Fading suppression method and system based on phi-otdr, electronic equipment and storage medium
By setting the first and second sampling periods in the φ-OTDR system and using the frequency drift rate to limit frequency drift changes, combined with segmented processing of digital signals and vector rotation, the phase fading problem caused by laser frequency drift is solved, and the detection accuracy is improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QUALSEN (GUANGZHOU) TECH CO LTD
- Filing Date
- 2025-09-23
- Publication Date
- 2026-07-21
Smart Images
Figure CN121140927B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fiber optic sensing technology, and more specifically, to a fading suppression method, system, electronic device, and storage medium based on φ-OTDR. Background Technology
[0002] As a highly sensitive distributed fiber optic vibration sensing technology, the φ-OTDR system can effectively sense external disturbances by detecting the phase change of the backscattered Rayleigh light in the fiber. Therefore, the φ-OTDR system is widely used in security protection and monitoring scenarios in various fields.
[0003] However, in existing φ-OTDR systems, the laser in the φ-OTDR will generate frequency drift, and as time goes by, the frequency drift of the laser will continue to accumulate, causing the signal acquired by the φ-OTDR system to be affected by the frequency drift, resulting in phase fading and ultimately reducing the detection accuracy of the φ-OTDR system. Summary of the Invention
[0004] This invention provides a fading suppression method, system, electronic device, and storage medium based on φ-OTDR, which is used to suppress phase fading of optical signals and improve the detection accuracy of φ-OTDR systems.
[0005] According to a first aspect of this application, a fading suppression method based on φ-OTDR is provided, the method comprising: A first sampling period and a second sampling period are obtained, wherein the first sampling period is determined based on the frequency drift rate of the φ-OTDR, and the second sampling period is composed of the first sampling period as a preset multiple; The optical fiber is sampled using a φ-OTDR at the first sampling period to obtain the digital signal of each first sampling period of the optical fiber. For each second sampling period, the first sampling period in the second sampling period with a preset sequence is used as the reference period for each first sampling period in the second sampling period; The digital signal of the first sampling period is subjected to fading suppression based on the digital signal of the corresponding reference period to obtain the fading-suppressed digital signal of the first sampling period.
[0006] Since the frequency drift rate in a φ-OTDR is fixed, the frequency drift accumulates over time. When it accumulates to a certain level, it affects the phase of the digital signal acquired by the φ-OTDR. Therefore, this invention determines the first sampling period based on the frequency drift rate of the φ-OTDR and the second sampling period based on a preset multiple of the first sampling period. Then, from the second sampling period, the first sampling period with a preset sequence is used as the reference period for each first sampling period in the corresponding second sampling period. This can be understood as the total frequency drift generated by the φ-OTDR between the reference periods in two consecutive second sampling periods being fixed, and the total frequency drift is stable and insignificant compared to the frequency of the pulsed laser emitted by the φ-OTDR. Therefore, the digital signal of the reference period can be used to effectively suppress phase fading of the digital signal in the corresponding first sampling period.
[0007] Optionally, obtaining the first sampling period and the second sampling period includes: The first sampling period is determined based on the frequency drift rate of the φ-OTDR, so that the frequency drift change generated by the φ-OTDR in the first sampling period does not exceed a preset frequency drift threshold. The second sampling period is obtained by multiplying the first sampling period by the preset multiple.
[0008] By setting a frequency drift threshold, the frequency drift variation in the first sampling period can be better limited, thereby effectively limiting the total frequency drift generated between two consecutive reference periods. This makes the total frequency spectrum relatively stable for the frequency of the pulsed laser emitted by the φ-OTDR, thus effectively suppressing phase fading.
[0009] Optionally, the digital signal includes segmented digital signals of several frequency bands; The step of performing fading suppression on the digital signal of the first sampling period based on the digital signal of the corresponding reference period to obtain the fading-suppressed digital signal of the first sampling period includes: The segmented digital signals of each frequency band in the first sampling period are fading suppressed according to the segmented digital signals of the corresponding frequency band in the corresponding reference period to obtain the segmented suppression signals of each frequency band in the first sampling period. The segmented suppression signals of each frequency band in the first sampling period are spliced together according to the order of the frequency bands to obtain the fading-suppressed digital signal of the first sampling period.
[0010] By dividing the digital signal into segmented digital signals of several frequency bands, the processing capability of segmented digital signals of different frequency bands can be improved. At the same time, parallel processing can be performed based on the segmented digital signals of each frequency band, effectively improving the processing efficiency.
