Optical time domain reflectometer ghosting recognition method and system and computer readable storage medium

Abstract

The invention relates to the technical field of optical fiber measurement, in particular to an optical time domain reflectometer ghosting recognition method and system and a computer readable storage medium, and the method comprises the steps: extracting first position information of an actual reflection peak in an OTDR curve; performing pulse transmission path simulation to obtain second position information of a simulated ghosting peak; and judging whether the deviation between the first position information and the second position information is smaller than a threshold value or not, and if so, judging that the actual reflection peak is a ghosting reflection peak. According to the recognition method provided by the invention, the paths possibly formed by all ghosting events can be traversed through recursion of the pulse transmission paths, and in the recursion process, the total loss of the pulse transmission paths is calculated, the recursion frequency is limited, and the shortest path regression is adopted, so that invalid pulse transmission paths can be further eliminated, and the recognition efficiency is improved. And the identification efficiency is improved. Meanwhile, a Pearson's correlation coefficient analysis method is adopted, so that the ghosting recognition accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber measurement, and particularly relates to a method and system for identifying ghosts in an optical time domain reflectometer and a computer-readable storage medium. Background Art

[0002] An optical time domain reflectometer (OTDR) is a tool that measures the loss of an optical fiber link by transmitting sensing pulses into the optical fiber and detecting the Rayleigh scattering signals of the pulses. By analyzing the attenuation and spikes in the OTDR curve, loss and reflection events in the optical fiber can be located. However, "ghost" signals sometimes appear in the OTDR curve. As Figure 1 shown, the generation of "ghosts" is because there are two or more strong reflection points in the optical fiber, and the sensing pulses are reflected back and forth multiple times between the multiple reflection points.

[0003] "Ghost" events can easily lead to misjudgment in OTDR event identification. Therefore, it is necessary to identify "ghosts" in the OTDR curve. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the above technologies to some extent, and for this purpose, a method for identifying ghosts in an optical time domain reflectometer is proposed, including:

[0005] Extracting the first position information of the actual reflection peak in the OTDR curve;

[0006] Performing pulse transmission path simulation to obtain the second position information of the simulated ghost peak;

[0007] Judging whether the deviation between the first position information and the second position information is less than a threshold value. If so, determining that the actual reflection peak is a ghost reflection peak.

[0008] Further, the method for identifying ghosts in the optical time domain reflectometer further includes:

[0009] Obtaining the number and position of loss events in the OTDR curve;

[0010] If the number of loss events is greater than a threshold value, the loss magnitude is greater than a threshold value, and the positions of the loss events are in a multiple relationship, determining that the first loss event is an end event and the remaining loss events are ghost events.

[0011] Further, the deviation calculation formula between the first position information and the second position information includes:

[0012] E = ±(a + L·b + SR)

[0013] Among them, E represents the measurement error; a and b are fitting coefficients according to the actual measurement error of the OTDR device; L represents the measurement distance, and SR represents the sampling interval.

[0014] Further, the performing of the pulse transmission path simulation includes:

[0015] It is set that the intermediate reflection points except the starting reflection point and the ending reflection point will reflect and transmit the pulsed light, generating a tree-shaped pulse transmission structure;

[0016] Perform traversal simulation on the tree-shaped pulse transmission structure.

[0017] Further, when performing traversal simulation on the tree-shaped pulse transmission structure, first determine whether there is a reflection peak in the shortest return path of the node. If not, it is determined that there is no ghost reflection peak for the node and its subordinate nodes.

[0018] Further, when performing traversal simulation on the tree-shaped pulse transmission structure, limit the simulated path length based on the path loss; the path loss is calculated based on the optical fiber link loss and the reflection loss.

[0019] Further, the OTDR ghost recognition method further includes:

[0020] Determine whether the similarity between the target reflection peak and the true reflection peak is greater than the threshold. If so, determine that the target reflection peak is a ghost reflection peak.

[0021] Further, measure the similarity between the target reflection peak and the true reflection peak based on the Pearson correlation coefficient; among them, the calculation formula of the Pearson correlation coefficient is:

[0022]

[0023] Among them, ρ X,Y represents the correlation coefficient between X and Y; X represents the OTDR data of the target reflection peak; Y represents the OTDR data of the true reflection peak; cov(X,Y) represents the covariance between X and Y; σ X represents the standard deviation of X; σ Y represents the standard deviation of Y.

[0024] This application also proposes an OTDR ghost recognition system, including:

[0025] An information extraction module, used to extract the first position information of the actual reflection peak in the OTDR curve;

[0026] A path simulation module, which performs pulse transmission path simulation to obtain the second position information of the simulated ghost peak;

[0027] A result determination module, configured to determine whether the deviation between the first position information and the second position information is less than a threshold. If so, it is determined that the actual reflection peak is a ghost reflection peak.

[0028] The present application also provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is executed by a processor, it is at least used to implement the above-mentioned OTDR ghost recognition method.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: The recognition method provided by the present invention can traverse all possible paths formed by "ghost" events by recursively calculating the pulse transmission path. During the recursive process, the total loss of the pulse transmission path is calculated to limit the number of recursions. At the same time, by judging whether a reflection peak is formed when the sensing pulse directly returns to the starting point of the optical fiber during the recursive process, invalid pulse transmission paths can be further excluded, thereby effectively improving the ghost recognition efficiency. For the identified "ghost" reflection peaks, by calculating the similarity between the "ghost" reflection peaks and the corresponding real reflection peaks, the "ghost" reflection peaks with low similarity can be filtered out, improving the ghost recognition accuracy.

[0030] Other features and advantages of the present invention will be described in the following description, and some of them will become obvious from the description, or be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures specifically pointed out in the written description and the drawings. The technical solutions of the present invention will be further described below through the drawings and embodiments. Description of the Drawings

[0031] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0032] Figure 1 It is a schematic diagram of the formation reason of the ghost reflection peak given in the embodiment;

[0033] Figure 2 It is a schematic diagram of the OTDR ghost recognition method given in the embodiment;

[0034] Figure 3 It is an OTDR measurement curve given in the embodiment;

[0035] Figure 4 It is a tree structure diagram of the recursive result of the pulse transmission path given in the embodiment;

[0036] Figure 5 It is a reflection peak curve of a suspected ghost given in the embodiment;

[0037] Figure 6 True reflection peak curve graph given for the embodiment;

[0038] Figure 7 Schematic diagram of the optical time domain reflectometer ghost recognition system given for the embodiment;

[0039] Figure 8 Schematic diagram of the electronic device given for the embodiment;

[0040] Figure 9 Schematic diagram of the computer-readable storage medium given for the embodiment. Detailed implementation manners

[0041] The present invention will be described below with reference to the accompanying drawings. The preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0042] Figure 2 The optical time domain reflectometer ghost recognition method given for the present invention includes:

[0043] Extract the first position information of the actual reflection peak in the OTDR curve;

[0044] Conduct pulse transmission path simulation to obtain the second position information of the simulated ghost peak;

[0045] Judge whether the deviation between the first position information and the second position information is less than the threshold. If so, determine that the actual reflection peak is a ghost reflection peak.

[0046] According to some embodiments of the present application, the OTDR ghost recognition method includes:

[0047] Obtain the OTDR measurement curve from the OTDR measurement device, and extract information such as the position of the reflection event, the reflectivity (reflection power / incident power), and the event loss magnitude therein. Take the fiber starting point as one of the reflection events, its position is 0, and the reflectivity R is calculated from the set fiber refractive index n The event loss magnitude is 0.

[0048] Suppose there are a total of N reflection events. When N≤2, it is determined that there is no "ghost" event among the reflection events, and "ghost" recognition is not required; when N≥3, for all N obtained reflection events, arrange them in ascending order of distance, where event R1 is the fiber starting point, and event R N is the Nth reflection event.

[0049] During OTDR measurement, the sensing pulse is emitted from the fiber starting point and travels forward along the fiber. The sensing pulse transmission path can be recursively processed according to the following rules. When the sensing pulse is at reflection event R n (1≤n≤N), the next reflection event Z passed by the sensing pulse can be expressed as:

[0050]

[0051] According to the above formula, for the optical fiber starting point R1, only the transmitted light of the sensing pulse transmitted from the optical fiber starting point to the second reflection event R2 is considered; for the last reflection point R N , only the reflected light of the sensing pulse reflected from R N to R N-1 is considered; for the reflection event R2 - R N-1 , part of the sensing pulse is transmitted forward along the optical fiber, and part is reflected and transmitted backward along the optical fiber. Therefore, the next reflection event passed through includes R n-1 and R n+1 .

[0052] Similarly, according to the above formula, all possible transmission paths of the sensing pulse can be obtained recursively. Whenever the sensing pulse returns to the optical fiber starting point R1, if the pulse power is strong enough, a spike will be formed in the OTDR curve. When there is only a single reflection in the transmission path of the sensing pulse, the formed spike is a real reflection peak; if there are multiple reflections in the sensing pulse path, the formed spike is a "ghost" reflection peak. By judging the number of reflections in all possible transmission paths of the pulse, the possible positions where the "ghost" may appear can be predicted.

[0053] Finally, if the deviation between the predicted position of the "ghost" reflection peak and the position of the reflection event in the OTDR curve is less than the distance error, it can be determined that the reflection event in the OTDR curve is a "ghost" reflection event, otherwise it is a real reflection event. Since the "ghost" reflection peak is not an actual reflection peak and does not generate strong reflected light, it can be removed from the reflection events.

[0054] Further, the method for identifying "ghost" in an optical time domain reflectometer further includes:

[0055] Obtaining the number and position of the loss events in the OTDR curve;

[0056] If the number of loss events is greater than the threshold, the loss magnitude is greater than the threshold, and the positions of the loss events are in a multiple relationship, it is determined that the first loss event is the end event, and the remaining loss events are "ghost" events.

[0057] According to some embodiments of the present application, the method for identifying "ghost" further includes: when there are multiple large loss events in the OTDR curve and the event positions are in a multiple relationship, it can be directly determined that the first large loss event is the end event, and all subsequent "ghost" events are filtered out.

[0058] Further, the deviation calculation formula for the first position information and the second position information includes:

[0059] E = ±(a + L·b + SR)

[0060] Among them, E represents the measurement error; a and b are fitting coefficients according to the actual measurement error of the OTDR device; L represents the measurement distance, and SR represents the sampling interval.

[0061] According to some embodiments of the present application, the distance error calculation formula based on the empirical formula of the OTDR measurement error with the measurement distance is as follows:

[0062] E = ±(a + L·b + SR)

[0063] Among them, E represents the measurement error; a and b are fitting coefficients according to the actual measurement error of the OTDR device; L represents the measurement distance, and SR represents the sampling interval.

[0064] In this embodiment, if the deviation between the predicted reflection peak position and the reflection event position in the OTDR curve is less than the distance error, it indicates that the predicted reflection peak information (i.e., whether it is a ghost image) can represent the corresponding true reflection peak information.

[0065] According to some other embodiments of the present application, as Figure 3 shown, from the obtained OTDR measurement curve, it can be seen that there are a total of 7 events including the fiber starting point and 6 reflection events. The information such as the positions, reflectivities, and losses extracted from these 7 events is shown in Table 1:

[0066] Table 1

[0067]

[0068]

[0069] Among them, the reflectivity of the fiber starting point is the calculated value of the fiber refractive index, the fiber refractive index is 1.467, and the reflectivity R calculated from the set fiber refractive index is 0.0358. In this embodiment, the empirical formula of the OTDR device measurement error with the measurement distance is:

[0070] E = ±(3 + L×0.002 + 1)

[0071] Among them, E is the measurement error, and L represents the measurement distance.

[0072] Furthermore, perform pulse transmission path simulation, including:

[0073] Set that the intermediate reflection points except the starting reflection point and the ending reflection point will reflect and transmit the pulsed light to generate a tree-shaped pulse transmission structure;

[0074] Perform traversal simulation on the tree-shaped pulse transmission structure.

[0075] According to some embodiments of the present application, for Figure 3All 7 reflection events obtained from the corresponding embodiments are arranged in ascending order of distance. According to the reflection event Z formula, the pulse transmission path is recursively calculated. The recursive result is as follows: Figure 4 As shown by Figure 4 it can be seen that the pulsed light emitted from the starting point of the optical fiber propagates forward along the optical fiber to the reflection point R2. After passing through the reflection point R2, a part of the pulsed light is reflected back to the starting point R1 of the optical fiber, and a part of the pulsed light continues to propagate to R3 after transmission. A part of the pulsed light that returns to the starting point R1 of the optical fiber enters the detector and is detected, forming a reflection peak on the OTDR curve. Another part is reflected by R1 and returns to the optical fiber. Therefore, only the subsequent propagation path of the sensing pulse reflected by R1 needs to be considered during the recursive process. At the same time, a part of the pulsed light that propagates to R3 is reflected, and another part continues to be transmitted. According to the above rules, all transmission paths of the pulsed light can be recursively obtained.

[0076] Furthermore, when traversing and simulating the tree-shaped pulse transmission structure, it is first determined whether there is a reflection peak in the shortest return path of the node. If not, it is determined that there is no ghost reflection peak in this node and its subordinate nodes.

[0077] According to some embodiments of the present application, in order to improve the efficiency of ghost recognition, for each reflection event, it can be first determined whether a reflection peak is formed when the sensing pulse directly returns to the starting point of the optical fiber from this reflection event. Since the optical fiber link loss corresponding to the sensing pulse directly returning to the starting point of the optical fiber is the smallest, if no reflection peak is generated in the OTDR curve when directly returning to the starting point of the optical fiber, the sensing pulse reflected from this reflection point will pass through more reflections when returning to the starting point of the optical fiber through other paths, resulting in an increase in link loss and a smaller received pulse power, and thus the "ghost" phenomenon cannot occur. That is, if there is no reflection peak corresponding to the shortest return path of a certain reflection node, it means that there is no ghost when directly returning through this reflection point. The subordinate branches of this node will undergo more reflections and more optical fiber losses, and the generated reflected pulse energy is lower. Therefore, the ghost calculation can no longer be performed on the subordinate branches of this node, thereby improving the efficiency of ghost recognition.

[0078] Based on the same principle, during the recursive process, the path with smaller loss can be preferentially recursively calculated, so as to identify ghost events in advance and improve the recognition efficiency.

[0079] Taking Figure 4 the traversal simulation of the corresponding tree-shaped pulse transmission structure as an example, whenever the sensing pulse returns to the starting point R1 of the optical fiber, if the pulse power is strong enough, a spike will be formed in the OTDR curve. When there is only a single reflection in the sensing pulse transmission path, the formed spike is a real reflection peak; if there are multiple reflections in the sensing pulse path, the formed spike is a "ghost" reflection peak. In Figure 3Among them, the pulsed light of R1 that returns through the R1→R2→R1 path has only undergone a single reflection during the transmission process. Therefore, the formed reflection peak is the true reflection peak corresponding to R2, which is Event 2 located at 2.317 km in Table 1. The pulsed light of R1 that returns through the R1→R2→R1→R2→R1 path has undergone 3 reflections in total. The generated reflection peak is a ghost reflection peak, and its location can be predicted through the pulse transmission path to be 2.317×4 / 2 = 4.634 km (where 2.317 km is the transmission distance from R1 to R2, and the path passes through 4 times in total. Since the OTDR measures the round-trip path length, the corresponding event location in the measurement result needs to be divided by 2). Therefore, it can be predicted that a "ghost" may appear at 4.634 km. In the actual measurement result, there is a reflection event at 4.625 km, and the measurement error at 4.625 km in this embodiment is 13.25 m. Since the deviation of 9 m between the predicted "ghost" reflection peak position and the reflection event 4 position is less than the measurement error, it is determined that the reflection event 4 is a "ghost" reflection event. Since the "ghost" reflection peak is not an actual reflection peak and does not generate strong reflected light, it is excluded from the reflection events.

[0080] In the above manner, a total of 5 "ghost" paths are identified. R4 - R7 are all "ghost" events, and their paths and corresponding positions are respectively:

[0081] R1→R2→R1→R2→R1, 4.634 km;

[0082] R1→R2→R3→R2→R1→R2→R3→R2→R1, 7.568 km;

[0083] R1→R2→R1→R2→R3→R2→R1, 6.101 km;

[0084] R1→R2→R3→R2→R1→R2→R1, 6.101 km;

[0085] R1→R2→R3→R2→R3→R2→R1, 5.251 km;

[0086] During the transmission process, in order to improve the efficiency of ghost recognition, the loss of the link can be calculated. The reflection losses of R1 - R7 are shown in Table 2:

[0087] Table 2

[0088]

[0089] To improve the efficiency of ghost recognition, for each reflection event, it is first possible to determine whether a reflection peak is formed when the sensing pulse returns directly from this reflection event to the starting point of the optical fiber. For example, in the path of R1→R2→R3→R2→R3→R2→R3, it is possible to preferentially determine whether a reflection peak is formed when directly returning from the last reflection point R3 to the starting point R1 of the optical fiber. Since no reflection peak is formed near the corresponding position of 6.718 km, it is thus possible to no longer consider the case where "ghosts" are formed by the reflection from R3 passing through other paths back to R1.

[0090] Furthermore, when traversing and simulating the tree-shaped pulse transmission structure, the simulated path length is restricted based on the path loss; the path loss is calculated based on the optical fiber link loss and the reflection loss.

[0091] According to some embodiments of the present application, since the sensing pulse undergoes multiple reflections and losses during transmission, resulting in a gradual decrease in pulse power, when it is lower than the detectable power, a "ghost" reflection peak cannot be formed. Therefore, the loss of the pulse transmission path can be calculated, and when the total path loss reaches the threshold, the recursion can be terminated.

[0092] In the calculation of the pulse transmission path loss, the optical fiber link loss and the reflection loss generated by the reflection event should be considered. The reflection loss generated by the sensing pulse after reflection can be expressed as:

[0093] RL n =-10×log10(Reflectivity n )

[0094] where Reflectivity n represents the reflectivity of the reflection point R n , RL n represents the reflection loss calculated for the reflection point R n , with the unit of dB. The total loss of the path is the sum of the optical fiber link loss and the reflection loss of the reflection event. A loss threshold can be set. When the total loss exceeds the threshold, the subsequent transmission path of the pulse can be not considered, reducing the number of recursions.

[0095] Taking R1→R2→R1→R2→R1→R2→R1 in Table 2 as an example, when transmitting to R1→R2→R1→R2→R1, the total loss of the link is 1.8 + 20.3058 + 1.8 + 14.4575 + 1.8 + 20.3058 + 1.8 = 60.2691 dB, which is less than the loss threshold of 75 dB, and the generated pulse can still be detected. When the transmission path is R1→R2→R1→R2→R1→R2→R1, the total path loss is 100.6324 dB, exceeding the loss threshold, and it can be no longer considered.

[0096] Furthermore, the method for recognizing ghosts in an optical time domain reflectometer further includes:

[0097] Determine whether the similarity between the target reflection peak and the true reflection peak is greater than the threshold. If so, determine that the target reflection peak is a ghost reflection peak.

[0098] According to some embodiments of the present application, through the above operations, reflection peaks suspected of being ghosts can be identified, and the corresponding true reflection peaks are the reflection points corresponding to the last reflection of the sensing pulse. Since both the ghost reflection peak and its corresponding true reflection peak are formed by reflection from the same reflection point, they should have a high similarity in terms of the width and pulse shape of the reflection peak. Extract the curve Y in the area around the reflection peak suspected of being a ghost, calculate the similarity between it and the curve X of the corresponding true reflection peak, and then determine whether it is a ghost.

[0099] Further, the similarity between the target reflection peak and the true reflection peak is measured based on the Pearson correlation coefficient; among them, the calculation formula of the Pearson correlation coefficient is:

[0100]

[0101] where ρ X,Y represents the correlation coefficient between X and Y; X represents the OTDR data of the target reflection peak; Y represents the OTDR data of the true reflection peak; cov(X,Y) represents the covariance between X and Y; σ X represents the standard deviation of X; σ Y represents the standard deviation of Y.

[0102] Since the value range of the Pearson correlation coefficient is [-1, 1], the closer it is to 1, the higher the similarity between the two reflection peaks. Therefore, by setting the similarity threshold, ghost reflection peaks with lower similarity can be filtered out, further improving the accuracy of ghost recognition.

[0103] Figure 5 is Figure 4 the shape of the reflection peak suspected of being a ghost at 7.558 km in the corresponding embodiment, Figure 6 is the shape of its corresponding true reflection peak. Taking the highest point of the reflection peak as the center, extract the curve shape within the pulse width range for similarity comparison. The calculated similarity between the reflection peak suspected of being a ghost and the true reflection peak is 0.91, which is greater than the set similarity threshold of 0.8, and it can be determined as a ghost reflection peak. Through this similarity calculation, reflection peaks with reduced similarity can be further filtered out, improving the recognition accuracy of ghost reflection peaks.

[0104] Based on the same technical concept, as Figure 7 shown, the present application also proposes an optical time domain reflectometer ghost recognition system, which includes:

[0105] An information extraction module, configured to extract the first position information of the actual reflection peak in the OTDR curve;

[0106] A path simulation module, which performs pulse transmission path simulation to obtain the second position information of the simulated ghost peak;

[0107] A result determination module, configured to determine whether the deviation between the first position information and the second position information is less than a threshold. If so, it is determined that the actual reflection peak is a ghost reflection peak.

[0108] As Figure 8 shown, the present application provides an electronic device, which includes a memory and a processor. A computer program or instruction is stored in the memory. When the computer program or instruction is executed by the processor, it is at least used to implement the above-mentioned OTDR ghost recognition method.

[0109] As Figure 9 shown, the present application provides a computer-readable storage medium. A computer program or instruction is stored in the computer-readable storage medium. When the computer program or instruction is executed by the processor, it is at least used to implement the above-mentioned OTDR ghost recognition method.

[0110] The present application also provides a computer program product. The computer program product is stored in a computer-readable storage medium. When the computer program product is executed by the processor, it is at least used to implement the above-mentioned OTDR ghost recognition method.

[0111] Obviously, those of ordinary skill in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and modifications.

Claims

1. A method for identifying ghost images of an optical time domain reflectometer, characterized in that: include: Extracting the first position information of the actual reflection peak in the OTDR curve; Perform pulse transmission path simulation to obtain second position information of simulated ghost peak; It is determined whether a deviation between the first position information and the second position information is less than a threshold value, and if so, it is determined that the actual reflection peak is a ghost reflection peak.

2. The method according to claim 1, characterized in that Also includes: Get the number and location of loss events in the OTDR trace; If the number of the loss events is greater than a threshold, the loss size is greater than a threshold, and the positions of the loss events are in a multiple relationship, then the first loss event is determined to be an end event, and the remaining loss events are ghost events.

3. The method according to claim 1, characterized in that The calculation formula for the deviation between the first position information and the second position information includes: E=±(a+L·b+SR) Wherein, E represents the measurement error; a and b are the fitting coefficients based on the actual measurement error of the OTDR device; L represents the measurement distance, and SR represents the sampling interval.

4. The method according to claim 1, characterized in that The pulse transmission path simulation comprises: It is set that all the intermediate reflection points except the starting reflection point and the ending reflection point will reflect and transmit the pulse light, thus generating a tree-shaped pulse transmission structure; A traversal simulation is performed on the tree-shaped pulse transmission structure.

5. The method according to claim 4, characterized in that When traversing and simulating the tree-shaped pulse transmission structure, it is first determined whether the shortest regression path of the node has a reflection peak. If not, it is determined that the node and its subordinate nodes do not have ghost reflection peaks.

6. The method according to claim 4, characterized in that When traversing and simulating the tree-shaped pulse transmission structure, the simulated path length is limited based on the path loss; the path loss is calculated based on the optical fiber link loss and the reflection loss.

7. The method according to claim 1, characterized in that Also includes: It is determined whether the similarity between the target reflection peak and the real reflection peak is greater than a threshold value, and if so, the target reflection peak is determined to be a ghost reflection peak.

8. The method according to claim 7, characterized in that The similarity between the target reflection peak and the real reflection peak is measured based on the Pearson correlation coefficient; wherein the calculation formula of the Pearson correlation coefficient is: Among them, ρ X,Y represents the correlation coefficient between X and Y; X represents the OTDR data of the target reflection peak; Y represents the OTDR data of the real reflection peak; cov(X,Y) represents the covariance of X and Y; σ X represents the standard deviation of X; σ Y represents the standard deviation of Y.

9. An optical time domain reflectometer ghost recognition system, characterized in that: include: An information extraction module, used to extract the actual reflection peak first position information in the OTDR curve; A path simulation module performs pulse transmission path simulation to obtain second position information of simulated ghost peaks; The result determination module is used to determine whether the deviation between the first position information and the second position information is less than a threshold value, and if so, determine that the actual reflection peak is a ghost reflection peak.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program or instruction, and when the computer program or instruction is executed by a processor, it is used to implement at least the method according to any one of claims 1 to 8.

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