Disclosed are distributed fiber optic sensing arrangements that—in sharp contrast to the prior art—utilize C-OTDR capabilities to detect an optical fiber end point while still maintaining operational DFOS vibration/acoustic signal sensing functions. Advantageously, such operations are performed automatically without requiring a manual confirmation. A change is made in digital signal processing in the C-OTDR operation by bypassing a high-pass-filtering stage when calculating intensity changes such that the DC signal component is preserved and used to differentiate from a “no-fiber” section. It then calculates the no-fiber section's signal level and uses a back-tracking operation to determine the fiber end automatically.

Systems, methods, and structures for efficiently identifying individual fibers located in a deployed cable that advantageously reduces laborious field efforts while reducing service outage time. The systems and methods locate a targeted fiber in a cable (“Cable ID”) and then identify the targeted fiber (“Fiber ID”) by detecting DFOS signal attentions—without cutting the optical fiber. Two distinct determinations may be made namely, Cable ID and Fiber ID. DFOS operation detects vibration signals occurring along a sensor fiber. As implemented, Cable ID is an interactive-machine learning-based algorithm that automatically locates cable position along a sensor fiber route. Fiber ID detects a signal attenuation by bending a group of fibers with bifurcation to pinpoint a targeted individual fiber within a fiber cable.

There is provided a system for determining multiple baselines for detecting events in a conduit. The system comprises an optical fiber interrogator for interrogating optical fiber; and one or more processors communicative with the optical fiber interrogator and memory having stored thereon computer program code configured, when executed by the one or more processors, to cause the one or more processors to perform a method. The method comprises, for each of multiple channels of the conduit, each channel comprising a portion of the conduit: obtaining phase data for the channel, the phase data being obtained by causing the optical fiber interrogator to interrogate optical fiber positioned alongside the conduit; and determining one or more baselines from the phase data. As a result, events in the conduit may be detected with fewer false positives.

Distributed fiber optic sensors formed by covering the fibers with tubing are provided. The tubing including responsive materials formulated or configured to, responsive to exposure to one of a target chemical species and a target radiation particle, change a relative size and generate a localized effect on or in the optical fiber.

Aspects of the present disclosure describe systems methods and structures for avoiding saturation caused phase jump in systems that extract information from the phase of a complex sequence and exhibit an overflow or “spike” in the output of a high-pass filter. Operationally, during phase unwrapping—when an output signal exceeds a supported range—it is adjusted to be back in range by adding N.Math.2π, to a phase where N is negative or positive integer, depending on the direction to be adjusted.

Distributions of a Brillouin frequency shift and a Rayleigh frequency shift in optical fibers set up in a material are measured from scattered waves of pulse laser light entered into the optical fibers, and distributions of pressure, temperature, and strain of the material along the optical fibers at a measurement time point are analyzed using coefficients that are inherent to the set up optical fibers and correlate pressure, temperature, and strain of material with the Brillouin frequency shift and the Rayleigh frequency shift.

A vibration measurement system and relative method to monitor multiphase flows in extraction wells or conduits, by analysis of backscattered multimode fiber light comprising: • a sensing multimode optical fiber; • an optical source, containing a high coherence laser that emits optical pulses to be sent in said sensing fiber; • a photonic lantern with 3 or more single-mode optical fiber ports and one multimode fiber port that is connected to the sensing multimode fiber; • an optical receiver, comprising a number of photodetectors equal to the number of the single-mode optical fiber ports of said photonic lantern minus 1, wherein each photodetector is connected to each of said single-mode ports; • a system for processing output signals from the optical receiver, the optical source being connected to one of the single-mode optical fiber ports and the other single-mode fibers being connected to the optical receiver. A process is also described for reconfiguring an optical reflectometry system already installed at a facility to be monitored.

There is provided a system for determining multiple baselines for detecting events in a conduit. The system comprises an optical fiber interrogator for interrogating optical fiber; and one or more processors communicative with the optical fiber interrogator and memory having stored thereon computer program code configured, when executed by the one or more processors, to cause the one or more processors to perform a method. The method comprises, for each of multiple channels of the conduit, each channel comprising a portion of the conduit: obtaining phase data for the channel, the phase data being obtained by causing the optical fiber interrogator to interrogate optical fiber positioned alongside the conduit; and determining one or more baselines from the phase data. As a result, events in the conduit may be detected with fewer false positives.

A process including the following steps: injecting in an optical fiber a first optical pump at a first optical frequency that evolves in time or not, and a second optical pump at a second optical frequency that evolves in time or not, the first optical frequency and the second optical frequency being different at each given time; a first detection of a first Rayleigh backscattered signal at the first optical frequency from the optical fiber; a second detection, separated from the first detection, of a second Rayleigh backscattered signal at the second optical frequency from the optical fiber; and analyzing the detected first Rayleigh backscattered signal and the detected second Rayleigh backscattered signal.

A system comprises a housing, a light source, a light guide configured to guide a light from the light source. The light guide includes a plurality of detection target configured to provide optical effect on the light in accordance with a bend state of the light guide. A light detector is configured to detect the light emitted from the light guide and provide information of the detected light. A communication unit is configured to transmit wirelessly the information of the detected light. The communication unit is disposed in the housing.