JPH06201839A - Submarine station - Google Patents

Abstract

PURPOSE:To store observation data on all movements of the earth submarine crust without increasing the storage capacity of a storage device even when movements of the earth's crust exceeding the presupposed number occur. CONSTITUTION:The submarine station is constituted in such a way that a diastrophism detection part 17 and an occurrence number-of-times counter 15 are installed, that the occurrence number of movements of the earth's crust is counted, that observation data stored in a data storage part 23 is compressed by using a data compression part 19 when the occurrence number of movements of the earth's crust exceeds the preset number and that the compressed observation data is stored in a storage part 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an undersea station which is installed in the sea or on the seabed and is provided with an observation device for observing crustal movements occurring on the seabed.

[0002]

2. Description of the Related Art As a device for observing crustal movements of the deep sea floor along a trench in which an ocean plate sinks, a system has been proposed in which a submarine station equipped with an observing device for observing crustal movements is installed on the deep sea floor. In this system, in order to be able to store long-term observation data,
The observation data is stored using a large-capacity storage device such as an optical disk.

Further, as a method of storing observation data, when an occurrence of an earthquake on the deep sea floor is detected, a method of storing the observation data only for a certain period after the occurrence of the occurrence of the earthquake is used. Even if the observation data is converted into a multi-bit digital value with a short sampling interval in order to obtain detailed data regarding fluctuations, the total amount of these data does not exceed the amount that can be stored in the storage device. .

[0004]

However, in the configuration proposed above, the storage capacity of the storage device is determined according to the expected frequency of earthquakes, and the usable storage area is determined for each set period. ing. Therefore, if the number of earthquakes exceeds the expected number of times within the set period, the amount of data to be stored will exceed the amount of data that can be stored in the storage area defined as the usage area. With respect to seismic waveform data that exceeded the limit, there was a problem that such data could not be stored.

The present invention was devised to solve the above problems, and an object thereof is to increase the storage capacity of a storage device even when crustal movements occur more than the number of times assumed in advance. The purpose is to provide an undersea station that can store observation data of all crustal movements.

[0006]

In order to solve the above-mentioned problems, the undersea station of the present invention is applied to an undersea station provided in the sea or at the bottom of the sea and provided with an observation device for observing crustal movements, and is preset. When the observation period is the observation period and the observation data is the observation period, the data storage unit that stores the observation data during the observation period and the crustal movement that detects the occurrence of crustal movement based on the observation data A detection unit, an occurrence counter that counts the number of times that the crustal movement detection unit detects crustal movements during the observation period, and a data storage unit when the count value of the occurrence counter exceeds a preset value. A data compression unit that reads the stored observation data and compresses the read observation data, and a compression unit that compresses the observation data. A configuration that includes a storage device for storing the observation data. Further, a configuration is adopted in which the data storage unit is a storage area provided in the storage device.

[0007]

When the count value of the number-of-occurrence counter exceeds a preset value due to frequent crustal movements, the total amount of data to be stored in the storage device is larger than the total amount of data that can be stored in the storage device. Becomes Therefore, the data compression unit reads the observation data stored in the data storage unit and compresses the read observation data to reduce the total amount of the observation data to a data amount that can be stored in the storage device. Then, the observation data whose total amount has been reduced is guided to the storage device and stored therein.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an undersea station according to the present invention will be described below with reference to the drawings.

FIG. 2 is an explanatory view showing a long-term seafloor observation system to which an embodiment of the undersea station according to the present invention is applied. The outline of this system will be described below.

In the figure, it is the seabed to be observed,
On the seabed 83 along the trench 82 where the ocean plate sinks, an undersea station 10 with a frame formed in a substantially square pyramid as a structural member and 16 data transmission buoys 88 detachably attached to each is installed. Has been done.

An observation device for observing crustal movements is attached to the subsea station 10, and a storage device and other devices (described later in detail) are provided for storing observation data sent from the observation device. Has been.

The observed data are as follows:
Of the data transmission buoys 88 attached to the undersea station 10, the data transmission buoy 88 to be levitated is stored inside. The data transmission buoy 88, which was detached from the subsea station 10 and floated above the sea surface 87, is a communication satellite.
(Inmarsat-C) 84 Sends observation data.

Therefore, the observation data transmitted from the data transmission buoy 88 is relayed by the communication satellite 84 to the ground station 85.
Received at. Then, the observation data received by the ground station 85 is guided to a ground station 86 whose main part is an arithmetic unit for processing the observation data via a data line such as a telephone line and is analyzed.

FIG. 1 shows an undersea station 10 according to the present invention.
FIG. 3 is a block diagram showing an electrical configuration of one embodiment. First, the mutual connection of the blocks will be described.

The output of the observation instrument 12 is led to the buffer memory 16 via the A / D converter 14, and the output of the seismograph 13 is A / D.
It is sent to the buffer memory 16 via the D converter 15. The output of the buffer memory 16 is introduced into the storage device 22.

The output of the A / D converter 15 is also given to the crustal movement detecting section 17, and the output of the crustal movement detecting section 17 is given to the occurrence counter 18 and the buffer memory 16. The output from the number-of-occurrence counter 18 is led to the rewrite buffer memory 20 and the format conversion unit 21.

The output of the storage device 22 is sent to the rewrite buffer memory 20, and the output of the rewrite buffer memory 20 is introduced to the format conversion section 21. The output of the format conversion unit 21 is given to the storage device 22, and the output of the storage device 22 is guided to the data transmission buoy 88 attached to the undersea station 10.

In this embodiment, the observation device 11 is
It consists of two blocks, the observation instrument 12 and the seismograph 13, and the data compression unit 19 includes a rewrite buffer memory 20.
And the format conversion unit 21. The data storage unit 23 is a storage area provided inside the storage device 22.

The details of the configuration of each block will be described below.

The observation instrument 12 is a hydrophone for detecting underwater sound, an inclinometer for detecting the inclination of the seabed installed, a flow velocity meter for detecting the velocity and direction of the tidal current, and a salinity concentration for detecting the salinity concentration of seawater. The block consists of a thermometer, a thermometer that detects the temperature of seawater, a depth meter that detects the depth of the seabed, and a heat flow meter that detects the static temperature (crustal temperature) of the seabed. The seismograph 13 is a block that detects shaking of the seabed where the undersea station 10 is installed.

The A / D converter 14 is a block for A / D converting the output of each instrument of the observation instrument 12 and sending the converted output to the buffer memory 16 as observation data. The sampling interval depends on the type of instrument. Different (the output of the hydrophone is a voice band signal, so its sampling interval is set to the shortest).

The A / D converter 15 is a block that A / D converts the output of the seismograph 13 and sends the converted output as observation data to the buffer memory 16 and the crustal movement detection unit 17. The memory 16 is a memory for temporarily storing the data output from each of the A / D converters 14 and 15.

The storage device 22 is a large-capacity storage device composed of an optical disk capable of writing and erasing data.

The data storage unit 23 is a storage area assigned to the inside of the storage device 22 in order to store observation data in an observation target period which is a preset period (one month), and is a buffer memory. This area is where the observation data temporarily stored in 16 is stored.

In FIG. 1, one data storage unit
Although only 23 is shown in the figure, in the actual device, since the duration of observation at the deep sea floor is one year, 12 observation periods are set in advance, and the block of the data storage unit 23 is set. The number is 12 corresponding to the number of observation target periods. Note that the number of blocks in the data storage unit 23 does not necessarily have to correspond to the number of observation target periods.

Based on the A / D converted output of the seismograph 13, the crustal deformation detecting section 17 determines that a crustal deformation has occurred when a signal indicating the shaking of the seabed appears in the output of the seismograph 13.
It is a block that outputs an output indicating the detection to the occurrence counter 18.

The occurrence number counter 18 is a block for counting the number of times the crustal deformation detecting section 17 detects crustal deformation. The rewriting buffer memory 20 has a preset count value of the occurrence number counter 18. When it exceeds the value, it is a block for reading and storing the observation data stored in the data storage unit 23.

Further, when the count value of the occurrence counter 18 exceeds a preset value, the format conversion section 21 adapts the adaptive prediction code to the digital value indicating each value of the data stored in the rewrite buffer memory 20. The observation data is compressed by using the digitization method. The compressed observation data is sent to the data storage unit 23 and is a block for storage.

The data transmission buoy 88 internally stores the observation data stored in the storage device 22 in the latest observation target period. When it is separated from the undersea station 10 and floats above the sea surface 87, it serves as a block for transmitting the stored observation data to the communication satellite 84.

The operation of one embodiment of the present invention having the above configuration will be described below.

When one of the 12 observation periods starts, the data storage unit 23 is set in the storage device 22 as a storage area for observation data in the observation period (that is, data storage). The unit 23 serves as a mere storage area for the observation data when the observation data is not compressed, and serves as a temporary storage area for the observation data when the observation data is compressed. Data storage area).

In this state, the observation data from the observation instrument 12 (excluding the observation data from the hydrophone) is
It is converted into a digital value by the A / D converter 14 and stored in the buffer memory 16. When a predetermined amount of observation data is stored in the buffer memory 16, these observation data are sent to the data storage unit 23 and stored therein.

When crustal deformation occurs on the sea floor while repeating the above operation, a signal waveform indicating crustal deformation appears in the output of the seismograph 13, so this crustal deformation is detected by the crustal deformation detecting section 17.

Therefore, the crustal movement detector 17 gives the buffer memory 16 an instruction to start storing the observation data from the seismograph 13 and the observation data from the hydrophone. Further, the crustal movement detection unit 17 gives an instruction to the occurrence counter 18 to update the count value by one.

As a result of the above operation, the buffer memory 16
The observation data from the seismograph 13 and the hydrogen are stored for a certain period after the start of the crustal movement.
When this period elapses, the buffer memory 16
The observation data stored in is sent to the data storage unit 23,
Remembered.

The above operation is repeated each time a crustal deformation occurs. Therefore, the observation data is sequentially stored in the data storage unit 23.

When the count value of the occurrence counter 18 exceeds a preset value due to frequent occurrence of crustal deformation in the repetition of the above operation, a large amount of observation data has already been stored in the data storage unit 23, and therefore the data storage unit The remaining empty area in 23 is extremely small (there is no free area to store the observation data when the crustal deformation occurs next time).

Therefore, when the count value of the occurrence number counter 18 exceeds a preset value, the rewrite buffer memory 20 reads out and stores the observation data stored in the data storage unit 23, and thereby the data storage unit Create an empty area at 23. The format conversion unit 21 also performs data compression on the observation data stored in the rewriting buffer memory 20, and stores the compressed observation data in the data storage unit 23.
Store it in the empty area.

By the above operation, an empty area is created in the data storage unit 23 for the observation data of the crustal movement that occurs thereafter. When a crustal deformation occurs and the observation data is stored in this empty area, the value of the occurrence counter 18 is also updated by one.

In response to this update of the occurrence counter 18, the rewrite buffer memory 20 again reads the observation data from the data storage unit 23 and stores it. In addition, the format conversion unit 21 further compresses the observation data again, and sends the compressed observation data to the data storage unit 23. That is, the data compression unit 19 creates a new empty area in the data storage unit 23 without losing the observation data of the crustal movement that has already been stored.

After that, the same operation is repeated, and when a crustal deformation occurs, an empty area for storing the observation data when the next crustal deformation occurs is stored in the data storage unit 23.
In order to create the above, the data compression unit 19 further compresses the observation data stored in the data storage unit 23.

When the observation period ends,
The observation data stored in the data storage unit 23 is sent to the data transmission buoy 88 and stored therein (at this time, the observation data stored in the data storage unit 23 is maintained in that state). After that, the data transmission buoy 88 is separated from the undersea station 10 and floats toward the surface of the sea. Then, the data transmission buoy 88 transmits the observation data stored therein to the communication satellite 84 when it floats.

Since the number of occurrences of crustal deformation is small, if the observation period ends without the count value of the occurrence counter 18 reaching a preset value, it is stored in the data storage unit 23. The observed data is maintained in the formatted state sent from the buffer memory 16.

The present invention is not limited to the above embodiment, and the observation data compression method by the format conversion unit 21 has been described for the case where the observation data is compressed by the adaptive predictive coding method for digital data. As other configurations, it is possible to use, for example, a logarithmic compression method or a compression method such as an ADM method, and further, a configuration in which observation data is thinned out at regular intervals, or an observation that shows a slight crustal movement. It is possible to adopt a configuration of thinning out data, a configuration of discarding lower bits, or the like.

As a method for detecting the crustal movement in the crustal movement detecting section 17, the case where the crustal movement is detected based on only the output of the seismograph 13 has been described. It is possible to adopt a configuration in which the crustal movement is detected based on both the output of the above and the output of the hydrophone.

Further, when the storage capacity of the buffer memory 16 is set to a capacity for storing all of the observation data in the observation target period, the buffer memory 16 can be used as the data storage unit 23 (in this case, the buffer memory 16 is used). A configuration in which the output of the memory 16 is guided to the storage device 22 and directly to the format conversion unit 21 and the rewriting buffer memory 20 is omitted is used.In this configuration, when it is not necessary to compress the observation data ( If the crustal movement does not occur frequently), the observation data in the buffer memory 16 is directly guided to the storage device 22 and stored therein.

Regarding the installation position of the undersea station 10, the case where the position is on the seabed has been described.
It is possible to configure the installation position in the sea.

[0048]

The undersea station according to the present invention is provided with a crustal movement detecting section and an occurrence number counter to count the number of times of crustal movements, and when the number of crustal movements exceeds a preset number. By compressing the observation data stored in the data storage unit using the data compression unit and storing the compressed observation data in the storage device, the total amount of observation data is set as the amount of data that can be stored in the storage device. Therefore, even when the crustal deformation occurs more than the number of times assumed in advance, it is possible to store the observation data of all crustal deformation without increasing the storage capacity of the storage device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of an embodiment of an undersea station according to the present invention.

FIG. 2 is an explanatory diagram showing an outline of a seabed long-term observation system to which an embodiment of the undersea station of the present invention is applied.

[Explanation of symbols]

 11 Observation device 17 Crustal movement detection unit 18 Occurrence counter 19 Data compression unit 22 Storage device 23 Data storage unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kyohiko Mitsuzawa 2-15 Natsushima-cho, Yokosuka City, Kanagawa Prefecture Ocean Science and Technology Center

Claims (2)

[Claims] 1. An undersea station provided in the sea or at the bottom of the sea where an observing device for observing crustal movements is installed, and a preset period is set as an observation target period, and the data observed by the observing device is observed data. , The data storage unit that stores the observation data during the observation period, the crustal deformation detection unit that detects the occurrence of crustal movement based on the observation data, and the crustal movement detection unit that detects the crustal movement during the observation period. An occurrence counter that counts the number of times of detection, and when the count value of the occurrence counter exceeds a preset value, the observation data stored in the data storage unit is read and the read observation data is compressed. A data compression unit and a storage device for storing the observation data compressed by the data compression unit Underwater station characterized by. 2. The data storage unit is a storage area provided in the storage device.
Undersea station described.