Vessel Identification System, Information Processing Apparatus, Vessel Identification Method, and Program

Abstract

To provide a ship identification system, an information processing device, a ship identification method, and a program capable of improving ship identification or efficiency.SOLUTION: A ship identification system according to an embodiment comprises: a plurality of ships which communicate with each other in a wireless manner using a signal in a certain frequency band; and an information processing device for receiving the signal, and estimating at least two or more ships communicating with each other among the plurality of ships based on a flying object which observes a sea area where the signal is transmitted from the sky, the signal received by the flying object, and an image of the sea area observed by the flying object.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a ship identification system, an information processing device, a ship identification method, and a program.

Background Art

[0002] An automatic ship identification system (Automatic Identification System, hereinafter referred to as "AIS") is known in which an artificial satellite collects signals transmitted by ships on the ocean and automatically identifies each ship based on the signals collected by the artificial satellite. The signals transmitted from the ship include the position information of the ship and the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a sea area where ships are concentrated (hereinafter referred to as a ship congestion sea area), the signal detection ability by AIS tends to decrease. As a countermeasure, profiling the images of the sea observed by an artificial satellite and the radio waves collected by the artificial satellite has been studied. However, when the transmission frequency of the signals transmitted from the ship is low, or when there are a plurality of ships estimated to be the signal transmission sources in the ship congestion sea area, it is difficult to identify each ship. In addition, maintaining various observations for sparsely occurring ship information sources in wide-area observations increases the resource burden.

[0005] The present invention has been made in consideration of such circumstances, and one of its objects is to provide a ship identification system, an information processing device, a ship identification method, and a program that can improve the identifiability or efficiency of ships.

Means for Solving the Problems

[0006] One aspect of the present invention is a ship identification system including: a plurality of ships that wirelessly communicate with each other using signals in a certain frequency band; an aircraft that receives the signals and observes the sea area where the signals are transmitted from above; an information processing device that estimates at least two or more ships that communicate with each other among the plurality of ships based on the signals received by the aircraft and the image of the sea area observed by the aircraft.

Effect of the Invention

[0007] According to one aspect of the present invention, the identifiability or efficiency of ships can be improved.

Brief Description of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] Hereinafter, with reference to the drawings, embodiments of the ship identification system, information processing apparatus, ship identification method, and program of the present invention will be described.

[0010] (First Embodiment) [Ship Identification System] FIG. 1 is a conceptual diagram of a ship identification system 1 according to the first embodiment. As shown in the figure, the ship identification system 1 includes, for example, a plurality of ships S, at least one aircraft V, and at least one ground station G.

[0011] The plurality of ships S perform wireless communication with each other using signals in a certain frequency band. Specifically, the plurality of ships S perform wireless communication with each other in accordance with international VHF (Very High Frequency). International VHF is also called a ship common communication system.

[0012] In international VHF, a certain ship calls other ships that can be communication partners using radio waves in a frequency band that can be received by an unspecified number of nearby ships called the calling and response channel, and other ships are required to respond to the ship that made the call using the calling and response channel. Further, in international VHF, a plurality of ships that have established mutual communication using the calling and response channel are required to switch to a frequency band called the communication channel from the calling and response channel and perform wireless communication with each other using the radio waves of that communication channel. The calling and response channel may be, for example, 70CH. The frequency band of the calling and response channel is an example of the "first frequency band", the radio waves of the calling and response channel are an example of the "first signal", the frequency band of the communication channel is an example of the "second frequency band", and the radio waves of the communication channel are an example of the "second signal".

[0013] The aircraft V receives radio waves transmitted under the rules of international VHF. Further, the aircraft V observes the sea area where the radio waves were transmitted from above. For example, the aircraft V observes a ship congestion area where a plurality of ships S are concentrated, or observes a vast ocean where a plurality of ships S are not concentrated. Hereinafter, the ship congestion area where a plurality of ships S are concentrated and the vast ocean where they are not will be simply referred to as the "sea area" for explanation.

[0014] As shown in the figure, while navigating over the sea, the aircraft V may observe the sea by irradiating a microwave beam toward the sea where the ship S exists and receiving the reflected wave (echo) of the beam, or may observe the sea by detecting infrared rays and visible light on the sea. These observation results are typically converted into image data.

[0015] The flying object V is, for example, an artificial satellite. This artificial satellite may form a cluster such as a satellite megaconstellation or a cluster of satellite groups, and may function as a synthetic aperture radar. The flying object V is not limited to an artificial satellite, and may be a flying object that navigates over the ground, such as an aircraft or a drone. Also, each function may be possessed by separate flying objects V and they may cooperate. Furthermore, some functions may be formed by a plurality of flying objects V.

[0016] The ground station G is a radio station installed on the ground. The ground station G receives from the flying object V the international VHF radio waves received by the flying object V, the images of the sea area observed by the flying object V, etc., or transmits to the flying object V instructions regarding observations (for example, the timing to observe, the location to observe, etc.).

[0017] [Observation device] FIG. 2 is a configuration diagram of the observation device 100 according to the first embodiment. The observation device 100 is mounted on the flying object V. For example, the observation device 100 includes an antenna 110, a transceiver 120, a transceiver control unit 130, an observation sensor 140, and a storage unit 150.

[0018] The antenna 110 may be, for example, a phased array antenna in which a plurality of antenna elements are arranged, or a large deployable antenna. Also, the antenna 110 may be a synthetic aperture radar.

[0019] The transceiver 120 receives radio waves of a call response channel or a call channel via the antenna 110. Also, the transceiver 120 may supply a pulse signal of a specific frequency to the antenna 110 and irradiate a pulsed microwave toward the sea via the antenna 110. Furthermore, the transceiver 120 may receive the reflected wave of the irradiated radio wave via the antenna 110.

[0020] The transmission / reception control unit 130 controls the transceiver 120 to receive radio waves of a call response channel or a call channel, or controls the transceiver 120 to transmit and receive microwaves. That is, the transmission / reception control unit 130 controls the transceiver 120 so that the antenna 110 functions as a passive radar, or controls the transceiver 120 so that the antenna 110 functions as an active radar.

[0021] The transmission / reception control unit 130 is realized, for example, by a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit) executing a program or an API (Application Programming Interface) stored in the storage unit 150. Further, the transmission / reception control unit 130 may be realized by hardware (circuit) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array), or may be realized by cooperation between software and hardware. Further, the program referred to by the processor may be stored in the storage unit 150 in advance, or may be stored in a removable storage medium such as a DVD or a CD-ROM, and installed from the storage medium to the storage unit 150.

[0022] The observation sensor 140 is a sensor capable of remotely sensing the sea, and is, for example, an infrared sensor that detects infrared rays on the sea or a camera that images the sea.

[0023] The memory unit 150 is realized by, for example, an HDD (Hard Disc Drive), a flash memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), a ROM (Read Only Memory), a RAM (Random Access Memory), or the like. Programs executed by a processor, for example, are stored in the memory unit 150.

[0024] [Information Processing Apparatus] FIG. 3 is a configuration diagram of the information processing apparatus 200 according to the first embodiment. The information processing apparatus 200 may be installed in the above-described ground station G or data centers in various places. Further, part or all of the configuration of the information processing apparatus 200 may be installed in an artificial satellite having the observation apparatus 100. Further, part or all of the configuration of the information processing apparatus 200 may be installed in another artificial satellite (an artificial satellite not having the observation apparatus 100) in a satellite orbit or in an offshore base. For example, when the information processing apparatus 200 is installed in the ground station G, the information processing apparatus 200 includes an antenna 202, a transceiver 204, a communication interface 206, an input interface 208, an output interface 210, a processing unit 220, and a memory unit 240.

[0025] The antenna 202 is, for example, a parabolic antenna or a phased array antenna.

[0026] The transceiver 204 irradiates microwaves toward the flying object V via the antenna 202. Further, the transceiver 120 receives the observation result from the flying object V via the antenna 202. The observation result includes international VHF radio waves (radio waves of a call response channel and a communication channel), received information, or an image of the observed sea area. When the information processing apparatus 200 is installed in a data center, the antenna 202 and the transceiver 204 may be omitted.

[0027] When the information processing apparatus 200 is installed in the ground station G, the communication interface 206 communicates with data centers in various locations via the ground communication network. When the information processing apparatus 200 is installed in the data center, the communication interface 206 communicates with the ground station G via the ground communication network. The ground communication network is, for example, a WAN (Wide Area Network), a LAN (Local Area Network), or the like. The communication interface 206 includes, for example, a NIC (Network Interface Card) or the like.

[0028] The input interface 208 receives various input operations from the user, converts the received input operations into electrical signals, and outputs them to the processing unit 220. For example, the input interface 208 includes a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touch panel, and the like.

