Distributed earthquake early warning system

Abstract

The invention relates to the technical field of data processing, in particular to a distributed earthquake early warning system, which comprises a sensing optical fiber system, a data acquisition system, a data processing system and a data processing system, the data acquisition system converts the seismic wave attenuation signal of the target area into a seismic waveform, and sends the seismic waveform and the vibration intensity to the optical fiber control system; the optical fiber control system obtains the geographic space position and the time label, and sends the seismic waveform, the vibration intensity, the time label and the geographic space position to the local seismic control system through the distributed communication system; the local earthquake control system receives the data and sends the data to the data summarization and big data analysis system; the data summarization and big data analysis system determines earthquake occurrence information according to the time label and the geographic space position; the earthquake early warning system generates an earthquake emergency plan. The method has the effects of improving the monitoring range and reducing the cost.

Description

Technical Field

[0001] The present application relates to the field of data processing technology, and in particular to a distributed earthquake early warning system. Background Art

[0002] As modern cities grow larger, earthquakes, as a serious natural disaster, cause more and more losses. Although countries usually establish relatively complete earthquake monitoring systems, compared with the vast land area, they often require a large amount of investment, and the subsequent maintenance and operation also require long-term investment. With the continuous development of the economy and the continuous expansion of urban circles, the damage caused by earthquakes is also increasing, and the investment in earthquake early warning is also rising.

[0003] Fiber optic sensors can be used to monitor vibrations and are often used in perimeter protection, stress monitoring and other fields. With the development of science and technology, the continuous improvement and upgrading of the system and the reduction of costs, its application scope is becoming wider and wider, and more and more areas are adopting it. However, it is often used for security warning in small areas, and the long-distance warning currently does not exceed 100 kilometers. Therefore, this type of security system is generally a small system and cannot monitor independent areas such as pipelines, communities and mining areas in a targeted manner. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a distributed earthquake early warning system.

[0005] In a first aspect, the present application provides a distributed earthquake early warning system, which adopts the following technical solution: A distributed earthquake early warning system, comprising a local earthquake bureau monitoring network, an optical fiber sensing vibration monitoring network and a distributed communication system, wherein the local earthquake bureau monitoring network comprises a local earthquake control system, a data aggregation and big data analysis system and an earthquake early warning system, and the optical fiber sensing vibration monitoring network comprises an optical fiber control system, a sensing optical fiber system and a data acquisition system, wherein: A sensing optical fiber system, used for collecting seismic wave attenuation signals and vibration intensity in a target area, and sending the seismic wave attenuation signals and the vibration intensity in the target area to the data acquisition system, wherein the target area is a residential area and / or a mining area; A data acquisition system, used for converting the seismic wave attenuation signal of the target area into a seismic waveform, and sending the seismic waveform and the vibration intensity to the optical fiber control system; an optical fiber control system for acquiring the geographic spatial position of the sensing optical fiber system and collecting the time tag of the seismic wave attenuation signal, and sending the seismic waveform, the vibration intensity, the time tag and the geographic spatial position to the local seismic control system through the distributed communication system; A local earthquake control system, configured to receive the earthquake waveform, the vibration intensity, the time tag and the geographic space location and send them to the data aggregation and big data analysis system; A data aggregation and big data analysis system, for determining earthquake occurrence information according to the time tag and the geographic space location, wherein the earthquake occurrence information is whether an earthquake has occurred or not; The earthquake early warning system is used to generate earthquake emergency plans based on earthquake occurrence information.

[0006] In a preferred embodiment, the present application may be further configured as follows: the data aggregation and big data analysis system is used to determine earthquake occurrence information according to the time tag and the geographic space location, including: determining an earthquake propagation range based on the time tag and the geospatial location; Determining whether the earthquake propagation range is greater than a preset earthquake propagation range; If yes, an earthquake occurred; if no, an earthquake did not occur.

[0007] In a preferred embodiment, the present application can be further configured such that if an earthquake occurs, the data aggregation and big data analysis system performs the following steps: Determine the earthquake source location according to the earthquake waveform, the time tag and the geographic space location; Acquiring the earthquake intensity, and evaluating earthquake damage information based on the earthquake intensity and the earthquake intensity; Correspondingly, the earthquake early warning system generates an earthquake emergency plan according to the earthquake source location and the earthquake damage information.

[0008] In a preferred embodiment of the present application, the earthquake damage information includes: the number of casualties and the number of damaged buildings; the data aggregation and big data analysis system evaluates the earthquake damage information based on the vibration intensity and the vibration severity, including: Determining the number of target building damages corresponding to the vibration intensity according to a preset correspondence between vibration intensity and the number of building damages and the vibration intensity; The time of occurrence of the earthquake is obtained, and the number of casualties is determined based on the time of occurrence of the earthquake and the vibration intensity.

[0009] In a preferred embodiment, the present application may be further configured such that the data aggregation and big data analysis system determines the number of casualties according to the earthquake occurrence time and the vibration intensity, including: Determining a target number of casualties corresponding to the vibration intensity according to a preset correspondence relationship between the vibration intensity and the number of casualties and the vibration intensity; Determining whether the earthquake occurrence time is a preset sleeping time; If not, the target number of casualties is corrected according to the time of occurrence of the earthquake, and the corrected target number of casualties is determined as the number of casualties; If so, the target number of casualties is determined as the number of casualties.

[0010] In a preferred embodiment, the present application may be further configured as follows: the local earthquake bureau monitoring network also includes a local earthquake monitoring sensor system, wherein: A local earthquake monitoring sensor system, used for collecting earthquake wave attenuation signals in non-target areas, and sending the earthquake wave attenuation signals in the non-target areas to the data aggregation and big data analysis system; Accordingly, the data aggregation and big data analysis system is used to determine whether there is an earthquake based on the seismic wave attenuation signal in the non-target area; A local earthquake control system, for generating an acquisition command for the target area after an earthquake in the non-target area is determined, and sending the acquisition command to the optical fiber control system; The optical fiber control system is used to send the seismic waveform, the vibration intensity, the time tag and the geographic space position of the target area to the local seismic control system through the distributed communication system after receiving the acquisition command.

[0011] In a preferred embodiment, the present application may be further configured as follows: Obtaining the vibration duration of the target area; Determine whether the vibration duration is greater than a preset duration threshold, or determine whether the earthquake waveform type change information conforms to earthquake characteristics; If the duration of the vibration is greater than a preset duration threshold, or the earthquake waveform type change information conforms to the earthquake characteristics, the earthquake waveform, the vibration intensity, the time tag and the geographic space position are sent to the local earthquake control system through the distributed communication system.

[0012] In a preferred embodiment, the present application can be further configured to also include a timing system for providing time to the optical fiber control system.

[0013] In summary, this application includes the following beneficial technical effects: The optical fiber sensing system is widely installed in the target area and can collect vibration signals in the target area in real time. All data collected by the optical fiber sensing system are then transmitted to the monitoring network of the local earthquake bureau and comprehensively analyzed to determine the earthquake information and issue early warnings. Compared with the existing technology, it can not only monitor densely populated communities and key protection areas, but also use the optical fiber vibration sensing system to collect data, which also realizes the utilization of existing sensing resources and reduces construction and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a structural diagram of a distributed earthquake early warning system in an embodiment of the present application; Figure 2 It is an information flow diagram of a distributed earthquake early warning system in an embodiment of the present application. DETAILED DESCRIPTION

[0015] The following is combined with Figure 1 To Attachment Figure 2 This application is described in further detail.

[0016] After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed, but such modifications are protected by patent law as long as they are within the scope of the claims of this application.

[0017] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] In addition, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article, unless otherwise specified, generally means that the associated objects before and after are in an "or" relationship.

[0019] The present invention proposes a distributed earthquake monitoring system that integrates the independent optical fiber sensor data. On the one hand, it makes full use of the existing sensor resources and greatly reduces the construction and maintenance costs of the earthquake sensor network by sharing. On the other hand, since the independent optical fiber distributed sensor network is mainly concentrated in areas that need key protection or densely populated communities, it can also produce a preliminary assessment of earthquakes in key protection areas.

[0020] like Figure 1As shown, it is a structural diagram of a distributed earthquake early warning system provided by an embodiment of the present application. The distributed earthquake early warning system includes a local earthquake bureau monitoring network and multiple optical fiber sensing vibration monitoring networks. The local earthquake bureau monitoring network includes at least a timing system, a distributed communication system, and a data aggregation and big data analysis system; each optical fiber sensing vibration monitoring network is provided with a timing system and a distributed communication system; the local earthquake bureau monitoring network and each optical fiber sensing vibration monitoring network can realize data transmission through the distributed communication system. The timing system can adopt a dual system of satellite timing or wireless communication timing.

[0021] The following is a further detailed description of the embodiments of the present application in conjunction with the accompanying drawings. Figure 2 As shown, it is an information flow chart of a distributed earthquake early warning system provided in an embodiment of the present application.

[0022] A distributed earthquake early warning system includes a local earthquake bureau monitoring network, an optical fiber sensing vibration monitoring network and a distributed communication system. The local earthquake bureau monitoring network includes a local earthquake control system, a data aggregation and big data analysis system and an earthquake early warning system. The optical fiber sensing vibration monitoring network includes an optical fiber control system, a sensing optical fiber system and a data acquisition system.

[0023] In the embodiment of the present application, the optical fiber sensing vibration monitoring network includes multiple sensing optical fiber systems; the optical fiber control system and the data acquisition system are both located in the control center of the optical fiber sensing vibration monitoring network.

[0024] Among them, the sensing optical fiber system is used to collect the seismic wave attenuation signal and vibration intensity of the target area, and send the seismic wave attenuation signal and vibration intensity of the target area to the data acquisition system. The target area is a residential area and / or a mining area.

[0025] Specifically, the sensing optical fiber system is composed of several optical fibers, all of which are located in the residential area and / or mining area. In the embodiment of the present application, the sensing optical fiber system will collect the seismic wave attenuation signal and vibration intensity of the target area in real time and send them to the data acquisition system.

[0026] The data acquisition system is used to convert the seismic wave attenuation signal in the target area into a seismic waveform, and send the seismic waveform and vibration intensity to the optical fiber control system.

[0027] Specifically, the process of converting the seismic wave attenuation signal into a seismic waveform includes: determining the rate of change of the seismic wave with the propagation distance based on the seismic wave attenuation signal, and then determining the seismic waveform corresponding to the change rate based on the correspondence between the seismic waveform and the change rate; the data acquisition system can send the seismic waveform and vibration intensity to the optical fiber control system by wired transmission or wireless transmission; the embodiment of the present application does not limit the specific process of determining the rate of change of the seismic wave with the propagation distance based on the seismic wave attenuation signal.

[0028] The fiber optic control system is used to obtain the geographic spatial position of the sensing fiber optic system and collect the time tag of the seismic wave attenuation signal, and send the seismic waveform, vibration intensity, time tag and geographic spatial position to the local seismic control system through a distributed communication system.

[0029] Specifically, the geographic spatial location can be composed of longitude and latitude, and the time tag is determined by the timing system in the fiber optic sensing vibration monitoring network; in the embodiment of the present application, the timing system adopts a dual system of satellite timing and wireless communication timing, which can effectively ensure the safety and availability of timing; wherein, the distributed communication system and the wireless communication timing system are both installed at the local earthquake bureau monitoring network control center and the fiber optic sensing vibration monitoring network control center, and by setting up a distributed communication system, data transmission between the fiber optic sensing vibration monitoring network and the local earthquake bureau monitoring network can be realized.

[0030] The local earthquake control system is used to receive earthquake waveforms, vibration intensity, time tags and geospatial locations and send them to the data aggregation and big data analysis system.

[0031] Specifically, a distributed communication system is set up in the monitoring network of the local earthquake bureau, and the local earthquake control system can receive earthquake waveforms, vibration intensity, time tags and geographic space locations through the distributed communication system.

[0032] The data aggregation and big data analysis system is used to determine earthquake occurrence information based on time tags and geographic spatial locations. Earthquake occurrence information refers to whether an earthquake has occurred or not.

[0033] Specifically, the data aggregation and big data analysis system is installed at the control center of the local earthquake bureau's monitoring network. The data aggregation and big data analysis system determines earthquake occurrence information based on time tags and geographic spatial locations, including: Determine earthquake propagation range based on time tags and geospatial locations; Determine whether the earthquake propagation range is greater than the preset earthquake propagation range; If yes, an earthquake occurred; if no, an earthquake did not occur.

[0034] Specifically, the earthquake propagation range represents the area of ​​vibration. The embodiment of the present application does not limit the specific process of determining the earthquake propagation range according to the time tag and the geographic space position, and the existing technology can be used; the preset earthquake propagation range is pre-set by the technician, and the preset earthquake propagation ranges corresponding to different target areas can be the same or different, and the embodiment of the present application does not limit it. When the earthquake propagation range is greater than the preset earthquake propagation range, it indicates that an earthquake has occurred in the target area; otherwise, it indicates that an earthquake has not occurred in the target area.

[0035] Furthermore, if an earthquake occurs, the data aggregation and big data analysis system performs the following steps: Determine the earthquake source location based on earthquake waveform, time tag and geospatial location; Obtain the earthquake intensity and assess earthquake damage information based on the earthquake intensity and earthquake intensity; Accordingly, the earthquake early warning system generates an earthquake emergency plan based on the epicenter location and earthquake damage information.

[0036] Specifically, the embodiments of the present application do not limit the specific process of determining the source location based on the earthquake waveform, time tag and geographic spatial location. The data aggregation and big data analysis system obtains the earthquake intensity from the earthquake intensity information library, which is generated and updated in real time by the earthquake bureau side equipment. The embodiments of the present application do not limit the process of generating the earthquake intensity by the earthquake bureau side equipment. Earthquake damage information includes the number of casualties and the number of damaged buildings.

[0037] Among them, the process of data aggregation and big data analysis system evaluating earthquake damage information based on vibration intensity and vibration severity includes: According to the preset correspondence between the vibration intensity and the number of damaged buildings and the vibration intensity, the number of damaged target buildings corresponding to the vibration intensity is determined; Obtain the time of earthquake occurrence, and determine the number of casualties based on the time of earthquake occurrence and the intensity of shaking.

[0038] Specifically, the correspondence between the preset vibration intensity and the number of damaged buildings is determined based on multiple historical data, including: obtaining multiple historical vibration intensity information of the target area, the historical vibration intensity information includes the occurrence frequency corresponding to the historical vibration intensity and the number of damaged buildings each time; for each historical vibration intensity, according to the occurrence frequency and the number of damaged buildings corresponding to all occurrence frequencies, determine the average number of damaged buildings corresponding to each historical vibration intensity, and then establish the preset correspondence between the vibration intensity and the number of damaged buildings; match the vibration intensity and the corresponding relationship to obtain the number of damaged target buildings. The earthquake occurrence time is the time corresponding to the first acquisition of the seismic wave attenuation signal.

[0039] Among them, according to the time of the earthquake and the intensity of the shaking, the number of casualties is determined as follows: Determine the target number of casualties corresponding to the vibration intensity according to the preset correspondence between the vibration intensity and the number of casualties and the vibration intensity; Determine whether the earthquake occurs at the preset sleeping time; If not, the target number of casualties is revised according to the time of the earthquake, and the revised target number of casualties is determined as the number of casualties; If so, the target number of casualties is determined as the number of casualties.

[0040] Specifically, the construction process of the preset correspondence between the vibration intensity and the number of casualties is the same as the establishment process of the correspondence between the vibration intensity and the number of building damages, and the embodiments of the present application will not be repeated. The preset sleeping time is 20:00 on the same day to 6:00 in the morning of the next day. It can be understood that when the earthquake occurs when the time is not within the preset sleeping time (i.e., the daytime period), the rate of people in the house is much lower than the rate of people in the house when the earthquake occurs when the time is within the preset sleeping time. At this time, the number of casualties in the target area will also decrease, so it is necessary to judge the time of the earthquake. If the earthquake occurs when the time is not within the preset sleeping time, the preset correction coefficient is obtained, and the preset correction coefficient is set by the technician, and then the corrected target number of casualties is determined according to the calculation formula. The calculation formula is: the corrected target number of casualties = the target number of casualties * the preset correction coefficient, in the embodiment of the present application 0 < correction coefficient < 1, and the corrected target number of casualties is determined as the number of casualties; otherwise, no correction is required. It can be understood that the rate of people in the house in the target area is different in different time periods, so the number of casualties is determined in combination with the preset sleeping time to effectively improve the accuracy of the determination of the number of casualties.

[0041] Furthermore, the earthquake early warning system can generate earthquake emergency plans based on the earthquake source location and earthquake damage information.

[0042] Specifically, earthquake damage information can be sent to the staff-side equipment of the Earthquake Bureau. The staff-side equipment of the Earthquake Bureau provides a corresponding earthquake emergency plan based on the epicenter location and earthquake damage information, and inputs the earthquake emergency plan into the earthquake early warning system to enable the earthquake early warning system to generate an earthquake emergency plan.

[0043] Furthermore, the functions of the data aggregation and big data analysis system also include sending the epicenter location and earthquake damage information to the early warning website.

[0044] The local seismic bureau monitoring network also includes local earthquake monitoring sensor systems, including: The local earthquake monitoring sensor system is used to collect seismic wave attenuation signals in non-target areas and send the seismic wave attenuation signals in non-target areas to the data aggregation and big data analysis system; Accordingly, the data aggregation and big data analysis system is used to determine whether an earthquake occurs based on the seismic wave attenuation signal in the non-target area; A local earthquake control system is used to generate an acquisition command for a target area when an earthquake in a non-target area is determined, and send the acquisition command to the optical fiber control system; After receiving the acquisition command, the fiber optic control system is used to send the earthquake waveform, vibration intensity, acquisition time and geographic location of the target area to the local earthquake control system through the distributed communication system.

[0045] Specifically, the non-target area is a non-residential area or a non-mining area; the process of determining whether an earthquake has occurred in a non-target area by the data aggregation and big data analysis system is the same as the process of determining earthquake information in a target area, and the embodiments of the present application will not be repeated. After the data aggregation and big data analysis system determines that an earthquake has occurred in a non-target area, the local earthquake control system generates a collection command for the target area and sends it to the optical fiber control system to determine whether an earthquake has occurred in the target area.

[0046] The functions of the fiber optic control system also include: Get the vibration duration of the target area; Determine whether the duration of the vibration is greater than a preset duration threshold, or determine whether the information on the change in the type of earthquake waveform conforms to earthquake characteristics; If the duration of the vibration is greater than the preset duration threshold, or if the information on the change in the type of earthquake waveform meets the characteristics of an earthquake, the earthquake information of the target area will be sent to the local earthquake control system through a distributed communication system.

[0047] Specifically, the preset time threshold is pre-set by the technician; in the embodiment of the present application, an earthquake is determined to have occurred when the seismic waveform changes from a longitudinal wave waveform to a transverse wave waveform; therefore, when the optical fiber control system determines that there is long-term vibration in the target area (i.e., the duration is greater than the preset time threshold), or, the optical fiber control system determines that there are obvious seismic features in the target area (i.e., the seismic waveform in the target area changes from a longitudinal wave to a transverse wave), the optical fiber control system sends a seismic wave attenuation signal to the local seismic control system.

[0048] The above description is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A distributed earthquake early warning system, characterized in that: It includes a local earthquake bureau monitoring network, an optical fiber sensing vibration monitoring network and a distributed communication system. The local earthquake bureau monitoring network includes a local earthquake control system, a data aggregation and big data analysis system and an earthquake early warning system. The optical fiber sensing vibration monitoring network includes an optical fiber control system, a sensing optical fiber system and a data acquisition system, wherein: A sensing optical fiber system, used for collecting seismic wave attenuation signals and vibration intensity in a target area, and sending the seismic wave attenuation signals and the vibration intensity in the target area to the data acquisition system, wherein the target area is a residential area and / or a mining area; A data acquisition system, used for converting the seismic wave attenuation signal of the target area into a seismic waveform, and sending the seismic waveform and the vibration intensity to the optical fiber control system; an optical fiber control system for acquiring the geographic spatial position of the sensing optical fiber system and collecting the time tag of the seismic wave attenuation signal, and sending the seismic waveform, the vibration intensity, the time tag and the geographic spatial position to the local seismic control system through the distributed communication system; A local earthquake control system, configured to receive the earthquake waveform, the vibration intensity, the time tag and the geographic space location and send them to the data aggregation and big data analysis system; A data aggregation and big data analysis system, for determining earthquake occurrence information according to the time tag and the geographic space location, wherein the earthquake occurrence information is whether an earthquake has occurred or not; The earthquake early warning system is used to generate earthquake emergency plans based on earthquake occurrence information.

2. The distributed earthquake early warning system according to claim 1, characterized in that: The data aggregation and big data analysis system is used to determine earthquake occurrence information according to the time tag and the geographic space location, including: determining an earthquake propagation range based on the time tag and the geospatial location; Determining whether the earthquake propagation range is greater than a preset earthquake propagation range; If yes, an earthquake occurred; if no, an earthquake did not occur.

3. The distributed earthquake early warning system according to claim 2, characterized in that: If an earthquake occurs, the data aggregation and big data analysis system performs the following steps: Determine the earthquake source location according to the earthquake waveform, the time tag and the geographic space location; Acquiring the earthquake intensity, and evaluating earthquake damage information based on the earthquake intensity and the earthquake intensity; Correspondingly, the earthquake early warning system generates an earthquake emergency plan according to the earthquake source location and the earthquake damage information.

4. The distributed earthquake early warning system according to claim 3, characterized in that: The earthquake damage information includes: the number of casualties and the number of damaged buildings, The data aggregation and big data analysis system evaluates earthquake damage information according to the vibration intensity and the vibration severity, including: Determining the number of target building damages corresponding to the vibration intensity according to a preset correspondence between vibration intensity and the number of building damages and the vibration intensity; The time of occurrence of the earthquake is obtained, and the number of casualties is determined based on the time of occurrence of the earthquake and the vibration intensity.

5. The distributed earthquake early warning system according to claim 4, characterized in that: The data aggregation and big data analysis system determines the number of casualties according to the earthquake occurrence time and the vibration intensity, including: Determining a target number of casualties corresponding to the vibration intensity according to a preset correspondence relationship between the vibration intensity and the number of casualties and the vibration intensity; Determining whether the earthquake occurrence time is a preset sleeping time; If not, the target number of casualties is corrected according to the time of occurrence of the earthquake, and the corrected target number of casualties is determined as the number of casualties; If so, the target number of casualties is determined as the number of casualties.

6. The distributed earthquake early warning system according to claim 1, characterized in that: The local earthquake bureau monitoring network also includes a local earthquake monitoring sensor system, wherein: A local earthquake monitoring sensor system, used for collecting earthquake wave attenuation signals in non-target areas, and sending the earthquake wave attenuation signals in the non-target areas to the data aggregation and big data analysis system; Accordingly, the data aggregation and big data analysis system is used to determine whether there is an earthquake based on the seismic wave attenuation signal in the non-target area; A local earthquake control system, for generating an acquisition command for the target area after an earthquake in the non-target area is determined, and sending the acquisition command to the optical fiber control system; The optical fiber control system is used to send the seismic waveform, the vibration intensity, the time tag and the geographic space position of the target area to the local seismic control system through the distributed communication system after receiving the acquisition command.

7. The distributed earthquake early warning system according to claim 1, characterized in that: The functions of the optical fiber control system also include: Obtaining the vibration duration of the target area; Determine whether the vibration duration is greater than a preset duration threshold, or determine whether the earthquake waveform type change information conforms to earthquake characteristics; If the duration of the vibration is greater than a preset duration threshold, or the earthquake waveform type change information conforms to the earthquake characteristics, the earthquake waveform, the vibration intensity, the time tag and the geographic space position are sent to the local earthquake control system through the distributed communication system.

8. The distributed earthquake early warning system according to claim 1, characterized in that: It also includes a timing system for providing time to the optical fiber control system.

Images