Title:
OPTICAL PULSE TESTING METHOD AND OPTICAL PULSE TESTING DEVICE
Document Type and Number:
WIPO Patent Application WO/2021/075015
Kind Code:
A1
Abstract:
The purpose of the present invention is to propose, for DAS-P, a designing method using a minimum value N of a frequency multiplexing number for measuring an intended vibration frequency with tradeoff between a measured distance and an upper limit of measurable vibration frequencies taken into account. When a phase shift in any section of an optical fiber to be measured is denoted as A × sin(2πfvt), it is assumed that for A of smaller than π/2, N = 4Zfv/ν and that for A of π/2 or greater, N = 2Zfv/(ν·Arcsin(π/2A)). Here, fv denotes a vibration frequency, t denotes time, Z denotes the length of the optical fiber to be measured (measured distance), and ν denotes the speed of light in the optical fiber to be measured.
Inventors:
WAKISAKA YOSHIFUMI (JP)
IIDA DAISUKE (JP)
OSHIDA HIROYUKI (JP)
IIDA DAISUKE (JP)
OSHIDA HIROYUKI (JP)
Application Number:
PCT/JP2019/040821
Publication Date:
April 22, 2021
Filing Date:
October 17, 2019
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE (JP)
International Classes:
G01H9/00
Foreign References:
| JP2017026503A | 2017-02-02 | |||
| US20190238178A1 | 2019-08-01 | |||
| CN109210385A | 2019-01-15 | |||
| JP2018036107A | 2018-03-08 |
Other References:
IIDA, DAISUKE : "Study on frequency dependence in vibration distribution measurement using frequency-multiplexed phase OTDR", PROCEEDINGS OF THE 2016 IEICE COMMUNICATION SOCIETY CONFERENCE 2; SAPPORO, JAPAN; SEPTEMBER 20-23, 2016, 1 September 2016 (2016-09-01) - 23 September 2016 (2016-09-23), JP, pages 311, XP009535379
A. MASOUDIT. P. NEWSON: "Contributed Rview: Distributed optical fibre dynamic strain sensing", REVIEW OF SCIENTIFIC INSTRUMENTS, vol. 87, 2016, pages 011501
KEN'ICHI NISHIGUCHILI CHE-HSIENARTUR GUZIKMITSUNORI YOKOYAMAKINZO MASUDA: "Fabrication of Fiber-Optic Distributed Acoustic Sensor and Its Signal Processing", IEICE TECH. REP., vol. 115, no. 202, 2015, pages 29 - 34
G. YANG ET AL.: "Long-Range Distributed Vibration Sensing Based on Phase Extraction from Phase-Sensitive OTDR", IEEE PHOTONICS JOURNAL, vol. 8, no. 3, 2016, XP011607611, DOI: 10.1109/JPHOT.2016.2552820
YOSHIFUMI WAKISAKA, DAISUKE IIDA, KEIJI OKAMOTO, HIROYUKI OSHIDA: "Shuuhasuu tajuuisou OTDR wo mochiita bunpushindoukeisokuhouhou (Distributed Vibration Sensing Method with Frequency-Multiplexed Phase-OTDR) ", 2019 IEICE SOCIETY CONFERENCE, 27 August 2019 (2019-08-27)
D. IIDAK. TOGET. MANABE: "Distributed measurement of acoustic vibration location with frequency multiplexed phase-OTDR", OPT. FIBER TECHNOL., vol. 36, 2017, pages 19 - 25, XP085114643, DOI: 10.1016/j.yofte.2017.02.005
MARIA ROSARIO FERNANDEZ-RUIZHUGO F. MARTINS: "Steady-Sensitivity Distributed Acoustic Sensors", J. LIGHTWAVE TECHNOL., vol. 36, 2018, pages 5690 - 5696, XP011697725, DOI: 10.1109/JLT.2018.2877849
C. D. BUTTERG. B. HOCKER: "Fiber optics strain gauge", APPL. OPT., vol. 17, 1978, pages 2867 - 2869
A. E. ALEKSEEV ET AL., LASER PHYS., vol. 29, 2019, pages 055106
See also references of EP 4047333A4
A. MASOUDIT. P. NEWSON: "Contributed Rview: Distributed optical fibre dynamic strain sensing", REVIEW OF SCIENTIFIC INSTRUMENTS, vol. 87, 2016, pages 011501
KEN'ICHI NISHIGUCHILI CHE-HSIENARTUR GUZIKMITSUNORI YOKOYAMAKINZO MASUDA: "Fabrication of Fiber-Optic Distributed Acoustic Sensor and Its Signal Processing", IEICE TECH. REP., vol. 115, no. 202, 2015, pages 29 - 34
G. YANG ET AL.: "Long-Range Distributed Vibration Sensing Based on Phase Extraction from Phase-Sensitive OTDR", IEEE PHOTONICS JOURNAL, vol. 8, no. 3, 2016, XP011607611, DOI: 10.1109/JPHOT.2016.2552820
YOSHIFUMI WAKISAKA, DAISUKE IIDA, KEIJI OKAMOTO, HIROYUKI OSHIDA: "Shuuhasuu tajuuisou OTDR wo mochiita bunpushindoukeisokuhouhou (Distributed Vibration Sensing Method with Frequency-Multiplexed Phase-OTDR) ", 2019 IEICE SOCIETY CONFERENCE, 27 August 2019 (2019-08-27)
D. IIDAK. TOGET. MANABE: "Distributed measurement of acoustic vibration location with frequency multiplexed phase-OTDR", OPT. FIBER TECHNOL., vol. 36, 2017, pages 19 - 25, XP085114643, DOI: 10.1016/j.yofte.2017.02.005
MARIA ROSARIO FERNANDEZ-RUIZHUGO F. MARTINS: "Steady-Sensitivity Distributed Acoustic Sensors", J. LIGHTWAVE TECHNOL., vol. 36, 2018, pages 5690 - 5696, XP011697725, DOI: 10.1109/JLT.2018.2877849
C. D. BUTTERG. B. HOCKER: "Fiber optics strain gauge", APPL. OPT., vol. 17, 1978, pages 2867 - 2869
A. E. ALEKSEEV ET AL., LASER PHYS., vol. 29, 2019, pages 055106
See also references of EP 4047333A4
Attorney, Agent or Firm:
OKADA, Kenji et al. (JP)
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