Title:
DISTORTION CHANGE MEASURING DEVICE AND DISTORTION CHANGE MEASURING METHOD
Document Type and Number:
WIPO Patent Application WO/2021/260757
Kind Code:
A1
Abstract:
The purpose of the present disclosure is to measure, at a high sampling rate, the distribution of vibrations applied to core wires after branching. A distortion change measuring device according to the present disclosure performs the following: causing first chirped pulse light, that has a chirp in which the frequency linearly changes over a time period, to be incident on measured optical fibers, which have been branched by a coupler, at a reference time; acquiring a first scattered light signal for the first chirped pulse light; causing second chirped pulse light, in which the chirp has been reversed on the time axis from that of the first chirped pulse light, to be incident on the measured optical fibers at each monitoring time; acquiring a second scattered light signal for the second chirped pulse light; reversing the first scattered light signal on the time axis and obtaining a shift amount serving as the maximum correlation between a shifted waveform and the waveform of the second scattered light signal; and calculating, by using the shift amount, the change in the distortion amount of the measured optical fibers from the reference time to each of the monitoring times.
Inventors:
WAKISAKA YOSHIFUMI (JP)
ONO SHINGO (JP)
IIDA DAISUKE (JP)
OSHIDA HIROYUKI (JP)
ONO SHINGO (JP)
IIDA DAISUKE (JP)
OSHIDA HIROYUKI (JP)
Application Number:
PCT/JP2020/024332
Publication Date:
December 30, 2021
Filing Date:
June 22, 2020
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE (JP)
International Classes:
G01B11/16; G01D5/353; G01L1/24
Foreign References:
| JP2016142618A | 2016-08-08 | |||
| JP2009042005A | 2009-02-26 | |||
| JP2016142618A | 2016-08-08 |
Other References:
ALI. MASOUDIT. P. NEWSON: "Contributed Review: Distributed optical fibre dynamic strain sensing", REVIEW OF SCIENTIFIC INSTRUMENTS, vol. 87, 2016, pages 011501
Z. PANK. LIANGQ. YEH. CAIR. QUZ. FANG: "Phase-sensitive OTDR system based on digital coherent detection, in Optical Sensors and Biophotonics", PROCEEDINGS OF SPIE, vol. 8311, 2011
DA-PENG ZHOUZENGGUANG QINWENHAI LILIANG CHENXIAOYI BAO: "Distributed vibration sensing with time-resolved optical frequency-domain reflectometry", OPT. EXPRESS, vol. 20, 2012, pages 13138 - 13145
DA-PENG ZHOULIANG CHENXIAOYI BAO: "Distributed dynamic strain measurement using optical frequency-domain reflectometry", APPL. OPT., vol. 55, 2016, pages 6735 - 6739
YAHEI KOYAMADAMUTSUMI IMAHAMAKENYA KUBOTAKAZUO HOGARI: "Fiber-Optic Distributed Strain and Temperature Sensing With Very High Measurand Resolution Over Long Range Using Coherent OTDR", J. LIGHTWAVE TECHNOL., vol. 27, 2009, pages 1142 - 1146, XP011256380
SASCHA LIEHRSVEN MUNZENBERGERKATERINA KREBBER: "Wavelength-scanning coherent OTDR for dynamic high strain resolution sensing", OPT. EXPRESS, vol. 26, 2018, pages 10573 - 10588
LIHI SHILOHAVISHAY EYAL: "Distributed acoustic and vibration sensing via optical fractional Fourier transform reflectometry", OPT. EXPRESS, vol. 23, 2015, pages 4296 - 4306
See also references of EP 4170281A4
Z. PANK. LIANGQ. YEH. CAIR. QUZ. FANG: "Phase-sensitive OTDR system based on digital coherent detection, in Optical Sensors and Biophotonics", PROCEEDINGS OF SPIE, vol. 8311, 2011
DA-PENG ZHOUZENGGUANG QINWENHAI LILIANG CHENXIAOYI BAO: "Distributed vibration sensing with time-resolved optical frequency-domain reflectometry", OPT. EXPRESS, vol. 20, 2012, pages 13138 - 13145
DA-PENG ZHOULIANG CHENXIAOYI BAO: "Distributed dynamic strain measurement using optical frequency-domain reflectometry", APPL. OPT., vol. 55, 2016, pages 6735 - 6739
YAHEI KOYAMADAMUTSUMI IMAHAMAKENYA KUBOTAKAZUO HOGARI: "Fiber-Optic Distributed Strain and Temperature Sensing With Very High Measurand Resolution Over Long Range Using Coherent OTDR", J. LIGHTWAVE TECHNOL., vol. 27, 2009, pages 1142 - 1146, XP011256380
SASCHA LIEHRSVEN MUNZENBERGERKATERINA KREBBER: "Wavelength-scanning coherent OTDR for dynamic high strain resolution sensing", OPT. EXPRESS, vol. 26, 2018, pages 10573 - 10588
LIHI SHILOHAVISHAY EYAL: "Distributed acoustic and vibration sensing via optical fractional Fourier transform reflectometry", OPT. EXPRESS, vol. 23, 2015, pages 4296 - 4306
See also references of EP 4170281A4
Attorney, Agent or Firm:
OKADA, Kenji et al. (JP)
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