Abstract

Described herein in is an acoustic system and method for tracking and identifying trends or behavioural characteristics or properties of multiple sound producing targets or objects across a geographical area. The method and system may be used independently of or as a supplement to bespoke tracking technology associated with such objects or targets. The acoustic method includes repeatedly transmitting, at multiple instants, interrogating optical signals into each of one or more optical fibres distributed across the geographical area and forming at least part of an installed fibre-optic communications network. Next the method includes receiving, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of optical fibres, the scattering influenced by acoustic disturbances caused by the multiple objects within the

IPC Classes  ?

• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means

Abstract

An interface device connected between a telecommunication network and a distributed acoustic sensing (DAS) device. The interface device includes: a first signal splitter configured to receive a probe signal from the DAS device and split the probe signal into a first portion and a second portion; a signal analyzing module configured to receive the first portion of the probe signal and determine whether peak and/or average power of the probe signal is below predetermined peak and/or average power threshold values; and a delay device configured to receive the second portion of the probe signal and delay propagation of the second portion of the probe signal to the telecommunication network by an amount of time taken by the signal analyzing module to analyze the first portion of the probe signal.

IPC Classes  ?

• H04B 10/61 - Coherent receivers
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• H04B 10/60 - Receivers
• H04Q 11/00 - Selecting arrangements for multiplex systems
• H04R 23/00 - Transducers other than those covered by groups

Abstract

A distributed fibre optic sensing (DFOS) method is disclosed. The method includes (a) repeatedly transmitting interrogating optical signals into at least one optical fibre: (b) receiving backscattered optical signals in a distributed manner along the at least one optical fibre: (c) combining the backscattered optical signals and an optical reference signal: (d) processing the combined signals to determine at least one polarisation state change of the backscattered optical signals along the at least one optical fibre; and (e) determining at least one birefringence event based on the at least one polarisation state change

IPC Classes  ?

• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]

Abstract

Methods for reducing the number of redundant cable paths in a multi-path redundant fiber optic cable network are disclosed. A method includes: monitoring cable paths in the fiber optic cable network using distributed fiber optic sensing to detect cable break events; measuring cable break rates for the cable paths in the fiber optic cable network over a period of time based on the detected cable break events; determining availability of the fiber optic cable network over the period of time, the availability determined based on the number of redundant cable paths in the fiber optic cable network and the cable break rates of the cable paths; and providing an indication when the fiber optic cable network achieves a target availability with at least one less redundant cable path.

IPC Classes  ?

• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• G01M 11/00 - Testing of optical apparatusTesting structures by optical methods not otherwise provided for
• H04B 10/07 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems
• H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
• H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal

Goods & Services

Downloadable software for sensing sounds; musical sound recordings; vehicle tracking apparatus, namely, gps navigation devices; electrical tracking apparatus, namely, gps navigation devices; detection apparatus including real-time detection apparatus, namely, radar detectors; real-time data processing apparatus, namely, data processors; apparatus for displaying the path followed by a vehicle, namely, gps navigation devices; optical fibre cables; electric connections for use with optical fibre cables; electrooptical acoustic, vibration, sound, vehicle and electrical sensors; sensor systems comprised of fiber-optic acoustic, vibration, sound, vehicle and electrical sensors; sensors for measuring speed, not for medical use; electric sensors for real time data input apparatus; electric sensors for real time data output apparatus; passive electric acoustic, vibration, sound and electrical sensors other than for medical use; fibre optic cables; fibre optic link installations, namely, fibre optic couplings; optical fibre cables; optical fibres; vibration sensors incorporating optical fibres; leak detection apparatus and instruments, namely, leak detectors for vacuum pumps; electronic apparatus for detecting leaks, namely, leak detectors for vacuum pumps; cable installations for the transmission of data, namely, telecommunications cables; apparatus for locating electric cables, namely, cable locators; apparatus for recording the positions of cables, namely, cable locators; acoustic pulse-echo ranging apparatus in the nature of range finders for industrial use; echo ranging devices, namely, range finders; range finders; sight range finders Scientific research services including the preparation of scientific and technical reports and analysis of data obtained from fibre optic sensing apparatus; scientific research services including the preparation of scientific and technical reports and analysis of data obtained from vehicle tracking apparatus, electrical tracking apparatus, sensors and detection apparatus including real-time sensors and detection apparatus; scientific and technological research services relating to the provision of information and data obtained utilising a link to fibre optic sensing apparatus; sensing as a service, namely, Internet of Things[ IoT] based detection software services in the nature of providing temporary use of online non-downloadable software for detecting the location of devices in the internet of things; data as a service, namely, Internet of Things[ IoT] based detection data decryption services; platform as a service featuring computer software platforms for management and analysis of scientific and technological information and data obtained by utilising sensing devices; software as a service services featuring software for navigating vehicles; scientific and technological design services, namely, engineering design services; design of computer hardware and software; technological information, advisory and consultancy services relating to fibre optic acoustic and vibration sensing technologies

