Long-distance OPGW optical cable local strain detection method and system

Abstract

The invention discloses a long-distance OPGW optical cable local strain detection method and system, and the method comprises the steps: adjusting probe light to be continuously output, carrying out the measurement of an OPGW optical cable, obtaining the Brillouin frequency shift of the OPGW optical cable, and converting the Brillouin frequency shift into a strain curve; based on the strain curve and a tower detailed list, obtaining a corresponding relation between the tower and the strain curve, and based on the corresponding relation, determining a strain area of the tower top of the tower; adjusting the probe light into pulse type output, adjusting the width and delay of the pulse type probe light based on the determined strain area, and enabling the pump light and the probe light to interact in a tower top calibration area; and measuring a tower top calibration area based on the pump light and the probe light which interact with each other to obtain local strain data of the tower top.

Description

Technical Field

[0001] The present invention relates to the field of distributed optical fiber measurement technology, and more particularly to a method and system for detecting local strain of a long-distance OPGW optical cable. Background Art

[0002] Fiber-optic composite overhead ground wires (OPGWs) serve as the ground wire for power grids. Their internal optical fibers carry data transmission for the power communication network, making their safe and stable operation crucial to grid security. During service, OPGW cables are susceptible to extreme weather conditions such as icing, strong winds, and lightning strikes, which can cause increased local strain and stress on the internal fiber core, resulting in additional attenuation or interruption. Therefore, strain monitoring of OPGW cables plays a vital role in assessing their operational status, predicting their lifespan, and locating faults. Due to the long distances of OPGW cables, traditional methods for measuring internal core strain often employ Brillouin scattering-based sensing schemes, namely BOTDA or BOTDR. Over long distances, their spatial resolution is typically on the order of tens of meters, making it difficult to accurately analyze local strain. Furthermore, strain measurements on the OPGW cable core are primarily located at the tops of connecting towers and at junction boxes. Strain monitoring along the entire cable would generate excessive redundant data, impacting data storage and analysis.

[0003] Therefore, a technology is needed to realize local strain detection of long-distance OPGW optical cables based on precise delay of detection light pulses. Summary of the Invention

[0004] The technical solution of the present invention provides a long-distance OPGW optical cable local strain detection method and system to solve the problem of how to perform long-distance OPGW optical cable local strain detection based on the precise delay of the detection light pulse.

[0005] In order to solve the above problems, the present invention provides a method for detecting local strain of a long-distance OPGW optical cable, the method comprising:

[0006] Adjust the detection light to a continuous output, measure the OPGW optical cable, obtain the Brillouin frequency shift of the OPGW optical cable, and convert the Brillouin frequency shift into a strain curve;

[0007] Based on the strain curve and the tower list, obtaining a correspondence between the tower and the strain curve, and determining a strain area at the top of the tower based on the correspondence;

[0008] Adjusting the probe light to a pulsed output, adjusting the width and delay of the pulsed probe light based on the determined strain region, and allowing the pump light and the probe light to interact in a calibrated region at the top of the tower;

[0009] Based on the interaction between pump light and probe light, the calibration area of ​​the tower top is measured to obtain the local strain data of the tower top.

[0010] Preferably, adjusting the detection light to a pulsed output comprises:

[0011] Outputting continuous light through a tunable laser, and dividing the continuous light into a first branch and a second branch through a single-mode fiber coupler;

[0012] The continuous light of the first branch is modulated into pulsed light by an acousto-optic modulator, and the electric pulse driving signal of the acousto-optic modulator is generated by a signal source module; the pulsed light with adjusted width and amplitude is input to the first end of the optical fiber to be tested;

[0013] The connecting light of the second branch is modulated into detection light via an electro-optical modulator, and the radio frequency signal of the electro-optical modulator is generated by the signal source module; the modulated detection light is input to the second end of the optical fiber to be tested via a semiconductor optical amplifier and a random polarization scrambler.

[0014] Preferably, a switch control signal is generated by the signal source module, and the output of the detection light is controlled by the switch control signal.

[0015] Preferably, the splitting ratio of the first branch and the second branch is 20:80.

[0016] Preferably, adjusting the width and delay of the pulsed detection light includes:

[0017] A pulse sequence is generated by the signal source module, one tower corresponds to one pulse signal, and the distance between two adjacent continuous towers corresponds to the delay between the two pulse signals.

[0018] According to another aspect of the present invention, the present invention provides a long-distance OPGW optical cable local strain detection system, the system comprising:

[0019] An initialization unit is used to adjust the detection light to a continuous output, measure the OPGW optical cable, obtain the Brillouin frequency shift of the OPGW optical cable, and convert the Brillouin frequency shift into a strain curve;

[0020] a determining unit configured to obtain a correspondence between the tower and the strain curve based on the strain curve and the tower list, and determine a strain area at the top of the tower based on the correspondence;

[0021] an adjustment unit, configured to adjust the probe light into a pulsed output, adjust the width and delay of the pulsed probe light based on the determined strain region, and enable the pump light and the probe light to interact in a calibration region at the top of the tower;

[0022] The result unit is used to measure the calibration area of ​​the tower top based on the interaction between the pump light and the detection light to obtain the local strain data of the tower top.

[0023] Preferably, the adjustment unit is used to adjust the detection light to a pulsed output, and is further used to:

[0024] Outputting continuous light through a tunable laser, and dividing the continuous light into a first branch and a second branch through a single-mode fiber coupler;

[0025] The continuous light of the first branch is modulated into pulsed light by an acousto-optic modulator, and the electric pulse driving signal of the acousto-optic modulator is generated by a signal source module; the pulsed light with adjusted width and amplitude is input to the first end of the optical fiber to be tested;

[0026] The connecting light of the second branch is modulated into detection light via an electro-optical modulator, and the radio frequency signal of the electro-optical modulator is generated by the signal source module; the modulated detection light is input to the second end of the optical fiber to be tested via a semiconductor optical amplifier and a random polarization scrambler.

[0027] Preferably, a switch control signal is generated by the signal source module, and the output of the detection light is controlled by the switch control signal.

[0028] Preferably, the splitting ratio of the first branch and the second branch is 20:80.

[0029] Preferably, the adjustment unit is used to adjust the width and delay of the pulsed detection light, and is also used to:

[0030] A pulse sequence is generated by the signal source module, one tower corresponds to one pulse signal, and the distance between two adjacent continuous towers corresponds to the delay between the two pulse signals.

[0031] The present invention provides a method and system for detecting local strain in long-distance OPGW optical cables. The method comprises: adjusting the probe light output to a continuous mode, measuring the OPGW optical cable, obtaining the Brillouin frequency shift of the OPGW optical cable, and converting the Brillouin frequency shift into a strain curve; obtaining a correspondence between the tower and the strain curve based on the strain curve and a detailed list of towers, and determining the strain region at the top of the tower based on the correspondence; adjusting the probe light output to a pulsed mode, adjusting the width and delay of the pulsed probe light based on the determined strain region, and allowing the pump light and probe light to interact in a calibration region at the tower top; and measuring the calibration region at the tower top based on the interacting pump light and probe light to obtain local strain data at the tower top. The present invention provides a method and system for detecting local strain in long-distance OPGW optical cables based on precise delay of the probe light pulse. By replacing the continuous probe light in the BOTDA system with pulsed probe light and precisely controlling its delay, local strain measurement of the OPGW optical cable splice box and tower top is achieved, thereby achieving higher efficiency in OPGW optical cable strain detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0033] Figure 1 This is a flow chart of a method for detecting local strain of a long-distance OPGW optical cable according to a preferred embodiment of the present invention;

[0034] Figure 2 Schematic diagram of long-distance OPGW optical cable strain detection based on precise delay of detection light pulses according to a preferred embodiment of the present invention;

[0035] Figure 3 Schematic diagram of a long-distance OPGW optical cable strain detection device based on detecting precise delay of optical pulses according to a preferred embodiment of the present invention; and

[0036] Figure 4 The figure is a structural diagram of a long-distance OPGW optical cable local strain detection system according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0037] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to provide a thorough and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments shown in the accompanying drawings is not intended to limit the present invention. In the accompanying drawings, identical elements are denoted by the same reference numerals.

[0038] Unless otherwise specified, the terms used herein (including technical terms) have the meanings commonly understood by those skilled in the art. In addition, it is understood that terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0039] Figure 1 The figure is a flow chart of a method for detecting local strain of a long-distance OPGW optical cable according to a preferred embodiment of the present invention.

[0040] The present invention proposes a long-distance OPGW optical cable local strain detection method based on the precise delay of the detection light pulse. By replacing the continuous detection light in the BOTDA system with pulsed detection light and precisely controlling its delay, the local strain measurement of the OPGW optical cable junction box and the tower top can be realized, thereby achieving higher OPGW optical cable strain detection efficiency.

[0041] The probe light pulse proposed in the present invention replaces the continuous probe light in the traditional BOTDA system with a pulsed probe light. This allows the pump light and probe light to interact only at a localized location in the optical fiber. Precise delay control of the probe light pulse enables strain measurement at the OPGW optical cable junction box and tower top. Because energy is transferred from the pump light to the probe light when the pump light and probe light interact in the optical fiber, excessive energy transfer from the pump light can lead to a decrease in the pump light pulse's signal-to-noise ratio and waveform distortion during long-distance sensing, affecting the sensing distance. The probe light pulse proposed in the present invention replaces the continuous probe light with a pulsed probe light. The pump light interacts with the probe light only at a localized location in the optical fiber. This significantly reduces the energy transferred from the pump light to the probe light, allowing the pump light pulse to travel longer distances in the optical fiber without a significant decrease in the signal-to-noise ratio or waveform distortion. Furthermore, due to the reduced energy transfer of the pump light, the BOTDA system can use narrower pulses for long-distance sensing, resulting in improved spatial resolution and enabling more precise measurement of local strain under long-distance sensing conditions. By pulse modulating and precisely delaying the detection light, the pump light and the detection light can interact only in the key strain measurement areas at the junction box and the top of the tower to generate effective strain data. The scattered signals at other locations are zero and do not need to be processed. This also greatly reduces the pressure on data processing and data storage, and further improves the efficiency of the OPGW optical cable strain detection system.

[0042] like Figure 1 As shown, the present invention provides a method for detecting local strain of a long-distance OPGW optical cable, the method comprising:

[0043] Step 101: Adjust the detection light to a continuous output, measure the OPGW optical cable, obtain the Brillouin frequency shift of the OPGW optical cable, and convert the Brillouin frequency shift into a strain curve;

[0044] The present invention adjusts the detection light into a continuous output. At this time, the system works like a BOTDA system, obtains the Brillouin frequency shift along the OPGW optical cable core in one measurement, and converts the Brillouin frequency shift into strain.

[0045] Step 102: Based on the strain curve and the tower list, obtaining a correspondence between the tower and the strain curve, and determining a strain region at the top of the tower based on the correspondence;

[0046] The present invention obtains the corresponding relationship between the connected towers and the strain curve based on the strain measurement results and the tower detailed list, selects all strain areas near the tower top (including the joint box and the tower top strain area), and marks their corresponding positions.

[0047] Step 103: Adjust the probe light to a pulsed output. Based on the determined strain region, adjust the width and delay of the pulsed probe light, and allow the pump light and the probe light to interact in the calibration region at the top of the tower.

[0048] The present invention adjusts the detection light into a pulsed output, and adjusts the pulse width and delay according to the calibrated strain area near the tower top, so that the pump light and the detection light interact in the calibrated area of ​​the tower top. Figure 2 shown.

[0049] Step 104: Measure the tower top calibration area based on the interacting pump light and probe light to obtain local strain data of the tower top.

[0050] The present invention performs a local strain measurement to obtain local strain data of the tower top, and the strain data of other areas are zero, which are all redundant invalid data.

[0051] Preferably, adjusting the detection light to a pulsed output comprises:

[0052] Outputting continuous light through a tunable laser, and dividing the continuous light into a first branch and a second branch through a single-mode fiber coupler;

[0053] The continuous light of the first branch is modulated into pulsed light by an acousto-optic modulator, and the electrical pulse driving signal of the acousto-optic modulator is generated by a signal source module; the pulsed light with adjusted width and amplitude is input to the first end of the optical fiber to be tested;

[0054] The connecting light of the second branch is modulated into detection light by an electro-optical modulator, and the radio frequency signal of the electro-optical modulator is generated by a signal source module; the modulated output detection light is input to the second end of the optical fiber to be tested after passing through a semiconductor optical amplifier and a random polarization scrambler.

[0055] Preferably, the splitting ratio of the first branch and the second branch is 20:80.

[0056] Preferably, a switch control signal is generated by a signal source module, and the output of the detection light is controlled by the switch control signal.

[0057] Preferably, adjusting the width and delay of the pulsed detection light includes:

[0058] A pulse sequence is generated through the signal source module, one tower corresponds to a pulse signal, and the distance between two adjacent continuous towers corresponds to the delay between the two pulse signals.

[0059] When the present invention uses the BOTDA system with precise time delay of detection light pulse to test the local strain in the key area of ​​the top of the OPGW optical cable tower, the continuous detection light is changed to pulsed detection light, which effectively improves the strain measurement performance of the present invention.

[0060] Combine Figure 3 To illustrate, the tunable laser 1 outputs continuous light with a frequency of v, which is divided into two upper and lower branches through the single-mode fiber coupler 2, with a splitting ratio of 20:80.

[0061] Upper branch: 20% laser power is modulated into pulsed light by acousto-optic modulator 3. The AOM's electrical pulse drive signal is generated by signal source module 10, and both pulse width and amplitude are adjustable. The modulated light pulse passes through erbium-doped fiber amplifier 4 and enters one end of the optical fiber under test 6 through port 1 of a single-mode circulator 5.

[0062] Lower branch: 80% of the laser's output power is modulated into probe light by an electro-optical modulator 7. The RF drive signal for the electro-optical modulator is generated by a signal source module 10 and is a single-frequency signal with an adjustable frequency range of 10 to 13 GHz. The modulated probe light then passes through a semiconductor optical amplifier 8, whose switch control is generated by the signal source module 10, achieving on-off and delay control of the probe light. In step 1, the switch control signal is high, and the probe light is continuously output. After its polarization state is disrupted by a random polarization scrambler 9, it enters the other end of the optical fiber to be measured 6 and interacts with the pump light. The resulting Brillouin backscattered light passes through port 3 of the circulator 5, passes through a fiber grating filter 12 to filter out the lower sideband, and is converted into an electrical signal by a photodetector 13. The electrical signal is collected by an acquisition card 11, thereby achieving Brillouin frequency shift and strain measurement for the entire circuit.

[0063] After the position and width of the connecting towers are calibrated, in step 103, the signal source module 10 is adjusted to generate a corresponding pulse sequence. Each pulse corresponds to a connecting tower, and the delay between two pulses represents the distance between adjacent connecting towers. Using the pulse sequence as a switch control signal, the continuous probe light is converted to a pulsed probe light. After passing through the random polarization scrambler 9, it enters the optical fiber under test and interacts with the pump light to achieve local Brillouin frequency shift and strain measurement at the connecting tower.

[0064] Because continuous probe light fills the fiber under test, its energy is continuously transferred to the probe light as it interacts with the pump light. As the sensing distance increases, the energy at the pump light front decreases, causing distortion in the pump pulse waveform and the measured Brillouin spectrum. This affects the accuracy of Brillouin frequency shift demodulation, and can even render the effective Brillouin frequency shift impossible to demodulate. Furthermore, as the pump light energy is depleted, its signal-to-noise ratio decreases, preventing accurate Brillouin spectrum demodulation and limiting the system's maximum sensing distance. Pulsed probe light reduces the interaction time between the probe light and the pump light, thereby reducing pump light energy consumption. This significantly improves both the system's spatial resolution and sensing distance, enabling longer sensing distances while achieving higher local spatial resolution. Since the strain at the tower top is of interest, the long-distance BOTDA system, based on precise time delay of the probe light pulse, processes and stores strain data only at the tower top, resulting in faster data processing and less data storage space.

[0065] The present invention is based on a long-distance OPGW optical cable local strain detection method based on the precise delay of the detection light pulse, which has the following advantages in OPGW optical cable strain detection:

[0066] Improve the strain sensing distance of OPGW optical cables: By reducing the active area of ​​pump light and detection light, the system sensing distance can be extended;

[0067] Improving the spatial resolution of OPGW cable strain: Since the energy transferred from pump light to detection light is reduced, narrower pump pulses can be used for sensing, improving the spatial resolution of the system.

[0068] Improve data processing speed and reduce strain data volume: Through pulsed detection light and precise pulse delay control, the system can measure only the critical strain areas at the junction box and tower top, effectively improving data processing speed and removing redundant strain data, further enhancing sensing efficiency.

[0069] Figure 4 The figure is a structural diagram of a long-distance OPGW optical cable local strain detection system according to a preferred embodiment of the present invention.

[0070] like Figure 4 As shown, the present invention provides a long-distance OPGW optical cable local strain detection system, the system comprising:

[0071] The initialization unit 401 is used to adjust the detection light to a continuous output, measure the OPGW optical cable, obtain the Brillouin frequency shift of the OPGW optical cable, and convert the Brillouin frequency shift into a strain curve;

[0072] The determining unit 402 is configured to obtain a correspondence between the tower and the strain curve based on the strain curve and the tower list, and determine a strain area at the top of the tower based on the correspondence;

[0073] An adjustment unit 403 is configured to adjust the probe light to a pulsed output, adjust the width and delay of the pulsed probe light based on the determined strain region, and enable the pump light and the probe light to interact in a calibration region at the top of the tower;

[0074] The result unit 404 is configured to measure the tower top calibration area based on the interacting pump light and probe light to obtain local strain data of the tower top.

[0075] Preferably, the adjustment unit 403 is used to adjust the detection light to a pulsed output, and is further used to:

[0076] Outputting continuous light through a tunable laser, and dividing the continuous light into a first branch and a second branch through a single-mode fiber coupler;

[0077] The continuous light of the first branch is modulated into pulsed light by an acousto-optic modulator, and the electrical pulse driving signal of the acousto-optic modulator is generated by a signal source module; the pulsed light with adjusted width and amplitude is input to the first end of the optical fiber to be tested;

[0078] The connecting light of the second branch is modulated into detection light by an electro-optical modulator, and the radio frequency signal of the electro-optical modulator is generated by a signal source module; the modulated output detection light is input to the second end of the optical fiber to be tested after passing through a semiconductor optical amplifier and a random polarization scrambler.

[0079] Preferably, a switch control signal is generated by a signal source module, and the output of the detection light is controlled by the switch control signal.

[0080] Preferably, the splitting ratio of the first branch and the second branch is 20:80.

[0081] Preferably, the adjustment unit 403 is used to adjust the width and delay of the pulsed detection light, and is also used to:

[0082] A pulse sequence is generated through the signal source module, one tower corresponds to a pulse signal, and the distance between two adjacent continuous towers corresponds to the delay between the two pulse signals.

[0083] A long-distance OPGW optical cable local strain detection system according to a preferred embodiment of the present invention corresponds to a long-distance OPGW optical cable local strain detection method according to another preferred embodiment of the present invention, and will not be described in detail here.

[0084] It will be understood by those skilled in the art that the embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention may be implemented in various computer languages, for example, the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0085] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0086] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0087] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0088] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0089] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

[0090] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0091] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / / the [means, component, etc.]" are to be interpreted openly as referring to at least one instance of a means, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily need to be performed in the exact order disclosed, unless explicitly stated otherwise.

Claims

1. A method for detecting local strain of a long-distance OPGW optical cable, the method comprising: Adjust the detection light to a continuous output, measure the OPGW optical cable, obtain the Brillouin frequency shift of the OPGW optical cable, and convert the Brillouin frequency shift into a strain curve; Based on the strain curve and the tower list, obtaining a correspondence between the tower and the strain curve, and determining a strain area at the top of the tower based on the correspondence; Adjusting the probe light to a pulsed output, adjusting the width and delay of the pulsed probe light based on the determined strain region, and allowing the pump light and the probe light to interact in a calibrated region at the top of the tower; Based on the interaction between pump light and probe light, the calibration area of ​​the tower top is measured to obtain the local strain data of the tower top.

2. The method according to claim 1, wherein adjusting the detection light to a pulsed output comprises: Outputting continuous light through a tunable laser, and dividing the continuous light into a first branch and a second branch through a single-mode fiber coupler; The continuous light of the first branch is modulated into pulsed light by an acousto-optic modulator, and the electric pulse driving signal of the acousto-optic modulator is generated by a signal source module; the pulsed light with adjusted width and amplitude is input to the first end of the optical fiber to be tested; The connecting light of the second branch is modulated into detection light via an electro-optical modulator, and the radio frequency signal of the electro-optical modulator is generated by the signal source module; the modulated detection light is input to the second end of the optical fiber to be tested via a semiconductor optical amplifier and a random polarization scrambler. 3 . The method according to claim 2 , wherein the signal source module generates a switch control signal, and the output of the detection light is controlled by the switch control signal.

4. The method according to claim 2, wherein the splitting ratio of the first branch to the second branch is 20:

80.

5. The method according to claim 2, wherein adjusting the width and delay of the pulsed detection light comprises: A pulse sequence is generated by the signal source module, one tower corresponds to one pulse signal, and the distance between two adjacent continuous towers corresponds to the delay between the two pulse signals.

6. A long-distance OPGW optical cable local strain detection system, the system comprising: An initialization unit is used to adjust the detection light to a continuous output, measure the OPGW optical cable, obtain the Brillouin frequency shift of the OPGW optical cable, and convert the Brillouin frequency shift into a strain curve; a determining unit configured to obtain a correspondence between the tower and the strain curve based on the strain curve and the tower list, and determine a strain area at the top of the tower based on the correspondence; an adjustment unit, configured to adjust the probe light into a pulsed output, adjust the width and delay of the pulsed probe light based on the determined strain region, and enable the pump light and the probe light to interact in a calibration region at the top of the tower; The result unit is used to measure the calibration area of ​​the tower top based on the interaction between the pump light and the detection light to obtain the local strain data of the tower top.

7. The system according to claim 6, wherein the adjustment unit is configured to adjust the detection light to a pulsed output, and further configured to: Outputting continuous light through a tunable laser, and dividing the continuous light into a first branch and a second branch through a single-mode fiber coupler; The continuous light of the first branch is modulated into pulsed light by an acousto-optic modulator, and the electric pulse driving signal of the acousto-optic modulator is generated by a signal source module; the pulsed light with adjusted width and amplitude is input to the first end of the optical fiber to be tested; The connecting light of the second branch is modulated into detection light via an electro-optical modulator, and the radio frequency signal of the electro-optical modulator is generated by the signal source module; the modulated detection light is input to the second end of the optical fiber to be tested via a semiconductor optical amplifier and a random polarization scrambler. 8 . The system according to claim 7 , wherein the signal source module generates a switch control signal, and the output of the detection light is controlled by the switch control signal. 9 . The system according to claim 7 , wherein the splitting ratio of the first branch to the second branch is 20:

80.

10. The method according to claim 7, wherein the adjusting unit is used to adjust the width and delay of the pulsed detection light, and is further used to: A pulse sequence is generated by the signal source module, one tower corresponds to one pulse signal, and the distance between two adjacent continuous towers corresponds to the delay between the two pulse signals.

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