[0029] The output interface 210 includes, for example, a display, a speaker, and the like. The display displays an image generated by the processing unit 220, a GUI (Graphical User Interface) for receiving various input operations from the operator, and the like. For example, the display is an LCD (Liquid Crystal Display), an organic EL (Electro Luminescence) display, or the like. The speaker outputs the information input from the processing unit 220 as sound.

[0030] The processing unit 220 includes, for example, an acquisition unit 222, a clustering processing unit 224, an estimation unit 226, a communication control unit 228, and an output control unit 230.

[0031] The components of the processing unit 220 are realized, for example, by a processor such as a CPU or GPU executing a program stored in the storage unit 240. Also, some or all of the components of the processing unit 220 may be realized by hardware (circuits) such as an LSI, ASIC, or FPGA, or may be realized by the cooperation of software and hardware. Further, the program referred to by the processor may be stored in the storage unit 240 in advance, or may be stored in a removable storage medium such as a DVD or CD-ROM and installed from the storage medium to the storage unit 240.

[0032] The storage unit 240 is realized, for example, by an HDD, flash memory, EEPROM, ROM, RAM, etc. For example, programs and the like are stored in the storage unit 240.

[0033] When the information processing apparatus 200 is installed in the ground station G, the acquisition unit 222 acquires the observation results by the flying object V via the antenna 202 and the transceiver 120. When the information processing apparatus 200 is installed in the data center, the acquisition unit 222 acquires the observation results by the flying object V via the communication interface 206.

[0034] The clustering processing unit 224 clusters a plurality of ships S existing on the sea based on the observation results acquired by the acquisition unit 222.

[0035] The estimation unit 226 estimates at least two or more ships S that communicate with each other among the clustered plurality of ships S.

[0036] When the flying object V needs to communicate with the ground station G, the communication control unit 228 controls the transceiver 204 so that uplink and downlink are performed. Also, the communication control unit 228 may transmit the processing results of the clustering processing unit 224 and the estimation unit 226 to data centers in various places via the communication interface 206.

[0037] The output control unit 230 outputs the processing results of the cluster processing unit 224 and the estimation unit 226 via the output interface 210.

[0038] [Flowchart] FIG. 4 is a flowchart showing a series of processing flows of the processing unit 220 according to the first embodiment. For example, when the information processing apparatus 200 is installed in the ground station G, the processing of this flowchart may be executed at the timing when the observation result of the flying object V is received by the transceiver 204. Further, when the information processing apparatus 200 is installed not in the ground station G but in an arbitrary data center, the processing of this flowchart may be executed at the timing when the observation result received by the ground station G from the flying object V is transmitted to the data center via the ground communication network. Further, when the observation device 100 mounted on the flying object V has some or all of the functions of the information processing apparatus 200, the processing of this flowchart may be executed by the observation device 100.

[0039] First, the cluster processing unit 224 determines whether or not radio waves of the call response channel have been transmitted based on the observation result of the flying object V acquired by the acquisition unit 222 (step S100). In other words, the cluster processing unit 224 determines whether or not radio waves of the call response channel have been detected or received by the flying object V.

[0040] When the cluster processing unit 224 determines that radio waves of the call response channel have been transmitted from the ship (when radio waves of the call response channel have been detected or received), the cluster processing unit 224 derives the error circle CIR of the radio waves of the call response channel, or acquires the derivation result of the error circle CIR, and further matches the imaging result of the sea area where the radio waves of the call response channel have been transmitted based on the derived or acquired error circle CIR (step S102). The imaging result may use the imaging data of the corresponding area that is updated periodically. Further, it may be the result of performing an observation request or imaging processing based on the error circle CIR.

[0041] For example, the cluster processing unit 224 may match the error circle CIR and the image of the sea area by superimposing the error circle CIR on the image of the sea area.

[0042] The error circle CIR of radio waves represents the positioning accuracy of the radio waves in a circular probability distribution. As described above, the image of the sea area includes an image obtained when the antenna 110 of the observation device 100 functions as an active radar (hereinafter referred to as a radar image), an infrared image captured by an infrared sensor, an image captured by a camera (visible light image), and the like.

[0043] Next, the clustering processing unit 224 clusters a plurality of ships S included in the image of the sea area superimposed on the error circle CIR of the radio waves of the call response channel (step S104).

[0044] FIG. 5 is a diagram schematically showing an example of an image of the sea area superimposed on the error circle CIR of the radio waves of the call response channel. As illustrated in FIG. 5, assume that there are a total of 7 ships S, namely S1 to S7, on the image of the sea area. In this case, the clustering processing unit 224 determines the ship S closest to the center of the error circle CIR among these 7 ships S as the main node.

[0045] The main node is a node that represents a central existence in a ship network when ships communicating with each other under international VHF are regarded as one network (hereinafter referred to as a ship network). In other words, the clustering processing unit 224 determines the ship S with the highest probability of calling other ships or responding to calls from other ships using the radio waves of the call response channel among these 7 ships S as the main node. In the example of FIG. 5, ship S1 is closest to the center of the error circle CIR. Therefore, ship S1 is determined as the main node.

[0046] When the cluster processing unit 224 determines the main node of the ship network, it determines, from among the plurality of ships S on the image of the sea area, the remaining ships S excluding the ship S determined as the main node as sub-nodes. A sub-node is a node indicating a subordinate existence in the ship network. The ship determined as a sub-node can be said to be, for example, a candidate for the true main node and indicates the possibility of a ship called from the ship of the main node.

[0047] For example, the cluster processing unit 224 narrows down the seven ships S1 to S7 on the image of the sea area to six ships S1 to S6 existing within the error circle CIR, and further, among the six ships S1 to S6 within the error circle CIR, the remaining ships S2 to S6 excluding the ship S1 determined as the main node are determined as sub-nodes. In other words, the cluster processing unit 224 determines as sub-nodes the ships S that may use the radio wave of the call response channel.

[0048] Instead of determining, from among the plurality of ships S existing within the error circle CIR, the remaining ships excluding the ship S determined as the main node as sub-nodes, the cluster processing unit 224 may determine, as sub-nodes, the top predetermined number of ships S close to the ship S determined as the main node among the remaining ships excluding the ship S determined as the main node from among the plurality of ships S on the image of the sea area.

[0049] Further, the cluster processing unit 224 may determine, as sub-nodes, the ships S existing within a predetermined distance around the ship S determined as the main node among the remaining ships excluding the ship S determined as the main node from among the plurality of ships S on the image of the sea area.

[0050] Then, the cluster processing unit 224 associates the sub-nodes with the main node via a link, thereby clustering, as one ship network, the ships S that may be communicating with each other using the radio wave of the call response channel among the plurality of ships S included in the image of the sea area.

[0051] FIG. 6 is a diagram showing an example of the clustering result in FIG. 5. In the case of the example of FIG. 5, the clustering processing unit 224 clusters ships S1 to S6, which are in contact with each other using radio waves on the call response channel, as a single ship network by linking ships S2 to S6 as sub-nodes to ship S1 as the main node. Hereinafter, the clustered ships S1 to S6 may be described as ship network a.

[0052] Returning to the description of the flowchart of FIG. 4. Next, the clustering processing unit 224 determines whether the image of the sea area has been updated based on the observation result acquired by the acquisition unit 222 (step S106). That is, the clustering processing unit 224 determines whether the sea area has been re-observed by the aircraft V based on the observation result acquired by the acquisition unit 222.

[0053] In addition, after confirming that the radio wave of the call response channel has been received, the clustering processing unit 224 may mark the corresponding sea area and perform observation requests and image processing regularly or whenever there is an opportunity to update the image. The update of the image may continue until the ship identification is completed, or may be suspended in a timely manner according to the interest.

[0054] When the image of the sea area is updated (that is, when the sea area is re-observed), the clustering processing unit 224 returns the process to S102, rematches the error circle CIR of the radio wave of the call response channel with the updated image of the sea area, and reclusters a plurality of ships S included in the image of the sea area superimposed with the error circle CIR.

[0055] FIG. 7 is a diagram showing an example of the reclustering result. As shown in the figure, the clustering processing unit 224 reclusters a plurality of ships S included in the image of the sea area while maintaining the link relationship with the sub-nodes without changing the main node.

[0056] Return to the description of the flowchart of FIG. 4. When the image of the sea area is not updated (that is, when the sea area is not re-observed), the cluster processing unit 224 determines whether radio waves of a communication channel have been transmitted over the sea area observed by the aircraft V based on the observation result acquired by the acquisition unit 222 (step S108). In other words, the cluster processing unit 224 determines whether radio waves of the communication channel have been detected or received by the aircraft V.

[0057] The determination of whether radio waves of the communication channel are detected or received may be efficiently performed by paying attention to the error circle CIR by the call response channel and performing radio wave observation processing and error circle CIR derivation.

[0058] When radio waves of the communication channel are transmitted (when radio waves of the communication channel are detected or received), the cluster processing unit 224 matches the error circle CIR of the radio waves of the communication channel with the image of the sea area observed by the aircraft V when the radio waves of the communication channel are transmitted (step S110).

[0059] Next, the cluster processing unit 224 clusters a plurality of ships S included in the image of the sea area superimposed on the error circle CIR of the radio waves of the communication channel (step S112).

[0060] FIG. 8 is a diagram schematically showing an example of an image of a sea area superimposed on an error circle CIR of radio waves of a communication channel. As illustrated in FIG. 8, assume that a total of seven ships S, S1 to S7, exist on the image of the sea area. In this case, the cluster processing unit 224 determines, in the same manner as the clustering process of S104, among these seven ships S, the ship S closest to the center of the error circle CIR as the main node. Also in the example of FIG. 8, since ship S1 is closest to the center of the error circle CIR, ship S1 is determined as the main node.

[0061] When the cluster processing unit 224 determines the main node, it determines the remaining ships S excluding the ship S determined as the main node from the plurality of ships S on the image of the sea area as sub-nodes.

[0062] For example, the cluster processing unit 224 narrows down the seven ships S1 to S7 on the image of the sea area to the three ships S1, S2, and S5 existing within the error circle CIR, and further, among the three ships S1, S2, and S5 within the error circle CIR, it determines the remaining two ships S2 and S5, excluding the ship S1 determined as the main node, as sub-nodes.

[0063] Also, the cluster processing unit 224 may determine, as sub-nodes, a predetermined number of the top ships S close to the ship S1 determined as the main node among the remaining six ships S2 to S7 excluding the ship S1 determined as the main node from the seven ships S1 to S7 on the image of the sea area, or may determine, as sub-nodes, the ships S existing within a predetermined distance around the ship S1 determined as the main node.

[0064] Then, the cluster processing unit 224 clusters, as one ship network, the ships S that may be communicating with each other using the radio waves of the communication channel among the plurality of ships S included in the image of the sea area by associating the sub-nodes with the main node via a link.

[0065] FIG. 9 is a diagram showing an example of the clustering result in FIG. 8. In the case of the example in FIG. 8, the cluster processing unit 224 clusters the ships S1, S2, and S5 as one ship network that communicates with each other using the radio waves of the communication channel by linking the ships S2 and S5 determined as sub-nodes to the ship S1 determined as the main node. Hereinafter, the clustered ships S1, S2, and S5 may be described as the ship network b.

[0066] Returning to the description of the flowchart in FIG. 4. Next, the cluster processing unit 224 determines whether radio waves of other communication channels were transmitted on the sea area observed by the aircraft V based on the observation results acquired by the acquisition unit 222 (step S114). In other words, the cluster processing unit 224 determines whether radio waves of other communication channels were detected or received by the aircraft V on the sea area.

[0067] For example, assume that after the radio wave of call channel X is transmitted over the sea area, the radio wave of call channel Y is transmitted. In this case, the cluster processing unit 224 determines that the radio wave of another call channel has been transmitted (the radio wave of another call channel has been detected or received).

[0068] When the radio wave of another call channel is transmitted over the sea area (when the radio wave of another call channel has been detected or received), the cluster processing unit 224 returns the process to S110, rematches the error circle CIR of the radio wave of the other call channel with the image of the sea area, and reclusters the plurality of ships S included in the image of the sea area superimposed with the error circle CIR.

[0069] FIG. 10 is a diagram schematically showing an example of an image of a sea area superimposed with the error circle CIR of the radio wave of another call channel. Also in the example of FIG. 10, seven ships S1 to S7 exist on the image of the sea area. In this case, the cluster processing unit 224 determines, in the same manner as the clustering process of S104, the ship S closest to the center of the error circle CIR among these seven ships S as the main node. In the example of FIG. 10, since the ship S5 is the closest to the center of the error circle CIR, the ship S5 is determined as the main node.

[0070] After determining the main node, the cluster processing unit 224 determines the remaining ships S excluding the ship S determined as the main node from the plurality of ships S on the image of the sea area as sub-nodes.