Abstract

Method and system for determining the condition of a cable are disclosed. The method includes: transmitting interrogating signals into a sensing optical fibre extending the length of the cable and receiving backscattered signals from the sensing optical fibre in response to the interrogating signals. The method further includes processing the backscattered signals to determine variations in strain or strain rate along the sensing optical fibre and determining the time history of the strain or strain rate to obtain accumulated strain data indicative of the condition of the cable at points along the cable.

IPC Classes  ?

• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
• G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis
• G01M 5/00 - Investigating the elasticity of structures, e.g. deflection of bridges or aircraft wings

Abstract

Method and system for determining an exposure point along a buried submarine cable are disclosed. The method includes transmitting interrogating signals into a sensing optical fibre extending the length of the submarine cable, and receiving backscattered signals from the sensing optical fibre in response to the interrogating signals. The method further includes processing the backscattered signals to determine temporal and/or spatial variation in strain along the sensing optical fibre, wherein a determined spatial and/or temporal variation in the strain is indicative of an exposure point and its location along the length of the buried submarine cable.

IPC Classes  ?

• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
• G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis
• H02G 9/02 - Installations of electric cables or lines in or on the ground or water laid directly in or on the ground, river-bed or sea-bottomCoverings therefor, e.g. tile
• H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
• H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal

Abstract

A distributed fiber optic sensing (DFOS) system and method record optical data in one or more optical fibers, calculate physical parameters from the recorded optical data, and compute locations of vehicles passing above or beside the one or more optical fibers based on the DFOS data. A method of determining a force exerted by an object onto a surface under the object using at least one optical fiber located below or adjacent to the surface includes measuring DFOS data arising from strain in the at least one optical fiber responsive to the force, determining at least one relationship between the measured DFOS data and the force and processing the measured DFOS data and the at least one relationship to determine the force.

IPC Classes  ?

• G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis
• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre

Abstract

There is provided a phase-sensitive optical time domain reflectometry (φ-OTDR)-based method for detecting a disturbance event in an optical fibre. The method includes determining the probability of occurrence of predetermined phase difference values between successive samples of a processed backscattered signal from the optical fibre, to detect the existence or otherwise of the disturbance event.

IPC Classes  ?

• H04B 10/071 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• G01M 11/00 - Testing of optical apparatusTesting structures by optical methods not otherwise provided for
• H04B 10/073 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an out-of-service signal
• H04B 10/077 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
• H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal

Abstract

A method of generating a geotechnical survey of a target area includes measuring DFOS data in an optical fiber located within a sensing distance of the target area and determining subterranean characteristics of the target area based on the measured DFOS data. A geotechnical surveying system may include an optical fiber and a DFOS device and a processor configured to calculate geotechnical data based on DFOS data.

IPC Classes  ?

• G01V 1/28 - Processing seismic data, e.g. for interpretation or for event detection
• G01V 1/18 - Receiving elements, e.g. seismometer, geophone
• G01V 1/30 - Analysis

Abstract

A method of determining a peak ground acceleration includes providing a DFOS instrument connected to at least one optical fiber and recording DFOS data with the DFOS instrument. The DFOS data includes strain data along the at least one optical fiber. The method also includes converting the strain data into complex Fourier coefficients, scaling the complex Fourier coefficients, applying an inverse transform to the scaled Fourier coefficients, and selecting a maximum value from an output of the inverse transform to identify the peak ground acceleration for a position along the at least one optical fiber.

IPC Classes  ?

• G01V 1/01 - Measuring or predicting earthquakes
• G01V 1/22 - Transmitting seismic signals to recording or processing apparatus

Abstract

Described herein in is an acoustic system and method for tracking and identifying trends or behavioural characteristics or properties of multiple sound producing targets or objects across a geographical area. The method and system may be used independently of or as a supplement to bespoke tracking technology associated with such objects or targets. The acoustic method includes repeatedly transmitting, at multiple instants, interrogating optical signals into each of one or more optical fibres distributed across the geographical area and forming at least part of an installed fibre- optic communications network. Next the method includes receiving, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of optical fibres, the scattering influenced by acoustic disturbances caused by the multiple objects within the observation period. The acoustic data is then demodulated from the optical signals and the acoustic data is processed to identify tracks made by the objects over a period of time across the area. Further, one or more characteristics of the tracks or tracked features, including start and end points, are analysed to identify relationship links between the dynamic objects and their locations or between the dynamic objects and other static or dynamic objects or fixtures or events in the geographic area for real time, historic or predictive analysis.

IPC Classes  ?

• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
• G01S 5/16 - Position-fixing by co-ordinating two or more direction or position-line determinationsPosition-fixing by co-ordinating two or more distance determinations using electromagnetic waves other than radio waves
• G01S 13/88 - Radar or analogous systems, specially adapted for specific applications
• G01S 13/93 - Radar or analogous systems, specially adapted for specific applications for anti-collision purposes
• G01S 15/88 - Sonar systems specially adapted for specific applications
• G01S 17/58 - Velocity or trajectory determination systemsSense-of-movement determination systems
• G01V 1/00 - SeismologySeismic or acoustic prospecting or detecting
• G01V 1/22 - Transmitting seismic signals to recording or processing apparatus
• G08G 1/04 - Detecting movement of traffic to be counted or controlled using optical or ultrasonic detectors

Abstract

A distributed fibre optic sensing (DFOS) method is disclosed. The method includes (a) repeatedly transmitting interrogating optical signals into at least one optical fibre; (b) receiving backscattered optical signals in a distributed manner along the at least one optical fibre; (c) combining the backscattered optical signals and an optical reference signal; (d) processing the combined signals to determine at least one polarisation state change of the backscattered optical signals along the at least one optical fibre; and (e) determining at least one birefringence event based on the at least one polarisation state change

IPC Classes  ?

• H04B 10/079 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
• G01D 5/26 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light
• G01D 5/34 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
• G01M 11/00 - Testing of optical apparatusTesting structures by optical methods not otherwise provided for
• H04B 10/07 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems
• H04B 10/075 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal
• H04B 10/25 - Arrangements specific to fibre transmission
• H04B 10/61 - Coherent receivers

Abstract

Described herein is a fibre optic sensing method and system for generating a dynamic digital representation of a plurality of objects and associated zones in a geographic area. In general, the disclosed method and system comprises (a) generating a zone feature dataset, including identifying and classifying the associated zones in the area, each zone being classified into a zone type based on static and/or quasi-static zone features and having at least two object-sensed conditions; (b) generating an object tracking dataset, including tracking signals of at least some of the plurality of objects in the geographic area using a distributed fibre optic sensing network, and processing the tracking signals to obtain object-specific tracking data; (c) generating an event dataset, including using the tracking data to determine when the conditions of the zones are changing; digitizing and storing the changed conditions of the zones; and (d) rendering a dynamic representation of the conditions of the zones. The disclosed method and system may be useful to deduce, represent and monitor object type, tracks, events and states of static and/or quasi-static features of the geographic area in a dynamic real-time digital model of the geographic area.

IPC Classes  ?

• G01C 21/00 - NavigationNavigational instruments not provided for in groups
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• G06N 3/08 - Learning methods

Abstract

An acoustic system and method is disclosed for providing spatial and temporal classification of a range of different types of sound producing targets in a geographical area. The system includes an optical signal transmitter arrangement for repeatedly transmitting, at multiple instants, interrogating optical signals into each of one or more optical fibres distributed across the geographical area and forming at least part of an installed fibre-optic communications network. An optical signal detector arrangement receives, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of optical fibres. A processing unit demodulates acoustic data from the optical signals, processes the acoustic data and classifies it in accordance with the target classes or types to generate a plurality of datasets including classification, temporal and location-related data, and a storage unit stores the datasets in parallel with raw acoustic or optical data which is time and location stamped so that it can be retrieved for further processing.

IPC Classes  ?

• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• G08B 13/16 - Actuation by interference with mechanical vibrations in air or other fluid

Abstract

A method of generating a geotechnical survey of a target area includes measuring DFOS data in an optical fiber located within a sensing distance of the target area and determining subterranean characteristics of the target area based on the measured DFOS data. A geotechnical surveying system may include an optical fiber and a DFOS device and a processor configured to calculate geotechnical data based on DFOS data.

IPC Classes  ?

• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means

Goods & Services

Optical fibre sensors; acoustic sensing apparatus; vibration sensing apparatus; software; sound recordings; vehicle tracking apparatus; electrical tracking apparatus; detection apparatus including real-time detection apparatus (other than for medical use); real-time data processing apparatus; apparatus for displaying the path followed by a vehicle; optical fibre cables; connections for use with optical fibre cables; apparatus for sensing movement; position sensing apparatus; electro-optical sensors; fibre optical sensors; sensors for measuring speed; sensors for real time data input apparatus; sensors for real time data output apparatus; vibration sensors; passive sensors (other than for medical use); fibre optic apparatus and cables; fibre optic link installations; optical fibre apparatus (other than for medical use); optical fibres; sensors incorporating optical fibres; leak detection apparatus and instruments; electronic apparatus for detecting leaks; cable installations for the transmission of data; apparatus for locating electric cables; apparatus for recording the positions of cables; acoustic pulse-echo ranging apparatus for industrial use; echo ranging devices; range finders; sight range finders; vibration detectors; vibration gauges; parts, components and accessories in respect of all of the aforementioned goods. Preparation of scientific and technical reports and analysis of data obtained from fibre optic sensing apparatus; preparation of scientific and technical reports and analysis of data obtained from vehicle tracking apparatus, electrical tracking apparatus, sensors and detection apparatus including real-time sensors and detection apparatus; scientific and technological services relating to the provision of information and data obtained utilising a link to fibre optic sensing apparatus; sensing as a service, namely Internet of Things [IoT] based detection software services; data as a service, namely Internet of Things [IoT] based detection data services; platform as a service; software as a service; scientific and technological design services; design of computer hardware and software; information, advisory and consultancy services relating to fibre optic acoustic and vibration sensing technologies; consultancy, advisory and information services in respect of all of the aforementioned services.

Goods & Services

(1) Optical fibre sensors; acoustic meters; Vibration meters; Vibration sensors; downloadable software for monitoring and recording data from acoustic, vibration, sound, vehicle and electrical sensing and tracking devices; Sound recordings in the form of discs, gramophone records, phonograph records, records, tapes, digital media files; vehicle tracking device; electrical tracking apparatus, namely, gps navigation receivers and transmitters; detection apparatus namely real-time detection apparatus for acoustic, vibration, sound, vehicle and electrical tracking; Downloadable software for recording and analyzing real time acoustic, vibration, sound, vehicle and electrical data; apparatus for displaying the path followed by a vehicle, namely, gps navigation devices; optical fibre cables; connections for use with optical fibre cables; Motion detectors; sensors for determining position; electro-optical sensors; fibre optical sensors; sensors for measuring speed; sensors for real time acoustic, vibration, sound, vehicle and electrical data; vibration sensors; sensors for passive acoustic, vibration, sound, vehicle and electrical data; Optical fibre and cables; fibre optic links; optical fibre telecommunication apparatus; optical fibres; acoustic, vibration, sound, vehicle and electrical sensors incorporating optical fibres; (electric) water leak detection sensors; electrical leak detection hardware with embedded operating system software; data transmission cables; electric cable locators; cable position indicators; surface acoustic wave sensors; Electromagnetic measuring detectors; Laser rangefinders; vibration detectors; vibration meters; parts and components in respect of all of the aforementioned goods. (1) Preparation of reports relating to science and technical reports for fibre optic sensing apparatus; Preparation of reports relating to science and technical reports for electrical tracking device; scientific and technological research, testing and analysis services in the field of fibre optic sensing apparatus; platform as a service (PaaS) services featuring computer operating software platforms for the management and connection of (third-party) Internet of Things (IoT) enabled acoustic, vibration, sound, vehicle and electrical sensing devices; Platform as a service (PaaS) services featuring computer operating software platforms for the management and analysis of data from (third-party) Internet of Things (IoT) enabled acoustic, vibration, sound, vehicle and electrical sensing devices, namely Internet of Things [IoT] based detection data services; Platform as a service (PaaS) featuring software for recording scientific and technological information and data obtained by utilising acoustic, vibration, sound, vehicle and electrical sensing devices; Software as a service (SaaS) featuring software for recording scientific and technological information and data obtained by utilising acoustic, vibration, sound, vehicle and electrical sensing devices; Scientific industrial design services; design of computer hardware and software; information, advisory and consultancy services relating to fibre optic acoustic and vibration sensing technologies; consultancy, advisory and information services in respect of all of the aforementioned services.

Abstract

A method of determining a peak ground acceleration includes providing a DFOS instrument connected to at least one optical fiber and recording DFOS data with the DFOS instrument. The DFOS data includes strain data along the at least one optical fiber. The method also includes converting the strain data into complex Fourier coefficients, scaling the complex Fourier coefficients, applying an inverse transform to the scaled Fourier coefficients, and selecting a maximum value from an output of the inverse transform to identify the peak ground acceleration for a position along the at least one optical fiber.

IPC Classes  ?

• G01V 1/22 - Transmitting seismic signals to recording or processing apparatus
• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre

Abstract

A distributed fiber optic sensing (DFOS) system and method record optical data in one or more optical fibers, calculate physical parameters from the recorded optical data, and compute locations of vehicles passing above or beside the one or more optical fibers based on the DFOS data. A method of determining a force exerted by an object onto a surface under the object using at least one optical fiber located below or adjacent to the surface includes measuring DFOS data arising from strain in the at least one optical fiber responsive to the force, determining at least one relationship between the measured DFOS data and the force and processing the measured DFOS data and the at least one relationship to determine the force.

IPC Classes  ?

• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
• G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis

Abstract

Described herein are methods and systems of distributed acoustic sensing, such as in an urban or metropolitan area involving a dedicated and established fibre optic communications network including a data centre. In general, the disclosed method and system includes the steps of (a) selecting an optical fibre cable installation having a path extending across a selected geographical area, the optical fibre cable installation including a bundle of optical fibres and forming part of a fibre-optic communications network, (b) determining characteristics associated with the optical fibre and/or the selected optical fibre installation, (c) transmitting outgoing light in the optical fibre, (d) receiving reflected light back scattered along the optical fibre, and (e) based on the reflected light and the determined characteristics, generating an alert signal representative of an acoustic event. The disclosed method and system are applied to detect acoustic events near or within the selected geographical area.

IPC Classes  ?

• G08B 13/186 - Actuation by interference with heat, light, or radiation of shorter wavelengthActuation by intruding sources of heat, light, or radiation of shorter wavelength using active radiation detection systems by interruption of a radiation beam or barrier using light guides, e.g. optical fibres
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• H04R 23/00 - Transducers other than those covered by groups

Abstract

This application is directed to distributed fiber optic sensing particularly across multiple fiber optic ports with multiple corresponding fiber optic paths. A method is implemented to repeatedly a train of optical signals through a fiber optic network including a plurality of optical fibers distributed across a geographic area using at least one optical signal transmitter, sequentially distribute optical signals in the train through the plurality of optical fiber via corresponding optical fiber ports using an optical switching arrangement, receive backscattered optical signals from the plurality of optical fibers demodulate data from the backscattered optical signals, process the data to identify at least some of the low-frequency weight-induced disturbances, and/or sense the backscattered optical signals in a reduced frequency range. The method is useful to detect low frequency weight-induced disturbances for object tracking against high noise clutter in the higher frequency signal bands.

IPC Classes  ?

• G01V 1/22 - Transmitting seismic signals to recording or processing apparatus
• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre

Abstract

A laser for a distributed fiber sensing system may have a frequency discriminator integrated with the laser. The laser may be an external cavity laser, with at least a portion of the laser cavity on a planar lightwave circuit, which also includes the frequency discriminator.

IPC Classes  ?

• H01S 3/08 - Construction or shape of optical resonators or components thereof
• H01S 5/50 - Amplifier structures not provided for in groups
• H01S 5/0683 - Stabilisation of laser output parameters by monitoring the optical output parameters
• H01S 5/06 - Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
• H01S 5/14 - External cavity lasers
• H01S 5/02 - Structural details or components not essential to laser action
• H01S 5/068 - Stabilisation of laser output parameters
• H01S 5/00 - Semiconductor lasers
• G02F 1/225 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour by interference in an optical waveguide structure
• G02F 1/21 - Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulatingNon-linear optics for the control of the intensity, phase, polarisation or colour by interference

Abstract

A distributed fiber sensing system may use an integrated coherent receiver. The integrated coherent receiver may include a planar lightwave circuit including various optical components.

IPC Classes  ?

• H04B 10/073 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an out-of-service signal
• H04B 10/61 - Coherent receivers

Abstract

Described herein are methods and systems of distributed acoustic sensing, such as in an urban or metropolitan area involving a dedicated and established fibre optic communications network including a data centre. In general, the disclosed method and system includes the steps of (a) selecting an optical fibre cable installation having a path extending across a selected geographical area, the optical fibre cable installation including a bundle of optical fibres and forming part of a fibre-optic communications network, (b) determining characteristics associated with the optical fibre and/or the selected optical fibre installation, (c) transmitting outgoing light in the optical fibre, (d) receiving reflected light back scattered along the optical fibre, and (e) based on the reflected light and the determined characteristics, generating an alert signal representative of an acoustic event. The disclosed method and system are applied to detect acoustic events near or within the selected geographical area.

IPC Classes  ?

• G08B 13/186 - Actuation by interference with heat, light, or radiation of shorter wavelengthActuation by intruding sources of heat, light, or radiation of shorter wavelength using active radiation detection systems by interruption of a radiation beam or barrier using light guides, e.g. optical fibres
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• H04R 23/00 - Transducers other than those covered by groups

Abstract

The present invention relates to a system for distributed acoustic sensing in a marine environment surrounding a repeater along a fibre-optic submarine communications cable. The system includes at least one distributed acoustic sensing (DAS) unit. Each DAS unit further includes a light source that is configured to transmit outgoing light in at least one fibre-optic sensing cable that is located in the marine environment and a receiver configured to receive reflected light that includes at least one optical property influenced by an acoustic disturbance in the marine environment. Each DAS unit further includes an optical multiplexer for multiplexing optical signals onto the fibre-optic submarine communications cable via the repeater where the optical signals carry information on the at least influenced optical property. A method for distributed acoustic sensing in the marine environment is also disclosed.

IPC Classes  ?

• G01V 1/38 - SeismologySeismic or acoustic prospecting or detecting specially adapted for water-covered areas
• G01V 3/08 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
• G01V 1/22 - Transmitting seismic signals to recording or processing apparatus

Abstract

Described herein are methods and systems of distributed acoustic sensing, such as in an urban or metropolitan area involving a dedicated and established fibre optic communications network including a data centre. In general, the disclosed method and system includes the steps of (a) selecting an optical fibre cable installation having a path extending across a selected geographical area, the optical fibre cable installation including a bundle of optical fibres and forming part of a fibre-optic communications network, (b) determining characteristics associated with the optical fibre and/or the selected optical fibre installation, (c) transmitting outgoing light in the optical fibre, (d) receiving reflected light back scattered along the optical fibre, and (e) based on the reflected light and the determined characteristics, generating an alert signal representative of an acoustic event. The disclosed method and system are thereby configured to detect acoustic events near or within the selected geographical area.

IPC Classes  ?

• G08B 13/18 - Actuation by interference with heat, light, or radiation of shorter wavelengthActuation by intruding sources of heat, light, or radiation of shorter wavelength
• G08B 13/186 - Actuation by interference with heat, light, or radiation of shorter wavelengthActuation by intruding sources of heat, light, or radiation of shorter wavelength using active radiation detection systems by interruption of a radiation beam or barrier using light guides, e.g. optical fibres
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• H04R 23/00 - Transducers other than those covered by groups

Abstract

An acoustic system and method is disclosed for providing spatial and temporal classification of a range of different types of sound producing targets in a geographical area. The system includes an optical signal transmitter arrangement for repeatedly transmitting, at multiple instants, interrogating optical signals into each of one or more optical fibres distributed across the geographical area and forming at least part of an installed fibre-optic communications network. An optical signal detector arrangement receives, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of optical fibres. A processing unit demodulates acoustic data from the optical signals, processes the acoustic data and classifies it in accordance with the target classes or types to generate a plurality of datasets including classification, temporal and location-related data, and a storage unit stores the datasets in parallel with raw acoustic or optical data which is time and location stamped so that it can be retrieved for further processing.

IPC Classes  ?

• G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• G08B 13/16 - Actuation by interference with mechanical vibrations in air or other fluid

Abstract

Described herein is a method and system of distributed acoustic sensing, such as in an urban or metropolitan area involving a dedicated and established fibre optic communications network including a data centre. In general, the disclosed method and system includes the steps of (a) selecting an optical fibre cable installation having a path extending across a selected geographical area, the optical fibre cable installation including a bundle of optical fibres and forming part of a fibre-optic communications network, (b) determining characteristics associated with the optical fibre and/or the selected optical fibre installation, (c) transmitting outgoing light in the optical fibre, (d) receiving reflected light back scattered along the optical fibre, and (e) based on the reflected light and the determined characteristics, generating an alert signal representative of an acoustic event. The disclosed method and system is thereby configured to detect acoustic events near or within the selected geographical area.

IPC Classes  ?

• G08B 13/18 - Actuation by interference with heat, light, or radiation of shorter wavelengthActuation by intruding sources of heat, light, or radiation of shorter wavelength
• G08B 13/186 - Actuation by interference with heat, light, or radiation of shorter wavelengthActuation by intruding sources of heat, light, or radiation of shorter wavelength using active radiation detection systems by interruption of a radiation beam or barrier using light guides, e.g. optical fibres
• G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
• H04R 23/00 - Transducers other than those covered by groups