Aspects of the present disclosure describe Rayleigh fading mitigation via short pulse coherent distributed acoustic sensing with multi-location beating-term combination. In illustrative configurations, systems, methods, and structures according to the present disclosure employ a two stage modulation arrangement providing short interrogator pulses resulting in a greater number of sensing data points and reduced effective sectional length. The increased number of data points are used to mitigate Rayleigh fading via a spatial combining process, multi-location-beating combining (MLBC) which uses weighted complex-valued DAS beating results from neighboring locations and aligns phase signals of each of the locations, before combining them to produce a final DAS phase measurement. Since Rayleigh scattering is a random statistic, the MLBC process allows capture of different statics from neighboring locations with correlated vibration/acoustic signal. The combined DAS results minimize a total Rayleigh fade, in both dynamic fading and static fading scenarios.

A method for producing a glass furnace, including a refractory portion, a waveguide with a measurement portion extending into the refractory portion and an interrogator connected to an input of the waveguide to inject an interrogation signal. The measurement portion incorporating a sensor to send a response signal to the interrogator in response to the injection. The interrogator analyzing the response signal and sending a message. Arranging, inside a mold, a temporary part configured to leave space for a compartment for the measurement portion. Preparing a starting feedstock and introducing the starting feedstock into the mold such that the part is embedded therein to obtain a preform. Hardening the preform to form the refractory portion. Removing the temporary part to make the compartment. Assembling the refractory portion with other constituent elements and introducing the measurement portion into the compartment and connecting the interrogator to the input of the waveguide.

A fiber Bragg grating (FBG) security component for single-party and multi-party monitoring is provided. The security component includes an optical fiber having a plurality of Bragg gratings. The Bragg gratings provide a spectral response that is randomized based on the manufacture of the security component. For single-party use, the spectral response provides a reproducible spectral signature when interrogated with an optical signal. For multi-party use, each party applies a known optical interrogation signal to the security component and applies an external stress known only to the respective monitoring party. The resulting shift in the spectral signature is unique to each monitoring party, making it extremely difficult to successfully counterfeit the security component's response for all such parties.

A medical device that includes a carrier member, one or more operative components disposed in the carrier member, an optical fiber at least partly disposed in the carrier member, and at least one fiber Bragg grating (FBG) sensor array associated with the optical fiber and disposed in the carrier member. The carrier member includes an insertion end and side walls that contact the subject's body during positioning of the carrier member in the subject's body. The at least one FBG sensor array measures contact forces at one or both of the insertion end and along the side walls of the carrier member during positioning of the carrier member in the subject's body. A multi-core optical fiber configured for use in a medical device for positioning in a subject's body is also provided. A system and method for guiding positioning of a medical device in a subject's body is also provided.

A utility pole degradation detection system according to the present disclosure includes: a sensing optical fiber (10) laid on a plurality of utility poles (30); a receiving unit (201) that receives vibration information detected by the sensing optical fiber (10); an identifying unit (202) that identifies a natural frequency of each of the plurality of utility poles (30) on the basis of the vibration information; and an analyzing unit (203) that analyzes a degradation state of at least one utility pole (30) among the plurality of utility poles (30) on the basis of a natural frequency of each of the plurality of utility poles (30).

Systems, and methods for automatically identifying an underground optical fiber cable length from DFOS systems in real time and pair it with GPS coordinates that advantageously eliminate the need for in-field inspection/work by service personnel to make such real-time distance/location determinations. As such, inefficient, error-prone and labor-intensive prior art methods are rendered obsolete. Operationally, our method disclosure involves driving vehicles including GPS to generate traffic patterns and automatically mapping traffic trajectory signals from a deployed buried fiber optic cable to locate geographic location(s) of the buried fiber optic cable. Traffic patterns are automatically recognized; slack in the fiber optic cable is accounted for; location of traffic lights and other traffic control devices/structures may be determined; and turns in the fiber optic cable may likewise be determined.

Systems, and methods for monitoring galloping of overhead transmission lines using distributed fiber optic sensing (DFOS) in combination with frequency domain decomposition (FDD) (frequency domain) algorithms/methods. A DFOS interrogator/analyzer is used to collect real-time data for pre-processing. The pre-processed data is further processed by processing algorithms, which provide results to a graphical user interface or other reporting mechanisms that provide real-time monitoring, alarming, and reporting of the galloping status of the overhead transmission lines.

A distributed optical fibre sensor is described which is arranged to measure one or more parameters as functions of position along a sensing optical fibre that extends along a path through an environment. The sensor includes a first probe light source arranged to generate pulses of first probe light in one or more first wavelength bands, a second probe light source arranged to generate pulses of second probe light in one or more second wavelength bands separate from said first wavelength bands, a wavelength division multiplexer arranged to launch the first probe light pulses and the second probe light pulses into the sensing optical fibre for backscatter within the sensing optical fibre, and a receiver arranged to receive and separately detect both Raman shifted components of the backscattered probe light, and coherent Rayleigh backscattered components of the second probe light.

Systems, and methods for automatically identifying individual fibers within an optical fiber cable that are experiencing some form of significant signal impairment such as a fiber cut. Operationally, distributed fiber optic sensing (DFOS) systems are used to detect reflected signals along the length of the affected fiber(s) and a determination of affected fiber(s) is made from changes in reflection characteristics.

A system for interrogating sensors in a fiber optical sensor network includes groups of sensors. The sensors in one group operate at different wavelengths, and the sensors of other groups may have overlapping wavelengths. A light source generates a broadband light signal, input and output means for guides the broadband light to the fiber optical sensor network for illuminating the sensors and for coupling the light signal coming from the sensors of the fiber optical sensor network to the detection system, and a detection system detects the received light signal, during a detection integration time. The system is arranged for selecting pre-dominantly the received light coming from the different sensors of a selected group of sensors using a code-division multiplexing technique and simultaneously detecting sensors of the selected group of sensors using a wavelength-division multiplexing technique.