- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 IEEE Conference on Antenna Measurements & Applications (CAMA) - Va?ster?s (2018.9.3-2018.9.6)] 2018 IEEE Conference on Antenna Measurements & Applications (CAMA) - Train Communication System with Distributed Antenna System using Optical Frequency Doubler in 90 GHz Band
摘要： A MilliMeter Wave (MMW) backhaul technology for advanced high-speed trains running a tunnel for a long distance is under development for the communication gathering a large number of passenger communications transmitting to the ground. The authors are studying a system that realizes large capacity communication between trains and the ground by arranging Distributed Antenna System (DAS) along with a long distance railway. In order to transmit a radio signal between distant antennas and the main frame of base station physically, it is necessary to avoid the influence of fiber dispersion for Radio over Fiber (RoF) which transmits a radio signal over the light. We are investigating RoF system with optical multiplication which can obtain doubled frequency after transmission. In this paper, we develop the vector modulation signal transmission by the RoF used for the downlink of the base station and report on the result of the packet communication experiment with the base station and the terminal.
关键词： DAS,RoF,millimeter wave,Frequency multiplication
更新于2025-11-28 14:23:57
-
[IEEE 2018 International Carnahan Conference on Security Technology (ICCST) - Montreal, QC, Canada (2018.10.22-2018.10.25)] 2018 International Carnahan Conference on Security Technology (ICCST) - Reliable Leak Detection in Pipelines Using Integrated DdTS Temperature and DAS Acoustic Fiber-Optic Sensor
摘要： Reliable and early detection of leaks in pipelines transporting liquid or gas is highly desirable. In this work, two orthogonal technologies based on high-sensitivity fiber-optic distributed sensing were integrated into one system and tested for their effectiveness in actual field installations. The first technology is based on temperature difference detection using Distributed Differential Temperature Sensor (DdTS or DDTS). The second is based on Distributed Acoustic Sensor (DAS), which uses Coherent Optical Time-Domain Reflectometry (C-OTDR). DdTS can almost instantaneously detect a temperature difference in the optical fiber as low as 0.0005 οC, while C-OTDR can detect minute wide-bandwidth acoustic signals. Both technologies can detect the location of a leak to within a few meters. Experimental results for water and nitrogen gas leaks detected by the integrated system are presented for two different installations in the field – one where the cable was buried directly in the soil and another where the cable was buried in soil inside a 2” conduit for about 29 km. DdTS reliably detected leaks at both installations, while DAS detected leaks only when the cable was buried directly in soil. Test results show that the integration of both DdTS and DAS technologies can increase the probability of leak detection and minimize false/nuisance alarms. The integrated system also detected third party interference (TPI), thus providing a one-system solution for pipeline integrity monitoring and intrusion detection up to 40 km from a central location.
关键词： Oil and Gas Pipeline,DdTS,Leak Detection,Fiber Optics Sensor,DTS,TPI,DAS,C-OTDR
更新于2025-09-23 15:22:29
-
Subsea Cable Condition Monitoring with Distributed Optical Fibre Vibration Sensor
摘要： A novel subsea cable condition monitoring technique based on embedded optical fibre inside the cable is demonstrated. It is shown that a distributed optical fibre vibration sensor can be used to map dynamic strains all along the cable simultaneously. It is experimentally shown that such system can fully quantify the location and strain level at each point on the cable as a function of time for both abrupt impact and cyclical loading. The sensing system demonstrated a spatial and strain resolution of 1m and 4με, respectively, over a 10km sensing range.
