202131008 VL - 2021 SP - Paper 8, 1 PB - European Association of Geoscientists & Engineers CY - Houten, Niederlande AN - OPUS4-52214 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Urban traffic monitoring using Distributed Acoustic Sensing along laid fiber optic cables N2 - The feasibility of traffic monitoring along a major urban road using Distributed Acoustic Sensing (DAS) is demonstrated. We present measurement results of conventional intensity-based DAS along a dark fiber in a tubed fiber optic cable buried roadside. With only minimal postprocessing different classes of traffic participants can be distinguished (cars, bikes, pedestrians). Different methods for pre-processing raw data are compared, especially with regard to providing suitable inputs for pattern recognition algorithms. Furthermore, the various challenges for automatized vehicle detection and classification related to varying sensitivity and inhomogeneous signal propagation are discussed. Sensitivity fluctuations and variations are in part inherent to the measurement technology and originate in part in ground conditions. The measurement quality and usefulness for traffic monitoring of intensity-based DAS is compared to that of state-of-the-art phase-resolved DAS, allowing quantitative evaluation of vibration signals. T2 - EAGE GeoTech 2021 Second EAGE Workshop on Distributed Fibre Optic Sensing CY - Online meeting DA - 01.03.2021 KW - Distributed fiber optic sensing KW - Distributed acoustic sensing KW - DAS KW - Traffic monitoring KW - Road condition monitoring PY - 2021 AN - OPUS4-52215 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Optical fibers for sensing applications: Towards ionizing radiation monitoring N2 - Overview about existing fiber optic sensing techniques including ionizing radiation monitoring. T2 - WP7 Meeting EU project PREDIS CY - Online meeting DA - 05.02.2021 KW - Fiber optic sensor KW - Radiation-induced attenuation KW - Radiation sensing fibers KW - Distributed sensing PY - 2021 AN - OPUS4-52090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Portella, Pedro Dolabella A1 - Krebber, Katerina T1 - Fiber Optic Sensors for SHM - From Laboratory to Industrial N2 - The paper highlights the research activities in Germany and Europe in the development of distributed fiber optic sensor for structural health monitoring (SHM) like the monitoring of geotechnical and civil infrastructures and presents selected results achieved within these projects. T2 - Conaendi & IEV 2021 CY - Online meeting DA - 09.03.2021 KW - Fiber KW - Optic KW - SHM PY - 2021 AN - OPUS4-52254 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe T1 - From on line sensor validation to in-situ monitoring of layer growth: coatings around fibre bragg gratings N2 - The lack of on-line validation procedures for structure-embedded fiber-optical strain sensors, in particular fiber-Bragg-gratings (FBG), resulted in limited applications in structural health monitoring (SHM). Degradation under service conditions and ageing as a result of climatic influences or delamination under load were unsolved Validation issues. This could be overcome by means of an auto-diagnosis procedure based on FBG-sensors coated by electrochemical deposition (ECD) with a magnetostrictive NiFe-coating on top of an adhesive Cu/Cr adhesive layer deposited by physical vapour deposition (PVD) around the FBG strain sensor. This allows at any time under Service a validation of sensor functionality, stability, and reliability. For this purpose, a magnetic strain-proportional reference field is introduced. The optical read-out is realized by the measurement of the Bragg-wavelength shift. The ratio of resulting strain and exciting magnetic reference field should be constant given that the sensor is in proper function. In principle, the magnetostrictive coating around the FBG should also work as on-line magnetic field sensor and other applications in material science. One of these applications is the in-situ monitoring of ECD processes as the deposition of the ECD NiFe-layer on the FBG revealed. Challenges are the monitoring of temperature, deposition stages/thickness, and resulting mechanical stress under given plating conditions. Monitoring problems can be solved by applying a pre-coated FBG to the electrolytic process as the shift of the Bragg wavelength is affected by both the temperature of the electrolyte near the substrate and the stress formation in the growing layer. The experimental FBG set-up and the quantitative determination of temperature- and stress-related strain are described for a nickeliron electrolyte. The in-situ measurement of Bragg wavelength shifts of a pre-coated FBG during electrochemical deposition allows a detailed analysis of stress states due to changes in the growth morphology of the layer. The separation of mechanical and thermal contributions to this shift provides information on the individual Deposition processes in terms of a process fingerprint. T2 - ICMCTF 2021 San Diego/on-line CY - Online meeting DA - 28.04.2021 KW - Fiber- Bragg-gratings (FBG) KW - Physical vapour deposition (PVD) KW - Electrochemical deposition (ECD) KW - Magnetostrictive coating KW - ECD NiFe-layer PY - 2021 AN - OPUS4-52898 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Distributed fiber optic sensing for monitoring of pipelines and submarine cables N2 - Division 8.6's competencies and work focus areas are shortly outlined and investigations related to pipeline and submarine power cable monitoring using different distributed fiber optic sensing techniques are presented with some results. Furthermore, BAM 8.6 expertise in the field of sensor application, embedding and integration is shown. T2 - Joint BAM-Vallourec Workshop "Knowledge Exchange NDT" CY - Online meeting DA - 02.09.2021 KW - Distributed fiber optic sensing KW - Infrastructure monitoring KW - DAS KW - DTS KW - Pipeline monitoring PY - 2021 AN - OPUS4-53189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed fiber optic radiation sensors N2 - In this work, we present our results achieved in several research activities for development of distributed fiber optic radiation sensors using glass and polymer optical fibers. The findings show that both the measurement of the radiation-induced attenuation (RIA) along the entire sensing fiber and the accompanying change in the refractive index of the fiber core can be used for distributed radiation monitoring. T2 - safeND CY - Online meeting DA - 10.11.2021 KW - Distributed fiber optic radiation sensors KW - Radiation-induced attenuation KW - Optical fiber sensor KW - Incoherent optical frequency domain reflectometry PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537531 DO - https://doi.org/10.5194/sand-1-15-2021 VL - 1 SP - 15 EP - 16 AN - OPUS4-53753 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Fibre optic sensors for monitoring tasks in a radiation environment N2 - The topic of the presentation are distributed fiber optic measurement techniques that can be used for long-term monitoring of strain, temperature and radiation distribution in the radiation environment. The fiber optic sensors applied to the surface of waste packages provide detection and localization of cracks. T2 - Workshop WP7.3 EU project PREDIS CY - Online meeting DA - 15.11.2021 KW - Distributed sensing KW - Fiber optic sensor KW - Radiation sensing fibers KW - Brillouin distributed fiber sensor KW - Distributed acoustic sensing PY - 2021 AN - OPUS4-53751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Distributed fiber optic radiation sensors N2 - In this work, we present our results achieved in several research activities for development of fiber optic dosimeters. The findings show that both the measurement of the radiation-induced attenuation (RIA) along the entire sensing fiber and the accom panying change in the refractive index of the fiber core can be used for distributed radiation monitoring in the kGy and MGy range, respectively. Depending on the fiber type and material the RIA shows varying response to dose rates, environmental temperatures and the wavelength of the laser source used. T2 - safeND CY - Online meeting DA - 10.11.2021 KW - Distributed sensing KW - Fiber optic radiation sensor KW - Radiation sensing fibers KW - Radiation-induced attenuation PY - 2021 AN - OPUS4-53752 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Monitoring von Strukturverhalten mittels integrierter verteilter faseroptischer Sensorik - Verteilte akustische Sensorik (DAS) N2 - Die verteilte faseroptische akustische Sensorik (DAS) wird vorgestellt, hinsichtlich ihrer Leistungsfähigkeit beschrieben und verschiedenste Anwendungsfelder, z.B. für das Zustandsmonitoring oder für seismische Messungen, beispielhaft gezeigt. Zudem werden mögliche Anwendungsfelder von DAS für den Kontext Kerntechnische Entsorgung (KTE) und Rückbau aufgezeigt. T2 - Online-Workshop „Dauerhafte Verschlussbauwerke für Endlager“ CY - Online meeting DA - 14.02.2022 KW - Verteilte faseroptische Sensorik KW - Verteilte akustische Sensorik KW - DAS KW - KTE KW - Monitoring Endlager PY - 2022 AN - OPUS4-54348 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Krebber, Katerina T1 - Phase error analysis and unwrapping error suppression in phase-sensitive optical time domain reflectometry N2 - Phase-sensitive optical time domain reflectometry becomes an effective tool to realize distributed sensing, and the optical phase of the received light is usually used to quantify the strain for both dynamic and static measurement. The analysis on the overall phase error has been improved by considering the proportionality of the detection noise to the local optical power. The estimation accuracy is greatly improved by using the proposed theory, the probability density of the estimation accuracy over 99% is > 0.6, ∼39 times larger than the previously reported method. The phase unwrapping may malfunction due to the noisy signal, causing large phase errors. Point break detection algorithms are used to locate the incorrect phase unwrapping points, so the temporal evolution of the phase retrieved at each position can be divided into several sections with different offset. The phase unwrapping error is then suppressed by removing the offset. KW - Phase unwrapping KW - Distributed fiber sensing KW - Acoustic sensing PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543919 DO - https://doi.org/10.1364/OE.446517 VL - 30 IS - 5 SP - 6934 EP - 6948 PB - Optica Publishing Group AN - OPUS4-54391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Königsbauer, Korbinian A1 - Wosniok, Aleksander A1 - Nöther, N. A1 - Schaller, B. T1 - Entwicklung eines praxistauglichen POF-basierten Messsystems mittels digitaler I-OFDR zur Dehnungsdetektion T1 - Development of a practicable POF-based measuring system using digital I-OFDR for strain detection N2 - Es wird ein faseroptisches Messsystem vorgestellt, welches auf Basis der Rayleigh-Rückstreumessung eine ortsauflösende Detektion von signifikant großen Dehnungen bei Bauvorhaben im von Anwendern geforderten Größenordnungsbereich von 3 % bis 10 % ermöglicht. Mit dem Verfahren der digitalen inkohärenten optischen Frequenzbereichsreflektometrie (I-OFDR) werden materialspezifische Vorteile robuster perfluorierter polymeroptischer Fasern (PF-POF) erschlossen. Für den angestrebten industriellen Einsatz für die Zustandsüberwachung im Bereich des Tunnel- und Spezialtiefbaus soll die spezifische Rückstreuzunahme in der PF-POF hochauflösend gemessen werden. Diese Veröffentlichung zeigt in ersten Projektergebnissen die Eignung des digitalen I-OFDR für eine Dehnungsdetektion von bis zu 10%. N2 - A fiber-optic measurement system is presented which, based on Rayleigh backscatter measurement, enables distributed detection of significantly large strains in construction projects in the range of 3 % to 10 % required by end users. The method of digital incoherent optical frequency domain reflectometry (I-OFDR) is used exploiting material-specific advantages of robust perfluorinated polymer optical fibers (PF-POF). For the intended industrial application for structural health monitoring in the field of tunnel construction and specialised civil and underground engineering, the specific backscatter increase in the PF-POF is to be measured with high resolution. This publication shows in first project results the suitability of the digital I-OFDR for strain detection up to 10%. T2 - 21. ITG/GMA-Fachtagung CY - Nuremberg, Germany DA - 10.05.2022 KW - Backscatter measurement KW - Optical fiber sensors KW - POF KW - I-OFDR KW - Strain measurement PY - 2022 SN - 978-3-8007-5835-7 SN - 0932-6022 VL - 303 SP - 139 EP - 143 PB - VDE VERLAG GMBH CY - Berlin · Offenbach AN - OPUS4-54851 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shaheen, Sabahat T1 - Coherent heterodyne OTDR based on geometric phase N2 - Results showing a Distributed Acoustic Sensing setup based on Geometric Phase as opposed to the traditionally measured Dynamic Phase. T2 - Meeting on PhD progress CY - Online Meeting DA - 09.08.2022 KW - Coherent Heterodyne KW - Distributed Acoustic Sensing KW - Geometric Phase PY - 2022 AN - OPUS4-55717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Distributed fiber optic sensing @BAM N2 - Research and developement activities of BAM regarding Distributed Fiber Optic Sensing are portrayed using exemplary previous and current projects. Shown results pertain to distributed acoustic sensing (DAS), distributed temperagture sensing (DTS) and distributed strain sensing (DSS). T2 - Seismic seminar FU Berlin (group Prof. Shapiro) CY - Online meeting DA - 15.09.2022 KW - Distributed fiber optic sensing KW - Distributed acoustic sensing KW - Distributed temperature sensing KW - Distributed strain sensing KW - Infrastructure monitoring PY - 2022 AN - OPUS4-55721 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shaheen, Sabahat T1 - Measurement of Geometric Phase using a φ-OTDR setup N2 - Geometric phase showing sensitivity to changes in polarisation state (SOP) and intensity of backscattered light is measured using a novel φ-OTDR setup based on coherent heterodyne detection. Principle is demonstrated using a polarisation scrambler inline a fiber-under-test. T2 - 27th Optical Fiber Sensors conference CY - Alexandria, United States DA - 29.08.2022 KW - Coherent Heterodyne KW - Geometric Phase KW - Distributed Fiber Optic Sensor PY - 2022 AN - OPUS4-55710 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shaheen, Sabahat T1 - Distributed fiber optic sensing for earthquake monitoring N2 - Earthquake monitoring using geometric phase. Planned foeld measurements at Horstwalde (BAM TTS) are discussed with Professor Serge Shapiro of Free University for a possible collaboration. T2 - Invitation for coolaboration on Earthquake Monitoring project CY - Online Meeting DA - 15.09.22 KW - Coherent Heterodyne KW - Geometric Phase KW - Distributed Fiber Optic Sensor PY - 2022 AN - OPUS4-55767 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Dual functionality of wavelength scanning coherent optical time domain reflectometer N2 - Wavelength scanning coherent optical time domain reflectometer (WS-COTDR) is a good candidate to spatially resolve the environmental information at comparatively low frequency. This paper reveals it can also work as a traditional optical time domain reflectometer (OTDR) to identify Fresnel reflection by averaging the obtained signal over the wavelength scanning range. Simultaneous distributed vibration sensing and a traditional OTDR measurement are experimentally demonstrated using the WS-COTDR system. T2 - European Workshop on Optical Fibre Sensors (EWOFS 2023) CY - Mons, Belgium DA - 23.05.2023 KW - Structural health monitoring KW - Distributed fiber sensing KW - Acoustic sensing PY - 2023 DO - https://doi.org/10.1117/12.2678098 VL - 12643 SP - 1 EP - 4 PB - SPEI AN - OPUS4-57590 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Dual-functionality of WS-COTDR for ground movement monitoring N2 - Wavelength scanning coherent optical time domain reflectometer (WS-COTDR) is a good candidate to spatially resolve the environmental information at comparatively low frequency. This paper reveals it can also work as a traditional optical time domain reflectometer (OTDR) to identify Fresnel reflection by averaging the obtained signal over the wavelength scanning range. Simultaneous distributed vibration sensing and a traditional OTDR measurement are experimentally demonstrated using the WS-COTDR system. T2 - European Workshop on Optical Fibre Sensors (EWOFS 2023) CY - Mons, Belgium DA - 23.05.2023 KW - Distributed fiber sensing KW - Acoustic sensing KW - Structural health monitoring PY - 2023 AN - OPUS4-57591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Königsbauer, Korbinian A1 - Wosniok, Aleksander A1 - Nöther, N. A1 - Schaller, M. B. T1 - POF-based digital I-OFDR for strain detection in road construction N2 - We report on the development of a field-proven distributed fiber optic sensing system for structural health monitoring in road construction and civil engineering. The system is based on a cost-efficient digital incoherent optical frequency domain reflectometry (I-OFDR) for distributed strain detection along a polymer optical fiber. In this method, the strain-induced backscatter increase in a graded-index multimode perfluorinated polymer optical fiber (PF-POF) is determined by measuring the complex transfer function of the sensing fiber using a compact digital data acquisition unit. T2 - European Workshop on Optical Fibre Sensors (EWOFS 2023) CY - Mons, Belgium DA - 23.05.2023 KW - Digital I-OFDR KW - Perfluorinated polymer optical fiber KW - Smart geosynthetics KW - Structural health monitoring KW - Road construction KW - Civil engineering PY - 2023 DO - https://doi.org/10.1117/12.2678436 SP - 1264326-1 PB - SPIE AN - OPUS4-57592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shaheen, Sabahat A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - phi-g OTDR utilizing geometric phase N2 - Geometric phase measured per beat period in a ϕ-OTDR based on coherent heterodyne detection is used to measure strain. Proposed method is robust to polarisation mismatch fading as a polarisation mismatch between interfering beams is not a hindrance to the measurement of the geometric phase. The Geometric phase is a function of the intensities of the interfering beams as well as the envelope of the beat signal. Its calculation does not require phase unwrapping and accordingly does not suffer the phase unwrapping errors. It is required to be equated with the traditionally measured phase by applying a scaling factor. The spatial resolution of the measured strain is reduced as it is calculated per beat period. Results are verified using a piezo-electric transducer inline a fiber-under-test. T2 - European Workshop on Optical Fibre Sensors (EWOFS 2023) CY - Mons, Belgium DA - 23.05.23 KW - Coherent Heterodyne KW - Geometric Phase KW - Distributed Fiber Optic Sensor PY - 2023 DO - https://doi.org/10.1117/12.2678295 SP - 1 EP - 5 PB - SPIE AN - OPUS4-57551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Akustisches SpRK Monitoring mit SEA und verteilten faseroptischen Sensoren N2 - Von Hand erzeugte Spanndrahtbrüche in einem BTE-Brückenträger wurden mit Schallemissionsanalyse und verteilter faseroptischer akustischer Sensorik detektiert bzw. gemessen. Eigenheiten und Ergebnisse der beiden Methoden werden dargestellt und ihre Performance verglichen. T2 - 12. Symposium "Experimentelle Untersuchungen von Baukonstruktionen" (SEUB) CY - Dresden, Germany DA - 01.06.2023 KW - Verteilte faseroptische akustische Sensorik KW - DAS KW - Brückenmonitoring KW - Spanndrahtbruchdetektion KW - Schallemissionsanalyse KW - SEA PY - 2023 AN - OPUS4-57580 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Xu, R. A1 - Hicke, Konstantin A1 - Chruscicki, Sebastian A1 - Marx, S. ED - Curbach, M. ED - Marx, S. ED - Scheerer, S. ED - Hampel, T. T1 - Akustisches SpRK-Monitoring mit SEA und verteilten faseroptischen Sensoren N2 - Im vorliegenden Bericht wurde untersucht, Spanndrahtbrüche in einem Brückenträger sowohl mittels Schallemissionsanalyse (SEA) als auch mit (eingebetteter) verteilter faseroptischer akustischer Sensorik (DAS) zu erkennen. Die Ergebnisse zeigen, dass die Bruchsignale anhand beider Messverfahren detektiert werden können. Die jeweils detektierten Drahtbrüche werden miteinander verglichen. Durch eine Gegenüberstellung werden SEA und DAS detailliert dargestellt. T2 - 12. Symposium "Experimentelle Untersuchungen von Baukonstruktionen" (SEUB) CY - Dresden, Germany DA - 01.06.2023 KW - Verteilte faseroptische akustische Sensorik KW - DAS KW - Brückenmonitoring KW - Spanndrahtbruchdetektion KW - Schallemissionsanalyse KW - SEA PY - 2023 SN - 978-3-86780-740-1 SN - 1613-6934 VL - 67 SP - 136 EP - 147 PB - Technische Universität Dresden - Fakultät Bauingenieurwesen CY - Dresden AN - OPUS4-57581 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shaheen, Sabahat T1 - ɸgOTDR utilizing Geometric Phase for Earthquake Monitoring N2 - Geometric phase measured per beat period1 in a ɸ-OTDR based on coherent heterodyne detection2 is used to measure strain3, instead of the traditionally measured dynamic phase. The new setup is referred to as a ɸgOTDR. Results are verified using a piezo-electric transducer inline a fiber-undertest. T2 - European Workshop on Optical Fibre Sensors (EWOFS 2023) CY - Mons, Belgium DA - 23.05.2023 KW - Geometric Phase KW - Distributed Fiber Optic Sensor KW - Coherent Heterodyne PY - 2023 AN - OPUS4-57607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Distributed fiber optic radiation sensors for nuclear applications N2 - Advantages and underlying principles of distributed fiber optic radiation sensing are discussed. Differences with regard to dose measurement range and resolution between glass optical fiber based sensing and polymer optical fiber based sensing are outlined. T2 - DGZfP SMIRT26 Laborbesuch (BAM) CY - Berlin, Germany DA - 10.07.2022 KW - Distributed fiber optic sensing KW - Fiber optic radiation monitoring KW - Distributed fiber optic radiation sensing PY - 2022 AN - OPUS4-55264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shaheen, Sabahat A1 - Hicke, Konstantin T1 - Geometric phase in distributed fiber optic sensing N2 - The geometric phase in the beat signal from coherent interference of two frequency-offset light beams is measured using a novel distributed optical fiber sensing setup. In a fiber optic medium, with changing beam intensities, to the best of our knowledge, ours is the first measurement of the mentioned geometric phase. Experimental results of applying a 100-Hz sinusoidal stimulus to a polarization scrambler and a piezoelectric transducer inline to an optical fiber are presented. The results may enable novel distributed fiber sensing techniques. KW - Distributed fiber optic sensing KW - Geometric phase measurement KW - Distributed vibration sensing KW - C-OTDR PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-556053 DO - https://doi.org/10.1364/OL.464259 VL - 47 IS - 15 SP - 3932 EP - 3935 PB - Optica CY - Washington D.C., USA AN - OPUS4-55605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Achievements and challenges of distributed polymer optical fiber sensors @BAM N2 - Monitoring of construction projects plays increasingly important role in the implementation of growing needs and requirements, especially in geologically difficult areas. This particularly concerns tunnelling and special civil engineering projects. The use of fiber optic sensors for structural health monitoring provides significant economic advantages regarding lower life-cycle costs of the civil infrastructure. We present our achievements in the development of distributed polymer optical fiber sensors based on Rayleigh and Brillouin scattering for early damage detection. T2 - POF Conference CY - Bilbao, Spain DA - 26.09.2022 KW - Distributed POF sensor KW - OTDR KW - OFDR KW - Smart geosynthetics PY - 2022 AN - OPUS4-56031 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Königsbauer, Korbinian A1 - Nöther, N. A1 - Schaller, M. B. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed POF sensors for structural health monitoring in civil construction applications N2 - In this paper, a cost-efficient distributed fiber optic measurement system based on Rayleigh scattering is presented. The distributed digital incoherent optical frequency domain reflectometry (I-OFDR) method is developed for detection of significantly large strain in the range from 3 % up to 10 % as required by end users. For this purpose, a vector network analyzer used in the I-OFDR is replaced by a compact and cost-effective digital data acquisition system. This digital emitting/receiving unit enables the recording of the complex transfer function carrying information about the local deformations along the entire sensing fiber. T2 - POF 2022 The 30th International Conference on Plastic Optical Fibers CY - Bilbao, Spain DA - 26.09.2022 KW - I-OFDR KW - PF-POF KW - Structural health monitoring KW - Rayleigh backscatter measurement KW - Strain detection PY - 2022 VL - 2022 SP - 152 EP - 155 AN - OPUS4-56060 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shaheen, Sabahat A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Phase-sensitive optical time domain reflectometry based on geometric phase measurement N2 - A phase-sensitive optical time domain reflectometer based on coherent heterodyne detection of geometric phase in the beat signal of light, is reported for the first time to our knowledge. The use of the geometric phase to extract strain makes it immune to polarisation diversity fading. This is because a polarisation mismatch between the interfering beams is not a hindrance to its measurement. The geometric phase is calculated using the amplitude of the beat signal and individual beam intensities without any need for phase unwrapping. It is measured per beat period and can be equated with the traditionally measured dynamic phase with appropriate scaling. The results show that the system based on the geometric phase successfully measures strain, free from polarisation mismatch fading and phase unwrapping errors, providing a completely novel solution to these problems. KW - Fiber optic sensing KW - Distributed acoustic sensing KW - DAS KW - Geometric phase KW - Pancharatnam–Berry phase KW - Berry phase PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570307 DO - https://doi.org/10.1038/s41598-023-29972-4 VL - 13 SP - 1 EP - 11 PB - Nature Portfolio CY - London AN - OPUS4-57030 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shaheen, Sabahat T1 - Earth's near surface characterisation using phi-OTDR based on Geometric Phase N2 - A novel DAS setup based on geometric phase is used to measure surface waves of the Earth. They carry useful information about the structure and material of the Earth. T2 - Optica Sensing Congress CY - Munich, Germany DA - 30.07.2023 KW - Geometric Phase KW - Distributed Fiber Optic Sensor KW - Surface waves KW - Coherent Heterodyne KW - Geophysics PY - 2023 AN - OPUS4-58043 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shaheen, Sabahat A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Earth’s near-surface characterisation using phi-OTDR based on geometric phase N2 - Phase-sensitive OTDR based on geometric phase for the first time detects surface waves generated by quarry blasts of 25 kg explosives. Inversion of dispersion curves provides depth profiles of shear-wave velocities of surface waves. T2 - Optica Sensing Congress CY - Munich, Germany DA - 30.07.2023 KW - Geophysics KW - Geometric Phase KW - Distributed Fiber Optic Sensor KW - Coherent Heterodyne KW - Surface waves PY - 2023 SP - 1 EP - 2 AN - OPUS4-58044 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Krebber, Katerina T1 - Novel fading suppression method for distributed optical fiber acoustic sensing N2 - A universal method based on alternating pulse widths is proposed to suppress the signal fading for all distributed acoustic sensors (DASs) and experimentally demonstrated by one DAS system based on a Mach-Zehnder interferometer. T2 - Optica Sensing Congress CY - Munich, Germany DA - 30.07.2023 KW - Distributed fiber sensing KW - Acoustic sensing KW - Fading suppression KW - Structural health monitoring PY - 2023 SP - 1 EP - 2 AN - OPUS4-58048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Krebber, Katerina T1 - Novel fading suppression method for distributed optical fiber acoustic sensing N2 - A universal method based on alternating pulse widths is proposed to suppress the signal fading for all distributed acoustic sensors (DASs) and experimentally demonstrated by one DAS system based on a Mach-Zehnder interferometer. T2 - Optica Sensing Congress CY - Munich, Germany DA - 30.07.2023 KW - Distributed fiber sensing KW - Acoustic sensing KW - Structural health monitoring KW - Fading suppression PY - 2023 AN - OPUS4-58049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Thomas, P. T1 - Phase Error Evaluation via Differentiation and Cross-Multiplication Demodulation in Phase-Sensitive Optical Time-Domain Reflectometry N2 - Phase-sensitive optical time-domain reflectometry (jOTDR) is a technology for distributed vibration sensing, where vibration amplitudes are determined by recovering the phase of the backscattered light. Measurement noise induces phase errors, which degrades sensing performance. The phase errors, using a differentiation and cross-multiplication (DCM) algorithm, are investigated theoretically and experimentally in a jOTDR system based on a phase retrieval configuration consisting of an imbalanced Mach–Zehnder interferometer (IMZI) and a 3 x 3 coupler. Analysis shows that phase error is highly dependent on the AC component of the obtained signal, essentially being inversely proportional to the product of the power of the light backscattered from two locations. An analytical expression was derived to estimate the phase error and was confirmed by experiment. When applied to the same measurement data, the error is found to be slightly smaller than that obtained using in-phase/quadrature (I/Q) demodulation. The error, however, increases for longer measurement times. KW - Distributed fiber sensing KW - Phase-sensitive optical time-domain reflectometry KW - Phase error PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580501 UR - https://www.mdpi.com/2304-6732/10/5/514 DO - https://doi.org/10.3390/photonics10050514 SN - 2304-6732 VL - 10 IS - 5 SP - 1 EP - 14 PB - MDPI CY - Basel AN - OPUS4-58050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shaheen, Sabahat A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Blast-Assisted Subsurface Characterisation Using a Novel Distributed Acoustic Sensing Setup Based on Geometric Phases N2 - A novel DAS setup based on geometric phases in coherent heterodyne detection is applied for the first time to the characterisation of the Earth’s subsurface. In addition, an optimisation of the proposed setup in terms of its spatial resolution is also presented for the first time. The surface waves are generated by strong blasts of 25 kg of explosives at a dedicated test site. A 10 km dark fiber link in the vicinity of the test site connected to the test setup records the resulting strain signals. The spike-free and low-noise strain data thus obtained minimize post-processing requirements, making the setup a candidate for real-time seismic monitoring. An analysis of the dispersion characteristics of the generated surface waves is performed using a recently reported optimised seismic interferometric technique. Based on the dispersion characteristics, the shear wave velocities of the surface waves as a function of the depth profile of the Earth’s crust are determined using an optimised evolutionary algorithm. KW - Geophysics KW - Geometric Phase KW - Distributed Fiber Optic Sensor KW - Distributed Acoustic Sensing KW - Earthquake Monitoring KW - Seismology PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-591913 DO - https://doi.org/10.3390/s24010030 VL - 24 IS - 1 SP - 1 EP - 12 PB - MDPI AN - OPUS4-59191 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Verteilte POF-basierte faseroptische Sensoren zur Infrastrukturüberwachung in der Geotechnik N2 - Wir präsentieren unsere Forschungsergebnisse zur Entwicklung eines faseroptischen Sensorsystems mit polymeroptischen Fasern integriert in Geokunststoffe für die Überwachung von geotechnischen Anlagen. Das Sensorsystem dient der räumlichen Auflösung lokaler Dehnungsereignisse im für Anwender signifikanten Größenordnungsbereich von 3 % bis 10 %. Das gesamte Sensorkonzept besteht aus einem praxistauglichen Messsystem basierend auf der digitalen inkohärenten optischen Frequenzbereichsreflektometrie (I-OFDR) und einer Sensormatte in Form eines Geotextils mit integrierten faseroptischen perfluorierten polymeroptischen Fasern (PF-POFs). T2 - DGZfP Fachtagung Bauwerksdiagnose 2024 CY - Berlin, Germany DA - 29.02.2024 KW - Ortsverteilte faseroptische Sensorik KW - Optische Frequenzbereichsreflektometrie KW - Bauwerksüberwachung KW - Sensorbasierte Geokunststoffe PY - 2024 AN - OPUS4-59633 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Distributed acoustic sensing to monitor ground motion/movement at multi-frequency bands N2 - A novel distributed acoustic sensing technique is proposed that exploits both phase and amplitude of the Rayleigh backscattered light to quantify the environmental variation. The system employs a wavelength-scanning laser and an imbalanced Mach-Zehnder interferometer to acquire the reflection spectra and the phase of the detected light, respectively. Fading-free and low-frequency measurements are realized via the crosscorrelation of the reflection spectra. The discrete crosscorrelation is used to circumvent the nonlinear frequency sweeping of the laser. Based on the phase of the backscattered light, it is possible to quantify fast environmental variations. The whole system requires no hardware modification of the existing system and its functionality is experimentally validated. The proposed system has the potential to monitor ground motion/movement at very low frequency band like subsidence around mining areas and at high frequency band like earthquakes and vibrations induced by avalanches. KW - Distributed acoustic sensing KW - DAS KW - Distributed fiber optic sensing KW - Ground motion detection KW - Subsidence monitoring PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596129 DO - https://doi.org/10.1109/JLT.2024.3358495 VL - 42 IS - 18 SP - 1 EP - 8 PB - Optical Society und IEEE Photonics Society AN - OPUS4-59612 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Faseroptisches Monitoring von Brückenbauwerken N2 - Die Möglichkeiten von verteilter faseroptischer Sensorik (DFOS) im Allgemeinen und für das Monitoring von Bauwerken im Besonderen werden dargestellt und beispielhafte Anwendungen von DFOS im Kontext Brückenmonitoring illustriert. T2 - DGZfP Fachtagung Bauwerksdiagnose 2024 CY - Berlin, Germany DA - 29.02.2024 KW - Bauwerksüberwachung KW - Brückenmonitoring KW - Verteilte faseroptische Sensorik KW - Dynamische Strukturantwort KW - Spanndrahtbruchdetektion PY - 2024 AN - OPUS4-59613 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Approaching distributed ground motion sensing at high and low frequency ranges N2 - The phase and reflection spectrum of a standard distributed acoustic sensor based on an interferometer are used for fast and slow dynamic measurements, respectively, enabling the system to simultaneously measure various types of ground movement. T2 - 28th International Conference on Optical Fiber Sensors (OFS-28) CY - Hamamatsu, Japan DA - 20.11.2023 KW - Distributed acoustic sensing KW - Ground movement monitoring KW - Geomonitoring KW - Interferometer-based KW - DAS PY - 2023 AN - OPUS4-59097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Approaching distributed ground motion sensing at high and low frequency ranges N2 - The phase and reflection spectrum of a standard distributed acoustic sensor based on an interferometer are used for fast and slow dynamic measurements, respectively, enabling the system to simultaneously measure various types of ground movement. T2 - 28th International Conference on Optical Fiber Sensors (OFS-28) CY - Hamamatsu, Japan DA - 20.11.2023 KW - Distributed acoustic sensing KW - Ground movement monitoring KW - Geomonitoring KW - Interferometer-based KW - DAS PY - 2023 SP - 1 EP - 4 PB - Optica CY - Washington D.C., USA AN - OPUS4-59098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - POF-based monitoring system using digital I-OFDR for strain detection in road construction N2 - We present a prototype of a distributed POF sensing system for strain detection in road construction and civil engineering ready to be used in practical applications. The system is based on a cost-efficient digital incoherent optical frequency domain reflectometry (I-OFDR). In this approach, the strain-induced changes in the Rayleigh backscattering profile along a perfluorinated polymer optical fiber (PF-POF) are determined by measuring the complex transfer function of the sensing fiber using a compact digital data acquisition unit. The digital unit replaces an oversized vector network analyzer (VNA) enabling suitability of the measurement system for out-door use and providing a significant reduction of the total system costs at the same time. The entire sensor con-cept includes the use of geosynthetics with integrated PF-POFs as two-dimensional sensor structures for geotech-nical applications. The robustness and the functionality of the distributed POF I-OFDR sensors were proven in the field. The field test involved embedding of two geomats, each with two polymer optical sensor loops, into the embankment of the federal road B 91 in a section near Leipzig. The measurements conducted after the sensor-based geomats had been installed confirmed both the potential of such smart geosynthetics and the functionali-ty of the digital I-OFDR prototype. T2 - POF2023 CY - Cork, Irland DA - 17.09.2023 KW - Digital I-OFDR KW - Distriubuted polymer optical fiber sensor KW - Smart geosynthetics KW - Strain detection KW - Structural health monitoring PY - 2023 AN - OPUS4-58423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shaheen, Sabahat T1 - Earth‘s near surface characterisation using DAS based on geometric phase N2 - Results obtained from field measurements using a novel distributed acoustic sensor based on geometric phase. The target application is Seismology where we attempt to characterise the Earth's subsurface. T2 - Colaboration on Earthquake Monitoring project with Freue University CY - Berlin, Germany DA - 18.09.2023 KW - Geometric Phase KW - Distributed Fiber Optic Sensor KW - Seismology KW - Coherent Heterodyne KW - Subsurface KW - Earth KW - Surface waves KW - Geophysics PY - 2023 AN - OPUS4-58460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Königsbauer, Korbinian T1 - Entwicklung eines praxistauglichen auf POF basierenden Messsystems mittels digitaler I-OFDR zur Dehnungsdetektion N2 - Es wird ein faseroptisches Messsystem vorgestellt, welches auf Basis der Rayleigh-Rückstreumessung eine ortsauflösende Detektion von signifikant großen Dehnungen bei Bauvorhaben im von Anwendern geforderten Größenordnungsbereich von 3 % bis 10 % ermöglicht. Mit dem Verfahren der digitalen inkohärenten optischen Frequenzbereichsreflek-tometrie (I-OFDR) werden materialspezifische Vorteile robuster perfluorierter polymeroptischer Fasern (PF-POF) erschlossen. Für den angestrebten industriellen Einsatz für die Zustandsüberwachung im Bereich des Tunnel- und Spezialtiefbaus soll die spezifische Rückstreuzunahme in der PF-POF hochauflösend gemessen werden. In diesem Vortrag wird gezeigt, dass sich in ersten Projektergebnissen das digitale I-OFDR für eine Dehnungsdetektion von bis zu 10% eignet. T2 - 21. ITG/GMA-Fachtagung CY - Nuremberg, Germany DA - 10.05.2022 KW - I-OFDR KW - Structure health monitoring KW - Dehnungsdetektion KW - Reyleigh-Rückstreumessung PY - 2022 AN - OPUS4-56717 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin A1 - Liao, Chun-Man A1 - Chruscicki, Sebastian A1 - Breithaupt, Mathias T1 - Vibration Monitoring of Large-Scale Bridge Model using Distributed Acoustic Sensing N2 - Results of DAS measurements along a large-scale concrete bridge model are presented. The improvement of measurable dynamic strain range is demonstrated. Vibration modes obtained by DAS correspond well to those determined from broadband seismometer measurements. T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Distributed acoustic sensing KW - Vibration modes KW - Bridge monitoring KW - WS-COTDR KW - Fiber-optic vibration monitoring PY - 2022 SP - 1 EP - 4 PB - Optica CY - Washington D.C., USA AN - OPUS4-56082 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Königsbauer, Korbinian T1 - Distributed POF sensors for structural health monitoring in civil construction applications N2 - In this presentation, a cost-efficient distributed fiber optic measurement system based on Rayleigh scattering is shown. The distributed digital incoherent optical frequency domain reflectometry (I-OFDR) method is devel-oped for detection of significantly large strain in the range from 3 % up to 10 % as required by end users. For this purpose, a vector network analyzer used in the I-OFDR is replaced by a compact and costeffective digital data acquisition system. This digital emitting/receiving unit enables the recording of the complex transfer function carrying information about the local deformations along the entire sensing fiber. T2 - POF 2022 The 30th International Conference on Plastic Optical Fibers CY - Bilbao, Spain DA - 26.09.2022 KW - I-OFDR KW - Perfluorinated polymer optical fiber (PF-POF) KW - Strain detection KW - Structural health monitoring. PY - 2022 AN - OPUS4-56714 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Using DAS for monitoring of infrastructures and for seismic sensing applications N2 - After describing the basics of distributed fiber optic sensing in general and distributed fiber optic acoustic sensing (DAS) in particular, several currently and previously investigated fields of application of DASin infrastructure monitoring and seismic monitoring are presented. A focus is placed on seismic measurements and DAS measurements determining the dynamic responses of concrete structures to certain stimuli. T2 - Meeting of the WAVE Initiative Hamburg CY - Online meeting DA - 09.02.2023 KW - Distributed acoustic sensing KW - DAS KW - Dynamic structural response KW - Seismic measurements KW - Bridge monitoring KW - Traffic monitoring PY - 2023 AN - OPUS4-57007 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin T1 - Introduction to group 8.6 N2 - A brief introduction of group 8.6 and the research work on the application of fiber sensing. T2 - DIU Besuch CY - Berlin, Germany DA - 05.05.2023 KW - Structural health monitoring KW - Distributed fiber sensing KW - Distributed acoustic sensing KW - Practical application PY - 2023 AN - OPUS4-57430 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Shaheen, Sabahat T1 - Distributed acoustic sensing using geometric phase and its application to seismology N2 - This thesis deals with the development of a novel optical fiber sensing scheme based on geometric phase for sensing strain and its application to seismology. Interference of two coherent frequency offset electromagnetic waves gives rise to a geometric phase in the resulting beat signal. The existence of this phase was recently reported along with requisite conditions for its existence. This thesis proposes to detect and use this geometric phase in the context of distributed and dynamic fiber optic strain sensing, also known as distributed acoustic sensing (DAS). In the first part, I devise a novel DAS hardware setup capable of detecting the geometric phase considering that its measurement methods require the measurement of beam intensities and the beat signal’s envelope. The geometric phase is a function of relative intensity and polarisation state of two interfering beams. Therefore, its measurement is verified by determining its relation on these quantities using a polarisation scrambler and a piezoelectric transducer, inline an optical fiber. It is a fundamental study that has implications in coherent optical communication and novel sensing mechanisms. The second part involves using the geometric phase in DAS for measurement of strain. I attempt to replace the traditionally measured dynamic phase in a DAS setup with the geometric phase. This is made possible by the fact that the geometric and dynamic phases are reportedly coupled over every beat period such that their sum remains constant. However, the spatial resolution for geometric phase is lower as it is measured per beat period. I determine an equivalence for the two phases empirically as well as optimum test parameters such as the required frequency offset between the interfering beams. The advantages offered by the use of geometric phase are demonstrated; geometric phase can be measured even when the two interfering beams have non-identical polarisation states, unlike the traditionally measured dynamic phase. Moreover, it does not require phase unwrapping and is therefore free from unwrapping errors. In the third and final part, the setup, after optimisation, is tested in the field to detect seismic waves travelling on the surface of the Earth in response to a set of blasts carried out at a test-site. The surface waves are used for the characterisation of the structure and material properties of the first tens of meters of the Earth with applications in earthquake monitoring, resource exploration and infrastructure planning. In short, this study is the first of its kind to measure geometric phase in beat signal of light using optical fiber medium and to measure strain with it, for which a novel hardware setup and a novel sensing mechanism is designed and tested in addition to its application in real-world seismology measurements. KW - C-OTDR KW - Distributed fiber optic sensing KW - Distributed vibration sensing KW - Geometric phase measurement PY - 2024 SP - 1 EP - 89 PB - Technische Universität Carolo-Wilhelmina CY - Braunschweig AN - OPUS4-60956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Fibre Optic Sensing @BAM N2 - The profile of division 8.6 Fibre Optic Sensors is shown, underlining specific competencies and know-how. Furthermore, several current application examples of the use of distributed fiber optic sensing for condition and state monitoring are presented. T2 - Visit and technical tour of OECD/NEA CODAP working group led by Gesellschaft für Anlagen- und Reaktorsicherheit CY - Berlin, Germany DA - 19.09.2024 KW - Distributed fiber optic sensing KW - Condition monitoring KW - Geomonitoring KW - Structural health monitoring KW - Embedded fiber optic sensor PY - 2024 AN - OPUS4-61080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Krebber, Katerina T1 - Configuration simplification and data reduction in a DAS system for monitoring large infrastructures N2 - The distributed acoustic sensor based on an imbalanced Mach-Zehnder interferometer with a 3×3 coupler is simplified by using a balanced detector instead of three identical photodetectors. The obtained data is reduced by two third accordingly. T2 - Optica Sensing Congress 2024 CY - Toulouse, France DA - 15.07.2024 KW - Data reduction KW - Distributed fiber optic sensing KW - System simplification PY - 2024 SP - 1 EP - 2 PB - Optica CY - Washington D.C., USA AN - OPUS4-60840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin T1 - Configuration simplification and data reduction in a DAS system for monitoring large infrastructures N2 - The distributed acoustic sensor based on an imbalanced Mach-Zehnder interferometer with a 3×3 coupler is simplified by using a balanced detector instead of three identical photodetectors. The obtained data is reduced by two third accordingly. T2 - Optica Sensing Congress 2024 CY - Toulouse, France DA - 15.07.2024 KW - Distributed fiber sensing KW - System simplification KW - Data reduction PY - 2024 AN - OPUS4-60841 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin A1 - Lu, Xin A1 - Chruscicki, Sebastian A1 - Krebber, Katerina T1 - Measurement of Slowly Changing and Quasi-Static Strain Signals for Ground Motion Monitoring Applications using Distributed Acoustic Sensing N2 - The suitability of wavelength-scanning COTDR for distributed dynamic strain sensing (DAS) along buried fiber cables for long-term geotechnical monitoring applications is demonstrated by experiments showing the method’s capability to demodulate slowly varying and quasi-static signals. T2 - Optica Sensing Congress 2024 CY - Toulouse, France DA - 15.07.2024 KW - Ground motion KW - Ground movement monitoring KW - Distributed fiber optic sensing KW - Quasi-static signals KW - Geomonitoring PY - 2024 SP - 1 EP - 2 PB - Optica CY - Washington D.C., USA AN - OPUS4-60816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Measurement of Slowly Changing and Quasi-Static Strain Signals for Ground Motion Monitoring Applications using Distributed Acoustic Sensing N2 - The suitability of wavelength-scanning COTDR for distributed dynamic strain sensing (DAS) along buried fiber cables for long-term geotechnical monitoring applications is demonstrated by experiments showing the method’s capability to demodulate slowly varying and quasi-static signals T2 - Optica Sensing Congress 2024 CY - Toulouse, France DA - 15.07.2024 KW - Distributed acoustic sensing KW - Ground movement monitoring KW - Geomonitoring KW - Quasi-static signals KW - Distributed fiber optic sensing PY - 2024 AN - OPUS4-60817 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shaheen, Sabahat T1 - Photonic crystal fibers for microwave signal processing N2 - We present a novel design of an optical True Time Delay Line based on a 19-core Photonic Crystal Fiber that operates in a broad radiofrequency signal processing range from 1 to 67 GHz on a 10-km link, thus enabling simultaneous signal distribution and processing. T2 - 2021 IEEE Photonics Conference (IPC) CY - Vancouver, BC, Canada DA - 18.10.2021 KW - Delay lines KW - Photonic crytal fibers KW - Optical fibers PY - 2021 SN - 978-1-6654-1601-6 DO - https://doi.org/10.1109/IPC48725.2021.9592934 SP - 1 EP - 3 PB - IEEE AN - OPUS4-56582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shaheen, Sabahat A1 - Hicke, Konstantin T1 - Measurement of Geometric Phase using a φ-OTDR setup N2 - Geometric phase showing sensitivity to changes in polarisation state and intensity of backscattered light is measured using a novel φ-OTDR setup based on coherent heterodyne detection. Principle is demonstrated using a polarisation scrambler inline a fiber-under-test. T2 - Optical Fiber Sensors 2022 CY - Alexandria, Virginia, United States DA - 29.08.2022 KW - Coherent Heterodyne KW - Geometric Phase KW - Distributed Fiber Optic Sensor PY - 2022 SN - 978-1-957171-14-2 SP - W4.72 AN - OPUS4-56116 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zabihi, Mohammadmasoud A1 - Krebber, Katerina T1 - Approach for Faster Signal Processing in Փ-OTDR Systems Based on Directional Measurement of Fiber Slices Interaction N2 - In this study, a signal processing approach for heterodyne Փ-OTDR and C-OTDR systems that can obtain external perturbation and its frequency content in a faster way is proposed. We can detect vibrations with the same or better SNR using this processing approach, only with a single step and fast calculation. Fig. 12 shows the comparison of the normalized measurement time for the gamma matrix method and the conventional method throughout the three experiments. The speed of processing using a gamma matrix is ~35%–50% faster compared to a conventional method in high frequency test (PZT), low frequency test (walking) and street monitoring test. The processing speed in low frequency test is normally a bit lower than the similar high frequency one, since we must use higher number of time frames. Also, in street test we have higher speed because we can select wider gauges. KW - Փ-OTDR PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560492 DO - https://doi.org/10.1364/OPTCON.456421 VL - 1 IS - 8 SP - 1837 EP - 1847 PB - Optica Publishing Group CY - Washington, DC AN - OPUS4-56049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zabihi, Mohammadmasoud A1 - Krebber, Katerina T1 - Laser source frequency drift compensation in Φ-OTDR systems using multiple probe frequencies N2 - In this study, an approach for mitigation of LSFD in Φ-OTDR systems was proposed. By using one probe pulse as a reference in a system with two or more probe frequencies, we can remove unwanted low frequency noise that is originally caused by the laser source. Although LSFD is problematic issue, it is not the only source of low frequency noise. Change in temperature, humidity, physical surroundings, environment, etc., can result in such noises. The proposed method; however, is expected to highly suppresses all of these effects, regardless of their source, either in the time or frequency domain. For comparing reference and probe signals, there are sophisticated methods, rather than normal differentiation, available for use. Some of these methods have a close relationship with CPD methods and can further enhance the results. These methods can be further discussed in an independent research or future work. The proposed method is very helpful for increasing accuracy in passive and active seismic monitoring, reservoir monitoring, underwater monitoring, etc. It also helps using relatively simpler laser sources and make the whole system price-efficient, as well as processing data without lengthy compensation algorithms. KW - Frequency Drift KW - Փ-OTDR KW - LSFD PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560517 DO - https://doi.org/10.1364/oe.460302 SN - 1094-4087 VL - 30 IS - 11 SP - 19990 EP - 19998 PB - Optica CY - Washington, DC AN - OPUS4-56051 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Fibre Optic Sensors (Division 8.6) N2 - Fiber optic sensing technology being researched and developed at BAM and its numerous applications/ use cases is presented briefly after a short introductory part on the fundamentals of (distributed) fiber optic sensing. T2 - BAM - RCNDE (UK) Webinar CY - Online meeting DA - 13.11.2024 KW - Distributed fiber optic sensing KW - Structural health monitoring KW - Condition monitoring KW - DAS KW - Embedded fiber optic sensors PY - 2024 AN - OPUS4-61643 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Krebber, Katerina T1 - Suppression of Rayleigh fading induced errors in φOTDR by different pulse widths for improving the reliability of civil infrastructure monitoring N2 - Rayleigh fading is a widely observed phenomenon in the many fields, such as wireless communication and optical imaging. It is also the main factor limiting the performance of the phase-sensitive optical time domain reflectometry (φOTDR). The low SNR at the fading points results in a large measurement error, severely affecting the reliability of civil infrastructure monitoring. The proposed method involves changing the pulse width during measurements to suppress the impact of fading. Experimental result shows that the number of fading points is greatly reduced by ∼ 96 % and the measurement error is reduced by more than 5 times. Unlike existing methods, this approach requires no hardware modifications, making it applicable to almost all current phase-based φOTDR systems. The versatility and effectiveness of this method make it an excellent candidate for infrastructure monitoring and related fields. KW - Distributed fiber sensing KW - Optical fiber sensing KW - Phase-sensitive optical time domain reflectometry KW - Infrastructure monitoring KW - Rayleigh fading PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614208 DO - https://doi.org/10.1016/j.optlastec.2024.111927 SN - 1879-2545 VL - 181 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-61420 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Distributed fiber optic sensing for monitoring of underground facilities N2 - Distributed fiber optic sensing (DFOS) technique is a promising and robust non-destructive testing tool that can seamlessly acquire environmental conditions over large scales. Therefore, it has found extensive applications in structural health monitoring. Its appeal for monitoring underground facilities lies in the intrinsic properties of the optical fiber, such as immunity to magnetic interference, small size, chemical inertia, etc. This paper provides a concise overview of DFOS applications in underground facility monitoring. Following a brief introduction to the working principle of the DFOS technique, various examples are provided to demonstrate how distributed fiber sensors contribute to monitoring underground facilities. The paper presents unpublished field test results with an emphasis in the energy sector, including monitoring gas storage facilities, geothermal reservoir exploration, and ground movement detection. Furthermore, the paper identifies several directions for enhancing the DFOS system. T2 - SPIE Photonics Europe CY - Strasbourg, France DA - 07.04.2024 KW - Underground gas storage KW - Distributed fiber sensing KW - Geothermal borehole KW - Ground movement KW - Leakage detection KW - Structure health monitoring PY - 2024 AN - OPUS4-60146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Distributed fiber optic sensing for monitoring of underground facilities N2 - Distributed fiber optic sensing (DFOS) technique is a promising and robust non-destructive testing tool that can seamlessly acquire environmental conditions over large scales. Therefore, it has found extensive applications in structural health monitoring. Its appeal for monitoring underground facilities lies in the intrinsic properties of the optical fiber, such as immunity to magnetic interference, small size, chemical inertia, etc. This paper provides a concise overview of DFOS applications in underground facility monitoring. Following a brief introduction to the workingbnprinciple of the DFOS technique, various examples are provided to demonstrate how distributed fiber sensors contribute to monitoring underground facilities. The paper presents unpublished field test results with an emphasis in the energy sector, including monitoring gas storage facilities, geothermal reservoir exploration, and ground movement detection. Furthermore, the paper identifies several directions for enhancing the DFOS system. T2 - SPIE Photonics Europe CY - Strasbourg, France DA - 07.04.2024 KW - Structure health monitoring KW - Geothermal borehole KW - Distributed fiber optic sensing KW - Ground movement KW - Leakage detection PY - 2024 DO - https://doi.org/10.1117/12.3023571 SN - 0277-786X VL - 13001 SP - 1 EP - 10 PB - SPIE AN - OPUS4-60384 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Distributed polymer optical fiber sensors using digital I-OFDR for geotechnical infrastructure health monitoring N2 - We present a distributed polymer optical fiber sensor system for deformation monitoring of geotechnical infrastructure. The sensor system is based on the digital incoherent optical frequency domain reflectometry (I-OFDR) for the detection of local strain events along a perfluorinated polymer optical fiber (PF-POF) used as a sensing fiber. For the best possible load transfer, the PF-POFs were integrated onto geosynthetics which pose a sensor carrier for the sensing fiber. By using elastic PF-POF instead of a standard glass fiber as a sensing fiber the strain range of geosynthetics-integrated fiber optic sensors could be extended up to 10 % in accordance with the end-user requirements. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Digital I-OFDR KW - Distributed polymer optical fiber sensor KW - Distributed strain sensing KW - Smart geosynthetics KW - Structural health monitoring PY - 2024 AN - OPUS4-60308 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Königsbauer, Korbinian A1 - Nöther, Nils A1 - Färber, Jan A1 - Schaller, M.-Barbara A1 - Krebber, Katerina T1 - Distributed polymer optical fiber sensors using digital I-OFDR for geotechnical infrastructure health monitoring N2 - We present a distributed polymer optical fiber sensor system for deformation monitoring of geotechnical infrastructure. The sensor system is based on the digital incoherent optical frequency domain reflectometry (I-OFDR) for the detection of local strain events along a perfluorinated polymer optical fiber (PF-POF) used as a sensing fiber. For the best possible load transfer, the PF-POFs were integrated onto geosynthetics which pose a sensor carrier for the sensing fiber. By using elastic PF-POF instead of a standard glass fiber as a sensing fiber the strain range of geosynthetics-integrated fiber optic sensors could be extended up to 10 % in accordance with the end-user requirements. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Digital I-OFDR KW - Distributed polymer optical fiber sensor KW - Ddistributed strain sensing KW - Smart geosynthetics KW - Structural health monitoring PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603096 SP - 1 EP - 7 PB - NDT.net AN - OPUS4-60309 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisermann, R. A1 - Esterl, F. A1 - Schuchardt, M. A1 - Breithaupt, Mathias A1 - Plath, R. T1 - Distributed acoustic/vibration sensing: Towards advanced transformer condition monitoring N2 - A novel method for transformer vibration monitoring using intensity-based distributed acoustic/vibration sensing (DAS/DVS) is presented. Fibre optic sensors were fully integrated into an oil-filled medium voltage distribution transformer. Opencircuit in-situ measurements were carried out using a single and three-phase supply with an electrical power of up to 30 kVA. Spectral analysis of the mechanical vibrations were performed by measuring the frequency response of the transformer using plain fibre- and transducer-based DVS approaches. The results were compared with the spectra of a microphone mounted on the outside of the transformer housing and the electrical measurements on the high voltage side. Using the fibre optic DVS based monitoring we were able to detect changes in operating power and frequency. Further it could be shown, that it is possible to identify anomalous behaviour such as electrical/mechanical noise sources using the determined vibration spectra. T2 - 2024 IEEE International Conference on High Voltage Engineering and Applications (ICHVE) CY - Berlin, Germany DA - 18.08.2024 KW - Distributed acoustic sensing KW - DAS KW - Transformer monitoring PY - 2024 DO - https://doi.org/10.1109/ICHVE61955.2024.10676084 SP - 1 EP - 4 PB - IEEE CY - New York City, New York, USA AN - OPUS4-61798 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisermann, R. T1 - Distributed acoustic/vibration sensing: Towards advanced transformer condition monitoring N2 - A novel method for transformer vibration monitoring using intensity-based distributed acoustic/vibration sensing (DAS/DVS) is presented. Fibre optic sensors were fully integrated into an oil-filled medium voltage distribution transformer. Opencircuit in-situ measurements were carried out using a single and three-phase supply with an electrical power of up to 30 kVA. Spectral analysis of the mechanical vibrations were performed by measuring the frequency response of the transformer using plain fibre- and transducer-based DVS approaches. The results were compared with the spectra of a microphone mounted on the outside of the transformer housing and the electrical measurements on the high voltage side. Using the fibre optic DVS based monitoring we were able to detect changes in operating power and frequency. Further it could be shown, that it is possible to identify anomalous behaviour such as electrical/mechanical noise sources using the determined vibration spectra. T2 - 2024 IEEE International Conference on High Voltage Engineering and Applications (ICHVE) CY - Berlin, Germany DA - 18.08.2024 KW - Distributed acoustic sensing KW - Condition monitoring KW - Transformer monitoring PY - 2024 AN - OPUS4-61799 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Christensen, J. B. A1 - Jørgensen, A. A. A1 - Vandborg, M. H. A1 - Thomas, P. J. A1 - Lu, Xin A1 - Failleau, G. A1 - Eisermann, R. A1 - Grüner-Nielsen, L. A1 - Balslev-Harder, D. A1 - Lassen, M. A1 - Krenek, S. T1 - Fiber-artefact methodology and calibration framework for Brillouin-based fiber sensing N2 - We propose, and demonstrate, the use of a fiber-optical measurement artefact as a metrological tool for traceable distance calibration of distributed optical fiber sensors. The constructed fiber artefact consists of a lead-in fiber coupled to a fiber loop using a 3-dB coupler and is used to calibrate both a home-build Brillouin-OTDR setup and a custom version of a commercial Brillouin-OTDR interrogator build for distributed temperature sensing. For both interrogators, we demonstrate distance calibrations with 1-meter uncertainty (k=1) in the offset length and 0.1 % (1 m/km) uncertainty (k = 1) in the distance scale factor. In addition, it is shown that the fiber artefact can be used to assess undesired distance-dependent measurement biases. KW - Distributed temperature sensing KW - Metrology KW - Distributed optical fiber sensing KW - Brillouin optical time-domain reflectrometry PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618853 DO - https://doi.org/10.1364/OE.544659 SN - 1094-4087 VL - 32 IS - 26 SP - 45483 EP - 45493 PB - Optica Publishing Group AN - OPUS4-61885 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin T1 - Progress review N2 - We report on the progress on calibration and characterization of distributed temperature sensing systems as a part of the European INFOTherm project. The most research results were achieved in the framework of the Work Package 2. T2 - Midterm meeting of INFOTherm project CY - Copenhagen, Denmark DA - 25.03.2025 KW - Humidity sensor KW - Optical fibre sensors KW - Distributed temperature sensing PY - 2025 AN - OPUS4-63007 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wang, Kun T1 - Exploring INFOTherm and current research N2 - This presentation introduces the INFOTherm project aiming to standardize and improve fiber-optic temperature sensing. Current research focuses on how humidity affects the temperature sensitivity of polyimide-coated fibers. T2 - Tagung am Yokohama National University und Besuch einiger Labors CY - Yokohama, Japan DA - 03.03.2025 KW - Optical fiber sensor KW - INFOTherm KW - Distributed temperature sensing PY - 2025 AN - OPUS4-63088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hüsken, Götz A1 - Pirskawetz, Stephan A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Gründer, Klaus-Peter A1 - Kadoke, Daniel T1 - The load-bearing behaviour of a reinforced concrete beam investigated by optical measuring techniques N2 - Bending beams and slabs are typical examples for structural elements used for reinforced concrete structures such as bridge girders, T-beams and bridge decks. Their strength related failure modes at maximum loading can be divided into bending and shear failure. The failure of beams loaded in bending can occur with or without indication. Therefore, conventional design concepts aim on failure modes with sufficient indication (e.g. large deflections or cracks), as it occurs in the case of secondary flexural compression failure. These indicating factors can also be used for Structural Health Monitoring (SHM) of civil infrastructure systems (e.g. bridges) to identify structural changes. In this context, non-destructive testing (NDT) methods offer different techniques for measuring deflections or crack formation and opening. However, profound knowledge on the determining failure modes of bending beams and their detection by NDT methods is required for the reliable application of SHM. Different NDT methods have been used in this study for analysing the load-bearing behaviour of a reinforced concrete beam in bending. The different measuring techniques are briefly described and their applicability is discussed by means of experimental results. For this purpose, the load-bearing behaviour of a reinforced concrete beam having a span of 2.75 m was investigated in a four-point bending flexural test at laboratory scale. The focus is on the characterization of determining failure modes by optical NDT and the comparison with classical measuring techniques (e.g. deformation measurements by displacement transducers). The bending beam was equipped with two single-mode (SM) sensor fibres. One fibre served as Distributed Optical Fibre Sensor (DOFS), whereas the other fibre contained Fibre Bragg Grating (FBG) sensors. In addition, optical deformation measurements using Digital Image Correlation (DIC) and Stereophotogrammetry (SP) were conducted. KW - Concrete beam KW - Bending KW - Digital image correlation KW - Stereophotogrammetry KW - Distributed fibre optic sensor KW - Fibre bragg grating PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524762 DO - https://doi.org/10.1617/s11527-021-01699-6 VL - 54 IS - 3 SP - Article 102 PB - Springer AN - OPUS4-52476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit A1 - Hering, Marcus T1 - Eine Machbarkeitsstudie zur Skalierung von Sprengversuchen an Stahlbetonbauteilen N2 - Sprengversuche sind erforderlich, um Explosionsereignisse auf Grund von Unfällen oder Anschlägen zu untersuchen und um das Schutzniveau für Menschen und Anlagen in kritischen Infrastrukturen zu bewerten. Die Durchführung von Feldversuchen in großem Maßstab für komplexe Szenarien ist sehr ressourcenintensiv. Verlässliche Experimente im kleinen Maßstab sind eine vielversprechende Alternative. Die Skalierungsgesetze für die Bemessung von Stahlbetonkonstruktionen unter Explosionsbelastung sind jedoch nicht hinreichend etabliert. Die Forschungsarbeit fokussiert sich auf Stahlbetonstrukturen, die für die Standardisierung von skalierten Sprengversuchen in Frage kommen. Im Rahmen der Machbarkeitsstudie wurden auf dem TTS-Gelände Sprengversuche an Probekörpern unterschiedlicher Größe durchgeführt. Dabei wurden verschiedene horizontal gelagerte Stahlbetonplatten getestet und unterschiedlichen Explosionsbelastungen ausgesetzt. Die Sprengversuche umfassten verschiedene Messtechniken zur Quantifizierung der Explosionslast sowie des Verhaltens der Stahlbetonplatten. Die Explosionslast wurde mit bündig eingebauten piezoelektrischen Druckmessern gemessen, während Beschleunigungssensoren und flächig applizierte verteilte faseroptische Sensorik verwendet wurden, um das dynamische Verhalten der Platte unter Explosionsbelastung zu charakterisieren. Darüber hinaus wurden Schädigungsmerkmale ebenfalls mit verteilter faseroptischer Sensorik ermittelt. Die Anwendung solcher Messtechniken sowie die Nutzung verschiedener numerischer Softwaretools bieten die Möglichkeit die Skalierungsgesetze zu verifizieren bzw. anzupassen. T2 - BBK - Fachkongress Forschung für den Bevölkerungsschutz 2025 CY - Bonn, Germany DA - 05.02.2025 KW - Sprengversuch KW - Skalierung KW - Faseroptik PY - 2025 AN - OPUS4-62509 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Hicke, Konstantin A1 - Breithaupt, Mathias A1 - Strangfeld, Christoph T1 - Distributed Humidity Sensing in Concrete Based on Polymer Optical Fiber N2 - We present a preliminary investigation on distributed humidity monitoring during the drying process of concrete based on an embedded polymer optical fiber (POF). The water dissipated into the POF changes several properties of the fiber such as refractive index, scattering coefficient and attenuation factor, which eventually alters the Rayleigh backscattered light. The optical time Domain reflectometer (OTDR) technique is performed to acquire the backscattered signal at the wavelengths 650 nm and 500 nm, respectively. Experimental results show that the received signal increases at 650 nm while the fiber attenuation factor clearly increases at 500 nm, as the concrete dries out. In the hygroscopic range, the information retrieved from the signal change at 650 nm agrees well with the measurement result of the electrical humidity sensors also embedded in the concrete sample. KW - Distributed fiber optic sensing KW - Distributed humidity sensing KW - Polymer optical fibers KW - Concrete drying KW - Material moisture KW - Embedded humidity sensors PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537644 DO - https://doi.org/10.3390/polym13213755 SN - 2073-4360 VL - 13 IS - 21 SP - 3755 PB - MDPI CY - Basel, Switzerland AN - OPUS4-53764 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Auftakttreffen FOSsure „ Faseroptische Sensoren zur sicheren Zustandsbewertung von Massivbrücken“ N2 - Vorstellung der Vorarbeiten und Kernkompetenzen des Fachbereiches 8.6 hinsichtlich der Zustandsüberwachung von Brückenbauwerken im Rahmen eines Auftakttreffens im Forschungsprojekt FOSsure. T2 - Kick-off-Treffen FOSsure CY - Dresden, Germany DA - 16.04.2025 KW - DFOS KW - faseroptische Sensoren KW - Brückenmonitoring KW - Ortverteilte akustische Sensorik KW - COTDR PY - 2025 AN - OPUS4-62975 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - KI, Machine Learning und faseroptische Sensorik N2 - Die Verwendung von Methoden des Maschinellen Lernens (ML) und der Künstlichen Intelligenz (KI) im Fachbereich 8.6 Faseroptische Sensorik wird dargestellt. Die vielfältigen Möglichkeiten, Machine Learning auf Basis Künstlicher Neuronaler Netze (ANN) für eine schnelle und effiziente Datenverarbeitung eizusetzen werden demonstriert. Hierfür werden Beispiele für die Anwendungszwecke Messgrößenberechnung, Entrauschen, Interpolation, Bildverarbeitung und Messdatenauswertung aufgezeigt. T2 - Foresight Prozess AM, AP 4, Workshop „In Situ Sensorik“ CY - Online-Meeting DA - 09.11.2020 KW - Verteilte faseroptische Sensorik KW - KI KW - Künstliche Intelligenz KW - Machine Learning KW - Künstliche Neuronale Netze PY - 2020 AN - OPUS4-51545 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hofmann, Detlef T1 - Strukturüberwachung mit lokaler und verteilter faseroptischer Sensorik N2 - Der Vortrag gibt einen Überblick über die Einsatzmöglichkeiten faseroptischer Sensorik (FOS) als ZfP-Verfahren. Dabei werden an Beispielen lokale und verteilte faseroptische Verfahren zur Dehnungs-, Temperatur- und Risserfassung sowie zur akustischen Messung vorgestellt. Weiterhin werden Möglichkeiten zur Selbstdiagnose von FOS aufgezeigt. T2 - InnoTesting2020 "Innovative Ideen - neue Testmethoden" CY - Wildau, Germany DA - 27.02.2020 KW - Faseroptische Sensorik KW - Strukturüberwachung KW - Lichtwellenleiter KW - Zerstörungsfreie Prüfung KW - Selbstdiagnose PY - 2020 AN - OPUS4-51688 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martynec, T. A1 - Karapanagiotis, Christos A1 - Klapp, S. H. L. A1 - Kowarik, S. T1 - Machine learning predictions of surface migration barriers in nucleation and non-equilibrium growth N2 - Machine learning is playing an increasing role in the discovery of new materials and may also facilitate the search for optimum growth conditions for crystals and thin films. Here, we perform kinetic Monte-Carlo simulations of sub-monolayer growth. We consider a generic homoepitaxial growth scenario that covers a wide range of conditions with different diffusion barriers (0.4–0.55 eV) and lateral binding energies (0.1–0.4 eV). These simulations are used as a training data set for a convolutional neural network that can predict diffusion barriers and binding energies. Specifically, a single Monte-Carlo image of the morphology is sufficient to determine the energy barriers with an accuracy of approximately 10 meV and the neural network is tolerant to images with noise and lower than atomic-scale resolution. We believe this new machine learning method will be useful for fundamental studies of growth kinetics and growth optimization through better knowledge of microscopic parameters. KW - Machine learning KW - Surface migration barriers KW - Material engineering PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532523 UR - https://www.nature.com/articles/s43246-021-00188-1 DO - https://doi.org/10.1038/s43246-021-00188-1 SN - 2662-4443 VL - 2 SP - 1 EP - 9 PB - Springer Nature CY - London AN - OPUS4-53252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Eine Sammlung durch Maschinelles Lernen unterstützter Verteilter Faseroptischer Sensoren für Infrastrukturmonitoring T1 - A collection of machine learning assisted distributed fiber optic sensors for infrastructure monitoring N2 - In this paper, we present a collection of machine learning assisted distributed fiber optic sensors (DFOS) for applications in the field of infrastructure monitoring. We employ advanced signal processing based on artificial neural networks (ANNs) to enhance the performance of the dynamic DFOS for strain and vibration sensing. Specifically, ANNs in comparison to conventional and computationally expensive correlation and linearization algorithms, deliver lower strain errors and speed up the signal processing allowing real time strain monitoring. Furthermore, convolutional neural networks (CNNs) are used to denoise the dynamic DFOS signal and enable useable sensing lengths of up to 100 km. Applications of the machine learning assisted dynamic DFOS in road traffic and railway infrastructure monitoring are demonstrated. In the field of static DFOS, machine learning is applied to the well-known Brillouin optical frequency domain analysis (BOFDA) system. Specifically, CNN are shown to be very tolerant against noisy spectra and contribute towards significantly shorter measurement times. Furthermore, different machine learning algorithms (linear and polynomial regression, decision trees, ANNs) are applied to solve the well-known problem of cross-sensitivity in cases when temperature and humidity are measured simultaneously. The presented machine learning assisted DFOS can potentially contribute towards enhanced, cost effective and reliable monitoring of infrastructures. N2 - In diesem Beitrag stellen wir eine Sammlung von verteilten faseroptischen Sensoren (DFOS) vor, die mit Hilfe von Maschinellem Lernen arbeiten und für Anwendungen im Bereich der Infrastrukturüberwachung geeignet sind. Wir setzen hierbei fortschrittliche Signalverarbeitung auf der Grundlage Künstlicher Neuronaler Netze ein, um die Leistungsfähigkeit dynamischer DFOS für die Messung von Dehnungen und Vibrationen zu verbessern. Insbesondere Künstliche Neuronale Netze (ANNs) liefern im Vergleich zu konventionellen und rechenintensiven Korrelations- und Linearisierungsalgorithmen geringere Dehnungsfehler und beschleunigen die Signalverarbeitung, so dass eine Dehnungsüberwachung in Echtzeit möglich ist. Darüber hinaus wenden wir Convolutional Neural Networks (CNNs) an, um dynamische DFOS-Signale zu entrauschen und damit nutzbare Messlängen von bis zu 100 km zu ermöglichen. Es werden Anwendungsbeispiele dieser durch Maschinelles Lernen unterstützten dynamischen DFOS in den Bereichen des Straßenverkehrsmonitorings und der Zug- und Gleisüberwachung aufgezeigt. Im Bereich der statischen DFOS wird Maschinelles Lernen auf das Verfahren der Optischen Brillouin-Frequenzbereichsanalyse (BOFDA) angewendet. Insbesondere CNN erweisen sich hier als sehr robust gegenüber verrauschten Spektren und tragen zu deutlich kürzeren Messzeiten bei. Darüber hinaus werden verschiedene Algorithmen des maschinellen Lernens (lineare und polynome Regression, Entscheidungsbäume, ANNs) angewandt, um das bekannte Problem der Querempfindlichkeit bei DFOS in den Fällen zu lösen, in denen Temperatur und Feuchtigkeit gleichzeitig gemessen werden sollen. Die hier vorgestellten, durch Maschinelles Lernen unterstützten, DFOS können zu einer verbesserten, kostengünstigen und zuverlässigen Überwachung von Infrastrukturen beitragen. KW - Artificial neural networks KW - Brillouin sensing KW - Distributed acoustic sensing KW - Fibre optic sensors KW - Infrastructure monitoring PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569044 DO - https://doi.org/10.1515/teme-2022-0098 SN - 0171-8096 SP - 1 EP - 19 PB - De Gruyter AN - OPUS4-56904 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos T1 - Evaluation of the generalization performance of a CNN-assisted BOFDA system N2 - Brillouin Optical Frequency Domain Analysis (BOFDA) is a powerful and well-established method for static distributed sensing of temperature and strain. Recently, we demonstrated a BOFDA system based on convolutional neural network which shortens the measurement time considerably. In this paper, we apply leave-one-out cross validation to evaluate the generalization performance and provide an unbiased and reliable machine learning model for a time-efficient BOFDA system. T2 - 21. ITG/GMA Fachtagung Sensoren und Messsysteme 2022 CY - Nuremberg, Germany DA - 10.05.2022 KW - Fiber optics sensors KW - BOFDA KW - Brillouin distributed sensing KW - Machine learning PY - 2022 UR - https://www.ama-science.org/direct/tagungsband-sensoren-und-messsysteme-2022 SN - 978-3-8007-5835-7 SP - 289 EP - 292 PB - VDE VERLAG GMBH AN - OPUS4-55183 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Brillouin optical frequency-domain analysis for structural health monitoring N2 - We present our achievements in the development of distributed fiber optic sensing systems based on Brillouin optical frequency-domain analysis for structural health monitoring. The focus of the applications is on the gapless monitoring of geotechnical structures, large area infrastructures and electrical grids. The work includes the latest use of machine learning algorithms to reduce measurement time by coexistent increasing the measurement accuracy. T2 - 4th Workshop on Optomechanics and Brillouin Scattering CY - Erlangen, Germany DA - 14.06.2022 KW - Distributed sensing KW - BOFDA KW - Optical fiber sensor KW - Brillouin distributed fiber sensor PY - 2022 AN - OPUS4-55173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos T1 - Time-efficient CNN-assisted BOFDA N2 - Brillouin Optical frequency domain analysis (BOFDA) is a well-known technique in distributed Fiber sensing for temperature and strain monitoring. In this study, we applied a signal post-processing method based on convolutional neural networks (CNNs) and we show that in comparison to conventional methods based on Lorentzian curve fitting (LCF), our CNN model is more robust against noise and can shorten the measurement time by more than 9 times. This will open the way for applications, where faster monitoring is needed. T2 - Machine learning workshop CY - Online meeting DA - 18.03.2021 KW - Temperature and strain sensing KW - Machine learning KW - Distributed fiber-optic sensors PY - 2021 AN - OPUS4-52305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Heidenreich, F. A1 - Herten, M. T1 - Verwendung faseroptischer Messtechnik im Zuge wiederholter Eignungsprüfungen an Verpressankern N2 - Im Rahmen des Ausbaus des Dortmund-Ems-Kanals wurden an der Schleuse Gleesen Forschungsanker installiert, die Rückschlüsse auf das Tragverhalten in Folge des chemischen Angriffs kalklösender Kohlensäure geben sollen. Die Forschungsanker werden seit der Erstellung im Jahr 2017 mit verteilter faseroptischer Sensorik während der jährlichen Eignungsprüfungen untersucht. Die Ergebnisse der Jahre 2017 bis 2019 werden im Folgenden dargestellt. T2 - Messen in der Geotechnik 2020 CY - Braunschweig, Germany DA - 20.02.2020 KW - Faseroptische Sensorik KW - Rayleigh Rückstreuung KW - Verpressanker KW - Chemischer Angriff KW - Rissbildung PY - 2020 SN - 978-3-948141-02-8 DO - https://doi.org/10.24355/dbbs.084-201912181435-0 IS - 110 SP - 297 EP - 323 AN - OPUS4-51687 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -