Data correction device, optical pulse tester, optical fiber measurement system, data correction method, and data correction program

Abstract

To provide a data correction device, an optical pulse tester, an optical fiber measurement system, a data correction method and a data correction program for enhancing convenience of a user.SOLUTION: A data correction device 100 includes: an acquisition unit 140 for acquiring measurement data from an optical pulse tester 200 for measuring an event present in an optical fiber to be measured; a display unit 150 for displaying a difference between a known event and a detected event so that a user can confirm the difference; an input unit 110 for receiving an operation input for correcting the detected event from the user; and a correction unit 130 for correcting the detected event based on the operation input received from the user.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a data correction device, a data correction method, and a data correction program for correcting measurement data of an optical fiber measured by an optical pulse tester, as well as an optical pulse tester and an optical fiber measurement system for measuring an optical fiber. [Background technology]

[0002] As described in Patent Document 1, in an optical pulse tester that detects events related to optical fibers, it is known to examine the validity of the detected events. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-53542 A Summary of the Invention [Problem to be solved by the invention]

[0004] Measurement data of events such as optical fiber connection points or fusion points may differ from actual event information. If a user knows the actual event information beforehand, the measurement data of the events is manually corrected. If there are a large number of optical fiber events, the measurement data correction work becomes cumbersome. There is a demand for improving the convenience of the measurement data correction work.

[0005] The present disclosure has been made in consideration of the above-mentioned points, and aims to provide a data correction device, an optical pulse tester, an optical fiber measurement system, a data correction method, and a data correction program that can improve the convenience of correcting measurement data of optical fiber events. [Means for solving the problem]

[0006] A (1) data correction device according to some embodiments includes an acquisition unit that acquires measurement data from an optical pulse tester that measures events present in a measured optical fiber, a display unit that displays a known event and a detected event so that a user can confirm a difference between a known event whose presence in the measured optical fiber is known in advance and a detected event detected from the measurement data, an input unit that receives an operation input from the user to correct the detected event, and a correction unit that corrects the detected event based on the operation input received from the user.

[0007] By displaying the difference between a known event and a detected event, the user can check only the events to be corrected. By being able to check only the events to be corrected, the user can easily and efficiently perform correction operations on the detected events detected from the measurement data. As a result, user convenience is improved.

[0008] In one embodiment (2) of the data correction device described in (1) above, the display unit may display, as the difference, an event among the detected events that is not included in the known events, and display, as the difference, an event among the known events that is not included in the detected events. In this way, it becomes even easier for a user to recognize an event to be corrected. As a result, user convenience is improved.

[0009] In one embodiment (3) of the data correction device described in (2) above, the display unit may include an input data display unit that displays the known events, and a measurement data display unit that displays the detected events. The input data display unit may display an event that is not included in the detected events but is included only in the known events, in association with a blank space in the measurement data display unit. The measurement data display unit may display an event that is not included in the known events but is included only in the detected events, in association with a blank space in the input data display unit. This makes it even easier for the user to recognize events to be corrected. As a result, user convenience is improved.

[0010] In one embodiment (4) of the data correction device described in (3) above, the input data display unit and the measurement data display unit may not display events common to the known events and the detected events. In this way, a user can recognize only events to be corrected that are not common to the known events and the detected events. As a result, user convenience is improved.

[0011] In one embodiment (5) of the data correction device according to any one of (1) to (4) above, the display unit may include a waveform display unit that displays a waveform of the measurement data. When displaying a waveform corresponding to an event to be corrected among the detected events, the waveform display unit may display a range in which a position of the event to be corrected can be set. By displaying the range in which the position of the event can be set, it is possible to prevent a user from erroneously correcting the position of an event or adding an event to an incorrect position.

[0012] (6) In the data correction device according to the above (5) according to one embodiment, the waveform display unit may display a cursor for designating a position of the event to be corrected. The input unit may receive from the user an operation for moving the cursor and an operation for setting the position of the event to be corrected to the position of the cursor. The correction unit may correct the position of the event to be corrected to the position of the cursor. Being able to set the position of the detected event by operating the cursor allows the user to easily perform the correction operation. As a result, user convenience is improved.

[0013] (7) An optical pulse tester according to some embodiments includes the data correction device according to any one of (1) to (6) above.

[0014] According to some embodiments, there is provided an optical fiber measurement system including: the data correction device according to any one of (1) to (6) above; and an optical pulse tester that outputs measurement data to the data correction device.

[0015] A data correction method (9) according to some embodiments includes acquiring measurement data from an optical pulse tester that measures events present in a measured optical fiber, displaying the known events and the detected events so that a user can confirm a difference between a known event whose presence in the measured optical fiber is known in advance and a detected event detected from the measurement data, receiving an operation input from the user to correct the detected event, and correcting the detected event based on the operation input received from the user. Includes.

[0016] (10) A data correction program according to some embodiments causes a processor to acquire measurement data from an optical pulse tester that measures events present in a measured optical fiber, display the known events and the detected events so that a user can confirm a difference between a known event whose presence in the measured optical fiber is known in advance and a detected event detected from the measurement data, receive an operation input from the user to modify the detected event, and modify the detected event based on the operation input received from the user. Effect of the Invention

[0017] The data correction device, optical pulse tester, optical fiber measurement system, data correction method, and data correction program according to the present disclosure improve the convenience of correcting measurement data of optical fiber events. [Brief description of the drawings]

[0018] [Figure 1] 13 is a display screen of measurement data of an optical pulse tester according to a comparative example. [Diagram 2] 13 is an example of a waveform display screen including waveforms of events that were not automatically detected in measurement data of an optical pulse tester. [Diagram 3] 13 is an example of a waveform display screen including the waveform of an event that is automatically erroneously detected in measurement data of an optical pulse tester. [Figure 4] 1 is a block diagram showing an example configuration of an optical fiber measurement system according to an embodiment of the present disclosure. [Diagram 5] 13 is an example of a screen displayed on a display unit. [Figure 6] 1 is a flowchart illustrating an example of a procedure of a data correction method according to an embodiment of the present disclosure. [Figure 7] 10 is a flowchart showing an example of a procedure for automatically correcting measurement data. [Figure 8] FIG. 2 is a diagram illustrating an example of the configuration of an optical fiber to be measured. [Figure 9] 13 is an example of a screen for inputting events of an optical fiber to be measured in a table format. [Figure 10] 13 is an example of a screen for inputting events of an optical fiber to be measured using icons that resemble optical fibers and connection points. [Figure 11] 11 is a table showing an example of automatic detection results of events in an optical fiber to be measured. [Figure 12] 13 is an example of a screen for correcting measurement data. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The present disclosure relates to software or an apparatus for correcting measurement data from an optical time domain reflectometer (OTDR) for measuring the distance of an optical fiber or for measuring events such as a splice point or a break point.

[0020] When measuring optical fiber with an optical pulse tester, the measured optical fiber distance may differ depending on the wavelength of the light being measured. Even when measuring optical fiber of the same length, the measured distance may differ due to differences in refractive index depending on the wavelength. When measuring a measurement path with many events over a short distance multiple times, the distance of each event may differ, making it difficult to tally up the data.

[0021] In addition, events such as splices or breaks in optical fibers may not be properly detected due to the shape of the waveform detected by the optical pulse tester. For example, an event may not be detected because the change in the waveform at the position where an event should be detected in the optical fiber is too small. In addition, an event may be detected at a position where no event exists due to noise superimposed on the waveform detected by the optical pulse tester.

[0022] As described above, if an event is not detected properly, the user needs to manually correct the event detection result. However, the correction work of a large number of measurement data increases the user's workload. In order to reduce the workload, the user desires to automatically correct the position of each event when the length of the optical fiber or the distance between each connection point is known in advance.

[0023] Therefore, according to the present disclosure, when a user analyzes the length, splice points, break points, etc. of an optical fiber from the measurement data of an optical pulse tester, the measurement data is automatically corrected to match the actual length of the optical fiber by inputting distance information of the optical fiber in advance. Automatic correction of the measurement data makes it easier for the user to perform analysis. Also, if the actual distance between each splice point of the optical fiber differs from the analysis result of the measurement data, the differing parts can be presented to the user. Presenting the differing parts to the user makes it easier for the user to confirm or correct the data. As a result, the user's workload is reduced.

[0024] Hereinafter, an embodiment of the present disclosure will be described in comparison with a comparative example.

[0025] (Comparative Example) In optical communication systems that use optical signals for data communication, optical fibers are used as a medium for transmitting optical signals. When laying, relocating, or maintaining optical fibers, it is necessary to evaluate the length of the optical fiber or the loss or reflection at the connection points. An optical time domain reflectometer (OTDR) is used as a measuring instrument for evaluation. An optical time domain reflectometer is a device that inputs an optical pulse into the optical fiber under test, measures the power of the backscattered light or the light that returns to the input end due to Fresnel reflection in the time domain, and displays or analyzes the result.

[0026] Backscattered light etc. returns to the incident side with a delay time proportional to the distance from the reflection point. A waveform obtained by detecting the power of light backscattered or Fresnel reflected at a fusion point, a connector connection point, a branch point, a bend point, a cut point etc. has a characteristic shape. Therefore, events such as a fusion point, a connector connection point, a branch point, a bend point, a cut point etc. are detected based on the waveform obtained by detecting the power of the light. Also, the distance from the start point of the measured optical fiber to the event is measured. The detection of the above-mentioned event may be performed by the optical time domain tester itself, or may be performed by a PC (Personal Computer) application that acquires and analyzes measurement data from the optical time domain tester.

[0027] In the system according to the comparative example, the optical pulse tester detects events in the optical fiber based on the waveform measured on the optical fiber. The optical pulse tester displays the detected measurement data on a display unit 90 including a waveform display unit 91 and a measurement data display unit 92 as shown in FIG. 1. The waveform display unit 91 displays the waveform measured by the optical pulse tester. In the waveform display unit 91, a marker 93 is added to the detected event. That is, the detected event may be displayed diagrammatically with an icon such as the marker 93. In the example of FIG. 1, five events and the end of the optical fiber are detected. The measurement data display unit 92 displays information about the detected events as an event list.

[0028] In the system according to the comparative example, a detected event is drawn on the waveform as a marker 93, so that the user can determine that the marker 93 representing the detected event is placed at a correct position relative to a characteristic point of the waveform. Also, the detected events are displayed in a list format, so that the user can check the connection points of the optical fiber to be measured at a glance.

[0029] The distance from the input end of the optical fiber under test to each event is calculated based on the time it takes for light to return to the input end of the optical fiber under test. However, due to differences in the refractive index of optical fibers, the actual length of the optical fiber may differ from the result calculated based on the time it takes for light to return.

[0030] When a user knows the length of the fiber, or the position of the splice point or the location of the anomaly in advance, the user may correct the distance from the input end of the measured optical fiber to each event to the actual fiber length. In this case, the user manually edits the distance to each event. However, when there are many events or a large amount of measurement data, the work may become very cumbersome. In addition, the time required for the work may become excessive. In addition, when the relationship between the algorithm for detecting an event and the shape of the obtained waveform satisfies a specific condition, an event may occur in which an event is not detected at a location where an event should be present, or an event is detected at a location where an event should not be present.

[0031] A case where an event is not properly detected will be described based on the waveforms shown in Figures 2 and 3. The horizontal axis of the waveform graphs in Figures 2 and 3 represents the distance from the start point of the optical fiber, and the vertical axis represents the magnitude of the optical loss in the optical fiber.

[0032] FIG. 2 shows an example of a measured waveform when an event is not detected correctly. The points surrounded by the dashed frames shown as A01, A02, and A03 are points where an event should exist. The waveforms surrounded by the dashed frames shown as A01 and A03 have a step-like shape, so they are considered to be points where optical fibers are fused. The waveform surrounded by the dashed frame shown as A02 has a large rising shape, so they are considered to be points where optical fibers are connected by a connector. The user can easily see that these waveform shapes indicate the presence of an event by visual inspection. However, when the device analyzes the waveform, it may fail to detect an event. In fact, a marker corresponding to the event is not attached to the part surrounded by the dashed frame shown as A02 in FIG. 2. In other words, the part surrounded by the dashed frame shown as A02 in FIG. 2 is not detected as an event even though an event should exist. When a marker corresponding to an event is not attached in this way, it is determined that the detection of the event has failed. If the event detection fails, the user must manually set the event on the waveform represented as A02.

[0033] FIG. 3 shows an example of a measured waveform when a non-existent event is detected. The waveform surrounded by the dashed frame shown as B01 and B05 has a step, and is therefore considered to be a fused point. The waveform surrounded by the dashed frame shown as B02 has a rising shape, and is therefore considered to be a point connected by a connector. On the other hand, the waveform surrounded by the dashed frame shown as B03 and B04 remains linear and does not have a characteristic change, and is therefore considered to be neither a fused point nor a connected point. However, a marker corresponding to the event is attached. In other words, the waveform surrounded by the dashed frame shown as B03 and B04 is determined to have been erroneously detected as an event. When an event is erroneously detected, the user must manually delete the events detected for the waveforms shown as B03 and B04.

[0034] Here, the user needs to check the waveform from the start point to the end point of the optical fiber or the detected event list to check whether the optical fiber events have been properly detected. Furthermore, if the user finds that the optical fiber events have not been properly detected, the user needs to manually correct the event detection results. The more the optical fiber measurement data increases, the greater the burden of checking the event detection results and correcting the event detection results. There is a demand for improving user convenience so as to reduce the user's workload.

[0035] Hereinafter, in the present disclosure, an optical fiber measurement system and a data correction device 100 (see FIG. 4) that can improve the convenience of the user will be described. The purpose of the present disclosure is to improve the convenience of the event detection function by providing an event distance correction function and an event distance editing function that is easy for the user to understand by a UI (User Interface). In addition, in the present disclosure, when information such as the length of the optical fiber to be measured or the position of the connection point is known, the distance is automatically corrected when the event analysis is performed by inputting the distance information of each event into the software in advance. In addition, when the event detection result differs from the data input in advance, the time required for correcting the event position is reduced by providing a GUI (Graphical User Interface) having a function of correcting the event and a function of guiding the user.

[0036] (Example of optical fiber measurement system configuration) As shown in FIG. 4, an optical fiber measurement system according to an embodiment of the present disclosure includes a data correction device 100 and an optical time domain reflectometer (OTDR) 200.

[0037] <Data correction device 100> The data correction device 100 includes a display unit 150 , an operation input unit 110 , a storage unit 120 , an event correction unit 130 , and an acquisition unit 140 .

[0038] The display unit 150 may be configured to include various displays such as a liquid crystal display. The display unit 150 may be configured as a touch panel display that displays a GUI that functions as the operation input unit 110 and accepts input from a user. In other words, the display unit 150 may be configured integrally with the operation input unit 110.

[0039] 5, the display unit 150 displays a file list 154, a waveform display section 151, an input data display section 152, and a measurement data display section 153. The contents of information that the display unit 150 displays in each section will be described later. The display unit 150 may display a cross key 111, an event setting button 112, and a confirmation completion button 113 as a GUI of the operation input unit 110.

[0040] The operation input unit 110 may be configured to include an input device that accepts input from a user. The input device may include, for example, a keyboard or physical keys, or may include a touch panel or a touch sensor, or a pointing device such as a mouse. The operation input unit 110 may be configured as a touch panel display integrated with the display unit 150 as described above. The operation input unit 110 is also simply referred to as an input unit.

[0041] In this embodiment, the display unit 150 is configured integrally with the operation input unit 110. The display unit 150 displays a cross key 111, an event setting button 112, and a confirmation completion button 113 as a GUI of the operation input unit 110. The display unit 150 detects a touch input by the user and accepts the operation input to the GUI.

[0042] The storage unit 120 stores various information used in the operation of the data correction device 100, or programs for realizing the functions of the data correction device 100. The storage unit 120 may function as a work memory for a processor included in the data correction device 100. The storage unit 120 may be configured, for example, as a semiconductor memory. The storage unit 120 may be configured to include a volatile memory or a non-volatile memory. At least a part of the storage unit 120 may be configured as a storage device connected to the outside of the data correction device 100.

[0043] The acquiring unit 140 acquires measurement data from the optical pulse tester 200. The acquiring unit 140 may include a communication device for connecting to other devices such as the optical pulse tester 200 so as to be able to communicate with each other via wired or wireless communication. The communication device may include, for example, a communication interface such as a LAN (Local Area Network) or RS-232C or RS-485. The communication device is not limited to these and may include various other communication interfaces.

[0044] The event correction unit 130 corrects the measurement data acquired by the acquisition unit 140. The event correction unit 130 may automatically correct the measurement data, or may correct the measurement data based on a user's operation acquired from the operation input unit 110. The event correction unit 130 may be configured to include a processor such as a CPU (Central Processing Unit). The event correction unit 130 may achieve a predetermined function by causing the processor to execute a predetermined program. The event correction unit 130 may be configured to include a dedicated circuit such as an FPGA (Field Programmable Gate Array). The event correction unit 130 is also simply referred to as a correction unit.

[0045] The data correction device 100 may further include a control unit that controls each of the components. The control unit may include a processor such as a CPU. The control unit may be integrated with the event correction unit 130.

[0046] The data correction device 100 may be realized as a computer such as a desktop PC (Personal Computer) or a notebook PC, etc. The data correction device 100 may be realized as a mobile terminal such as a smartphone or a tablet.

[0047] <Optical Time Domain Reflectometer 200> The optical pulse tester 200 inputs an optical pulse into the optical fiber under test and measures in the time domain the power of backscattered light or light returning to the input end due to Fresnel reflection. The backscattered light etc. returns to the input end with a delay time according to the distance from the scattering or reflection point and the refractive index of the optical fiber under test along the path the light travels. The optical pulse tester 200 outputs measurement data that correlates the power of the light returning to the input end with the delay time.

[0048] The measurement data is represented as a waveform of detected optical power. The waveform of detected optical power backscattered or Fresnel reflected at an event of the measured optical fiber, such as a fusion point, a connector connection point, a branch point, a bend point, or a cut point, has a characteristic shape. By analyzing the characteristic shape included in the waveform of detected optical power, an event of the measured optical fiber, such as a fusion point, a connector connection point, a branch point, a bend point, or a cut point, is detected. Furthermore, the distance from the start point of the measured optical fiber to the event is measured based on the delay time corresponding to the characteristic shape included in the waveform. In the present disclosure, the detection of the event or the measurement of the distance to the event is performed by the data correction device 100 that acquires the measurement data from the optical pulse tester 200.

[0049] The detection of an event or the measurement of a distance to an event may be performed by the main body of the optical time domain tester 200. In this case, the data correction device 100 may be configured as a part of the optical time domain tester 200. In other words, the optical time domain tester 200 may be configured to include the data correction device 100.

[0050] (Example of operation of data correction device 100) The data correction device 100 acquires measurement data of the measured optical fiber from the optical pulse tester 200 using the acquisition unit 140. The data correction device 100 detects events of the measured optical fiber from the measurement data. An event of the measured optical fiber detected from the measurement data is also called a detected event. The detection result of the event based on the measurement data includes information that specifies the type and position of the detected event. The position of the event is expressed as a distance from the incident end of the measured optical fiber.

[0051] On the other hand, the data correction device 100 acquires route information of the measured optical fiber. The route information of the measured optical fiber includes information for identifying the type and position of an event whose existence is known in advance in the measured optical fiber. The route information of the measured optical fiber is data input in advance by a user, and is also called input data. In other words, the input data is route information of the measured optical fiber input in advance by a user. An event whose existence is known in advance in the measured optical fiber is also called a known event. The input data includes information for identifying a known event. The input data may be data input by a user who operates the data correction device 100, or may be data input by another user. The input data is assumed to be stored in advance in the storage unit 120. The input data may be stored in an external device of the data correction device 100.

[0052] The data correction apparatus 100 corrects the position of the detected event based on the position of a known event specified in the input data. For example, the data correction apparatus 100 corrects the position of the detected event so as to match the position of a known event corresponding to the detected event.

[0053] The data correction device 100 may not be able to correct the position of at least some of the detected events based on the input data. For example, there may be no known event corresponding to the detected event. In this case, the data correction device 100 may not be able to simply correct the position of the detected event to match the position of the known event identified in the input data.

[0054] In addition, an event corresponding to a known event may not be detected from the measurement data. In this case, data correction device 100 cannot correct the position of the undetected detected event. Furthermore, data correction device 100 cannot automatically add an event that was not automatically detected as a detected event.

[0055] In this way, when a difference exists between the detected event and the known event, data correction apparatus 100 cannot automatically correct the detected event.

[0056] The data correction device 100 allows the user to confirm the detected events that could not be corrected, and corrects them as necessary. The detected events that the data correction device 100 could not correct are also referred to as correction target events. When a correction target event exists, the data correction device 100 displays the waveform of the measurement data corresponding to the correction target event on the display unit 150. When the user judges that the correction target event needs to be actually corrected by looking at the waveform of the measurement data displayed on the display unit 150, the user inputs a correction operation to the operation input unit 110. The data correction device 100 corrects the correction target event according to the correction operation received by the operation input unit 110. When the user judges that the correction target event does not need to be corrected, the data correction device 100 confirms the correction target event as it is without correcting it.

[0057] A specific operation example of the data correction device 100 will be described below. The data correction device 100 may execute a data correction method including the procedures of the flowcharts illustrated in Fig. 6 and Fig. 7. The data correction method may be realized as a data correction program executed by a processor constituting the data correction device 100. The data correction program may be stored in a non-transitory computer-readable medium.

[0058] <Automatic detection and correction of measurement data> 6, the event corrector 130 of the data corrector 100 acquires measurement data of the measured optical fiber from the optical pulse tester 200 via the acquirer 140, and detects a characteristic shape included in the waveform of the measurement data as an event (step S1). The event corrector 130 calculates the distance from the input end to the event, which indicates the position of the event, based on the index of reference (IOR) of the measured optical fiber set in the data corrector 100 and the optical delay time.

[0059] Here, due to a difference between the group refractive index of the measured optical fiber set in the data correction device 100 and the group refractive index of the actual measured optical fiber, an error may occur between the position of the detected event and the actual position of the event in the measured optical fiber. The event correction unit 130 automatically corrects the measurement data (step S2). That is, the event correction unit 130 automatically corrects the position of the detected event detected from the measurement data.

[0060] When multiple events are detected from the measurement data, the event correction unit 130 performs automatic correction for the multiple detected events in order. Before performing automatic correction, the event correction unit 130 obtains input data, which is route information of the measured optical fiber measured by the optical pulse tester 200, from the storage unit 120 or an external device. As described above, the input data, which is route information of the measured optical fiber, includes information for identifying the position of the known event. The input data may further include information for identifying the type of the known event.

[0061] Here, the optical fiber under test in this embodiment is assumed to be an optical fiber in which five events, No. 1 to No. 5, exist between the input end connected to the optical time domain reflectometer (OTDR) 200 and the terminal end (E), as illustrated in Fig. 8. The optical fiber under test includes six different optical fibers. The six optical fibers are connected by five events.

[0062] Input data for identifying the positions of each of the five events present in the measured optical fiber in FIG. 8 may be input using a table-type input interface as exemplified in FIG. 9. The input data may be input using a GUI as exemplified in FIG. 10. The GUI exemplified in FIG. 10 includes an icon 114 representing an event such as a connection point included in the path of the measured optical fiber, an icon 115 for adding an event at the end of the measured optical fiber, and an input box 116 for inputting the distance to the event. The icon 114 may be configured to be able to change the type of event. The icon 115 may be configured to be able to specify the type of event to be added. The form of the GUI is not limited to the above-mentioned example and may be realized in other forms.

[0063] The data correction device 100 may receive input data at the data correction device 100. The data correction device 100 may obtain input data input at an external device.

[0064] The event correction unit 130 executes automatic correction of the measurement data according to the procedure of the flowchart in Fig. 7. The event correction unit 130 starts automatic correction of the measurement data (step S11). That is, the event correction unit 130 starts automatic correction of the position of the detected event detected from the measurement data. When multiple events are detected from the measurement data, the event correction unit 130 selects the multiple detected events as events to be automatically corrected in order from the incident end of the measured optical fiber, and determines whether the target event is correctable (step S12). When the target event is associated with a known event identified by the input data, the event correction unit 130 determines that the target event is correctable.

[0065] If the target event can be corrected (step S12: YES), the event corrector 130 performs automatic correction on the target event (step S13). Specifically, the event corrector 130 corrects the position of the target event to match the position of a known event identified by the input data. In other words, the event corrector 130 corrects the position of the target event to match the input data. After executing the procedure of step S13, the event corrector 130 proceeds to the procedure of step S15.

[0066] If the target event is not correctable (step S12: NO), the event corrector 130 marks the target event as an error (step S14). After executing the procedure of step S14, the event corrector 130 proceeds to the procedure of step S15.

[0067] The event corrector 130 determines whether the correction of the target events is completed up to the end of the measured optical fiber (step S15). That is, the event corrector 130 determines whether all the detected events detected from the measurement data of the measured optical fiber are correctable, and determines whether the automatic correction of the correctable events is completed.

[0068] If the event corrector 130 has not completed the correction up to the terminal of the measured optical fiber (step S15: NO), it selects the next event as the event to be automatically corrected, and executes the procedures from step S12 onward. If the event corrector 130 has completed the correction up to the terminal of the measured optical fiber (step S15: YES), it ends the automatic correction of the measurement data (step S16).

[0069] When the automatic correction of the measurement data is completed, the event corrector 130 saves a file of the measurement data after the automatic correction. The event corrector 130 may save the measurement data after the automatic correction by storing it in the storage unit 120 or an external device.

[0070] If at least one event cannot be corrected, the event correction unit 130 may associate an identifier indicating that there is an error with the measurement data including the event that could not be corrected and store the measurement data, so that the measurement data including the event that could not be corrected can be distinguished.

[0071] An event corresponding to a known event identified in the input data may not be detected from the measurement data. That is, at least some of the known events may not be detected from the measurement data. In this case, the event correction unit 130 may store the measurement data including the undetected event in association with an identifier indicating that there is an error, so that the measurement data including the undetected event can be distinguished from the measurement data including the undetected event.

[0072] If the measurement data is corrected according to the input data and if all known events identified by the input data are detected from the measurement data, the event correction unit 130 may associate an identifier indicating that the measurement data is error-free and store the measurement data.

[0073] The event correction unit 130 may store a file of the measurement data after the automatic correction together with the input data used to perform the automatic correction of the measurement data. The input data used to perform the automatic correction of the measurement data is also referred to as the corresponding input data of the measurement data.

[0074] As an example of automatic correction, assume that automatic correction is performed to match the positions of detection events illustrated as a table in Fig. 11 with the positions of known events specified by the input data in Fig. 9. Detection events No. 1, 2, and 3 before automatic correction in Fig. 11 correspond to known events No. 1, 2, and 3 in Fig. 9. Detection event No. 4 before automatic correction in Fig. 11 corresponds to known event No. 5 in Fig. 9. Event correction unit 130 corrects the positions of detection events No. 1, 2, 3, and 4 before automatic correction in Fig. 11 to match the positions of known events No. 1, 2, 3, and 5 in Fig. 9.

[0075] On the other hand, the detection event No. 5 in Fig. 11 does not correspond to any of the known events included in the input data in Fig. 9. In other words, the input data in Fig. 9 does not include a known event corresponding to the detection event No. 5 in Fig. 11. The event correction unit 130 determines that automatic correction cannot be performed on the detection event No. 5 before automatic correction in Fig. 11, and marks the detection event No. 5 as an error. Furthermore, when saving measurement data including the detection event after automatic correction, the event correction unit 130 may associate an identifier indicating that there is an error with the measurement data including the detection event that could not be corrected.

[0076] Moreover, the detected events in Fig. 11 do not include an event corresponding to the known event No. 4 included in the input data in Fig. 9. When saving the measurement data after automatic correction, the event correction section 130 may associate an identifier indicating that there is an error in the measurement data containing an undetected event.

[0077] After executing the procedure of step S16, the event corrector 130 returns to the flowchart of FIG. 6, finishes executing the procedure of automatic correction of step S2, and proceeds to the procedure of step S3.

[0078] <Manual correction of measurement data> The event correction unit 130 determines whether the input data and the measurement data match (step S3). Specifically, the event correction unit 130 determines that the input data and the measurement data match when all the detection events detected from the measurement data after the automatic correction are common to all the known events included in the corresponding input data. Conversely, the event correction unit 130 determines that the input data and the measurement data do not match when there is an event that is included in the detection events but not included in the known events. The event correction unit 13 also determines that the input data and the measurement data do not match when there is an event that is not included in the detection events but is included in the known events. When the event correction unit 130 determines that the input data and the measurement data match (step S3: YES), the data correction device 100 ends the execution of the procedure of the flowchart in FIG. 6. That is, the data correction device 100 completes the correction of the measurement data.

[0079] If the event correction unit 130 determines that the input data and the measurement data do not match (step S3: NO), the data correction device 100 displays the measurement data to be corrected on the display unit 150 (step S4). The measurement data to be corrected is the measurement data that does not match the input data. Also, the measurement data to be corrected is the measurement data that includes the event to be corrected.

[0080] Data correction device 100 receives an input by the user at operation input unit 110 to select a file of measurement data to be corrected, and displays on display unit 150 the selected measurement data and the corresponding input data.

[0081] 12, data correction device 100 may display the selected measurement data and corresponding input data on display unit 150. Display unit 150 displays a measurement data file, a measurement data waveform, input data, or a detection result of an event based on the measurement data on a screen. In other words, the screen displayed on display unit 150 includes a file list 154, a waveform display unit 151, an input data display unit 152, and a measurement data display unit 153. In addition, the screen displayed on display unit 150 further includes a cross key 111, an event setting button 112, and a confirmation completion button 113, which are the GUI of operation input unit 110.

[0082] The file list 154 displays the files of the measurement data after automatic correction in a list format. The file list 154 may display whether or not there is an error in the measurement data of the file in a format such as OK or NG, in association with the file name. Measurement data with an error is measurement data to be corrected, which includes an event to be corrected. By displaying whether or not there is an error in the measurement data, the user can easily find the file of the measurement data to be corrected, which includes an event to be corrected. As a result, user convenience is improved.

[0083] The waveform display unit 151 displays the waveform of the measurement data. The vertical axis of the graph showing the waveform of the measurement data is the power of the light scattered at the scattering point or reflected at the reflection point of the measured optical fiber and returned to the incident end. The horizontal axis is the distance from the incident end of the measured optical fiber to the scattering point or reflection point of the light.

[0084] The input data display unit 152 displays the positions of known events specified by the input data. The positions of known events are expressed as the distance from the incident end of the measured optical fiber to each known event. The known events of the measured optical fiber are assumed to be five events No. 1 to No. 5 in Fig. 9. The event displayed as No. E indicates the end of the measured optical fiber.

[0085] The measurement data display unit 153 displays information about the detected events detected from the measurement data. In the display example of Fig. 12, the measurement data display unit 153 displays the position and section refractive index of the detected events as information about the detected events. The position of the detected events is expressed as the distance from the incident end of the measured optical fiber to each detected event. The section refractive index is the group refractive index of the section including each event after correction in the measured optical fiber.

[0086] Data correction apparatus 100 displays the selected measurement data and corresponding input data on display unit 150 so that the detected events correspond to the known events.

[0087] The input data display section 152 and the measurement data display section 153 may display events common to the detection events of the measurement data and the known events of the corresponding input data side by side. In the display example of Fig. 12, the events common to the detection events of the measurement data and the known events of the corresponding input data are displayed as four events No. 1, 2, 3, and 5 on the input data display section 152 and the measurement data display section 153. The four known events No. 1, 2, 3, and 5 displayed on the input data display section 152 correspond to the four known events No. 1, 2, 3, and 4 in Fig. 9, respectively. The four detection events No. 1, 2, 3, and 5 displayed on the measurement data display section 153 correspond to the four detection events No. 1, 2, 3, and 4 in Fig. 11, respectively.

[0088] When there is an undetected event that has not been detected in the measurement data among the known events identified by the input data, the measurement data display unit 153 displays the column corresponding to the undetected event as a blank column. The input data display unit 152 displays the known event corresponding to the undetected event next to the blank column of the measurement data display unit 153. In the display example of FIG. 12, the column No. 4 of the measurement data display unit 153 is blank, as surrounded by a dashed rectangle indicated as C01. The blank column of the measurement data display unit 153 indicates that the known event No. 4 of the input data display unit 152 is an event that has not been detected in the measurement data. In other words, the blank column of the measurement data display unit 153 indicates that an undetected event exists in the measurement data.

[0089] When there is a false-detection event not included in the known events among the detection events detected from the measurement data, the input data display unit 152 displays the column corresponding to the false-detection event as a blank column. The measurement data display unit 153 displays the false-detection event next to the blank column in the input data display unit 152. In the display example of FIG. 12, the detection event No. 6 is displayed in the measurement data display unit 153 as surrounded by a dashed rectangle indicated as C02. In contrast, the column for the event No. 6 in the input data display unit 152 is blank. The blank column in the input data display unit 152 indicates that an event not included in the known events has been falsely detected from the measurement data. In other words, the blank column in the input data display unit 152 indicates that a false-detection event exists in the measurement data.

[0090] As described above, the display unit 150 displays the known event and the detected event so that the user can check the difference between the known event and the detected event. In this way, the user can easily recognize the event to be corrected. As a result, the user's convenience is improved.

[0091] The display unit 150 may display, as differences, events among the detected events that are not included in the known events, and events among the known events that are not included in the detected events. In this way, the user can more easily recognize the events to be corrected. As a result, the user's convenience is improved.

[0092] The display unit 150 may include an input data display unit 152 that displays known events identified by the input data, and a measurement data display unit 153 that displays detected events detected from the measurement data. The input data display unit 152 may display events that are not included in the detected events but are included only in the known events in association with blank spaces in the measurement data display unit 153. The measurement data display unit 153 may display events that are not included in the known events but are included only in the detected events in association with blank spaces in the input data display unit 152. This allows the user to more easily recognize events to be corrected. As a result, user convenience is improved.

[0093] The input data display unit 152 and the measurement data display unit 153 do not need to display events that are common to the known events and the detected events. In this way, the user can recognize only the events to be corrected that are not common to the known events and the detected events. As a result, user convenience is improved.

[0094] The undetected event No. 4 and the erroneously detected event No. 6, which are surrounded by dashed rectangles indicated as C01 and C02, correspond to events to be corrected. Events to be corrected may be displayed in different ways so as to be distinguished from events that are not to be corrected. In the display example of FIG. 12, an asterisk (*) is added to the number in the No. column of the event to be corrected. Events to be corrected may be displayed, for example, with hatching or coloring added to the background of the display column. Events to be corrected are not limited to these ways and may be displayed in various other ways.

[0095] Returning to the flowchart in Fig. 6, data correction device 100 accepts a correction operation of a detected event by a user through operation input unit 110 (step S5). That is, data correction device 100 accepts an operation input by the user to correct a detected event through operation input unit 110. Specifically, data correction device 100 accepts an input by the user through operation input unit 110 to select an event to be corrected from among the events displayed on input data display unit 152 and measurement data display unit 153. Data correction device 100 displays, on waveform display unit 151, the waveform of the portion of the measurement data corresponding to the selected event to be corrected.

[0096] In the display example of FIG. 12, the waveform display unit 151 displays a cursor 162 for specifying the post-correction position of the event together with the waveform of the measurement data of the portion corresponding to the event to be corrected. Setting the position of the detected event includes correcting the position of the detected event and adding a detected event. The operation input unit 110 accepts an operation input for moving the cursor 162 with the cross key 111, and an operation input for setting the position of the detected event to the position of the cursor 162 with the event setting button 112. Being able to set the position of the detected event by operating the cursor 162 allows the user to easily perform correction operations. As a result, user convenience is improved.

[0097] The waveform display unit 151 may further display a vertical line of an event setting range 161 that indicates a range within which the position of a detected event can be set. By displaying the event setting range 161, it is possible to prevent the user from erroneously correcting the position of an event or adding an event at an incorrect position.

[0098] When the event to be corrected is an undetected event, the user determines the position where the event should be detected based on the characteristics of the waveform shape. The user moves cursor 162 to the position where the user determines that the event should be detected, and taps, clicks, or presses event setting button 112 to specify the position where the event should be added. Event correction unit 130 of data correction device 100 adds a new event of the measurement data to the position specified by the user. Event correction unit 130 calculates the section refractive index so that the position of the newly added event matches the position of a known event corresponding to that event.

[0099] When the event to be corrected is a false positive event, the user determines whether to delete the event to be corrected or leave it as it is based on the characteristics of the waveform shape. For example, when the waveform of the part corresponding to the event to be corrected has an uncharacteristic shape such as a straight line, the user determines that the event to be corrected is actually a false positive event and inputs an operation to delete the event to be corrected. In response to the operation to delete the event to be corrected, the event correction unit 130 deletes the event to be corrected from the events of the measurement data.

[0100] If the waveform of the portion corresponding to the event to be corrected has a characteristic shape such as a step or spike, the user may determine that the event to be corrected is not a false positive event, but a previously unknown, unexpected event such as a disconnection, etc. In this case, the user does not input an operation to delete the event to be corrected, so as to leave the event to be corrected as is.

[0101] 6, data correction device 100 updates the display of the measurement data (step S6). Specifically, data correction device 100 reflects the display of the newly set event to be corrected or the deleted event to be corrected in input data display unit 152 and measurement data display unit 153.

[0102] Data correction device 100 determines whether the user has completed checking the measurement data (step S7). Data correction device 100 may determine that the checking is complete when the user taps, clicks, or presses check complete button 113. Data correction device 100 may also determine that the checking is complete when the input data and the measurement data match due to a correction operation by the user.

[0103] When data correction device 100 determines that the confirmation is not complete (step S7: NO), it returns to the procedure of step S4 and accepts a user's correction operation for the next event to be corrected.

[0104] When the data correction device 100 determines that the confirmation is complete (step S7: YES), it saves the corrected measurement data as the measurement result of the measured optical fiber (step S8). The data correction device 100 may save the measurement result by storing it in the memory unit 120 or an external device. The measurement result of the measured optical fiber may be used in an inspection report of the measured optical fiber, etc. After executing the procedure of step S8, the data correction device 100 ends the execution of the flowchart in FIG. 6. After executing the procedure of step S8, the data correction device 100 may return to the procedure of step S4 and accept an operation to select the next measurement data file.

[0105] <Summary> As described above, the data correction device 100 according to the present disclosure can automatically detect events in the measured optical fiber from the measurement data of the measured optical fiber measured by the optical pulse tester 200. Furthermore, the data correction device 100 can automatically correct the position of a detected event detected from the measurement data to match the position of a known event identified in the input data.

[0106] For example, the detection event No. 1 before automatic correction in Fig. 11 was analyzed as having a distance of 2.00139 km from the incident end and a section refractive index of 1.48. On the other hand, the detection event No. 1 after automatic correction displayed in the measurement data display unit 153 in Fig. 12 has been corrected as having a distance of 2.00000 km from the incident end and a section refractive index of 1.48103. In other words, the event correction unit 130 can correct the distance from the incident end to the detection event to match the position of a known event specified by the input data by correcting the section refractive index so as to be consistent with the correction of the distance.

[0107] Therefore, the data correction device 100 according to the present disclosure solves the problem that the length of the optical fiber calculated from the measurement data may differ from the actual length of the optical fiber due to differences in the refractive index of the optical fiber.

[0108] Furthermore, the data correction device 100 according to the present disclosure displays the difference between the detection event detected from the measurement data of the measured optical fiber and the known event identified in the input data. By checking the difference, the user need only check the event to be corrected that corresponds to the difference, without checking all the detection events. By being able to check only the events to be corrected, the user can easily or efficiently perform the correction operation of the detection event detected from the measurement data. As a result, user convenience is improved.

[0109] (Other embodiments) Another embodiment of the fiber optic measurement system and data correction apparatus 100 is described.

[0110] <Aspects of Data Correction Device 100> In the above-described embodiment, the data correction device 100 is configured as a device separate from the optical pulse tester 200. The functions of the data correction device 100 may be realized as part of the functions of the optical pulse tester 200. In other words, the functions of the data correction device 100 may be realized by firmware in the main body of the optical pulse tester 200. When the functions of the data correction device 100 are realized as part of the functions of the optical pulse tester 200, input data for identifying events whose existence in the measured optical fiber is already known may be input to the optical pulse tester 200 in a preparation stage for measuring the measured optical fiber with the optical pulse tester 200. Inputting the input data to the optical pulse tester 200 in advance reduces the number of steps required for editing events at the measurement site of the measured optical fiber, or the number of steps required for correcting measurement data when an event to be confirmed or inspected is not automatically detected.

[0111] <Display of the difference between measured data and input data> As described above, the input data display section 152 and the measurement data display section 153 of the display section 150 display the detected events detected from the measurement data and the known events identified by the corresponding input data so as to correspond to each other. The input data display section 152 and the measurement data display section 153 may display the detected events and the known events side by side or vertically in order to display the detected events and the known events in correspondence with each other. The input data display section 152 and the measurement data display section 153 may display the detected events and the known events in other manners, not limited to the manner of side by side or vertical, as long as the user can recognize the correspondence between the detected events and the known events.

[0112] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art can make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions included in each component can be rearranged so as not to cause logical inconsistencies, and multiple components can be combined into one or divided. [Explanation of symbols]

[0113] 100 Data correction device 110 operation input section (111: cross key, 112: event setting button, 113: confirmation completion button, 114, 115: icon, 116: input frame) 120 Storage section 130 Event Correction Unit 140 Acquisition Department 150 display section (151: waveform display section, 152: input data display section, 153: measurement data display section, 154: file list, 161: event setting range, 162: cursor) 200 Optical Time Domain Reflectometer (OTDR)

Claims

1. an acquisition unit that acquires measurement data from an optical time domain tester that measures events present in the optical fiber under test; a display unit that displays a known event and a detected event so that a user can confirm a difference between a known event whose presence in the measured optical fiber is known in advance and a detected event detected from the measurement data; and an input unit that receives an operation input from the user to modify the detected event; a correction unit that corrects the detected event based on an operation input received from the user; A data correction device comprising:

2. The display unit is displaying, as the difference, an event not included in the known events among the detected events; The data correction device according to claim 1 , wherein an event that is not included in the detected events among the known events is displayed as the difference.

3. the display unit includes an input data display unit that displays the known events and a measurement data display unit that displays the detected events; the input data display unit displays an event that is not included in the detected event but is included only in the known event in association with a blank space in the measurement data display unit; the measurement data display unit displays an event that is not included in the known events but is included only in the detected events in association with a blank space in the input data display unit. The data correction device according to claim 2 .

4. The data correction device according to claim 3 , wherein the input data display section and the measurement data display section do not display an event that is common to the known event and the detected event.

5. the display unit includes a waveform display unit that displays a waveform of the measurement data, The data correction device according to claim 1 , wherein the waveform display unit, when displaying the waveform corresponding to a correction target event among the detected events, displays a range in which a position of the correction target event can be set.

6. the waveform display unit displays a cursor for designating a position of the event to be corrected; the input unit receives, from the user, an operation of moving the cursor and an operation of setting a position of the event to be modified at a position of the cursor; The correction unit corrects a position of the event to be corrected to the position of the cursor. The data correction device according to claim 5 .

7. 7. An optical pulse tester comprising the data correction device according to claim 1.

8. 7. An optical fiber measurement system comprising: the data correction device according to claim 1; and an optical pulse tester that outputs measurement data to the data correction device.

9. acquiring measurement data from an optical time domain tester that measures events present in the optical fiber under test; displaying the known events and the detected events so that a user can confirm a difference between a known event whose presence in the measured optical fiber is known in advance and a detected event detected from the measurement data; receiving an operation input from the user to modify the detected event; modifying the detected event based on an operation input received from the user; A data correction method comprising:

10. acquiring measurement data from an optical time domain tester that measures events present in the optical fiber under test; displaying the known events and the detected events so that a user can confirm a difference between a known event whose presence in the measured optical fiber is known in advance and a detected event detected from the measurement data; receiving an operation input from the user to modify the detected event; modifying the detected event based on an operation input received from the user; A data correction program that causes a processor to execute the above.

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