Phi-OTDR-based phase fading suppression method and system, electronic equipment and medium

Abstract

The invention relates to the field of optical fiber sensing data processing, in particular to a phase fading suppression method and system based on a phi-OTDR (Optical Time Domain Reflectometer), electronic equipment and a medium, and the method comprises the steps: carrying out the signal collection of an optical fiber through the phi-OTDR according to a preset period, and obtaining a digital signal of the optical fiber in each period through photoelectric conversion; calculating a mean value signal of the digital signals of the current period and a plurality of historical periods as a reference signal of the current period; and performing phase fading suppression processing on the digital signal of the current period according to the reference signal of the current period to obtain a digital signal after phase fading suppression processing. The method is used for processing the phi-OTDR signal data, and compared with the prior art, the average value signal of the digital signals of the plurality of historical periods before the current period and the digital signals of the current period is calculated to serve as the reference signal, so that the current and historical inherent phase fading conditions can be effectively combined; therefore, phase fading suppression processing can be effectively carried out on the digital signal based on the reference signal.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical fiber sensing data processing, and more particularly, to a phase fading suppression method and system based on φ-OTDR, an electronic device and a medium. BACKGROUND

[0002] As a high-sensitivity distributed optical fiber vibration sensing technology, the φ-OTDR system can effectively perceive external disturbances by detecting the phase change of backscattered Rayleigh light in the optical fiber, and therefore the φ-OTDR system is widely used in security monitoring scenarios in various fields.

[0003] However, in the existing φ-OTDR system, due to the problems of mismatch between coherence length and pulse width, fiber birefringence effect, phase drift caused by external disturbance, light source frequency drift, etc., the light signal at some positions in the optical fiber produces destructive interference phenomenon, which makes the response amplitude of the light signal detected by the φ-OTDR system low, causes phase fading, and ultimately reduces the detection accuracy of the φ-OTDR system. SUMMARY

[0004] The present application provides a phase fading suppression method and system based on φ-OTDR, an electronic device and a medium, which are used to suppress the phase fading of the light signal and improve the detection accuracy of the φ-OTDR system.

[0005] According to a first aspect of the present application, a phase fading suppression method based on φ-OTDR is provided, the method comprising: acquiring a digital signal corresponding to each period of the optical fiber by performing signal acquisition on the optical fiber by φ-OTDR with a preset period; calculating a mean signal of the digital signals of the current period and a plurality of historical periods, and taking the mean signal as a reference signal of the current period; performing phase fading suppression processing on the digital signal of the current period according to the reference signal of the current period to obtain a digital signal of the current period after phase fading suppression processing.

[0006] Since there are events such as jitter noise and frequency drift of the laser in the φ-OTDR that cause phase fading, and even when setting the reference signal for suppressing the phase fading, the accuracy of the reference signal will be affected by disturbances. Therefore, by using the digital signals of the historical periods in combination with the digital signal of the current period to obtain the reference signal of the current period, the present application can effectively extract the inherent fading condition from the digital signals of the historical periods and the current period, and use the extracted inherent fading condition to obtain a digital signal equivalent to the case where the optical fiber is not subjected to external vibration as the reference signal, so as to effectively realize phase fading suppression processing by using the reference signal.

[0007] Optionally, the digital signal includes segmented signals of several frequency bands; the mean signal includes segmented mean signals of several frequency bands. The calculation of the average signal of the digital signal of the current period and several historical periods includes: The segmented signals of the historical period and the segmented signals of the current period are accumulated according to frequency bands to obtain the accumulated signals of each frequency band. Obtain the total number of periods for the historical period and the current period; Based on the total number of cycles, calculate the segmented mean signal of the accumulated signal for each frequency band.

[0008] By dividing the digital signal into segments of several frequency bands, the processing capability for segments of different frequency bands can be improved. At the same time, parallel processing can be performed based on the segments of each frequency band, effectively improving processing efficiency. Optionally, the segmented signal includes the position signal of each position point on the optical fiber; The step of accumulating the segmented signals of the historical period and the segmented signals of the current period according to frequency bands to obtain the accumulated signals of each frequency band includes: For each frequency band, the position signals of each historical period and the position signals of the current period are accumulated according to the corresponding position points to obtain the accumulated signal of the corresponding frequency band.

