226 results about "Optical time-domain reflectometer" patented technology

The invention discloses an optical cable fault positioning method based on an OTDR (Optical Time Domain Reflectometer), and relates to the technical field of optical cable fault positioning. Periodic waveform data of an optical cable is acquired through OTDR equipment, an echo spectrum is generated, a dynamic threshold algorithm is introduced according to the echo spectrum to carry out fault event identification, and a dynamic threshold value is generated; the processing end judges whether a fault point area exists in the echo based on the dynamic threshold value, if yes, the distance between the fault point and the OTDR equipment is calculated through propagation time delay, the spatial position of the fault point is determined, and after multiple fault points are recognized, fault types are classified according to reflection intensity. According to the positioning method, a dynamic threshold algorithm is introduced, so that the system has adaptive capacity to background environment change, the robustness of the system under long-distance, high-loss optical cable or severe noise conditions is remarkably enhanced, and weak reflection fault or hidden fault events neglected by a traditional method can be effectively identified.

The invention discloses an optical cable icing galloping online monitoring system based on a BOTDR, and belongs to the technical field of distributed optical fiber sensing. The system comprises an optical module, a signal processing module and a data processing module, the optical module is used for generating a detection light signal and interacting with a sensing optical fiber to obtain a Brillouin scattering signal, and then the Brillouin scattering signal is converted into an electric signal; the signal processing module is used for performing frequency down-conversion, signal filtering and digital acquisition on the electric signal to obtain multiple groups of Brillouin scattering signal data; the data processing module is used for processing the multiple groups of Brillouin scattering signal data and extracting a Brillouin frequency shift center frequency; temperature and strain distribution along the optical cable is obtained according to the frequency shift, and temperature and strain states are transmitted to a QT upper computer through PCIE for real-time display. According to the invention, high-precision and long-distance optical cable icing galloping monitoring can be realized, reliable early warning and safety guarantee are provided, and technical support is provided for maintenance and management of an electric power system.

The invention relates to the technical field of optical fiber monitoring and maintenance, and discloses an optical fiber monitoring method, device and equipment, a storage medium and a computer program product, and the method comprises the steps: enabling pulse light of a preset period to be coupled into a to-be-detected low-loss optical fiber based on an optical fiber amplifier and a variable optical attenuator, and generating a backward scattering light signal; converting the backward scattering light signal into an electric pulse signal by using a single-photon detector, and counting the electric pulse signal by using a preset period as a period through a synchronous clock to obtain a counting result; adjusting the power of the variable optical attenuator according to a counting result, and drawing a target signal curve of the to-be-measured low-loss optical fiber based on an adjustment result; and analyzing the target signal curve to obtain a monitoring result of the to-be-measured low-loss optical fiber. The power is dynamically adjusted in different measurement sections, and the multi-section measurement results are superposed, so that the dynamic range of the single-photon optical time domain reflectometer is remarkably expanded, and the loss and dead pixels of the low-loss optical fiber can be reflected more comprehensively and accurately.

The invention relates to the technical field of optical signal processing and analysis, and particularly provides a seabed crustal activity monitoring method based on a differential phase sensitive optical time domain reflectometer, which comprises the following steps: carrying out differential processing on an echo optical pulse signal to obtain a first differential echo matrix; and setting a dynamic window constraint to obtain a second differential echo matrix. The second differential echo matrix includes a low rank term, a sparse term, and a noise term. And constructing a global optimization problem according to the second differential echo matrix, and solving a sparse item estimation matrix corresponding to the sparse item. And separating irrelevant activities in the sparse item estimation matrix to obtain a target activity matrix, and then obtaining a monitoring result. According to the method, non-low-rank trend features such as slow-varying interference are converted into low-rank features through differential processing, periodic and regular components in received signals are clearer, periodic events and sudden events can be separated through a low-rank sparse decomposition model, human-related activities are further separated, and the accuracy of the received signals is improved. Accurate monitoring of the sudden movement of the seabed crust is realized.

The invention relates to a phase-sensitive optical time domain reflectometer based on multi-frequency reference switching. Continuous laser generated by a continuous laser is divided into a local path and a detection path through an optical coupler; the local path is input to the polarization coherent receiving module, the detection path is incident to a light intensity modulator driven by the signal generation circuit module, and the light intensity modulator is converted into a multi-frequency pulse laser sequence with intensity modulation; the multi-frequency pulse laser sequence enters the sensing optical fiber to be measured through the optical circulator; generated Rayleigh backscattered light and local continuous laser are subjected to beat frequency coherent receiving in a polarization coherent receiving module through a circulator; and the signal acquisition circuit adopts a demodulation algorithm to compensate phase drift and sensitivity difference of detection pulse demodulation signals with different frequencies so as to realize dynamic strain sensing. Compared with the prior art, the phase drift and the sensitivity difference between the frequencies are extracted to realize the compensation of the interleaved signals, and the method does not depend on the fixed reference frequency, so that the robustness and the adaptability of the system in a complex environment are remarkably enhanced.

The invention relates to the technical field of data processing, and provides a data processing method for testing avionics equipment, which comprises the following steps of: testing a communication optical cable of an aircraft communication system through an optical time domain reflectometer; analyzing the deviation between the loss value of the reflection intensity of the optical signal at each moment and the reflection loss threshold value to obtain the fault probability of the optical cable in the monitoring time period; analyzing the difference between the moment when the optical signal reaches the bending position of the optical cable and the moment corresponding to the peak point, and obtaining the reflection unpredictability of the optical signal in the monitoring time period; combining the light source power difference to obtain an optical cable performance error in the monitoring time period; obtaining the extra loss degree of the optical cable in the monitoring time period by combining the change condition of the temperature data; determining a test result correction coefficient of the monitoring time period; and correcting the reflected signal oscillogram, and testing the communication optical cable. The invention aims to solve the problem that the actual performance judgment of the optical cable is influenced by the fine change interference of various factors in the optical signal propagation process of the communication optical cable.

The invention relates to an electric power communication optical fiber fault monitoring and visualization method and system, and belongs to the technical field of optical fiber communication monitoring, and the method comprises the following steps: carrying out the real-time monitoring of an electric power communication optical fiber through a non-intrusive monitoring system, collecting an optical power signal in real time, and constructing an optical fiber resource database; when the non-intrusive monitoring system detects that optical power attenuation exceeds a preset threshold value, an optical time domain reflectometer OTDR is started to perform intrusive detection on an abnormal optical fiber, and an OTDR echo curve is obtained; extracting a composite feature vector of an OTDR echo curve, and identifying a fault type through a multi-stage fusion algorithm in combination with historical fault record data; according to the OTDR detection point coordinates, the optical path distance and the geographic information data, the position of a fault point is calculated, and the optical fiber topology, the position of the fault point and the fault type of the fault point are displayed in a visual interface. According to the invention, accurate fault identification and quick response are realized, and the operation and maintenance efficiency is improved.

The invention discloses an optical cable early warning method, system and device and a storage medium, and the method comprises the steps: obtaining monitoring data, and predicting a risk event and a risk point according to the monitoring data and a trained cross-modal large model; the monitoring data comprises any one or more of vibration data, image data or audio data; detecting a fault point and a fault event of the optical cable by using an optical time domain reflectometer; and if the risk point is matched with the fault point, evaluating a risk level according to the risk event and the fault event, and performing early warning according to the risk level. The embodiment of the invention can quickly and accurately monitor and early warn the optical cable, and can be widely applied to the technical field of optical cable transmission.

The invention discloses a communication optical cable line fault rapid positioning system, which comprises optical time domain reflectometers and a remote monitoring center, and is characterized in that two optical time domain reflectometers with different optical pulse wavelengths are respectively connected to two ends of a communication optical cable line through wavelength division multiplexers on corresponding sides; the optical time domain reflectometer analyzes a reflected light signal received by the optical time domain reflectometer through a built-in intelligent algorithm, quickly calculates the position of a fault point and judges the type of the fault; the intelligent algorithm comprises a loss positioning algorithm, a reflection peak identification algorithm and a microbend loss analysis algorithm; the loss positioning algorithm is used for detecting the position of a fault point and distinguishing an optical fiber breakpoint and a loss type fault; the reflection peak recognition algorithm is used for detecting a fault point position; the microbend loss analysis algorithm is used for detecting and distinguishing microbend loss and other types of loss; the system has the advantages of being stable in detection system, good in detection effect, rapid in fault positioning and more accurate in detection result, and automatic detection, remote detection and remote monitoring and management of optical cable faults can be conveniently achieved.

The invention relates to a phase-sensitive optical time domain reflectometer based on a parallel frequency division multiplexing sequence. Continuous laser is divided into a local path and a detection path through an optical coupler; the local path is input to the polarization coherent receiving module, the detection path is converted into a pulse laser sequence with intensity modulation through a light intensity modulator driven by a radio frequency signal provided by the signal generation circuit module, and the radio frequency signal is composed of two frequency division multiplexing sequences with difference; the pulse laser sequence enters the sensing link to be measured to generate Rayleigh backscattered light, and the Rayleigh backscattered light and local continuous laser are subjected to beat frequency coherent receiving through a circulator; and the signal acquisition circuit is used for sampling and analyzing the interference signal, and performing frequency domain comparison on an interleaving result of the two frequency division multiplexing pulse sequences to eliminate a harmonic frequency and retain a real strain signal frequency. Compared with the prior art, the non-harmonic strain signal measurement is realized, the high-frequency response performance and the high-precision strain measurement capability are excellent, and meanwhile, the long-distance coverage capability is also realized.

The invention relates to an optical time domain reflectometer and a control method of the optical time domain reflectometer, and relates to the technical field of photoelectricity. The optical time domain reflectometer OTDR comprises a single photon detector, and the OTDR is used for being connected with an optical fiber to be measured; the OTDR is further used for sending a plurality of detection signals to the optical fiber to be detected in sequence and receiving a plurality of detection echo signals from the optical fiber to be detected in sequence, and the detection echo signals are used for indicating the transmission state of the same section of transmission area in the optical fiber to be detected; performing amplitude reduction processing on each detection echo signal at a certain time interval to obtain a processed detection echo signal; the positions, corresponding to the same section of transmission area, of the signal sections subjected to amplitude reduction processing in the different processed detection echo signals are not completely the same; each processed detection echo signal is subjected to photoelectric conversion based on the single-photon detector to obtain a first electric signal, a first OTDR oscillogram is output based on the multiple first electric signals, and the first OTDR oscillogram is used for indicating the transmission state of the same section of transmission area. Therefore, the problem of OTDR curve distortion can be solved.

The invention provides a BOTDR (Brillouin optical time domain reflectometry) system fusing Stokes-anti-Stokes light and a demodulation method, and belongs to the technical field of Brillouin distributed optical fiber sensing. The narrow linewidth laser is used for generating continuous optical signals; the input end of the coupler is connected with the laser, and the output end is connected with the pulse light branch and the local oscillator light branch. The pulsed light branch comprises a semiconductor optical amplifier, a random scrambler, a first erbium-doped optical fiber amplifier and a circulator which are connected in sequence; the local oscillator light branch comprises an electro-optical modulator, and the electro-optical modulator regulates and controls sideband frequency through a microwave module; the second erbium-doped optical fiber amplifier is used for extracting the Stokes light and the anti-Stokes light; the single-mode coupler mixes the double-sideband local oscillator light with the anti-Stokes light and the Stokes light; and the electrical beat frequency signals are acquired, filtered and enveloped and demodulated through an acquisition card. The detection capability of the Brillouin scattering signal is enhanced, the system structure is simplified, and the hardware cost and the maintenance difficulty are reduced.

An Optical Time Domain Reflectometer (OTDR) includes a transmitter configured to transmit first OTDR pulses, at a first pulse period and at a wavelength λ, over a fiber under test; a receiver configured to receive signals from the fiber under test; and circuitry configured to set the first pulse period and to average measurements resulting from the received signals, wherein the OTDR is configured to operate with a second OTDR at another end of the fiber under test for a bidirectional OTDR measurement, wherein the second OTDR uses the same wavelength λ and transmits second OTDR pulses at a second pulse period, different from the first pulse period.

The invention relates to the technical field of data processing, and discloses a gateway service integrated management method and system based on an FTTR demand. The method comprises the following steps: carrying out topology scanning on a test signal of an optical time domain reflectometer to obtain a room-level FTTR topology mapping table, carrying out feature extraction on service traffic of each room according to deep packet inspection to obtain a room function identification tag library, and carrying out attenuation compensation on a corresponding room optical port by an optical power meter to obtain an FTTR link quality evaluation matrix, and bandwidth allocation is carried out through a reinforcement learning algorithm to obtain a room-level QoS strategy configuration set, and building data interaction is carried out based on an MQTT protocol to obtain an FTTR gateway service integrated management scheme. According to the invention, the intelligent level of FTTR network room-level management and the resource allocation efficiency are improved. According to the invention, the real-time performance of optical fiber link quality monitoring and the collaboration of building network management are improved.

The invention relates to the technical field of optical fiber sensing, and provides an event positioning method, system and device based on OTDR data and a medium, and the method comprises the steps: obtaining an OTDR data input condition, and generating adversarial network denoising; slicing the de-noised OTDR data and the variance and differential curve thereof, wherein the length is between one and a plurality of pulse widths; respectively inputting the sliced data into three feature extraction modules, wherein each feature extraction module is a series structure of a convolution layer, a batch normalization layer and an activation layer; combining the output features and inputting the combined output features into a high-efficiency channel attention layer to obtain an initial probability sequence; the initial probability sequence is binarized through a threshold value x, a binary sequence L is formed, and a point with the value being 1 in the binary sequence L represents that an event exists. According to the method, the problem that an OTDR event positioning algorithm is sensitive to a threshold value can be solved.

The invention discloses a positioning system and method applied to an optical cable fault position, relates to the technical field of optical cable fault positioning, and solves the problems that a positioning result has relatively large deviation in a complex environment and the positioning accuracy is high due to the fact that an existing OTDR (Optical Time Domain Reflectometer) fault positioning method cannot directly and accurately convert a test core length into a specific geographic space position. And the requirement of high-precision geographic space positioning is difficult to meet. The method comprises the following steps: acquiring initial data of an optical fiber link, and establishing a spatial model of the optical fiber link based on the initial data; the method comprises the following steps: segmenting a light link to obtain a plurality of optical cable segments; obtaining a logic distance of a fault point in the optical fiber link based on the OTDR; correcting the length of each optical cable line segment to obtain a target line segment length of each optical cable line segment; and calculating the coordinates of the fault point in the optical fiber link based on the target line segment length of each optical cable line segment and the logic distance of the fault point in the optical fiber link. The technical problem is solved.

The invention discloses a communication optical cable searching method, electronic equipment and a computer readable storage medium, and belongs to the technical field of communication. According to the technical scheme, under the condition that preset disturbance stress is applied to a point location of an optical cable to be detected, polarization state information of detection light currently transmitted by a target optical cable is dynamically detected through a Brillouin optical time domain reflectometer correspondingly connected with the target optical cable; and according to the dynamically detected polarization state information, determining whether the to-be-identified optical cable at the to-be-detected optical cable point location is a target optical cable. According to the invention, on the basis that the optical cable is not damaged, the accuracy of searching and positioning the optical cable is improved.

The invention discloses a phi-OTDR (Optical Time Domain Reflectometer) vibration signal classification method based on multi-scale residual convolution and a bidirectional long-short-term memory network, relates to the technical field of phase-sensitive optical time domain reflectometer vibration sensing, and solves the problems of insufficient feature extraction, single model fusion mechanism, poor system real-time performance and the like of an existing phi-OTDR vibration signal classification method. The method is realized through the steps of a multi-scale deep convolutional network, a bidirectional long-short term memory network, a cross attention fusion module, a learnable gating mechanism and the like. A cross attention fusion module is adopted, association between spatial features and time sequence features is dynamically established in a double-path network, feature interaction and information coupling are deepened, and the sensing ability of the model to key information is remarkably improved. Meanwhile, the fusion proportion of the multi-path features is adaptively adjusted according to the actual distribution of the input features, background noise interference is effectively suppressed, and the robustness and discrimination performance of the model are enhanced. Accurate identification and classification of external vibration signals are realized.

The invention discloses a high-speed turn-off gating circuit, device and system for a single-photon detector, and belongs to the field of optical time domain reflectometers. A quenching broadening circuit is used for carrying out delay broadening on signal output of a discrimination circuit to generate a quenching pulse signal; a turn-off gate control pulse signal is generated through an FPGA module, the turn-off gate control pulse signal and the turn-off gate control pulse signal are combined to form a first mixed signal, and the first mixed signal is amplified by a driving circuit and then added to a negative electrode high-voltage bias end of an avalanche diode; the de-noising broadening circuit is used for generating a pulse signal which is synchronous with a quenching pulse but is delayed in phase, the FPGA module is used for generating a de-noising gating signal which is synchronous with a turn-off gating pulse but is delayed in phase, and the two signals are combined and superposed on a screening reference signal of the screening circuit; and the FPGA module is used for controlling and discriminating that a denoising pulse superposed by the reference signal is higher than the amplitude of an overshoot signal coupled in the load signal. According to the invention, false signals coupled to the load by gating can be eliminated, the gating mode does not influence photon response signals, and the response speed is high.

The invention provides a method and a system for quickly classifying unbalanced small sample events of a phi-OTDR (Optical Time Domain Reflectometer) system, aiming at obtaining higher classification accuracy and shorter classification time delay. The method comprises the following steps: firstly, in a data set construction stage, expanding an unbalanced small sample set into a sample set meeting requirements by providing a space correlation noise fusion sample enhancement method, so as to ensure sample requirements in model training; then, in order to solve the problem of signal classification of different time scales, a two-dimensional image construction method of a Gramb angle field of time scale transformation is provided, and rapid classification of non-fixed time scale events is solved by converting signals into two-dimensional images and performing interpolation operation. And finally, in order to reduce the model classification time delay and the requirements on computing resources, a high-precision intrusion signal classification model MobileNet-DAS is provided based on a lightweight network, so that the signal classification resource requirements and the classification time delay are reduced.

The invention provides a phase-sensitive optical time domain reflectometer system and method, and the system comprises a first polarization-maintaining coupler which is used for dividing laser generated by a DC laser, and obtaining first laser and second laser; the optical fiber measurement front-end module is used for processing the random signal through pulse shaping and multi-carrier modulation technologies to generate an electric signal, and sequentially performing modulation, amplification, Rayleigh scattering and amplification on the first laser after the electric signal is generated to obtain amplified Rayleigh backscattered light; the second polarization-maintaining coupler is used for dividing the second laser to obtain third laser and local oscillation light; the delay optical fiber is used for processing the third laser to obtain delay light; the third polarization-maintaining coupler is used for combining the delayed light and the amplified Rayleigh backscattered light to obtain combined light; the receiver is used for processing the combined light and the local oscillation light to obtain multiple paths of target electric signals; and the oscilloscope is used for processing multiple paths of target electric signals through low-pass and high-pass filters and a phase noise compensation algorithm so as to determine power and phase distribution. The system cost can be reduced.

The invention discloses a composite hose structure for fuel gas transmission, and relates to the technical field of fuel gas transmission and distribution equipment, the composite hose structure comprises a dual-mode quick sealing assembly, dual-mode monitoring is formed by an FBG sensor, a phase-sensitive optical time domain reflectometer and a carbon tube composite filament, the FBG sensor can capture fine strain of a reinforced fiber layer in real time, and the phase-sensitive optical time domain reflectometer can capture the fine strain of the reinforced fiber layer in real time; the phase-sensitive optical time domain reflectometer detects and captures stress waves generated by crack propagation in a material through broadband sound waves, early recognition of millimeter-level damage in a pipe is achieved, grids woven by carbon tube composite filaments are utilized, continuity of the grids is monitored in real time through alternating-current impedance measurement, and the detection accuracy of the millimeter-level damage in the pipe is improved. When local grid resistance is increased due to breakage of the reinforced fiber layer, a micro-damage area can be accurately positioned, when leakage occurs, the memory alloy spring receives an electric signal monitored by a dual-mode, then axial thrust is generated to push the outer side of the fluororubber sealing ring, the fluororubber sealing ring expands in the radial direction under the thrust action of the memory alloy spring, and the leakage is prevented. And rapid and effective mechanical hard sealing is realized.

The invention relates to the technical field of optical fiber sensing, in particular to a dual-channel information fusion vibration positioning device and method based on a dual-k method, and aims to improve a traditional single-channel amplitude demodulation phi-OTDR (AD-phi-OTDR) system to obtain a device with a dual-channel phase-sensitive optical time domain reflectometer module. Firstly, vibration signals are collected through a dual-channel amplitude demodulation phi-OTDR system, then the optimal sampling number is designed through the relation between the vibration frequency and the sampling period, the time consumed by system vibration positioning is shortened, the operation efficiency of the system is improved, then vibration positioning is conducted through a dual-k method, and finally vibration is judged through dual-channel information fusion. According to the invention, the authenticity of the signal is improved through dual-channel cross validation. And a dual-channel data fusion mechanism is used for effective discrimination, so that the anti-interference performance of the system is improved, and the reliability of vibration signal discrimination is further improved.

The invention belongs to the field of distributed optical fiber signal vibration event classification, and discloses a perimeter security area abnormal event identification method based on optical fiber signals. An optical fiber vibration event data set is collected through a phase-sensitive optical time domain reflectometer and preprocessed, and a training set is formed; the 1DCNN model is improved; inputting the training sample into the improved 1DCNN deep learning model for training, and obtaining a trained improved 1DCNN model; and abnormal event identification is carried out. The method improves the recognition accuracy of the abnormal events in the perimeter security area, and solves the problems that a traditional feature extraction method for optical fiber signals needs to manually manufacture features, seriously depends on expert knowledge and is weak in generalization ability, and the calculation amount is large in the process that an existing model carries out recognition through the optical fiber signals.

The system comprises a phi-OTDR distributed optical fiber sensing optical path, an AD acquisition module, an FPGA circuit and a host, a Rayleigh scattering light signal is generated through the distributed optical fiber sensing optical path, digital orthogonal demodulation is executed by the FPGA circuit after photoelectric conversion and AD acquisition module digitization, and the Rayleigh scattering light signal is transmitted to the host through the phi-OTDR distributed optical fiber sensing optical path. Extracting phase data; processing the phase data by adopting a Hilbert transform algorithm, and establishing a mapping relation between the phase difference and the vibration amplitude and frequency; the host receives the data and generates a time-position two-dimensional waterfall plot, and the running directions of the double trains are judged by analyzing the homonymy or reversibility of vibration point tracks; and calculating the displacement variation and the time difference of the two trains based on a time sequence analysis algorithm, optimizing speed data in combination with moving average filtering and Kalman filtering, and outputting the real-time positions and speeds of the two trains. According to the invention, accurate monitoring of the running state of the double trains is realized, and the accuracy, real-time performance and reliability of railway safety monitoring are improved.

The invention provides an optical fiber detection method and system for an optical time domain reflectometer, and relates to the technical field of power grids. According to the invention, the multi-wavelength backscattering signal of the optical fiber link to be detected is acquired, preprocessed and converted into the sample to be detected containing the multi-wavelength one-dimensional waveform data and the multi-wavelength two-dimensional diagram data at the same time, so that the sequence characteristic of the light intensity of each wavelength changing along with time is reserved; and spatial features of correlation and structural information between wavelengths can be reflected through data conversion construction, and multi-dimensional and structured representation of optical fiber events is realized. And combined analysis and recognition are carried out by combining a fault recognition model, and a time sequence rule in a one-dimensional waveform and a spatial distribution mode in a two-dimensional diagram are cooperatively mined, so that deep fusion and intelligent analysis of optical fiber fault spatial-temporal characteristics are realized, and the recognition capability of a complex fault mode is improved. The technical problem of low accuracy of optical fiber fault detection with a single wavelength at present is solved, and the accuracy and reliability of optical cable line fault detection are improved.

The invention discloses a phi-OTDR-based user falling optical fiber sensing monitoring method and system, and the method comprises the steps: carrying out the preprocessing of collected original optical fiber vibration signals which comprise a walking signal, a falling signal, a falling signal during walking, and a human static signal, and obtaining a target optical fiber vibration signal; feature extraction is carried out from three dimensions of a time domain, a frequency domain and a time-frequency domain, and primary features are obtained; screening the primary features through orthogonality analysis and difference analysis to obtain first-level features, and screening the first-level features through a genetic algorithm to obtain second-level features; screening the second-level features through a mutual information evaluation function to obtain target features; respectively inputting the target features into a plurality of behavior recognition models to obtain a result whether the user falls down or not, and when a falling-down result is obtained, obtaining falling-down position information of the user from the target optical fiber vibration signal; and triggering alarm information based on the tumble result and the tumble position information, and sending the alarm information to a terminal of a monitoring person of the user.

The invention discloses a strain tower positioning method and system based on a coherent detection type phi-OTDR and a standard deviation, and relates to the technical field of tower positioning. The method comprises the following steps: carrying out vibration monitoring on the whole OPGW optical cable by using a phi-OTDR system to obtain an optical fiber vibration signal; demodulating the optical fiber vibration signal to obtain a phase disturbance signal along the length direction of the optical fiber; fourier transform is carried out on the phase disturbance signal of each spatial position to obtain corresponding spectrum distribution; synthesizing the spectrum distribution of all spatial positions into a two-dimensional spectrum image, and processing the two-dimensional spectrum image by adopting an image enhancement algorithm; for each spatial position, a sliding window is adopted to calculate the spectrum standard deviation of the enhanced two-dimensional spectrum image; and identifying a spectrum distribution abrupt change area based on the spectrum standard deviation so as to position and connect the strain tower. The method has the advantages of no need of additional sensors, no need of field measurement and high automation degree. The method is suitable for tower intelligent identification and state monitoring in various power transmission line environments.

The invention discloses an online optical time domain reflectometer, and relates to the field of optical fiber detection, the online optical time domain reflectometer comprises an optical time domain reflectometer body, the outer wall of the optical time domain reflectometer body is fixedly connected with a wiring board, the outer wall of the wiring board is fixedly connected with an optical fiber connection port, and a network cable interface is embedded in the outer wall of the optical time domain reflectometer body. The optical time domain reflectometer body comprises a shell, a base and an online optical fiber detection mechanism. Received optical signal data are processed and analyzed, information such as attenuation, loss, connection points and fault points in an optical fiber is analyzed by measuring parameters such as signal strength and time delay in real time, data transmission and remote operation are achieved through network connection, and through online OTDR (Optical Time Domain Reflectometer) testing, the data transmission efficiency is improved. A user can know the quality conditions, including attenuation, loss, reflection loss and other parameters, of the whole optical fiber network, the network state is monitored in real time, potential problems are found in time, online optical fiber detection is achieved, and the detection efficiency is improved.

The invention discloses an optical time domain reflectometer based on ring structure modulation and a working method thereof, and relates to the technical field of optics. The optical time domain reflectometer comprises a laser, an optical fiber coupler, a semiconductor optical amplifier, an acoustic optical modulator, an optical isolator, a delay optical fiber, an erbium-doped optical fiber amplifier, a dense wavelength division multiplexer, a circulator, a Raman laser, piezoelectric ceramics, an arbitrary function generator, an arbitrary waveform generator, a polarization controller, a photoelectric balance detector, a data acquisition card, a computer and the like. Multi-frequency modulation is carried out based on an annular structure, the multi-frequency modulation range is only limited by the bandwidth of a detector and the sampling rate of an acquisition card, a pulse sequence is generated through modulation of the optical annular structure, dependence on the bandwidth performance of a microwave signal source and a modulator is reduced, and the bandwidth is improved; and by injecting the Raman light, the sensing distance is also increased, the equipment cost is effectively controlled, and meanwhile, a new scheme is provided for time sequence pulse sequence modulation.