KR20200114499A - Communication apparatus and method for between shore side and ship side - Google Patents

Abstract

The present invention may provide a communication apparatus between shore side and ship side, and a method thereof. According to the present invention, the communication apparatus may comprise: a ship communication control unit which is a satellite communication unit connected to a communication satellite and is installed on a ship to transmit a communication file to a shore communication unit; a ship positioning unit which periodically collects ship position information with a satellite navigation correction system during the operation of the ship; a weather forecast processing unit for collecting weather information by time and coordinates along a ship progress route for the ocean to be operated by the ship; a data management unit which records and stores the ship position information collected by the ship positioning unit, the weather information collected by the weather forecast processing unit, and the transmission speed for each communication file when transmitting the communication file through the ship communication control unit; and a weight adjustment unit which increases or decreases the transmission speed by applying a weight to the transmission speed based on the weather information corresponding to the ship position information of the data management unit at the transmission time of the communication file.

Description

Communication device and method between land and ship {COMMUNICATION APPARATUS AND METHOD FOR BETWEEN SHORE SIDE AND SHIP SIDE}

The present invention relates to an apparatus and method for communication between land and ship.

In general, communication networks have been developed as TCP/IP-based wired, wireless networks, and satellite communications starting with wired connections.

In particular, satellite communication is a communication method that communicates between an earth station and an earth station by using a communication satellite floating above the surface. It is a radio frequency band of 3 to 30 GHz and a wavelength of 1 to 10 Cm, which is a super high frequency (SHF) frequency band. It is used to provide various communication services and broadcasting services by using.

The SHF frequency band for satellite communication is usually 1 GHz or more, and since this band occupies most of the frequency band occupied by microwaves, it may be commonly referred to as microwaves.

The function of a communication satellite is similar to that of a relay station in terrestrial microwave communication, and it receives a signal emitted from a certain earth station, amplifies it, and retransmits it to another earth station.

That is, in the case of terrestrial microwave communication, since several repeaters are required in the middle of transmission for long-distance transmission, in consideration of this point, communication can be performed with a communication satellite floating above the surface as a repeater.

In addition, the path through which a transmitting earth station (e.g., land or sea) and a receiving earth station are connected through one satellite means a satellite link, and at this time, the signal from a certain earth station to the satellite is an uplink signal. A signal from a satellite to another earth station is called a downlink signal.

In the case of geostationary orbit satellites, only three satellites can cover the world's communication network except for the polar regions, enabling communication in a wide range. Since the SHF frequency band is used as a carrier, a lot of data can be transmitted quickly and the signal to be transmitted It has the advantage of being able to communicate by converting it to digital.

Accordingly, communication between the land and the ship is performed through a wireless network or satellite communication.

For example, communication between ships and land according to the prior art uses an inmarsat maritime satellite floating on earth's geostationary orbit.

However, satellite communication may cause a transmission delay of at least 238ms to a maximum of 278ms compared to terrestrial communication, and in terms of the amount and speed of web service traffic of terrestrial communication, it may require a lot of traffic to be used on a ship, and the effect of satellite solar eclipse. It is difficult to perform communication when receiving a signal, it is highly affected by the atmosphere or climate, and when there is solar interference, typhoons, heavy rain, heavy rain, and the satellite radio waves are scattered or absorbed by the water in the air, the signal strength is reduced. Due to rainfall attenuation or atmosphere attenuation, there is a disadvantage in that communication quality is abnormal or communication is temporarily stopped.

In particular, ships cannot enter the port when there is a tsunami in the case of unforeseen weather or rain and wind, but ships that have not been contacted due to communication failure or communication failure try to enter the inner port. You may be exposed to accidents due to communication situations, such as a major accident you encounter.

In addition, long-distance vessels traveling to and from the sea must periodically perform satellite communication with the land control center of the ground base station for possible maritime environments and weather conditions that may occur on the vessel's progress route. Various related safety information, accident information, and weather information may be faced with difficulties that may not be transmitted from the land control center.

In addition, the condition of the satellite communication network may be important in order to transmit data on land while sailing a ship.

There are also shaded areas for satellite communication within the ship's path (eg, ship operation section), and there are many sections with poor communication conditions.

In addition, there is a problem in that a file for communication to be transmitted over land can be continuously created periodically, attempts to transmit a file having a large file size are frequently failed, and files to be transmitted continue to accumulate.

In addition, the ship has the disadvantage of wasting only time while attempting to communicate without considering the weather or marine environment when attempting to transmit data or files in situations such as satellite communication failure or interruption. It is possible to reliably successfully transfer files from ship to shore even under adverse conditions by actively adjusting the communication speed or dividing and transmitting the file size in consideration of the size of the file to be attempted, communication speed, and weather conditions according to the location of the ship. Technology development is urgently required.

In the present invention, the transmission speed is increased or decreased based on the ship location information such as the current ship's latitude and longitude and the weather information at the current location, or in the case of a long-distance marine round-trip ship, in consideration of a successful case of communication in the same weather at the same location in the past. By controlling the communication speed or by adjusting the divided compression ratio and transmitting the file size by dividing and compressing the file size into a transferable file size, the success rate of file transfer can be increased, and a communication computer that uses a firewall switching hub or communicates with a communication satellite can be used. By monitoring the communication of other target computers in the ship, when accessing the Internet network through the satellite between the ship and land, the target computer inside the ship is exposed to the land Ethernet network due to a cyber attack, which can prevent the security vulnerability. It is intended to provide an apparatus and method for communication between ships.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those of ordinary skill in the technical field to which the present invention belongs from the following description. I will be able to.

In order to solve the problems as described above, the present invention includes a ship communication control unit installed on a ship to transmit a communication file to a land communication unit to a satellite communication unit connected to a communication satellite; A ship positioning unit that periodically collects ship position information with a satellite navigation correction system during the operation of the ship; A weather forecast processing unit for collecting weather information by time and coordinates along a ship progress route for the ocean to be operated by the ship; The ship location information collected by the ship positioning unit, the weather information collected by the weather forecast processing unit, and the transmission speed for each communication file when the communication file is transmitted through the ship communication control unit are recorded and stored. A data management unit; And a weight adjustment unit that increases or decreases the transmission speed by applying a weight to the transmission speed based on the weather information corresponding to the ship location information of the data management unit at the time of transmission of the communication file. A communication device may be provided.

In addition, the ship communication control unit, at the time of transmission of the communication file, determines that if the weather is bad based on the weather information for each ship location information of the ship, the communication state is lowered compared to the normal weather state, and the communication file The transmission of the communication file can be attempted by increasing the split compression ratio for.

In addition, the data management unit, the ship communication control unit, the ship position determination unit, the weather forecast processing unit and the weight application unit is accessiblely connected, and the ship position information or maritime environment information having a relationship with the weather information , Transmission rate information, transmission file information, and transmission success information can be recorded and managed by time or by event in the storage device of the data management unit in the form of a database.

In addition, in the ship communication control unit, fog, rainfall, snowfall, wind direction, wind speed, wave height, wave period, air pressure, and temperature by a plurality of measurement equipment provided on the ship to generate a correction value for the marine environment to be used for determining the transmission speed. The marine environment measuring unit that measures the measurement may be connected.

In addition, according to another aspect of the present invention, to transmit a communication file to the land communication unit through the communication satellite, the ship communication control unit installed on the ship connecting to the communication satellite; Periodically collecting ship position information by a satellite navigation correction system of a ship positioning unit during the operation of the ship; Collecting weather information for each time and coordinates by a weather forecast processing unit along the ship's progress route; Transmission speed is monitored based on the weather information and transmission speed information matched with the ship location information, and the transmission speed is calculated by adding a weighted value to the previous data transmission rate and a weighted value to the past successful transmission rate. Determining; Transmitting a communication file at the predetermined transmission rate; And when the transmission of the communication file to the land communication unit is successful through the communication satellite at the predetermined transmission rate, transmission success information having a successful transmission rate searchable for each of the ship location information and the weather information is transmitted by the data management unit. A method of communication between land and ship including the step of being stored in a storage device may be provided.

In addition, the transmitting of the communication file at the predetermined transmission rate may include: calculating, by the data management unit, a transmission rate of the transmission success file, and removing the transmission success file from the transmission folder; Sorting, by the data management unit, communication files in a transmission folder in the order of recent creation; Monitoring whether the most recent communication file in the transmission folder can be transmitted within a specific time period and attempting to transmit the communication file; And when transmission is not possible within the specific time, dividing and compressing the file size into a transferable file size, and attempting to transmit the divided compressed file.

According to the communication device and method between land and ship according to an embodiment of the present invention, satellite communication through a data management unit that records and manages ship location information, weather information, maritime environment information, transmission speed information, transmission file information, and transmission success information. There is an advantage of realizing reliable file transmission by increasing or decreasing the transmission speed of the city and adjusting the split compression ratio.

In addition, according to the communication device and method between land and ship according to an embodiment of the present invention, the ship communication control unit may be composed of a communication computer that performs satellite communication, and a target computer used inside the ship. There is an advantage of using a wall switching hub or monitoring communication between a communication computer and a target computer to improve communication security performance in a ship.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those of ordinary skill in the art from the following description. will be.

1 is a block diagram of a communication device between land and a ship according to an embodiment of the present invention.
FIG. 2 is a flowchart of a method of communicating between land and ships implemented by the apparatus shown in FIG. 1.
3 is a detailed flowchart of a communication file transmission step shown in FIG. 2.
4 is a detailed flowchart of an attempt to transmit a file for communication shown in FIG. 3.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The detailed description to be disclosed hereinafter together with the accompanying drawings is intended to describe exemplary embodiments of the present invention, and is not intended to represent the only embodiments in which the present invention may be practiced.

In the drawings, parts irrelevant to the description may be omitted in order to clearly describe the present invention, and the same reference numerals may be used for the same or similar components throughout the specification.

In the drawings, FIG. 1 is a configuration diagram of a communication device between land and a ship according to an embodiment of the present invention.

Referring to FIG. 1, the communication device 10 between the land and the ship includes a ship communication means 11 that can be provided in a ship, such as a system that is largely systematically connected, and a land communication means 12 that can be provided on land. And it may include a communication satellite 13 for connecting these means (11, 12) to a satellite communication network.

In more detail, the communication device 10 between the land and the ship is a configuration of the ship communication means 11, the ship communication control unit 100, the satellite communication unit 110, the weather forecast processing unit 120, the ship positioning unit 130 , Marine environment measurement unit 140, weight adjustment unit 150, data management unit 160, may mean a storage device 167.

Ship communication means (11) and land communication means (12) are satellite-using equipment, EPIRB (Emergency Position Indicating Radio Beacon), NBDP (Narrow Band Direct Printing Telegraphy) equipment for distress communication, safety communication, navigation alarm, and weather information. , Global maritime distress and safety system (GMDSS) including maritime satellite communication equipment (INMARSAT-C), comprehensive control system for fishing vessels (V-Pass), navigation from pier to pier for safety and security in the sea, and protection of the marine environment And e-Navigation system that processes the collection, integration, exchange, expression and analysis of marine information, satellite antenna, communication computer with satellite transmission/reception card, and satellite communication equipment for land control centers, so limited to specific devices May not be.

For example, the ship communication means 11 according to the present embodiment includes a firewall switching hub (not shown), and a communication computer that is connected to the firewall switching hub and can be interlocked with the satellite using equipment to communicate with the communication satellite 13 It may include (eg, onboard computers) and other target computers on board (eg, computers for networking for the operation of shipboard equipment or user computers for Internet use).

In addition, the ship communication means 11 may also include a software means capable of monitoring a cyber attack (e.g., comparison check and analysis) when accessing the Internet network through a satellite between the ship and land through a target computer and a communication computer, In this case, the target computer inside the ship can be exposed to the onshore Ethernet network and thus can be prevented from becoming vulnerable in terms of security.

The land communication means 12 is a land communication unit 20 provided on land to receive communication files from the ship communication means provided on the ship, including a server facility of a land control center or a computer capable of satellite communication, a satellite antenna, etc. I can.

For example, the land communication unit 20 may collectively refer to a satellite communication network facility for land, a control station, a reference station, and a server and a computer of a land control center, not shown.

The communication satellite 13 is connected between the ship communication means 11 and the land communication means 12, and is a satellite communication protocol (for example, Statistical Multi-Channel MAC Protocol) or an Internet protocol (for example, FTP (file transfer protocol), It may mean a geo-stationary orbit satellite that supports HTTP (Hypertext transfer protocol) and RDP (remote desktop protocol)) and a commercial satellite that provides other ship-related satellite communication services.

In more detail, the communication computer as the ship communication means 11 may be configured in the form of a ship communication control unit 100 and an additional device (not shown) related to satellite communication.

The ship communication control unit 100 transmits a communication file to the land communication unit 20 to the satellite communication unit 110 connected to the communication satellite 13, or is installed on the ship to receive communication signals or data from the communication satellite 13. There may be.

The ship positioning unit 130 is connected to the ship communication control unit 100 and may play a role of periodically collecting the ship position information 161 to the satellite navigation correction system during the operation of the ship.

The satellite navigation correction system may mean a device that can be mounted on a ship to process DGPS (Differential GPS: Differential Position Information).

Here, the DGPS (Differential GPS) can maximally correct location data whose accuracy is lowered by an error code.

In other words, DGPS refers to an error part of the location data received from a satellite from a reference station that knows accurate location data.

The ship positioning unit 130 having the DGPS configuration is connected to a DGPS control station and a reference station/DGPS site that plays a role of transmitting DGPS correction values, and improves position accuracy through the received correction values. It has an advantage that can be made.

The weather forecast processing unit 120 is connected to the ship communication control unit 100 and plays a role of collecting weather information for each time and coordinates along the ship's progress route for the ocean to be operated by the ship.

The data management unit 160 transmits the ship location information collected by the ship position determination unit 130, the weather information collected by the weather forecast processing unit 120, and the communication file through the ship communication control unit 100. It may play a role of recording and storing the transmission speed of each file for communication and providing the search result to the ship communication control unit 100 and the weight adjustment unit 150.

In addition, the data management unit 160 is accessably connected to the ship communication control unit 100, the ship positioning unit 130, the weather forecast processing unit 120, the marine environment measurement unit 140, and the weight application unit 150. And the marine environment information 163, transmission speed information 164, transmission file information 165, and transmission success information 166 having a relationship with the ship location information 161 or weather information 162 in a database format. The data management unit may play a role of recording and managing the storage device 167 by time or event.

For example, the transmission file information 165 may be composed of data and information identifiers for storing, sorting, deleting, and modifying communication files through a transmission folder.

In addition, the data management unit 160 may play a role of storing the past success rate in the transmission success information 166.

Here, in the case of a ship that travels to and from the ocean along the ship's progress route, ship location information 161, weather information 162, and transmission speed information 164 are stored in the storage device 167 of the data management unit 160 in real time. It can be recorded and managed in the form of history information.

That is, the transfer rate of success in the past may mean a transfer rate recorded when a file transfer is successful by transmitting in the same or similar location and the same or similar weather among the history information collected and recorded while the ship has been operating in the past.

This past success rate may be recorded and managed in the transmission success information 166 through the data management unit 160 or may be rate data that can be searched and used.

When the weight adjustment unit 150 tries to transmit a communication file based on weather information corresponding to the ship location information that can be recorded and managed in the data management unit 160 at the time of transmission of the communication file, the weight is applied to the transmission speed of the communication file. By applying the transmission rate to or from the above, the satellite communication success rate can be increased and the time required for communication success can be reduced.

In addition, when the communication file is transmitted, the ship communication control unit 100 determines that if the weather is not good based on the weather information for each ship location information of the ship, the communication state is lower than the normal weather state, and divides the communication file. It may also play a role of attempting to transmit the communication file by increasing the compression ratio.

In addition, the marine environment measurement unit 140 mentioned above may be connected to the ship communication control unit 100.

The marine environment measurement unit 140 generates a marine environment correction value to be used for determining the transmission speed of a communication file to be transmitted to the land communication unit 20 through the communication satellite 13 during the operation of the vessel, According to (not shown), it may consist of a device and operating program that measures fog, rainfall, snowfall, wind direction, wind speed, wave height, wave period, air pressure, and temperature.

Hereinafter, a communication method using the device configuration described above will be described.

FIG. 2 is a flow chart of a method for communication between land and ships implemented by the apparatus shown in FIG. 1, FIG. 3 is a detailed flowchart of the communication file transmission step shown in FIG. 2, and FIG. 4 is a communication file shown in FIG. This is a detailed flowchart of the transmission attempt step.

Referring to FIG. 2, a step (not shown) of connecting a ship communication control unit installed on a ship to a communication satellite may be initiated so as to transmit a communication file to a land communication unit through a communication satellite.

Various step-by-step descriptions to be described later, including the step of connecting to the communication satellite, may be automatically performed by a program set in the memory (not shown) of the ship communication control unit 100.

The connection of the communication satellite or adjustment of the transmission rate (eg, weight application) may be performed periodically or automatically according to a predetermined time, or may be performed when a communication connection event occurs by a user.

Thereafter, during the operation of the ship, a step (S100) of periodically collecting ship position information by the satellite navigation correction system of the ship positioning unit may be performed.

In addition, a step (S200) of collecting weather information for each time and coordinates by the weather forecast processing unit may be performed along the ship progress path of the ship.

Meanwhile, during the operation of the ship, a step (S300) of collecting the marine environment information around the ship by current ship location information may be further performed in order to correct more accurate weather information and weather information.

The marine environment information around the ship directly collected from the ship can be used as a correction value for weather information, or can be used to adjust the transmission speed in the form of a marine environment correction value.

The transmission speed is monitored (e.g., comparison check and analysis) based on the weather information and transmission speed information matched with the ship location information (S400), and if correction of the transmission speed is not necessary, the transmission speed is the previous data transmission speed. It can be maintained the same as (S550).

However, in order to overcome the satellite communication environment changed according to various reasons such as attenuation of rainfall or atmospheric attenuation analyzed according to the weather information collected or the weather information collected at the ship's location, the monitoring result is displayed in the ship location information. When it is necessary to adjust the transmission rate based on matching weather information, maritime environment information, and transmission rate information, a weighted value (e.g., the first value) to the previous data transmission rate and a weighted value applied to the past successful transmission rate The transmission rate can be determined by the sum of (eg, the second value).

Alternatively, the transmission speed is determined by adding a weighted value to the previous data transmission rate, a weighted value applied to the past successful transmission rate, and a value obtained by applying a dissolution environment correction value to the previous data transmission rate (e.g., a third value). Step S500 may be performed.

The data transfer rate just before the bad weather is the transfer time divided by the size of the transferred file. For example, if a 16KB file is transferred in 2 minutes, the transfer rate can be 8KB per minute.

However, when it is predicted that normal communication or communication at the existing transmission speed is not possible when considering the current ship location information and weather information or maritime environment information, the transmission speed can be adjusted.

That is, the corrected or adjusted transmission rate is 2.4 KB/min (eg, the first value) calculated by applying a weight of 30% to the previous data transmission rate (eg, multiplying by 0.3), ship location information, weather information, and transmission. As can be seen through the search for success information and transmission speed information, a weighted 70 on the past successful transmission rate (e.g. 6 KB/min) corresponding to the case in which the transmission of the communication file was successful in the same or similar location-specific weather as the current ship. The sum of 4.2 KB/min (eg, the second value) calculated by applying a% (eg, multiplying by 0.7) may result in a sum of 6.6 KB/min, which is the sum of the first value and the second value.

Here, the weight or the marine environment correction value may be determined through statistical data analysis data, big data analysis data, or simulation, and thus may not be limited to a specific value.

In addition, since the full speed of the communication file is determined by reflecting the weather for each location of the ship and the result of successful communication in the past, as a result, there is an advantage of reliably securing the satellite communication success rate of the current ship.

In addition, the step (S600) of transmitting the communication file at the predetermined transmission rate as described above may be performed through the ship communication control unit 100 and the satellite communication unit 110 of FIG. 1 described above.

In addition, the result of the communication file normally transmitted to the land communication unit 20 is stored in the form of transmission success information by the storage device 167 of the data management unit (S700), thereby determining or adjusting the transmission speed later. Can be used to

In the step (S700) stored by the storage device 167, when the transmission of the communication file to the land communication unit 20 through the communication satellite 13 at the predetermined transmission speed is successful, the ship location information 161 at that time. ) And the weather information 162 may mean that the transmission success information 166 having a searchable success rate is stored in the storage device 167 by the data management unit 160.

Referring to FIG. 3, in the step of transmitting a communication file at a predetermined transmission rate (S600), the data management unit calculates the transmission rate of the transmission success file and removes the transmission success file from the transmission folder (S610, S611, S612) can be made.

However, when the transmission file is not in the transmission folder due to transmission failure, the data management unit may perform a step (S620) of sorting the communication files in the transmission folder in the order of recent generation.

That is, during a transmission attempt or transmission failure, the ship may miss a predetermined communication timing, and when the latest updated communication file is further generated, there is a need to prevent retransmission of the previous communication file.

Accordingly, when retransmission is attempted, an advantage of being able to reliably transmit the latest communication file to land by sorting in the order of the latest fish may occur.

At this time, steps (S630, S640) of attempting to transmit the communication file by monitoring whether the most recent communication file in the transmission folder can be transmitted within a specific time (eg, 4 minutes) may be performed.

Here, the characteristic time may mean an interval for satellite access and communication, and in consideration of the usual location-related satellite update interval (e.g., 8 steps from 1 second to 5 minutes), it is selected between 1 second and 5 minutes. It may be any one time, and it may be a time setting value that can be selectively determined and not a fixed value.

4, even in an attempt to transmit a communication file before division (S640, S641), the communication files in the transmission folder are sorted in the order of the smallest data size (S642), and the communication file is transmitted based on the smallest data size. An attempting process (S643) may be made.

In addition, if transmission is not possible within a specific time, a step of attempting to transmit the divided compressed file by dividing and compressing the file size into a transferable file size (S631) and adjusting the divided compression ratio to increase the divided compression ratio (S632) may be performed. .

In other words, when transmitting a communication file, the transmission speed (e.g., communication speed) is measured, the file is divided and compressed enough to be transmitted within a certain time period, and the file size is transmitted by transmitting the data with the small file size divided according to the communication speed. If you try to send a large file and it eventually fails, the time-consuming case can be greatly improved.

In addition, after all transmission attempts, a process of checking the success of transmission to the land (S650, S633) or a process of checking whether all divided files have been transmitted, and performing a repetition attempt as a result of the check (S634) may be performed. It has the advantage of increasing the probability of success by attempting and securing the reliability of communication quality.

The embodiments of the present invention disclosed in the present specification and drawings are only provided for specific examples to easily explain the technical content of the present invention and to aid understanding of the present invention, and are not intended to limit the scope of the present invention.

Therefore, the scope of the present invention should be construed that all changes or modified forms derived based on the technical idea of the present invention in addition to the embodiments disclosed herein are included in the scope of the present invention.

100: ship communication control unit 110: satellite communication unit
120: weather forecast processing unit 130: ship positioning unit
140: marine environment measurement unit 150: weight adjustment unit
160: data management unit 167: storage device

Claims (4)

A ship communication control unit installed on a ship to transmit a communication file to a land communication unit to a satellite communication unit connected to the communication satellite;
A ship positioning unit that periodically collects ship position information with a satellite navigation correction system during the operation of the ship;
A weather forecast processing unit for collecting weather information by time and coordinates along a ship progress route for the ocean to be operated by the ship;
The ship location information collected by the ship positioning unit, the weather information collected by the weather forecast processing unit, and the transmission speed for each communication file when the communication file is transmitted through the ship communication control unit are recorded and stored. A data management unit; And
Communication between land and ship including a weight adjustment unit that increases or decreases the transmission speed by applying a weight to the transmission speed based on the weather information corresponding to the ship location information of the data management unit at the time of transmission of the communication file Device.
The method of claim 1,
The ship communication control unit,
At the time of transmission of the communication file, if the weather is not good based on the weather information for each vessel location information of the ship, it is determined that the communication state is lower than that of the normal weather state, and the split compression ratio for the communication file is increased to A communication device between land and ship that attempts to transmit communication files.
The method of claim 1,
The data management unit,
The ship communication control unit, the ship positioning unit, the weather forecast processing unit, and the weight application unit are accessiblely connected, and maritime environment information, transmission speed information, and transmission files having a relationship with the ship position information or the weather information A communication device between land and ship that records and manages information and transmission success information by time or by event in the storage device of the data management unit in the form of a database.
The method of claim 1,
In the ship communication control unit,
A marine environment measuring unit that measures fog, rainfall, snowfall, wind direction, wind speed, wave height, wave period, air pressure, and temperature is connected by a plurality of measurement equipment provided on the ship to generate a marine environment correction value to be used for determining the transmission speed. Communication device between land and ship.

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