[0009] Optionally, the step of performing phase fading suppression processing on the digital signal of the current period based on the reference signal of the current period to obtain the phase fading suppressed digital signal of the current period includes: Based on the segmented mean signal of each frequency band in the current period, the segmented signal of the corresponding frequency band in the current period is vector-rotated to obtain the segmented signal of each frequency band after vector rotation. The segmented signals after rotating the frequency band vectors are spliced ​​together according to the order of the frequency bands to obtain a spliced ​​signal, which is then used as the digital signal after phase fading suppression processing for the current period.

[0010] Vector rotation enables rapid phase fading suppression of the segmented signal based on the segmented mean signal, without changing the frequency of the segmented signal, thus facilitating subsequent reconstruction of the digital signal's frequency through splicing.

[0011] Optionally, before the step of calculating the average signal of the digital signals of the current period and several historical periods, and using the average signal as a reference signal for the current period, the method further includes: The historical periods of the current period are obtained from the periods preceding the current period and the periods most recent to the current period.

[0012] By obtaining the period closest to the current period as the historical period, and calculating the average signal of the digital signals of the historical period and the current period as the reference signal of the current period, the reference signal can be equivalent to the digital signal of the optical fiber under conditions where it has not been subjected to external vibrations in the recent period. Using the reference signal for phase fading suppression processing can better ensure that the phase of the digital signal after phase fading suppression processing in each period remains stable.

[0013] Optionally, the digital signal includes segmented signals across several frequency bands; The step of acquiring digital signals from the optical fiber at preset periods using a φ-OTDR to obtain digital signals for each period of the optical fiber includes: The optical fiber is sampled by a φ-OTDR at the preset period to obtain the digital real signal corresponding to each period of the optical fiber. The digital real signal is divided into segmented real signals of several frequency bands; The segmented real signals of each frequency band are converted into segmented complex signals of the corresponding frequency band, and the segmented complex signals of each frequency band are used as the segmented signals of the corresponding frequency band.

[0014] By acquiring segmented complex signals of several frequency bands corresponding to the digital real signals of each cycle, it is possible to quickly realize the vector rotation based on the corresponding segmented complex signals during the subsequent vector rotation process, thereby improving the efficiency of vector rotation.

[0015] Optionally, dividing the digital real signal into segmented real signals of several frequency bands includes: The digital real signal is convolved through several digital filters with different passband frequency ranges to obtain segmented real signals of several frequency bands; each frequency band of the segmented real signal is matched with the passband frequency range of each digital filter.

[0016] According to a second aspect of this application, a phase fading suppression system based on φ-OTDR is provided, the system comprising: The signal acquisition module is used to acquire signals from the optical fiber at a preset period using a φ-OTDR, thereby obtaining digital signals from each period of the optical fiber. The reference signal acquisition module is used to calculate the average signal of the digital signals of the current period and several historical periods, and use the average signal as the reference signal of the current period. The fading suppression module is used to perform phase fading suppression processing on the digital signal of the current period based on the reference signal of the current period, so as to obtain the phase fading suppressed digital signal of the current period.

[0017] According to a third aspect of this application, an electronic device is provided, comprising: Memory, used to store one or more computer programs; A processor, when the one or more computer programs are executed by the processor, implements the φ-OTDR-based phase fading suppression method described in the first aspect above.

[0018] According to a fourth aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the φ-OTDR-based phase fading suppression method described in the first aspect above.

[0019] Based on any of the above aspects, the phase fading suppression method, system, electronic device, and computer storage medium based on φ-OTDR provided in this application can effectively extract the inherent fading conditions from the historical and current period digital signals by combining the digital signals of the historical period with the digital signals of the current period. The extracted inherent fading conditions are then used to obtain a digital signal equivalent to the condition where the optical fiber is not subjected to external vibration as a reference signal, thereby enabling effective phase fading suppression processing using the reference signal. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic flowchart illustrating the steps of the phase fading suppression method provided in this embodiment.

