JP2904098B2 - Earthquake observation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earthquake observation system, and more particularly to an earthquake observation system which detects an earthquake, which is a natural phenomenon suddenly occurring on the sea floor, and transmits the detected data to a ground station without loss. It is about the system.

[0002]

2. Description of the Related Art In this type of conventional ocean bottom seismic observation system, equipment for earthquake observation is laid on the sea floor for a certain period,
After that, there is a method of collecting and collecting observation data, or a method of connecting the land station and the ocean bottom seismometer with a communication cable and collecting observation data at all times or as needed.

[0003]

In the former conventional seafloor seismic observation system described above, it is necessary to lay and collect seismic observing equipment at necessary places as needed, and laying and collecting on the seabed is extremely difficult. Difficult and costly, and it may not be possible to retrieve seismic equipment on the sea floor.

[0004] The latter seafloor seismic observation system has a fatal drawback that observation data cannot be collected if a land station at one point collapses due to an earthquake.

Accordingly, the present invention has been made to solve the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a low-cost seismic observation system capable of collecting seismic observations at multiple points on the seabed as required. Is to provide.

Another object of the present invention is to provide a seismic observation system in which observation data can be collected by providing redundancy even when a land station collapses due to an earthquake, thereby improving reliability. It is.

[0007]

According to the present invention, there is provided an earthquake observation system comprising: an optical multiplexer / demultiplexer provided at a predetermined location of an optical submarine communication cable connecting a plurality of ground stations; and a submarine earthquake connected to the optical multiplexer / demultiplexer. And seismic observation means for observation.

[0008] Each of the pre-Symbol ground station comprises means for transmitting the seismic observation command signal having a specific optical wavelength allocated in advance for the seismic observation means, said seismic observation means the seismic observation It has a receiving means for selectively extracting and receiving the command signal.

Further, the earthquake observation means includes a sensor for performing an earthquake observation in response to the earthquake observation command signal, and an optical signal having a specific light wavelength assigned to the earthquake observation means in advance. And transmitting means for converting the data to the optical submarine communication cable.

Further, the predetermined location is a plurality of locations, and an optical multiplexer / demultiplexer and an earthquake observation means are provided at each of the plurality of locations. It is characterized in that a unique optical wavelength for reception is assigned.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the present invention will be described. An optical multiplexer / demultiplexer is inserted at an arbitrary point of an optical communication cable connecting a plurality of ground stations, and seismic observation equipment is connected to the optical multiplexer / demultiplexer. ,
The transmission and reception of information between the seismic observation equipment and the ground station is performed by an optical wavelength multiplexing method.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic system diagram of an embodiment of the present invention. In FIG. 1, there are an A station 1 and a B station 2 which are ground stations, and these two stations are connected by an optical submarine communication cable 3. The optical submarine communication cable 3 is provided with a plurality of optical repeaters 4 at predetermined intervals. With this configuration, communication between the two ground stations A and B is possible.

Further, according to the present invention, seismometers 6-1 and 6-2 are provided at the seismic observing section, which is a necessary part of the sea floor. These seismometers 6-1 and 6-2 are connected to optical multiplexers / demultiplexers 5-1 and 5-2 inserted in the optical submarine communication cable 3, respectively.

The transmission of control information and the collection of observation data for observation by the seismometers 6-1 and 6-2 are assigned in advance to the respective seismometers 6-1 and 6-2. Wavelength multiplexing using unique optical wavelengths (WDM: Wavelength Dom
ain Multiplex) method. As a result, an observation command is transmitted from the ground station to each of the seismometers 6-1 and 6-2, and the respective observation data of the observers 6-1 and 6-2 is collected by the ground stations 1 and 2, respectively. can do.

FIG. 2 is a specific functional block diagram of the seismometer 6-1 of FIG. 1, and it is assumed that the other meters 6-2 have the same configuration. Referring to FIG. 2, the demultiplexed light from the optical multiplexer / demultiplexer 5-1 inserted into the optical submarine communication cable 3 is input to the optical multiplexer / demultiplexer 11 of the seismograph 6-1 and further demultiplexed, and band-passed. The signal is input to a filter (BPF) 12. Te this BPF12 smell, this earthquake observation meter 6-1
, Only the light of the unique wavelength assigned to is extracted.

The extracted optical signal of the wavelength is input to the optical / electrical signal converter 13, converted into an electric signal, and supplied to the earthquake sensor 14. If this electric signal is an earthquake observation command sent from the ground station 1 or 2, the sensor 14
Will perform seismic observation in response to this. If the electric signal is a command for transmitting the earthquake observation data transmitted from the ground station 1 or 2, the sensor 14 transmits the earthquake observation data in response to the command.

This observation data is transmitted to the electrical / optical signal converter 15
Is converted into an optical signal. At this time, the wavelength of the light is a unique wavelength assigned to the seismograph 6-1. Naturally, the wavelength is set to be different from the wavelength of the earthquake observation command or the earthquake observation data transmission command transmitted from the previous ground station. However, if the timings of these commands and observation data transmission are different, the same It is clear that the wavelengths may be used.

The observation data thus converted into an optical signal is input to the optical multiplexer / demultiplexer 5-1 inserted into the optical submarine communication cable 3 via the optical multiplexer / demultiplexer 11, and the cable 3
Is multiplexed with the communication information and transmitted to the ground station 1 or 2. The ground station 1 or 2 can collect the observation data by wavelength-separating and extracting the observation data using the BPF.

Here, when one ground station cannot transmit or receive information due to collapse due to an earthquake, the other ground stations can transmit and receive information. It is possible to collect the data of each earthquake observation.

In FIG. 1, two seismic observation units are provided. However, three or more observation units may be provided. In this case as well, optical multiplexing / demultiplexing is performed between each earthquake observation unit and the optical submarine communication cable. It is connected using a container.

[0022]

As described above, according to the present invention, an optical multiplexer / demultiplexer is inserted into a predetermined portion of an optical communication cable connecting a plurality of ground stations, and the seismograph is attached to the optical multiplexer / demultiplexer. connection,
The exchange of information between these seismometers and ground stations is WDM
By performing the method, it is possible to control and collect multipoint seismic observation data, and it is possible to collect observation data at all times or as needed. In addition, by using a plurality of ground stations, a redundant configuration is provided, and the failure of one ground station does not make it impossible to collect seismic observation data, thereby improving reliability.

[Brief description of the drawings]

FIG. 1 is a system block diagram of an embodiment of the present invention.

FIG. 2 is a block diagram showing a specific example of the seismograph shown in FIG.

[Explanation of symbols]

 1, ground station 3 optical submarine communication cable 4 repeater 5-1 5-2, 11 optical multiplexer / demultiplexer 6-1, 6-2 seismometer 12 BPF 13 optical / electrical signal converter 14 sensor unit 15 electricity / Optical signal converter

Claims (4)

(57) [Claims] An optical multiplexer / demultiplexer provided at a predetermined position of an optical submarine communication cable connecting a plurality of ground stations, and seismic observation means connected to the optical multiplexer / demultiplexer for observing a submarine earthquake. Earthquake observation system. 2. The ground station according to claim 1 , wherein each of said ground stations comprises :
Seismic view with a unique light wavelength pre-assigned to
Means for transmitting a measurement command signal, wherein the earthquake observation means comprises:
Receiving means for selectively extracting and receiving the earthquake observation command signal
Seismic observation system according to claim 1, wherein a. 3. The earthquake observation means according to claim 2 , wherein
Sensors that perform seismic observation in response to signals and the results of this observation
Is the unique light pre-assigned to this seismic
Converting said optical submarine communication cable into an optical signal having a wavelength
And transmitting means for transmitting the data to the terminal.
2. The earthquake observation system according to 2. 4. The method according to claim 1, wherein the predetermined location is a plurality of locations.
Optical multiplexer / demultiplexers and seismic observation means are provided at multiple locations, respectively.
And sent to each of these multiple seismic observation means
And that a unique optical wavelength for reception is assigned
The earthquake observation system according to claim 3, wherein: