TY - CONF A1 - Wosniok, Aleksander ED - Liao, Y. ED - Jin, W. ED - Sampson, D.D. ED - Yamauchi, R. ED - Chung, Y. ED - Nakamura, K. ED - Rao, Y. T1 - Brillouin gain spectrum characteristics for temperature compensation in fiber optic distributed strain sensor N2 - We studied Brillouin gain spectrum characteristics in single-mode optical fibers with different refractive index profiles to realize temperature-corrected distributed strain measurement. The measured Brillouin frequency shift (BFS) features much stronger dependence on the longitudinal strain in the sensor fiber than on the temperature distribution along the fiber optic sensor. By detection of slight structural changes in monitored civil structures, such as dams, pipelines and tunnels, the influence of temperature on the measured BFS cannot be neglected. T2 - OFS2012 - 22nd International conference on optical fiber sensors CY - Beijing, China DA - 15.10.2012 KW - Brillouin gain spectrum KW - BGS KW - Distributed Brillouin sensor KW - DBS KW - Fibre optic sensor KW - FOS KW - Brillouin optical frequency-domain analysis KW - BOFDA PY - 2012 DO - https://doi.org/10.1117/12.974841 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 8421 SP - 84219T-1 EP - 84219T-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-26978 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 - JOUR A1 - Karapanagiotis, Christos A1 - Wosniok, Aleksander A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Time-Efficient Convolutional Neural Network-Assisted Brillouin Optical Frequency Domain Analysis N2 - To our knowledge, this is the first report on a machine-learning-assisted Brillouin optical frequency domain analysis (BOFDA) for time-efficient temperature measurements. We propose a convolutional neural network (CNN)-based signal post-processing method that, compared to the conventional Lorentzian curve fitting approach, facilitates temperature extraction. Due to its robustness against noise, it can enhance the performance of the system. The CNN-assisted BOFDA is expected to shorten the measurement time by more than nine times and open the way for applications, where faster monitoring is essential. KW - Fiber-optic sensors KW - Machine learning KW - Temperature and strain monitoring KW - Brillouin distributed sensing PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524631 DO - https://doi.org/10.3390/s21082724 VL - 21 IS - 8 SP - 2724 PB - MDPI AN - OPUS4-52463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Hicke, Konstantin A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed humidity fiber-optic sensor based on BOFDA using a simple machine learning approach N2 - We report, to our knowledge for the first time, on distributed relative humidity sensing in silica polyimide-coated optical fibers using Brillouin optical frequency domain analysis (BOFDA). Linear regression, which is a simple and well-interpretable algorithm in machine learning and statistics, is utilized. The algorithm is trained using as features the Brillouin frequency shifts and linewidths of the fiber’s multipeak Brillouin spectrum. To assess and improve the effectiveness of the regression algorithm, we make use of machine learning concepts to estimate the model’s uncertainties and select the features that contribute most to the model’s performance. In addition to relative humidity, the model is also able to simultaneously provide distributed temperature information addressing the well-known cross-sensitivity effects. KW - Fiber optics sensors KW - Machine learning KW - Brillouin distributed sensing KW - Humidity sensing KW - Simultaneous temperature and humidity sensing PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546294 DO - https://doi.org/10.1364/OE.453906 VL - 30 IS - 8 SP - 12484 EP - 12494 PB - OPTICA AN - OPUS4-54629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nöther, N. A1 - Wang, S. A1 - Wosniok, Aleksander A1 - Glötzl, R. A1 - Schneider-Glötzl, J. ED - Xu, Y. L. ED - Zhu, S. ED - Xia, Y. ED - Ni, Y.Q. ED - Law, S.S. ED - Yin, J. H. ED - Su, Z.Q. T1 - Distributed Brillouin sensing in optical fibers: Soil displacement monitoring using sensor-equipped geogrids N2 - This paper reports on the application of distributed Brillouin fiber optic sensing to the monitoring of geotechnical structures. The presented approach to Brillouin sensing offers an alternative to the common pulse-based measurements by using the frequency domain analysis. The focus of the research and field-testing work is to collect reliable structural health monitoring data from large-scale structures while preserving the System’s versatility in terms of being suitable for different application environments (soil structures, foundations, concrete construction works, pipelines etc.) and its robustness in being well functioning in harsh environments. Upon reviewing the presented application test, it is concluded that Brillouin frequency domain based monitoring, when applied to geotechnical structures, is capable of providing accurate strain readings representing deformations of the soil body, and reliable temperature readings for generating temperature profiles of the entire structure. An overview of the frequency domain analysis of Brillouin sensing and its digital implementation is given, along with the experiences and insights drawn from an open field test of sensor-equipped geogrid mats. T2 - SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure CY - Hong Kong, China DA - 09.12.2013 KW - Structural health monitoring KW - Distributed sensing KW - Fiber-optic sensing KW - Brillouin sensing KW - Strain and temperature measurements KW - Sensor-equipped geosynthetics PY - 2013 SN - 978-962-367-768-4 SP - 290 EP - 295 AN - OPUS4-29914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aleksander, Wosniok A1 - Schreier, Andy T1 - Toward investigation of Brillouin scattering in multimode polymer and silica optical fibers N2 - In this paper, we present a study aimed at characterizing the optimal fiber optic components for Brillouin sensing in multimode fibers. For this purpose the use of single-mode and multimode circulators as well as couplers typically used in the Brillouin measurement setups was investigated. On the one hand the undesired coupling losses between conventional fiber optic measurement system components and a multimode sensor fiber can be overcome by replacing the singlemode components with their own multimode equivalents. On the other hand the use of multimode fiber optic circulators and multimode couplers affects the mode distribution of laser light which can impair the measurement signal backscattered in the multimode sensor fibers. In view of an increasing interest in high strain measurements using polymer optical fibers (POFs) as Brillouin-distributed sensors the investigation on Brillouin scattering effects in multimode fibers (MMFs) was performed on a low-loss perfluorinated graded-index polymer optical fiber (PFGI-POF). The obtained results were compared with those of a standard graded-index multimode (GI-MMF) silica glass optical fiber (GOF). This study confirms the relevance of the adaptation of the measurement system components to the use of the multimode sensor fibers. In addition, due to mode coupling effects occurring in the tested POF itself, the results show differences in the yield of the components adaptation in the sensory implementation of the two kinds of the tested optical fibers. T2 - SPIE’s 2017 International Symposium on Optics & Optoelectronics: Micro-structured and Specialty Optical Fibres CY - Prag, CZ DA - 26.04.2017 KW - Brillouin KW - Distributed sensing KW - Polymer optical fibre PY - 2017 SN - 978-1-5106-0965-5 SN - 978-1-5106-0966-2 DO - https://doi.org/10.1117/12.2267823 SN - 0277-786X VL - 10232 SP - 102320M-1 EP - 102320M-6 PB - SPIE AN - OPUS4-40471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Smart geosynthetics for structural health monitoring applications N2 - Responding to a growing need for intelligent monitoring of critical geotechnical and civil infrastructures, new multifunctional geotextiles and geogrids with integrated optical fibers were developed and investigated within several research projects. Such smart two-dimensional geosynthetics intercorporating optical fibers as distributed sensors provide solutions both for soil reinforcement, erosion control, drainage or environmental protection and for cost-effective monitoring of critical mechanical deformations and temperature distribution in geotechnical and masonry structures at the same time. The integrated fiber optic sensors provide online information about the condition of the monitored structure and about the occurrence and localization of any damage or degradation for the purpose of preventing a total collapse. The optical fibers have a serious advantage over other kinds of sensors due to their fibrous nature, so they can be ideally processed like standard textile yarns. The monitoring of extended geotechnical structures like dikes, dams, railways, embankments or slopes requires sensor technologies with measurement lengths of at least some hundred meters which can be realized by the use of silica fibers. However, the integration of silica fibers into geosynthetics during the manufacturing process experienced problems of sensor brittleness, low strain range not exceeding 2 % and bending-related attenuation increase optimized to the value of 1.5 dB/km. Unlike silica fibers, the integration of polymer optical fibers (POFs) into various geosynthetics was easily achieved free of bending losses enabling distributed high strain measurements up to 40 % using PMMA POFs. The first industrial product GEDISE based on a geogrid with