A machine learning system and method are provided for using fiber-optic Distributed Acoustic Sensor (DAS) and Distributed Temperature Sensor (DTS) data to predict pressure along one or more optical fiber cables. DAS and DTS data are used to train a model to predict pressure based on the DAS and DTS data corresponding to optical signals carried on the fiber cable(s). The trained model is then used to process acquired DAS and DTS data corresponding to optical signals carried on the fiber cable(s) to the predict pressure distributed along the cable(s).

Systems and methods are provided for interrogating a moving acoustic source using radar and processing data using a selection of motion compensation techniques adapted from synthetic aperture radar (SAR) to remove the effects of linear and nonlinear target motion so that the range-Doppler map retains only vibration information in the Doppler dimension. Vibration and sound waveforms can thus be selectively reproduced at specific ranges directly from the radar baseband waveform, without the need for additional complex analysis or audio processing.

A sensor system includes a sensor network comprising at least one optical fiber having one or more optical sensors. At least one of the optical sensors is arranged to sense vibration of an electrical device and to produce a time variation in light output in response to the vibration. A detector generates an electrical time domain signal in response to the time variation in light output. An analyzer acquires a snapshot frequency component signal which comprises one or more time varying signals of frequency components of the time domain signal over a data acquisition time period. The analyzer detects a condition of the electrical device based on the snapshot frequency component signal.

The invention relates to the technical field of mechanical vibration measurement, and discloses a device for accurately measuring mechanical vibration by photon counter. The device comprises a laser, an optical isolator, an adjustable attenuator, an optical fiber coupler, a single-photon counter and an FPGA post-processing module, wherein the laser enters the optical fiber coupler after passing through the optical isolator and the adjustable attenuator, and then enters into a measured object. The transmitted signal of the object to be measured returns to the optical fiber coupler and is output to the single-photon counter; the mechanical vibration of the measured object is analysed and obtained by the FPGA post-processing module connecting with the output terminal of the single-photon counter. This invention solves the problem that weak mechanical vibration is difficult to measure, and realizes microscopic vibration measurement of light-permeable objects such as nanofiber cavities by using a single photon counter.

The invention relates to the technical field of mechanical vibration measurement, and discloses a device for accurately measuring mechanical vibration by photon counter. The device comprises a laser, an optical isolator, an adjustable attenuator, an optical fiber coupler, a single-photon counter and an FPGA post-processing module, wherein the laser enters the optical fiber coupler after passing through the optical isolator and the adjustable attenuator, and then enters into a measured object. The transmitted signal of the object to be measured returns to the optical fiber coupler and is output to the single-photon counter; the mechanical vibration of the measured object is analysed and obtained by the FPGA post-processing module connecting with the output terminal of the single-photon counter. This invention solves the problem that weak mechanical vibration is difficult to measure, and realizes microscopic vibration measurement of light-permeable objects such as nanofiber cavities by using a single photon counter.

The invention relates to a measuring device (10) comprising aa measuring equipment (30) that is configured to be optically interrogated by a measuring instrument (20) by means of first optical signals in a first wavelength range, and a connecting optical fibre (100) for optically connecting aa measuring equipment (30) to a measuring instrument (20). The connecting optical fibre (100) comprises at least a first optical core (111) that is multimode in the first wavelength range and a second optical core (112) that is single-mode in a second wavelength range. The connecting optical fibre (100) comprises at least one first segment of functionalised optical fibre (120) that is such as to exhibit, at the second wavelength, an optical property that varies with an environmental parameter of the connecting optical fibre (100). The invention also relates to a measuring assembly and to an apparatus that comprises such a measuring assembly.

An optical fiber sensing system according to the present disclosure includes: an optical fiber (10) disposed to lie in a plurality of directions and configured to sense sound generated in a monitored area; a reception unit (20) configured to receive, from the optical fiber (10), an optical signal on which the sound is superimposed; and an identification unit (30) configured to analyze distribution of the sound sensed by the optical fiber (10) based on the optical signal and identify a generation position of the sound based on the analyzed distribution of the sound.

A long-distance high-precision optical fiber interference sensing and positioning system includes a sensing light path, a control terminal, a light source module, a front-end optical processing module, a back-end optical processing module, a photoelectric conversion module, a digital signal collection module and a MCU central processing module. The control terminal is provided with a signal processing and positioning device for calculating and positioning sensing signal positioning information. The present system can solve the security problem of an ultra-long-distance optical cable, can send alarm information in a timely manner with regard to an intrusion event by means of vibration positioning, and can also solve the problem of occupation of an optical cable channel, and improves the utilization efficiency of the optical cable by means of wavelength division multiplexing technology.

This application described methods and apparatus for distributed fibre optic sensing. A sensing apparatus has a modulator which modulates radiation from an optical source to interrogate a sensing optical fibre with a first interrogation pulse at a first frequency (F1) and a second interrogation pulse at a second, different, frequency (F2), both different in frequency from a local oscillator (LO). A mixer mixes backscatter from the sensing optical fibre with the local oscillator and supplies the mixed signal to a detector that provides a corresponding digital signal. A processor processes the digital signal (DX, DY) in a first and second processing channels to demodulate respective first and second phase signals based on the respective frequency difference between the first and second frequency and the local oscillator and determines a temporal difference between the first and second phase signals.

A system for monitoring at least one machine including a plurality of magnetic sensors synchronously sensing magnetic fields emitted by at least one machine, along a corresponding plurality of channels and outputting magnetic field emission signals corresponding to the magnetic fields, a signal analyzer receiving at least a portion of the magnetic field emission signals, performing analysis thereof, and providing an output based on the analysis, the output including at least an indication of a condition of the at least one machine, and a control module receiving the indication of the condition and initiating at least one of a repair event on the at least one machine, an adjustment to a maintenance schedule of the at least one machine and an adjustment to an operating parameter of the at least one machine based on the indication, whereby efficacy of the at least one machine is improved.