公开(公告)号：US20220364846A1

公开(公告)日：2022-11-17

申请号：US17636941

申请日：2019-09-03

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Daisuke IIDA ,  Keiji OKAMOTO ,  Hiroyuki OSHIDA

IPC: G01B11/16

Abstract: The present invention intends to provide an optical fiber cable sensing apparatus capable of measuring longitudinal directional distribution of curvature and torsion, without using a specially structured optical fiber sensor. This apparatus includes means for inputting data of longitudinal directional distribution of distortion (bending loss, polarization variation) measured for each optical fiber accommodated in an optical fiber cable to be measured and data indicating the position of each measurement object optical fiber on a cable cross section, means for calculating curvature vector κ of the optical fiber cable to be measured, at the same spot, based on the distortion (bending loss, polarization variation) of each optical fiber at the spot and the position of the optical fiber on the cable cross section, and means for calculating torsion τ of the optical fiber cable to be measured at the spot from the calculated curvature vector κ.

公开(公告)号：US20220327779A1

公开(公告)日：2022-10-13

申请号：US17634595

申请日：2019-08-19

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Masaaki INOUE ,  Hitoshi NIIGAKI ,  Yukihiro GOTO ,  Shigehiro MATSUDA ,  Toshiya OHIRA ,  Ryuji HONDA ,  Tomoya SHIMIZU ,  Hiroyuki OSHIDA

IPC: G06T17/20 ,  G06F30/18 ,  G01B11/00

Abstract: An object of the present disclosure is to provide a technique for creating a three-dimensional model of a line-like structure from a point cloud obtained using three-dimensional laser measuring equipment and detecting a three-dimensional model of a cable. A detection apparatus according to the disclosure includes a point cloud data input unit 12 that reads point cloud data where a structure that is present in a three-dimensional space is represented by a point cloud that is present in the three-dimensional space, a rule-based three-dimensional model generation unit 15 that combines linearly disposed point clouds into a group and generates a three-dimensional model of a line-like structure using a direction vector configured with point clouds included in the group, a machine learning-based three-dimensional model generation unit 14 that generates a three-dimensional model of a line-like structure based on a database that links point clouds and line-like structures, and a three-dimensional model merging unit that selects one of a plurality of three-dimensional models of line-like structures generated at an identical position in the three-dimensional space as a three-dimensional model of a line-like structure that is present in the three-dimensional space and merges three-dimensional models of the line-like structures that are present in the three-dimensional space.

公开(公告)号：US20220268566A1

公开(公告)日：2022-08-25

申请号：US17635557

申请日：2019-08-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Toshiya OHIRA ,  Yukihiro GOTO ,  Ryuji HONDA ,  Hiroyuki OSHIDA

IPC: G01B11/02 ,  G01B11/00 ,  G01B11/03 ,  G01C3/00

Abstract: An object of the present invention is to provide an information processing apparatus, an information processing method, and a program, which are capable of determining an owner of an attachment attached to a facility using a solid model of a facility extracted from three-dimensional point group data. The present invention determines the owner of the attachment from a planar positional relationship between the solid model of a columnar structure and the solid model of the attachment in the solid model. For example, a distance between a utility pole and a center of a point (a center of a ground boundary) at which a branch line or a post reaches a ground is acquired, and whether the branch line or the post is owned by a communication company or an electric power company is determined based on whether the distance exists in a constant threshold determined by the communication company or the electric power company.

公开(公告)号：US20220006521A1

公开(公告)日：2022-01-06

申请号：US17285719

申请日：2019-11-14

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yoshifumi WAKISAKA ,  Daisuke IIDA ,  Keiji OKAMOTO ,  Hiroyuki OSHIDA

IPC: H04B10/071

Abstract: It is an object to enable offline measurement with a high SN ratio of the phase of scattered light of an optical fiber to be measured in an optical receiving system for real-time measurement (direct measurement). The phase measurement method according to the present invention performs coherent detection of scattered light using a 90-degree optical hybrid, obtains an estimated quadrature component value by averaging a measured quadrature component value that is directly measured and a calculated quadrature component value obtained by Hilbert transforming a measured in-phase component value that is directly measured, obtains an estimated in-phase component value by averaging the measured in-phase component value and a calculated in-phase component value obtained by inverse Hilbert transforming the measured quadrature component value, and calculates the phase of scattered light based on the estimated quadrature component value and the estimated in-phase component value.

公开(公告)号：US20230288466A1

公开(公告)日：2023-09-14

申请号：US18016908

申请日：2020-08-07

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tomokazu ODA ,  Atsushi NAKAMURA ,  Daisuke IIDA ,  Hiroyuki OSHIDA

IPC: G01R29/08 ,  H04B10/073

CPC classification number: G01R29/0885 ,  H04B10/073 ,  H04B10/2581

Abstract: distribution of the any higher-order mode.

公开(公告)号：US20230126470A1

公开(公告)日：2023-04-27

申请号：US17798101

申请日：2020-02-28

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsushi NAKAMURA ,  Nazuki HONDA ,  Hiroyuki OSHIDA

IPC: G01M11/02

Abstract: An object of the present invention is to provide an immersion detection system and an immersion detection method capable of eliminating module replacement in the occurrence of immersion and simplifying system management. An immersion detection system according to the present invention includes: an immersion detection sensor having two optical fibers connected in series such that end faces of the two optical fibers abut on each other with a predetermined gap; an optical measurer that causes test light with a plurality of wavelengths to enter an optical transmission line having a plurality of the immersion detection sensors connected in series with optical fibers and measures a return loss of the test light at the immersion detection sensor for each of the wavelengths and for each of the immersion detection sensors; and a determiner that averages, for each of the immersion detection sensors, the return losses for the wavelengths and performs threshold determination on the presence or absence of immersion.

公开(公告)号：US20220398357A1

公开(公告)日：2022-12-15

申请号：US17642835

申请日：2019-09-18

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Shigehiro MATSUDA ,  Yukihiro GOTO ,  Ryuji HONDA ,  Hiroyuki OSHIDA

IPC: G06F30/18 ,  G06T11/20

Abstract: The purpose of the present disclosure is to make it possible to determine owners of cables from a positional relationship between the cables in an off-site equipment model acquired through a mobile mapping system (MMS). The present disclosure acquires cable models serving as solid models of cables extracted from three-dimensional point group data (S11), identifies a positional relationship of the cables from the cable models and determines owners of the cables from the positional relationship in accordance with a determination table defining a vertical relationship of the cables (S22), links information of the owners determined to the solid models, and creates a line diagram by using the cable models to which the information of the owners is linked.

公开(公告)号：US20220381645A1

公开(公告)日：2022-12-01

申请号：US17762185

申请日：2019-10-10

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsushi NAKAMURA ,  Tomokazu ODA ,  Daisuke IIDA ,  Hiroyuki OSHIDA ,  Yoshifumi WAKISAKA

IPC: G01M11/00

Abstract: An object of the present disclosure is to enable each inter-modal coupling efficiency at a connection point between few-mode optical fibers to be accurately acquired. The present disclosure involves: inputting pulsated pump light in a fundamental mode or a first higher-order mode into one end of an optical fiber under test constructed by connecting two optical fibers in series; inputting probe light having an optical frequency difference within a Brillouin frequency shift range with respect to the pump light into the other end of the optical fiber under test in the fundamental mode or the first higher-order mode; measuring a Brillouin gain distribution related to a distance of transmitted light intensity of probe light output from the one end into which the pump light was input; acquiring a transmittance at a connection point of the optical fiber under test by using the Brillouin gain distribution; and substituting the transmittance and a Brillouin gain coefficient unique to the optical fiber under test into an expression representing a transmittance at the connection point that occurs in a Brillouin gain distribution in each mode and solving a simultaneous equation to calculate each inter-modal coupling efficiency at the connection point.

公开(公告)号：US20220276123A1

公开(公告)日：2022-09-01

申请号：US17636930

申请日：2019-09-10

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsushi NAKAMURA ,  Daisuke IIDA ,  Hiroyuki OSHIDA

IPC: G01M11/02

Abstract: The purpose of the present disclosure is to provide a mode field diameter test method and test device that enable acquisition of a mode field diameter for an arbitrary higher-order mode. The present disclosure is a mode field diameter test method including: a test light incidence procedure for selectively causing test light to be incident in a mode subject to measurement, on one end of an optical fiber 10 under test; a far-field pattern measurement procedure for measuring a far-field pattern of the mode subject to measurement, with respect to a divergence angle θ at the other end of the optical fiber under test, by a far-field scanning technique; and a mode field diameter calculation procedure for calculating, using an equation, a mode field diameter from information about incident mode orders in the test light incidence procedure and the far-field pattern measured in the far-field pattern measurement procedure.

公开(公告)号：US20220128395A1

公开(公告)日：2022-04-28

申请号：US17427792

申请日：2020-01-22

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yoshifumi WAKISAKA ,  Daisuke IIDA ,  Keiji OKAMOTO ,  Hiroyuki OSHIDA

IPC: G01H9/00

Abstract: The present invention aims to provide a vibration detection method, a signal processing device, and a program according to which it is possible to accurately detect vibration physically applied to an optical fiber, using a simple determination reference. In a vibration detection method according to the present invention, scattered light of a given target segment of a measurement target fiber is indicated by vectors of an in-phase component and a quadrature component, and a triangular shape constituted by a near-end-side vector of the target segment and a far-end-side vector is used as a physical amount to be tracked. That is, it is determined whether or not there is vibration based on a change in shape of the triangular shape with respect to a reference state. This is a detection method in which DAS-I and DAS-P are combined, a simple determination reference such as shape change of a triangular shape is employed, and overlooking of vibration detection can be reduced.