关键词： Offshore wind farm,Cable fault monitoring,Subsea cable monitoring,Distributed Vibration Sensor (DVS),Submarine cable installation,Distributed Acoustic Sensor (DAS)
更新于2025-09-23 15:22:29
-
[IEEE 2017 IEEE 17th International Conference on Bioinformatics and Bioengineering (BIBE) - Washington, DC (2017.10.23-2017.10.25)] 2017 IEEE 17th International Conference on Bioinformatics and Bioengineering (BIBE) - A novel low-complexity framework in ultra-wideband imaging for breast cancer detection
摘要： In this research work, a novel framework is proposed as an efficient successor to traditional imaging methods for breast cancer detection in order to decrease the computational complexity. In this framework, the breast is divided into segments in an iterative process and in each iteration, the one having the most probability of containing tumor with lowest possible resolution is selected by using suitable decision metrics. After finding the smallest tumor-containing segment, the resolution is increased in the detected tumor-containing segment, leaving the other parts of the breast image with low resolution. Our framework is applied on the most common used beamforming techniques, such as delay and sum (DAS) and delay multiply and sum (DMAS) and according to simulation results, our framework can decrease the computational complexity significantly for both DAS and DMAS without imposing any degradation on accuracy of basic algorithms. The amount of complexity reduction can be determined manually or automatically based on two proposed methods that are described in this framework.
关键词： breast cancer detection,low complexity computational methods,DAS,DMAS,Microwave imaging
更新于2025-09-23 15:21:21
-
[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Distribution Acoustic sensor based flow measurement using flow-induced vibrations
摘要： In this paper, we demonstrated a non-invasive flowmeter based on optical fiber distribution acoustic sensor (DAS) system, in which the flow rate is measured by detecting Flow-Induced Vibrations(FIV) noise. The experiment results showed that the flow rate has a quadratic relationship with the standard deviation(SD) of the noise signal caused by the FIV.
关键词： Flowmeter,Vibration analysis,DAS,FIV
更新于2025-09-16 10:30:52
-
[IEEE 2019 2nd International Colloquium on Smart Grid Metrology (SMAGRIMET) - Split, Croatia (2019.4.9-2019.4.12)] 2019 2nd International Colloquium on Smart Grid Metrology (SMAGRIMET) - Fiber Optic Sensor Cable Based on Hollow Capillary Tube with Three Tightly Encapsulated Optical Fibers
摘要： Fiber optic sensor cable technology is relatively new field that combines a set of scientific and technical disciplines in a special way in order to meet industrial standards. In this paper we discuss one particular design for multipurpose and configuration multivalent optical fiber sensing. It has the potential to integrate more detection and measurement techniques in one cable body and this, in turn, largely contributes to installation cost optimization and directly impacts investment plans and industrial success. The article presents also a unique high-pressure high temperature lab facility conceptualized and constructed for testing and evaluation of this and similar optical fiber sensor cables.
关键词： fiber optic measurements,OFDR,acoustic sensors,BOTDA,BOTDR,DAS,Brillouin effect,optical fiber,pressure sensors,fully distributed optical fiber sensor,monitoring systems,strain sensors,temperature sensors,OTDR
更新于2025-09-16 10:30:52
-
Measurements of spectroscopic parameters of CO2 transitions for Voigt, Rautian, Galatry and speed-dependent Voigt profiles near 1.43 μm using the WM-DAS method
摘要： Linestrengths, self-broadening and narrowing coefficients for 8 absorption transitions of CO2 near 1.43 μm were measured using the wavelength modulation direct absorption spectroscopy (WM-DAS) at 300-1000 K and 5-20 kPa. The SNR was enhanced to 1500 for the peak absorbance around 5% at room temperature and remains at 550 for the peak absorbance around 1% at high temperatures by use of the WM-DAS method. The Voigt, Rautian, Galatry and quadratic speed-dependent Voigt profiles were used to recover the absorbance and retrieve the best-fit spectroscopic parameters and their temperature dependence. The quadratic speed-dependent Voigt profile was found to give the best combination of accuracy and robust lineshape parameters. The measured linestrengths and self-broadening coefficients compare well with the available values listed in the HITRAN/HITEMP database. The self-narrowing coefficients were also determined for GP, RP and qSDVP with analyses of the uncertainties in these spectroscopic parameters.
关键词： WM-DAS method,Galatry profile,speed-dependent Voigt profile,Voigt profile,spectroscopic parameters,Rautian profile,CO2
更新于2025-09-10 09:29:36