[0011] Optionally, the step of performing fading suppression on the segmented digital signals of each frequency band in the first sampling period based on the segmented digital signals of the corresponding frequency bands in the corresponding reference period to obtain segmented suppression signals for each frequency band in the first sampling period includes: The segmented digital signals of each frequency band in the first sampling period are vector-rotated according to the segmented digital signals of the corresponding frequency band in the corresponding reference period, and the segmented digital signals after vector rotation of each frequency band are used as the segmented suppression signals of the corresponding frequency band.
[0012] Vector rotation enables rapid phase fading suppression of the segmented digital signal without altering its frequency.
[0013] Optionally, the digital signal includes segmented digital signals of several frequency bands; The step of acquiring signals from the optical fiber using a φ-OTDR at the first sampling period to obtain digital signals for each first sampling period of the optical fiber includes: The optical fiber is sampled using a φ-OTDR at the first sampling period to obtain the digital real signal of each first sampling 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 segmented digital signals of the corresponding frequency band.
[0014] 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.
[0015] After the step of performing fading suppression on the digital signal of the first sampling period based on the digital signal of the corresponding reference period to obtain the fading-suppressed digital signal of the first sampling period, the method further includes: Phase demodulation is performed on the fading-suppressed digital signal of each first sampling period to obtain the phase information of each first sampling period; An initial phase time series is constructed based on the phase information of the first sampling period of a preset number; The initial phase time series is unwound to obtain the target phase time series.
[0016] According to a second aspect of this application, a fading suppression method system based on φ-OTDR is provided, the system comprising: The sampling period acquisition module is used to acquire a first sampling period and a second sampling period, wherein the first sampling period is determined based on the frequency drift rate of the φ-OTDR, and the second sampling period is composed of the first sampling period at a preset multiple. The signal acquisition module is used to acquire signals from the optical fiber using a φ-OTDR at the first sampling period, and to acquire the digital signals of the optical fiber at each of the first sampling periods. The reference period acquisition module is used to, for each second sampling period, take the first sampling period with a preset sequence position in the second sampling period as the reference period for each first sampling period in the second sampling period; The fading suppression module is used to perform fading suppression on the digital signal of the first sampling period based on the digital signal of the corresponding reference period, so as to obtain the fading-suppressed digital signal of the first sampling 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 fading suppression method based on φ-OTDR 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 fading suppression method described in the first aspect above.
[0019] Based on any of the above aspects, the fading suppression method, system, electronic device, and computer storage medium based on φ-OTDR provided in this application use a preset first sampling period and the frequency drift rate of φ-OTDR to determine a second sampling period, and use the second sampling period to limit the total frequency drift, so that the total frequency drift is relatively stable with respect to the frequency of the pulsed laser emitted by φ-OTDR. In this way, a first sampling period with a preset sequence can be selected from the second sampling period as a reference period for each first sampling period in the corresponding second sampling period, and the first sampling period is phase suppressed according to the corresponding reference period, which can effectively eliminate the phase fading caused by frequency drift. 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 diagram of the steps of the fading suppression method provided in this embodiment.
[0022] Figure 2 This is a schematic diagram of the steps for obtaining the second sampling period provided in this embodiment.
[0023] Figure 3 This is a system architecture diagram of the fading suppression system provided in this embodiment.
[0024] Figure 4 This is a device structure diagram 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] As a highly sensitive distributed fiber optic vibration sensing technology, the φ-OTDR system can effectively sense external disturbances by detecting the phase change of the backscattered Rayleigh light in the fiber. Therefore, the φ-OTDR system is widely used in security protection and monitoring scenarios in various fields.
[0029] However, in existing φ-OTDR systems, the laser in the φ-OTDR will generate frequency drift, and as time goes by, the frequency drift of the laser will continue to accumulate, causing the signal acquired by the φ-OTDR system to be affected by the frequency drift, resulting in 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 1 As shown, this embodiment provides a fading suppression method based on φ-OTDR, which may include the following steps: S1: Obtain the first sampling period and the second sampling period; S2: The optical fiber is sampled by φ-OTDR at the first sampling period to obtain the digital signal of each first sampling 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, and the Rayleigh scattered light returned from the optical fiber can be received by the φ-OTDR. The Rayleigh scattered light can then be analyzed and processed to obtain the digital signal.
[0032] As is understandable, a pulsed laser is emitted from the laser in the φ-OTDR into the optical fiber. The optical signals (Rayleigh scattered light) generated at various points in the fiber return sequentially to the transmitting end. The optical signals returning from the optical fiber are collected starting from the moment the pulsed laser is emitted. When the optical signal returned from the end of the optical fiber is collected, it can be understood that the φ-OTDR has collected the optical signals returned from all points in the optical fiber. The optical signals returned from all points can be analyzed to obtain the state of the optical fiber. Therefore, when the optical signal returned from the end of the optical fiber is received, a pulsed laser can be emitted into the optical fiber again to achieve continuous monitoring of the optical fiber.
[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 signal returned by the optical fiber in each first sampling period, converts the Rayleigh scattered light into an electrical signal through the photodetector in the φ-OTDR, and then converts the electrical signal into the 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 first sampling period.
[0034] In this embodiment, the first sampling period is determined based on the frequency drift rate of the φ-OTDR, and the second sampling period is composed of a preset multiple of the first sampling period.
[0035] In one implementation, such as Figure 2 As shown, step S1 may include the following sub-steps: S11: Determine the first sampling period based on the frequency drift rate of the φ-OTDR, so that the frequency drift change generated by the φ-OTDR in the first sampling period does not exceed a preset frequency drift threshold. S12: Obtain the second sampling period based on the product of the first sampling period and the preset multiple. As is well known, the laser in the φ-OTDR experiences frequency drift during use, specifically during the emission of pulsed laser light. The rate of frequency drift is considered stable and measurable, typically ranging from tens of kHz / s to MHz / s. Therefore, the frequency drift rate of the φ-OTDR can be tested and obtained in advance, and the first sampling period can be determined based on this rate. This limits the amount of frequency drift variation generated in the first sampling period and also limits the total frequency drift variation generated in the second sampling period.
[0036] In this embodiment, by limiting the maximum value of the total frequency drift change generated by the φ-OTDR in the second sampling period, it is ensured that the total frequency drift change generated in the second sampling period is relatively stable compared to the frequency of the pulsed laser emitted by the φ-OTDR and the frequency of the signal returned in the optical fiber. This allows the phase influence of frequency drift on the received signal of the φ-OTDR to be suppressed in the second sampling period.
[0037] Further, in this embodiment, the digital signal may include segmented digital signals of several frequency bands. It is understood that the pulsed laser emitted by the φ-OTDR laser is a sinusoidal swept-frequency signal. Assuming its swept-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 from pulsed lasers of different frequencies in the optical fiber are inconsistent, and also in order to improve the processing efficiency of phase fading suppression and enable parallel processing of digital signals of different frequency bands, in this embodiment, the signal returned by the optical fiber is divided into segmented digital signals of different frequency bands for processing. In one embodiment, step S2 may include the following sub-steps: S21: Acquire the signal from the optical fiber using a φ-OTDR with a first sampling period to obtain the digital real signal of each first sampling period of the optical fiber; S22: Divide the digital real signal into segmented real signals of several frequency bands; S23: 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 segmented digital signals of the corresponding frequency band.
[0038] Understandably, in step S21, the pulsed laser response signal obtained by the analog-to-digital converter is a digital real signal. This digital real signal represents a digital signal with real values, while the segmented complex signal represents a segmented digital signal with complex values. Since the digital real signal has real values, it is difficult to directly obtain its phase information. To effectively obtain the corresponding phase information and achieve phase fading suppression, 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.
[0039] Step S22 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.
[0040] For example, assuming the digital signal includes segmented digital signals in 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 in frequency bands fn~f1, f1~f2, and f2~fm can be output respectively.
[0041] 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.
[0042] S3: For each second sampling period, the first sampling period in the second sampling period with a preset sequence is used as the reference period for each first sampling period in the second sampling period; Wherein, the preset sequence number is the sequence number of the first sampling period set in the second sampling period according to the time order; for example, if each second sampling period contains 100 first sampling periods, the first sampling periods are set with sequence numbers 1-100 according to the time order. If the preset sequence number is 1, the first sampling period with sequence number 1 in each second sampling period can be used as the reference period for each first sampling period in the corresponding second sampling period.
[0043] In this embodiment, the second sampling period is obtained through step S1. As described above, the second sampling period is limited so that the total frequency drift change that occurs in the second sampling period is relatively stable and insignificant compared to the frequency of the pulsed laser emitted by the φ-OTDR and the frequency of the signal returned in the optical fiber.
[0044] Therefore, selecting the first sampling period with a preset sequence from the second sampling period as the reference period for each first sampling period in the corresponding second sampling period means that the time interval between the reference periods of two consecutive second sampling periods is fixed as the second sampling period. That is, the total frequency drift change generated between the reference periods of two consecutive second sampling periods can be considered stable and insignificant compared to the frequency of the pulsed laser emitted by the φ-OTDR and the frequency of the signal returned in the optical fiber. Therefore, the reference signal of the second sampling period can be used to suppress fading in each first sampling period in the second sampling period.
[0045] S4: The digital signal of the first sampling period is subjected to fading suppression according to the digital signal of the corresponding reference period to obtain the fading suppressed digital signal of the first sampling period.
[0046] Understandably, once the reference period of the second sampling period is obtained, the reference period is valid for all the first sampling periods in the second sampling period; conversely, for each first sampling period, fading suppression can be performed on the first sampling period through the reference signal of the second sampling period in which it is located.
[0047] In this embodiment, the digital signal may include segmented digital signals of several frequency bands, so step S4 may include the following sub-steps: The segmented digital signals of each frequency band in the first sampling period are fading suppressed according to the segmented digital signals of the corresponding frequency band in the corresponding reference period to obtain the segmented suppressed signals of each frequency band in the first sampling period; the segmented suppressed signals of each frequency band in the first sampling period are spliced together according to the order of the frequency bands to obtain the fading suppressed digital signal of the first sampling period.
[0048] Understandably, in this embodiment, in order to better obtain the phase information of the digital signal, the segmented digital signal can be a segmented complex signal; therefore, the step of performing fading suppression on the segmented digital signals of each frequency band in the first sampling period according to the segmented digital signals of the corresponding frequency band in the corresponding reference period to obtain the segmented suppression signal of each frequency band in the first sampling period may include: The segmented digital signals of each frequency band in the first sampling period are vector-rotated according to the segmented digital signals of the corresponding frequency band in the corresponding reference period, and the segmented digital signals after vector rotation of each frequency band are used as the segmented suppression signals of the corresponding frequency band.
[0049] In one embodiment, the step of vector-rotating the segmented digital signals of each frequency band in the first sampling period according to the segmented digital signals of the corresponding frequency band in the corresponding reference period may include: For each frequency band of the corresponding reference period, obtain the conjugate signal of the segmented digital signal; The segmented digital signal of each frequency band in the first sampling period is multiplied by the conjugate signal of the corresponding frequency band to obtain the segmented signal after vector rotation of each frequency band.
[0050] Understandably, the segmented digital signal is a segmented complex signal. Therefore, the vector rotation can be achieved by multiplying the segmented signal with the conjugate signal of the reference period's segmented digital 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 digital signal of the reference period as a reference vector into the real axis, and multiplying the segmented digital signal with the conjugate signal, the segmented digital signal is rotated based on the angle of the reference vector. This eliminates the fixed phase difference between the segmented digital signal and the reference vector, thereby effectively suppressing phase fading.
[0051] In this embodiment, after performing step S4 and obtaining the fading-suppressed digital signal of the first sampling 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 fading-suppressed digital signals of each of the first sampling periods to obtain the phase information of each of the first sampling periods; an initial phase time series is constructed based on the phase information of a preset number of the first sampling periods; the initial phase time series is de-wound to obtain the target phase time series.
[0052] In one optional implementation, the phase information of the first sampling 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 fading-suppressed digital signal is a complex signal, Q represents the imaginary part of the digital signal and P represents the real part of the digital signal. It is understood that 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. Further, in this embodiment, an initial phase time sequence is constructed based on the phase information of a preset number of the first sampling periods, so that the initial phase time sequence contains more continuous phase jumps, thereby accurately achieving unwinding and avoiding the influence of "false jumps".
[0053] Understandably, in this embodiment, the digital signal includes the optical signals returned from each location point in the optical fiber. Therefore, unwinding the digital signal can be understood as unwinding the phase of each location point on the optical fiber in time.
[0054] This embodiment also provides a fading suppression system based on φ-OTDR, such as Figure 3 As shown, the system includes: The sampling period acquisition module 11 is used to acquire the first sampling period and the second sampling period; In this embodiment, the sampling period acquisition module 11 can be used to perform... Figure 1 For a detailed description of the sampling period acquisition module 11 shown in step S1, please refer to the description of step S1.
[0055] The signal acquisition module 12 is used to acquire signals from the optical fiber using a φ-OTDR at the first sampling period, and to acquire digital signals of the optical fiber at each of the first sampling periods. In this embodiment, the signal acquisition module 12 can be used to perform... Figure 1 For a detailed description of the signal acquisition module 12 shown in step S2, please refer to the description of step S2.
[0056] The reference period acquisition module 13 is used to, for each second sampling period, take the first sampling period with a preset sequence position in the second sampling period as the reference period for each first sampling period in the second sampling period. In this embodiment, the reference period acquisition module 13 can be used to perform... Figure 1For a detailed description of the reference period acquisition module 13 shown in step S3, please refer to the description of step S3.
[0057] The fading suppression module 14 is used to perform fading suppression on the digital signal of the first sampling period based on the digital signal of the corresponding reference period to obtain the fading-suppressed digital signal of the first sampling period.
[0058] In this embodiment, the fading suppression module 14 can be used to perform... Figure 1 For a detailed description of the fading suppression module 14 shown in step S4, please refer to the description of step S4.
[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 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 φ-OTDR-based fading suppression method 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 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 fading suppression method based on φ-OTDR 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 fading suppression method based on φ-OTDR, characterized in that, The method includes: The first sampling period is determined based on the frequency drift rate of the φ-OTDR, so that the frequency drift change generated by the φ-OTDR in the first sampling period does not exceed a preset frequency drift threshold. The second sampling period is obtained by multiplying the first sampling period by a preset multiple; The optical fiber is sampled using a φ-OTDR at the first sampling period to obtain digital signals for each first sampling period of the optical fiber; the digital signals include segmented digital signals of several frequency bands. For each second sampling period, the first sampling period in the second sampling period with a preset sequence is used as the reference period for each first sampling period in the second sampling period; The segmented digital signals of each frequency band in the first sampling period are vector-rotated according to the segmented digital signals of the corresponding frequency band in the corresponding reference period, and the segmented digital signals after vector rotation of each frequency band are used as the segmented suppression signals of the corresponding frequency band in the first sampling period. The segmented suppression signals of each frequency band in the first sampling period are spliced together according to the order of the frequency bands to obtain the fading-suppressed digital signal of the first sampling period.
2. The fading suppression method based on φ-OTDR according to claim 1, characterized in that, The step of acquiring signals from the optical fiber using a φ-OTDR at the first sampling period to obtain digital signals for each first sampling period of the optical fiber includes: The optical fiber is sampled using a φ-OTDR at the first sampling period to obtain the digital real signal of each first sampling 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 segmented digital signals of the corresponding frequency band.
3. The fading suppression method based on φ-OTDR according to claim 2, 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.
4. The fading suppression method based on φ-OTDR according to any one of claims 1-3, characterized in that, After obtaining the fading-suppressed digital signal for the first sampling period, the method further includes: Phase demodulation is performed on the fading-suppressed digital signal of each first sampling period to obtain the phase information of each first sampling period; An initial phase time series is constructed based on the phase information of the first sampling period of a preset number; The initial phase time series is unwound to obtain the target phase time series.
5. A fading suppression system based on φ-OTDR, characterized in that, The system includes: The sampling period acquisition module is used to determine a first sampling period based on the frequency drift rate of the φ-OTDR, so that the frequency drift change generated by the φ-OTDR in the first sampling period does not exceed a preset frequency drift threshold; and to obtain a second sampling period based on the product of the first sampling period and a preset multiple. The signal acquisition module is used to acquire signals from the optical fiber using a φ-OTDR at the first sampling period, and to acquire digital signals of the optical fiber for each first sampling period; the digital signals include segmented digital signals of several frequency bands. The reference period acquisition module is used to, for each second sampling period, take the first sampling period with a preset sequence position in the second sampling period as the reference period for each first sampling period in the second sampling period; The fading suppression module is used to perform vector rotation on the segmented digital signals of each frequency band in the first sampling period according to the segmented digital signals of the corresponding frequency band in the corresponding reference period, and use the segmented digital signals after vector rotation of each frequency band as the segmented suppression signals of the corresponding frequency band in the first sampling period; and to splice the segmented suppression signals of each frequency band in the first sampling period according to the order of the frequency bands to obtain the fading suppressed digital signal of the first sampling period.
6. The fading suppression system based on φ-OTDR according to claim 5, characterized in that, The step of acquiring signals from the optical fiber using a φ-OTDR at the first sampling period to obtain digital signals for each first sampling period of the optical fiber includes: The optical fiber is sampled using a φ-OTDR at the first sampling period to obtain the digital real signal of each first sampling 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 segmented digital signals of the corresponding frequency band.
7. The fading suppression system 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. The fading suppression system based on φ-OTDR according to any one of claims 5-7, characterized in that, After obtaining the fading-suppressed digital signal of the first sampling period, the process further includes: Phase demodulation is performed on the fading-suppressed digital signal of each first sampling period to obtain the phase information of each first sampling period; An initial phase time series is constructed based on the phase information of the first sampling period of a preset number; The initial phase time series is unwound to obtain the target phase time series.
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 fading suppression method based on φ-OTDR as described in any one of claims 1-4.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute and implement the fading suppression method based on φ-OTDR as described in any one of claims 1-4.