[0071] For example, the cluster processing unit 224 narrows down the seven ships S1 to S7 on the image of the sea area to the four ships S1, S4 to S6 existing within the error circle CIR, and further, among the four ships S1, S4 to S6 within the error circle CIR, determines the remaining three ships S1, S4, and S6 excluding the ship S5 determined as the main node as sub-nodes.

[0072] In addition, the cluster processing unit 224 may determine, among the six ships S1 to S4, S6 to S7 excluding the ship S5 determined as the main node from the seven ships S1 to S7 on the image of the sea area, the top predetermined number of ships S close to the ship S5 determined as the main node as sub-nodes, or may determine the ships S existing within a predetermined distance around the ship S5 determined as the main node as sub-nodes.

[0073] Then, the cluster processing unit 224 clusters the ships S that may be communicating with each other using the radio waves of other communication channels as one ship network by associating the sub-nodes with the main node via a link among the plurality of ships S included in the image of the sea area.

[0074] FIG. 11 is a diagram showing an example of the clustering result in FIG. 10. In the example of FIG. 10, the cluster processing unit 224 links the ships S1, S4, and S6 determined as sub-nodes to the ship S5 determined as the main node, and clusters the ships S1, S4 to S6 as one ship network that communicates with each other using the radio waves of other communication channels. Hereinafter, the clustered ships S1, S4 to S6 may be described as the ship network c.

[0075] Returning to the description of the flowchart in FIG. 4, when radio waves of other communication channels are not being transmitted over the sea area (when radio waves of other communication channels are not detected or received), the estimation unit 226 estimates at least two or more ships S that communicate with each other based on the plurality of ship networks clustered by the cluster processing unit 224 (step S116).

[0076] For example, the estimation unit 226 estimates at least two or more vessels S that communicate with each other based on vessel network a that communicates using the radio waves of a call response channel, vessel network b that communicates using the radio waves of a certain call channel, and vessel network c that communicates using the radio waves of another call channel. Vessel network a is an example of a "first cluster", and vessel network b or c is an example of a "second cluster".

[0077] More specifically, the estimation unit 226 extracts at least two nodes that are common to all of vessel network a, vessel network b, and vessel network c, and estimates that the vessels S determined for the two extracted nodes communicate with each other.

[0078] FIG. 12 is a diagram combining vessel networks a, b, and c. In the illustrated example, vessels S1 and S5 are determined as main nodes or sub-nodes in their respective vessel networks. In this case, the estimation unit 226 estimates that vessels S1 and S5 communicate with each other. That is, the estimation unit 226 estimates that after either one of vessels S1 and S5 calls the other using the radio waves of the call response channel, the other replies to the one using the radio waves of the call response channel, and then vessels S1 and S5 communicate with each other using the radio waves of the call channel.

[0079] Returning to the description of the flowchart of FIG. 4. Next, the cluster processing unit 224 tracks at least two or more vessels S estimated to communicate with each other as a group of parties (step S118).

[0080] For example, when the image of the sea area is repeatedly updated, the cluster processing unit 224 tracks the parties over time by maintaining the nodes and links of the parties to be tracked on the repeatedly updated image (time-series image).

[0081] FIG. 13 is a diagram schematically showing a state of tracking a party. For example, when ships S1 and S5 are parties to be tracked, even if an image of the sea area is updated and the relative positional relationship between ships S1 and S5 fluctuates, the link between the node corresponding to ship S1 and the node corresponding to ship S5 is maintained.

[0082] Next, the output control unit 230 adds a ship profile or the like to the party to be tracked, and then outputs information regarding the party to be tracked via the output interface 210 (step S120).

[0083] FIG. 14 is a diagram showing an example of information regarding a party to be tracked. For example, when ships S1 and S5 are parties to be tracked, the output control unit 230 outputs information in which a profile of each ship is associated with the respective identification information of ships S1 and S5.

[0084] For example, when communicating with each other using the radio wave of the call response channel, the estimation unit 226 may estimate the identification information of each ship from the content spoken by the crew of each ship. For example, when a crew member on a ship named "AAA" calls a ship named "BBB", it is common to call in the content such as "BBB, BBB, this is AAA, AAA". Such speech content by the crew is decoded into the radio wave of the call response channel. Therefore, the estimation unit 226 extracts information such as the ship name by encoding the radio wave of the call response channel, and estimates the extracted information as identification information.