integrated PMMA POFs is on the market. Due to the five times lower attenuation of low-loss perfluorinated graded-index POFs (PFGI-POFs), compared to PMMA POFs, the measurement range can be extended to 500 m. The low-loss PFGI-POFs offer the possibility of implementation of Brillouin optical fiber frequency domain analysis (BOFDA) which will significantly improve the measurement accuracy and spatial resolution in comparison with existing POF-based distributed measurement methods like POF OTDR. The development of a distributed Brillouin system based on PFGI-POFs is in progress. T2 - The Fiber Society’s Spring 2017 Conference CY - Institut für Textiltechnik der RWTH Aachen, Germany DA - 17.05.2017 KW - Smart geosynthetics KW - Sensor-based geotextiles KW - Fiber optic sensor KW - Distributed sensing PY - 2017 AN - OPUS4-40319 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Liehr, Sascha T1 - Health monitoring of geotechnical structures by distributed fiber optic sensors N2 - Health monitoring of ground movement via highly sensitive fiber optic sensors allows operators to detect early potential or ongoing failures in critical geotechnical structures. Particularly, the fiber optic sensors can be embedded in geosynthetics which are nowadays widely used in many geotechnical applications including earth dikes, railway embankments, landfill liners, quarries and mines. Thereby, such smart geosynthetics can be used for reinforcement, layer separation, filtration or drainage while the embedded fiber optic sensors provide information about the condition of the geotechnical structures in real time. The paper highlights the results achieved in this innovative field in the framework of several German and European projects. The presented measurement methods for long-term monitoring are based on Brillouin scattering in silica glass optical fibers (GOFs) and optical time domain reflectometry (OTDR) in polymer optical fibers (POFs). T2 - AMA Conferences 2017 Sensor 2017 CY - Nürnberg, Germany DA - 30.05.2017 KW - Fiber optic sensor KW - Distributed sensor KW - Smart geosynthetics KW - Brillouin sensor KW - OTDR PY - 2017 SN - 978-3-9816876-4-4 DO - https://doi.org/10.5162/sensor2017/B7.4 SP - 280 EP - 285 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-40514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Sporea, D. A1 - Neguţ, D. A1 - Krebber, Katerina T1 - Gamma radiation influence on silica optical fibers measured by optical backscatter reflectometry and Brillouin sensing technique N2 - We have studied the influence of gamma rays on physical properties of different commercially available silica optical fibers stepwise irradiated up to a total dose of 100 kGy. The detection of radiation-induced changes in silica glass offers the possibility of using selected optical fibers as distributed radiation sensors. The measurements performed by us were based on optical backscatter reflectometry and Brillouin distributed sensing. The measurement methods enable an analysis of radiation-induced modification of the group refractive index and density of the optical fibers. The most distinct physical effect observed by us concerns the increase of the optical attenuation with rising total radiation doses. Quantitative measurement results indicate a crucial impact of fiber dopants on radiation-induced physical and sensory characteristics of silica optical fibers affected by differences in fiber fabrication techniques. Based on the obtained results, the suitability of distributed Brillouin sensing for dosimetry applications seems to be improved by modifying the refractive index profile of the fiber core. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, IRL DA - 31.05.2016 KW - Brillouin frequency shift KW - Lonizing radiation KW - Gamma radiation KW - Radiation dosimetry KW - Optical fiber sensor KW - Brillouin scattering KW - Distributed measurement KW - Backscatter reflectometry PY - 2016 SN - 978-1-5106-0219-9 DO - https://doi.org/10.1117/12.2236678 SN - 0277-786X VL - 9916 SP - Article Number: 99162J PB - Spie-Int Soc Optical Engineering CY - Bellingham, WA, USA AN - OPUS4-37083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Gamma radiation influence on silica optical fibers measured by optical backscatter reflectometry and Brillouin sensing technique N2 - We have studied the influence of gamma rays on physical properties of different commercially available silica optical fibers stepwise irradiated up to a total dose of 100 kGy. The detection of radiation-induced changes in silica glass offers the possibility of using selected optical fibers as distributed radiation sensors. The measurements performed by us were based on optical backscatter reflectometry and Brillouin distributed sensing. The measurement methods enable an analysis of radiation-induced modification of the group refractive index and density of the optical fibers. The most distinct physical effect observed by us concerns the increase of the optical attenuation with rising total radiation doses. Quantitative measurement results indicate a crucial impact of fiber dopants on radiation-induced physical and sensory characteristics of silica optical fibers affected by differences in fiber fabrication techniques. Based on the obtained results, the suitability of distributed Brillouin sensing for dosimetry applications seems to be improved by modifying the refractive index profile of the fiber core. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, IRL DA - 31.05.2016 KW - Brillouin frequency shift KW - Ionizing radiation KW - Gamma radiation KW - Radiation dosimetry KW - Optical fiber sensor KW - Brillouin scattering KW - Distributed measurement KW - Backscatter reflectometry PY - 2016 AN - OPUS4-37088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed Brillouin fiber optic sensor system for long-term structural health monitoring N2 - We report on the development of a distributed fiber optical sensor system for structural health monitoring of largc-scale geotechnical and civil infrastructures. The system is based on Brillouin frequency domain analysis (BOFDA) for distributed measurement of strain and temperature along Standard silica optical fibers used as sensors. By additional incorporation of the fiber optic sensors in geosynthetics, two-dimensional sensors can be realized. Such smart geosynthetics can be used for reinforeerneut of geotechnical and masonry structures and the embedded fiber optic sensors can provide information about the condition of the structures and detect the presence of any damages and destructions in real time. T2 - 16th International conference 'Technical dam control' CY - Wierchomla Mala, Poland DA - 29.09.2015 KW - Distributed fiber optical sensor KW - Brillouin frequency domain analysis KW - Smart geosynthetics KW - Structural health monitoring PY - 2015 SN - 978-83-64979-09-5 SP - 271 EP - 278 AN - OPUS4-34728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Health monitoring of geotechnical structures by distributed fiber optic sensors N2 - Health monitoring of ground movement via highly sensitive fiber optic sensors allows operators to detect early potential or ongoing failures in critical geotechnical structures. Particularly, the fiber optic sensors can be embedded in geosynthetics which are nowadays widely used in many geotechnical applications including earth dikes, railway embankments, landfill liners, quarries and mines. Thereby, such smart geosynthetics can be used for reinforcement, layer separation, filtration or drainage while the embedded fiber optic sensors provide information about the condition of the geotechnical structures in real time. The paper highlights the results achieved in this innovative field in the framework of several German and European projects. The presented measurement methods for long-term monitoring are based on Brillouin scattering in silica glass optical fibers (GOFs) and optical time domain reflectometry (OTDR) in polymer optical fibers (POFs). T2 - AMA Conferences 2017 Sensor 2017 CY - Nürnberg, Germany DA - 30.05.2017 KW - Fiber optic sensor KW - Distributed sensor KW - Smart geosynthetics KW - Brillouin sensor KW - OTDR PY - 2017 AN - OPUS4-40523 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreier, Andy A1 - Jeschke, T. A1 - Petermann, K. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Analytical model for mode-based insertion loss in ball-lensed coupling of graded-index silica and polymer fibres N2 - Analytical model for ball-lensed couplers to calculate the insertion loss for each optical mode. The basis for the calculation are commercial perfluorinated polymer optical (PFGI-POFs) and silica based fibres (SOFs). The modal power distribution for given misalignments are presented as well as the reflection-based losses at all optical interfaces. Additionally, the ball-lensed interconnection between PFGI-POF and SOF was theoretically demonstrated. T2 - POF 2017: 26th International Conference on Plastic Optical Fibres CY - Aveiro, Portugal DA - 13.09.2017 KW - Polymer optical fibre KW - Optical connector PY - 2017 VL - 2017 SP - 1 EP - 4 AN - OPUS4-41979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Wendt, Mario A1 - Wosniok, Aleksander T1 - Protection of critical infrastructure using fiber optic sensors embedded in technical textiles N2 - Terrorists and criminals more and more attack and destroy important infrastructures like routes, railways, bridges, tunnels, dikes and dams, important buildings. Therefore, reliable on-line and long-term monitoring systems are required to protect such critical infrastructures. Fiber optic sensors are well-suited for that. They can be installed over many kilometers and are able to measure continuously distributed strain, pressure, temperature and further mechanical and physical quantities. The very tiny optical fibers can be integrated into structures and materials and can provide information about any significant changes or damages of the structures. These so-called smart materials and smart structures are able to monitor itself or its environment. Particularly smart technical textiles with embedded fiber optic sensors have become very attractive because of their high importance for the structural health monitoring of geotechnical and masonry infrastructures. Such textiles are usually used for reinforcement of the structures; the embedded fiber optic sensors provide information about the condition of the structures and detect the presence of any damages and destructions in real time. Thus, critical infrastructures can be preventively protected. The paper will introduce this innovative field and will present the results achieved within several German and European projects. T2 - Fiber optic sensors and applications VII CY - Orlando, FL, USA DA - 2010-04-07 KW - Distributed sensors KW - Brillouin sensors KW - Polymer optical fibers (POF) KW - POF sensors KW - POF OTDR KW - Strain sensors KW - Technical textiles KW - Geotextiles KW - Fiber optic sensors PY - 2010 SN - 9780819481412 DO - https://doi.org/10.1117/12.851013 SN - 0277-786X VL - 7677 IS - 767707 SP - 1 EP - 14 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-21675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Peter A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Wendt, Mario A1 - Wosniok, Aleksander A1 - Schneider-Gloetzl, J. A1 - Gloetzl, R. T1 - Distributed fibre optic sensors embedded in technical textiles for monitoring of geotechnical and masonry structures T2 - Monitoring technologies workshop - MoDeRn (Proceedings) CY - Troyes, France DA - 2010-06-07 PY - 2010 IS - OP.7 SP - 71 EP - 72 AN - OPUS4-23041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Nöther, Nils A1 - Krebber, Katerina ED - Juergen Brugger, ED - Danick Briand, T1 - Distributed fibre optic sensor system for temperature and strain monitoring based on Brillouin optical-fibre frequency-domain analysis T2 - EUROSENSORS XXIII: sensors, actuators and micro/nanosystems CY - Lausanne, Switzerland DA - 2009-09-06 KW - BOFDA KW - Sideband technique KW - Fibre optic sensors KW - Distributed Brillouin sensors KW - Stimulated Brillouin scattering KW - Nonlinear optics PY - 2009 SN - 1876-6196 SP - 1 EP - 4(?) AN - OPUS4-20235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasinathan, Murugesan A1 - Rao, C.B. A1 - Murali, N. A1 - Jayakumar, T. A1 - Raj, B. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Analysis of stimulated Brillouin scattering characteristics in frequency domain T2 - ICOP 2009 - International conference on optics & photonics CY - Chandigarh, India DA - 2009-10-30 KW - BOFDA KW - Fibre optic sensors KW - Distributed Brillouin sensors KW - Stimulated Brillouin scattering KW - Nonlinear optics PY - 2009 SP - 1 EP - 5(?) AN - OPUS4-21150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasinathan, Murugesan A1 - Rao, C.B. A1 - Murali, N. A1 - Jayakumar, T. A1 - Raj, B. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Use of Brillouin optical time domain analyser in testing of adhesive bonding T2 - SENNET`09 - International conference on sensors and related networks CY - Vellore, India DA - 2009-12-08 KW - Brillouin KW - Frequency domain analysis KW - Time domain analysis KW - Adhesive KW - Bond evaluation KW - Temperature KW - Strain KW - Distributed sensor PY - 2009 SP - 190 EP - 192 CY - Vellore, India AN - OPUS4-21151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina ED - Francis Berghmans, ED - Mignani, Anna Grazia ED - Cutolo, Antonello ED - Patrick P. Meyrueis, ED - Thomas P. Pearsall, T1 - A distributed fiber optic sensor system for dike monitoring using Brillouin frequency domain analysis T2 - Optical Sensors 2008, April 7-10, 2008 CY - Strasbourg, France DA - 2008-04-07 KW - BOFDA KW - Brillouin sensing KW - Distributed strain measurement KW - Dike monitoring KW - Sensor-based geotextiles KW - Fibre optic sensors KW - Distributed sensors KW - Brillouin scattering PY - 2008 SN - 978-0-8194-7201-4 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7003 SP - 700303-1 - 700303-9 PB - SPIE CY - Bellingham AN - OPUS4-18274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wosniok, Aleksander A1 - Nöther, Nils A1 - Krebber, Katerina A1 - Thiele, E. T1 - Distributed monitoring of mechanical deformation in river dikes T2 - EUROSENSORS XXII CY - Dresden, Germany DA - 2008-09-07 KW - Fiber optic sensor KW - Distributed Brillouin sensor KW - Dike monitoring PY - 2008 SN - 978-3-00-025217-4 SP - 1457 EP - 1460 AN - OPUS4-18322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -