公开(公告)号：US20230400379A1

公开(公告)日：2023-12-14

申请号：US18034754

申请日：2020-11-02

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Tatsuya OKAMOTO ,  Daisuke IIDA ,  Yusuke KOSHIKIYA ,  Nazuki HONDA

IPC: G01M11/02 ,  G01M11/00 ,  H04B10/071

CPC classification number: G01M11/02 ,  G01M11/3172 ,  H04B10/071

Abstract: The present disclosure relates to a frequency modulation amount measuring device that measures an optical spectral shift of scattered light at a position in an optical transmission line, and calculates a frequency modulation amount at the position, using the measured optical spectral shift.

公开(公告)号：US20220107218A1

公开(公告)日：2022-04-07

申请号：US17429861

申请日：2020-01-29

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tatsuya OKAMOTO ,  Daisuke IIDA ,  Hiroyuki OSHIDA

IPC: G01H9/00 ,  G01M11/00

Abstract: It is an object of the present invention to provide an aerial optical fiber cable inspection method, an aerial optical fiber cable inspection device, and a program which can identify a cable sagging section from vibration sensing results. In the aerial optical fiber cable inspection method according to the present invention, a vibration distribution waveform along the longitudinal direction of an aerial optical fiber cable measured using an optical fiber vibration sensing device is received as an input, a standard deviation of the amplitude of vibration at each position in the vibration distribution waveform is calculated, and a section with a standard deviation larger than that of other sections is identified as a cable sagging section.

公开(公告)号：US20240271971A1

公开(公告)日：2024-08-15

申请号：US18682212

申请日：2021-08-16

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Tatsuya OKAMOTO ,  Daisuke IIDA ,  Yusuke KOSHIKIYA ,  Nazuki HONDA

IPC: G01D5/353

CPC classification number: G01D5/35361

Abstract: An object of the present invention is to provide a sensing system, a sensing method, and an analyzing device using OFDR in which a sensing range of strain/temperature is less likely to be limited by a frequency sweep width.
In the sensing method using OFDR, the sensing system according to the present invention employs sequential update, per measurement by one frequency sweep of the probe light, for setting the reference spectrum to the spectrum of an immediately preceding measurement, by which a spectral shift between an n-th measurement and an (n−1)th measurement is obtained, and the spectral shifts individually obtained between the measurements are integrated.

公开(公告)号：US20240175726A1

公开(公告)日：2024-05-30

申请号：US18283498

申请日：2021-03-25

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tatsuya OKAMOTO ,  Daisuke IIDA ,  Yusuke KOSHIKIYA ,  Nazuki HONDA

IPC: G01D5/353 ,  G01K11/32 ,  G01L1/24

CPC classification number: G01D5/35358 ,  G01K11/32 ,  G01L1/242

Abstract: The present disclosure generates an optical spectrogram, representing a temporal change in frequency characteristics, using a plurality of spectral data measured by an OFDR measurement instrument at different times, and filters the optical spectrogram in both a time direction and a frequency direction.

公开(公告)号：US20220103252A1

公开(公告)日：2022-03-31

申请号：US17427651

申请日：2020-01-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Daisuke IIDA ,  Nazuki HONDA ,  Tatsuya OKAMOTO ,  Yoshifumi WAKISAKA ,  Hiroyuki OSHIDA

IPC: H04B10/071 ,  H04B10/27 ,  H04B10/2507

Abstract: An object is to provide an optical fiber route search method, an optical fiber route search device, and a program that can efficiently confirm a path of an optical fiber that is installed over a long distance or across a large range. The optical fiber route search method according to the present invention carries out optical measurement that performs distributed measurement of the state of an optical fiber while applying a disturbance to the optical fiber in a portion in which wires of the optical fiber are parallel to each other, branch out, or intersect with each other (a proximity portion), and determines that the position in which the number of singularities (peaks or intensity fluctuations) fluctuates (becomes plural) is the position of the proximity portion from a distribution diagram obtained through the optical measurement.