[0022] Figure 2 This is a schematic diagram of the steps for obtaining the mean signal provided in this embodiment.

[0023] Figure 3 This is a schematic diagram of the functional modules of the phase fading suppression system provided in this embodiment.

[0024] Figure 4 This is a schematic diagram of the device structure of the electronic device provided in this embodiment. Detailed Implementation

[0025] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this application. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product; it is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0026] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] With the continuous development of fiber optic technology, more and more fields are beginning to utilize fiber optics for security monitoring. In the field of fiber optic sensing technology, the φ-OTDR system, as a highly sensitive distributed fiber optic vibration sensing technology, can effectively sense external disturbances by detecting phase changes in the backscattered Rayleigh light in the fiber. Therefore, the φ-OTDR system is widely used in security monitoring scenarios across various fields.

[0029] However, in existing φ-OTDR systems, problems such as mismatch between coherence length and pulse width, fiber birefringence effect, phase drift caused by external disturbances, and light source frequency drift cause destructive interference of optical signals at certain locations in the fiber. This results in low response amplitude of the optical signal detected by the φ-OTDR system, causing phase fading and ultimately reducing the detection accuracy of the φ-OTDR system.

[0030] This embodiment provides a technical solution that can solve the above problems. The specific implementation of this application will be described in detail below with reference to the accompanying drawings.

[0031] like Figure 1As shown, this embodiment provides a phase fading suppression method based on φ-OTDR, which may include the following steps: S1: The optical fiber is sampled by a φ-OTDR at a preset period to obtain the digital signal corresponding to each period of the optical fiber. In this embodiment, a pulsed laser can be emitted into an optical fiber connected to the φ-OTDR via a φ-OTDR. The φ-OTDR receives the Rayleigh scattered light returning from the optical fiber and analyzes and processes the Rayleigh scattered light to obtain the digital signal.

[0032] Understandably, when a pulsed laser is emitted from a φ-OTDR into an optical fiber, the optical signals (Rayleigh scattering light) generated at various points in the fiber sequentially return to the transmitting end. The optical signals returning from the fiber are collected starting from the moment the pulsed laser is emitted. When the optical signal returned from the end of the fiber is collected, it can be understood that the φ-OTDR has collected the optical signals returned from all points in the fiber. The optical signals returned from all points can be analyzed to obtain the state of the fiber. Therefore, when the optical signal returned from the end of the fiber is received, a pulsed laser can be emitted into the fiber again to achieve continuous monitoring of the fiber. Therefore, in this embodiment, the period can be an integer multiple of the interval between two pulsed laser emissions from the φ-OTDR.

[0033] The pulsed laser can be modulated by the laser of the φ-OTDR through an acousto-optic modulator, and the modulated pulsed laser can be amplified and emitted into the optical fiber. The φ-OTDR receives the optical signals returned by the optical fiber in each cycle, converts the Rayleigh scattered light into an electrical signal through a photodetector in the φ-OTDR, and then converts the electrical signal into a response signal of the optical fiber to the pulsed laser through an analog-to-digital converter. The response signal is then processed to finally obtain the digital signal of each cycle.

[0034] In this embodiment, the digital signal may include segmented signals of several frequency bands. It can be understood that the pulsed laser emitted by the laser of the φ-OTDR is a sinusoidal sweep frequency signal. Assuming that its sweep frequency range is fn~fm (fn<fm), the frequency range of the obtained digital signal is also fn~fm. Considering that the digital signals obtained by pulsed lasers of different frequencies in the optical fiber are inconsistent, and in order to improve the processing efficiency of phase fading suppression processing and enable digital signals of different frequency bands to be processed in parallel, in this embodiment, the signal returned by the optical fiber is divided into segmented signals of different frequency bands for processing.

[0035] In one implementation, step S1 may include the following sub-steps: S11: The optical fiber is sampled by φ-OTDR at the preset period to obtain the digital real signal corresponding to each period of the optical fiber; S12: Divide the digital real signal into segmented real signals of several frequency bands; S13: Convert the segmented real signals of each frequency band into segmented complex signals of the corresponding frequency band, and use the segmented complex signals of each frequency band as the segmented signals of the corresponding frequency band.

[0036] Understandably, in step S11, the pulsed laser response signal obtained by the analog-to-digital converter is a digital real signal, where the digital real signal represents a digital signal with real values, and the segmented complex signal represents a segmented signal with complex values. Since the digital real signal has real values, it is difficult to directly obtain its phase information. In order to effectively obtain the corresponding phase information and achieve phase fading suppression processing, the digital real signal needs to be converted into a corresponding complex signal. Therefore, in this embodiment, after obtaining the digital real signal, it is necessary to divide it into segmented real signals for each frequency band, and then convert the segmented real signals of each frequency band into segmented complex signals for the corresponding frequency band.

[0037] Step S12 may include: The digital real signal is convolved through several digital filters with different passband frequency ranges to obtain segmented real signals of several frequency bands; each frequency band of the segmented real signal is matched with the passband frequency range of each digital filter.

[0038] For example, assuming the digital signal includes segmented signals of three frequency bands: fn~f1, f1~f2, and f2~fm (fn<f1, f1<f2, f2<fm), three digital filters can be set. The passband frequency range of the three digital filters can be set to fn~f1, f1~f2, and f2~fm. Then, the digital real signal can be processed by the three digital filters respectively, and segmented real signals of frequency bands fn~f1, f1~f2, and f2~fm can be output respectively.

[0039] In a preferred embodiment, step S13 can use Hilbert transform to convert the segmented real signals of each frequency band into segmented complex signals of the corresponding frequency band; Hilbert transform is a mathematical method that can convert real signals into complex signals, and can quickly realize the conversion between the segmented real signals and the segmented complex signals.

[0040] S2: Calculate the average signal of the digital signals of the current period and several historical periods, and use the average signal as the reference signal of the current period; In this embodiment, the digital signal of the current period can be obtained through a sliding window, and the time window size and step size of the sliding window can be set to match the preset period. It can be understood that the historical period refers to the digital signal extracted through the sliding window prior to the current period.

[0041] In this embodiment, when the digital signal includes segmented signals of several frequency bands, it can be understood that the average signal includes segmented average signals of several frequency bands. Figure 2 As shown, step S2 may include the following sub-steps: S21: The segmented signals of the historical period and the segmented signals of the current period are accumulated according to frequency bands to obtain the accumulated signals of each frequency band. S22: Obtain the total number of periods of the historical period and the current period; S23: Calculate the segmented average signal of the accumulated signal for each frequency band based on the total number of cycles.

[0042] Understandably, this embodiment accumulates the segmented signals of the historical period and the segmented signals of the current period according to frequency bands. The historical period includes the inherent historical phase fading situation of the current period. Therefore, the accumulated signal and the corresponding segmented average signal contain the inherent phase fading situation of the current period and a period of time before the current period. Thus, the inherent fading situation can be used to obtain a digital signal equivalent to the condition where the optical fiber is not subjected to external vibration as a reference signal. Finally, the phase fading suppression processing can be effectively achieved using the reference signal.

[0043] Furthermore, in this embodiment, the segmented signal may include the position signals of each location point on the optical fiber, and step S21 may include the following steps: For each frequency band, the position signals of each historical period and the position signals of the current period are accumulated according to the corresponding position points to obtain the accumulated signal of the corresponding frequency band.

[0044] In a preferred embodiment, the following steps may be performed before step S2: The historical periods of the current period are obtained from the periods preceding the current period and the periods most recent to the current period.

[0045] Understandably, by obtaining the period closest to the current period as the historical period, and calculating the average signal of the digital signals of the historical period and the current period as the reference signal of the current period, the reference signal can be equivalent to the digital signal of the optical fiber under conditions where it has not been subjected to external vibrations in the recent period. This allows the phase of the digital signal after phase fading suppression processing in each period to be better maintained when the reference signal is used for subsequent phase fading suppression processing.

[0046] S3: Perform phase fading suppression processing on the digital signal of the current period based on the reference signal of the current period to obtain the digital signal after phase fading suppression processing of the current period.

[0047] In this embodiment, step S3 may include the following steps: Based on the segmented mean signal of each frequency band in the current period, the segmented signal of the corresponding frequency band in the current period is vector-rotated to obtain the segmented signal after vector rotation of each frequency band; the segmented signals after vector rotation of each frequency band are spliced ​​together according to the order of the frequency bands to obtain the spliced ​​signal, and the spliced ​​signal is used as the digital signal after phase fading suppression processing in the current period.

[0048] Understandably, in this embodiment, in order to better obtain the phase information of the digital signal, the segmented signal can be a segmented complex signal; correspondingly, since the segmented mean signal is obtained from the segmented signal, the segmented mean signal is also a complex signal. The segmented signal and the segmented mean signal can be considered as vectors, so the segmented mean signal can be used as the reference vector of the segmented signal, and the segmented signal can be vector-rotated based on the reference vector to quickly achieve phase fading suppression processing of the segmented signal.

[0049] In one implementation, the step of vector rotation of the segmented signals of the corresponding frequency bands in the current period based on the segmented average signals of each frequency band in the current period may include: For each frequency band of the current period, obtain the conjugate signal of the segmented mean signal; The segmented signals of each frequency band are multiplied by the conjugate signal of the corresponding frequency band to achieve vector rotation of the segmented signals, thereby obtaining the vector-rotated segmented signals of each frequency band.

[0050] Understandably, both the segmented mean signal and the segmented signal are complex signals. Therefore, the vector rotation can be achieved by multiplying the segmented signal with its conjugate signal. The conjugate signal is obtained by inverting the imaginary part of the complex signal while keeping the real part unchanged. By using the conjugate signal to introduce the segmented mean signal as a reference vector into the real axis, and by multiplying the segmented signal with the conjugate signal, the segmented signal is rotated based on the angle of the segmented mean signal. This eliminates the fixed phase difference between the segmented mean signal and the segmented signal, thereby effectively suppressing phase fading.

[0051] In this embodiment, after performing step S3 and obtaining the digital signal after phase fading suppression processing for the current period, in order to obtain the continuous phase situation of the optical fiber changing with time, an unwinding operation is required, which may include: Phase demodulation is performed on the digital signals of the current period and several historical periods to obtain the phase information of the current period and the phase information of each of the historical periods; an initial phase time series is constructed based on the phase information of the current period and the phase information of the historical periods; the initial phase time series is unwound to obtain the target phase time series.

[0052] In one optional implementation, the phase information of the current period and the historical period can be calculated using the phase calculation function atan(Q / P), where Q represents the quadrature component of the digital signal and P represents the co-directional component of the digital signal; further, since the digital signal after phase fading suppression processing is a complex signal, Q represents the imaginary part of the digital signal and P represents the real part of the digital signal.

[0053] Understandably, since the phase range of the phase information calculated by the phase calculation function atan(Q / P) is [-π, π], phase jumps will occur at the endpoints -π and π. Therefore, in order to obtain a stable and continuous phase, it is necessary to further unwind the calculated phase information. Furthermore, in this embodiment, an initial phase time series is constructed based on the phase information of the current period and the phase information of the historical periods. This initial phase time series contains more continuous phase jumps, thereby enabling accurate unwinding and avoiding the influence of "false jumps."

[0054] Understandably, in this embodiment, the digital signal includes the position signals of each position point on the optical fiber. Therefore, unwinding the digital signal can be understood as unwinding the phase of each position point on the optical fiber in time.

[0055] This embodiment also provides a phase fading suppression system based on φ-OTDR, such as Figure 3 As shown, the system may include: The signal acquisition module 11 is used to acquire signals from the optical fiber at a preset period using a φ-OTDR, and to acquire digital signals of each period of the optical fiber. In this embodiment, the signal acquisition module 11 can be used to perform... Figure 1 For a detailed description of the signal acquisition module 11 shown in step S1, please refer to the description of step S1.

[0056] The reference signal acquisition module 12 is used to calculate the average signal of the digital signals of the current period and several historical periods, and use the average signal as the reference signal of the current period. In this embodiment, the reference signal acquisition module 12 can be used to perform... Figure 1 For a detailed description of the reference signal acquisition module 12 shown in step S2, please refer to the description of step S2.

[0057] The fading suppression module 13 is used to perform phase fading suppression processing on the digital signal of the current period based on the reference signal of the current period, so as to obtain the phase fading suppressed digital signal of the current period.

[0058] In this embodiment, the fading suppression module 13 can be used to perform... Figure 1 For a detailed description of the fading suppression module 13 shown in step S3, please refer to the description of step S3.

[0059] This application provides an electronic device with the following structure: Figure 4 As shown.

[0060] The electronic device includes a memory 21, a processor 22, a communication module 23, and an input / output interface 24, etc. Optionally, the memory 21, the processor 22, the communication module 23, and the input / output interface 24 can be connected and communicate with each other through a bus 25.

[0061] The memory 21 is used to store one or more computer programs and to transfer the code of the computer programs to the processor 22; when the one or more computer programs are executed by the processor 22, the phase fading suppression method based on φ-OTDR in this embodiment of the application is implemented.

[0062] Optionally, the electronic device can be connected to a network via communication module 23 to communicate with other devices, such as terminals or servers, to achieve data interaction. The electronic device can be various forms of digital computers, exemplarily such as desktop computers, servers, workbenches, mainframes, or other types of computers. The electronic device can also be various forms of mobile terminals, exemplarily such as smartphones, tablets, wearable devices (such as helmets, glasses, watches, etc.), and other similar mobile terminals.

[0063] Optionally, the electronic device can connect to required input / output devices, such as a keyboard or display device, via the input / output interface 24. The electronic device itself may have a display device, and other display devices can also be connected externally via the input / output interface 24. Optionally, a storage device, such as a hard disk, can also be connected via the input / output interface 24 to store data from the electronic device, read data from the storage device, or store data from the storage device in the memory 21. It is understood that the input / output interface 24 can be a wired interface or a wireless interface. Depending on the actual application scenario, the device connected to the input / output interface 24 can be a component of the electronic device or an external device connected to the electronic device when needed.

[0064] Optionally, the memory 21 may be a volatile memory and / or a non-volatile memory. The volatile memory may be a random access memory, etc., and the non-volatile memory may be a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, or a flash memory, etc.

[0065] Optionally, the computer program stored in the processor 22 can be divided into one or more modules, which are stored in the memory 21 and executed by the processor 22 to perform the method provided in this embodiment. The one or more modules can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program in the electronic device.

[0066] Optionally, the processor 22 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the processor 22 include, but are not limited to, a central processing unit, a graphics processing unit, a digital signal processor, various special-purpose artificial intelligence computing chips, various processors running machine learning model algorithms, and can also be any suitable controller, microcontroller, processor, etc. The processor 22 executes the various methods and processes of this embodiment, exemplarily, such as a phase fading suppression method based on φ-OTDR according to an embodiment of this application.

[0067] Optionally, the bus 25 may include a path for transmitting information. Depending on its function, the bus 25 may be divided into an address bus, a data bus, a control bus, etc.

[0068] In an optional implementation, this application embodiment also provides a computer storage medium storing a computer program thereon, which, when executed by a computer, enables the computer to perform the methods described in the above-described method embodiments. Part or all of the computer program can be loaded and / or installed on the memory 21 of an electronic device. When the computer program is executed by the processor 22, one or more steps of a φ-OTDR-based phase fading suppression method according to this application embodiment can be performed.

[0069] Optionally, the computer-readable storage medium may be a random access memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, etc.

[0070] Obviously, the above embodiments of this application are merely examples for clearly illustrating the technical solution of this application, and are not intended to limit the specific implementation of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of this application should be included within the protection scope of the claims of this application.

Claims

1. A phase fading suppression method based on φ-OTDR, characterized in that, The method includes: The optical fiber is sampled by a φ-OTDR at a preset period to obtain the digital signal corresponding to each period of the optical fiber. Calculate the average signal of the digital signals of the current period and several historical periods, and use the average signal as the reference signal of the current period; The digital signal of the current period is subjected to phase fading suppression processing based on the reference signal of the current period to obtain the digital signal after phase fading suppression processing of the current period.

2. The phase fading suppression method based on φ-OTDR according to claim 1, characterized in that, The digital signal includes segmented signals of several frequency bands; the mean signal includes segmented mean signals of several frequency bands. The calculation of the average signal of the digital signal of the current period and several historical periods includes: The segmented signals of the historical period and the segmented signals of the current period are accumulated according to frequency bands to obtain the accumulated signals of each frequency band. Obtain the total number of periods for the historical period and the current period; Based on the total number of cycles, calculate the segmented mean signal of the accumulated signal for each frequency band.

3. The phase fading suppression method based on φ-OTDR according to claim 2, characterized in that, The segmented signal includes the position signal of each position point on the optical fiber; The step of accumulating the segmented signals of the historical period and the segmented signals of the current period according to frequency bands to obtain the accumulated signals of each frequency band includes: For each frequency band, the position signals of each historical period and the position signals of the current period are accumulated according to the corresponding position points to obtain the accumulated signal of the corresponding frequency band.

4. The phase fading suppression method based on φ-OTDR according to claim 2, characterized in that, The step of performing phase fading suppression processing on the digital signal of the current period based on the reference signal of the current period to obtain the phase fading suppressed digital signal of the current period includes: Based on the segmented mean signal of each frequency band in the current period, the segmented signal of the corresponding frequency band in the current period is vector-rotated to obtain the segmented signal of each frequency band after vector rotation. The segmented signals after rotating the frequency band vectors are spliced ​​together according to the order of the frequency bands to obtain a spliced ​​signal, which is then used as the digital signal after phase fading suppression processing for the current period.

5. The phase fading suppression method based on φ-OTDR according to any one of claims 1-4, characterized in that, Before the step of calculating the average signal of the digital signals of the current period and several historical periods, and using the average signal as a reference signal for the current period, the method further includes: The historical periods of the current period are obtained from the periods preceding the current period and the periods most recent to the current period.

6. The phase fading suppression method based on φ-OTDR according to any one of claims 1-4, characterized in that, The digital signal includes segmented signals across several frequency bands; The step of acquiring signals from the optical fiber using a φ-OTDR at preset periods to obtain the digital signal corresponding to each period of the optical fiber includes: The optical fiber is sampled by a φ-OTDR at the preset period to obtain the digital real signal corresponding to each period of the optical fiber. The digital real signal is divided into segmented real signals of several frequency bands; The segmented real signals of each frequency band are converted into segmented complex signals of the corresponding frequency band, and the segmented complex signals of each frequency band are used as the segmented signals of the corresponding frequency band.

7. The phase fading suppression method based on φ-OTDR according to claim 6, characterized in that, The segmented real signal that divides the digital real signal into several frequency bands includes: The digital real signal is convolved through several digital filters with different passband frequency ranges to obtain segmented real signals of several frequency bands; each frequency band of the segmented real signal is matched with the passband frequency range of each digital filter.

8. A phase fading suppression system based on φ-OTDR, characterized in that, The system includes: The signal acquisition module is used to acquire signals from the optical fiber at a preset period using a φ-OTDR, thereby obtaining digital signals from each period of the optical fiber. The reference signal acquisition module is used to calculate the average signal of the digital signals of the current period and several historical periods, and use the average signal as the reference signal of the current period. The fading suppression module is used to perform phase fading suppression processing on the digital signal of the current period based on the reference signal of the current period, so as to obtain the digital signal after phase fading suppression processing of the current period.

9. An electronic device, characterized in that, include: Memory, used to store one or more computer programs; A processor, when the one or more computer programs are executed by the processor, implements the phase fading suppression method based on φ-OTDR as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the phase fading suppression method based on φ-OTDR as described in any one of claims 1-7.

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