[0085] In addition, the estimation unit 226 may estimate the profile of each ship from the image of the sea area. The profile may include various information such as the equipment carried on the ship, the national flag, and the international signal flag. From such a profile, for example, it is output as the profile of the party to be tracked that ship S1 is equipped with a special antenna, the nationality is "XXX", ship S5 is equipped with a tanker, and the nationality is "YYY".

[0086] Further, the estimation unit 226 may add the profile of each ship from the AIS information matched with the image of the detected sea area.

[0087] Instead of or in addition to the output control unit 230 outputting information regarding the party to be tracked via the output interface 210, the communication control unit 228 may transmit information regarding the party to be tracked to data centers around the world via the communication interface 206. Thereby, the processing of this flowchart ends.

[0088] According to the first embodiment described above, a plurality of ships S perform wireless communication with each other using radio waves such as a call response channel or a call channel. The aircraft V receives radio waves such as a call response channel or a call channel, and observes from above the sea area (such as a ship congestion area) where the radio waves were transmitted. The information processing device 200 estimates at least two or more ships S that communicate with each other among the plurality of ships S based on the radio waves received by the aircraft V and the image of the sea area observed by the aircraft V. Thereby, the identifiability of the ships can be improved, and the efficiency can be improved.

[0089] (Second Embodiment) Hereinafter, the second embodiment will be described. The second embodiment is different from the first embodiment in that it is estimated that there is a dark ship among the plurality of ships S existing on the image of the sea area. A dark ship is a ship that intentionally stops an AIS signal or the like and conceals ship information. Further, a dark ship may be a ship that ignores a call from another ship S or the like. Hereinafter, the description will focus on the differences from the first embodiment, and the description of the points common to the first embodiment will be omitted. In the description of the second embodiment, the same parts as those in the first embodiment will be denoted by the same reference numerals and described.

[0090] The estimation unit 226 of the information processing apparatus 200 according to the second embodiment estimates that there is a dark ship among a plurality of ships S existing on the image of the sea area. For example, a ship Sx may repeatedly call another ship Sy on the call response channel, but the other ship Sy may not respond thereto. That is, the ship Sy may be rejecting the call from the ship Sx. Therefore, the estimation unit 226 estimates the ship Sy that rejects such a call as a dark ship.

[0091] According to the second embodiment described above, a ship that does not respond to a call from another ship S is estimated as a dark ship. As a result, the identifiability of ships that are not communicating with each other can also be improved.

[0092] (Third Embodiment) The third embodiment will be described below. For example, a ship Sx may repeatedly call another ship Sy on the call response channel, but the other ship Sy may not respond and may emit a radar signal indicating a specific behavior. That is, the ship Sy may be rejecting the call from the ship Sx and may be engaging in hostile acts in a procedure that ignores international law. Therefore, the estimation unit 226 estimates the ship Sy that rejects such a call and performs hostile acts as a specific ship. In this case, the calling party may be an aircraft or the like in addition to a ship, and a channel used for the same purpose may also be targeted.

[0093] (Other Embodiments) The following other embodiments will be described. Part or all of the functions of the information processing apparatus 200 described above may be provided in the observation device 100 mounted on the aircraft V. In this case, part or all of the flowchart in FIG. 4 may be executed by the observation device 100.

[0094] Further, the information processing apparatus 200 described above may limit the sea area or frequency range for image acquisition or reception processing of those radio waves based on the radio waves of the call response channel or the call channel received by the aircraft V, so as to make the observation request or data processing more efficient.

[0095] As described above, the embodiments for carrying out the present invention have been described using embodiments. However, the present invention is not limited to such embodiments, and various modifications and substitutions can be made without departing from the gist of the present invention.

Explanation of Signs

[0096] 1... Ship identification system, S... Ship, V... Aircraft, G... Ground station, 100... Observation device, 110... Antenna, 120... Transceiver, 130... Transceiver control unit, 140... Observation sensor, 150... Storage unit, 200... Information processing device, 202... Antenna, 204... Transceiver, 206... Communication interface, 208... Input interface, 210... Output interface, 220... Processing unit, 222... Acquisition unit, 224... Cluster processing unit, 226... Estimation unit, 228... Communication control unit, 230... Output control unit, 240... Storage unit

Claims

1. A plurality of ships that communicate wirelessly with each other using signals in a certain frequency band, An aircraft that receives the signal and observes the sea area where the signal was transmitted from above, An information processing device that overlays the error circle of the estimated position of the ship that transmitted the signal received by the aircraft and the image of the sea area observed by the aircraft, and based on the error circle and the image of the sea area that are overlapped with each other, estimates at least two or more ships that communicate with each other among the plurality of ships, A ship identification system comprising:

2. The plurality of ships communicate wirelessly with each other in accordance with international VHF, In the international VHF, a certain ship calls another ship that becomes a communication partner using a first signal that is a signal in a first frequency band that can be received by an unspecified number of ships. The other ship responds to the called ship using the first signal. A plurality of ships that have established mutual communication using the first signal communicate wirelessly with each other using a second signal that is a signal in a second frequency band different from the first frequency band, The aircraft receives the first signal and observes the sea area where the first signal was transmitted from above, The information processing device estimates at least two or more ships that communicate with each other among the plurality of ships based on the first signal observed by the aircraft and the image of the sea area observed by the aircraft The ship identification system according to claim 1.

3. The information processing device, When the first signal is received by the aircraft, the error circle of the estimated position of the ship that transmitted the first signal and the image of the sea area are overlaid, Among the plurality of ships included in the image of the sea area, the ship closest to the center of the error circle of the estimated position of the ship that transmitted the first signal is determined as the main node, and the remaining one or more ships excluding the ship determined as the main node from the plurality of ships are determined as sub-nodes, By associating the sub-nodes with the main node via a link, clustering the plurality of ships included in the image of the sea area, The ship identification system according to claim 2.

4. The information processing device, Estimate the identification information of the ship that transmitted the first signal from the first signal, Associate the estimated identification information with the ship determined as the main node, The ship identification system according to claim 3.

5. The information processing device determines, among the remaining one or more ships, a predetermined number of ships ranked higher and close to the ship determined as the main node as the sub-nodes. The ship identification system according to claim 3 or 4.

6. The information processing device determines, among the remaining one or more ships, ships existing within a predetermined distance around the ship determined as the main node as the sub-nodes. The ship identification system according to any one of claims 3 to 5.

7. When the sea area is re-observed by the flying object and the image of the sea area is updated, the information processing device re-clusters a plurality of ships included in the updated image of the sea area. The ship identification system according to any one of claims 1 to 6.

8. The information processing device When the second signal is received by the flying object, the error circle of the estimated position of the ship that transmits the second signal is superimposed on the image of the sea area. Among the plurality of ships included in the image of the sea area, the ship closest to the center of the error circle of the estimated position of the ship that transmits the second signal is determined as the main node, and the remaining one or more ships excluding the ship determined as the main node from the plurality of ships are determined as sub-nodes. By associating the sub-nodes with the main node via a link, a plurality of ships included in the image of the sea area are clustered. The ship identification system according to any one of claims 2 to 6.

9. Based on a first cluster formed by clustering based on the first signal and a second cluster formed by clustering based on the second signal, the information processing device estimates at least two or more ships that communicate with each other among the plurality of ships. The ship identification system according to claim 8.

10. The information processing device Estimates that the ships determined as nodes common to both the first cluster and the second cluster communicate with each other. The ship identification system according to claim 9.

11. An acquisition unit that acquires the signal and the image of the sea area from a flying object that observes the sea area from above while receiving the signal when a plurality of ships wirelessly communicate with each other using a signal in a certain frequency band. Superimpose the error circle of the estimated position of the ship that transmits the signal acquired by the acquisition unit on the image of the sea area, and based on the superimposed error circle and the image of the sea area, estimate at least two or more ships that communicate with each other among the plurality of ships. An information processing apparatus comprising the same.

12. A plurality of ships wirelessly communicate with each other using a signal in a certain frequency band. An aircraft receives the signal and observes the sea area where the signal is transmitted from above. An information processing apparatus superimposes the error circle of the estimated position of the ship that transmits the signal received by the aircraft on the image of the sea area observed by the aircraft, and based on the superimposed error circle and the image of the sea area, estimates at least two or more ships that communicate with each other among the plurality of ships. A ship identification method.

13. On a computer, When a plurality of ships wirelessly communicate with each other using a signal in a certain frequency band, acquire the signal and the image of the sea area from an aircraft that receives the signal and observes the sea area where the signal is transmitted from above. Superimpose the error circle of the estimated position of the ship that transmits the acquired signal on the image of the sea area, and based on the superimposed error circle and the image of the sea area, estimate at least two or more ships that communicate with each other among the plurality of ships. A program for causing the same to be executed.

14. On the computer, By limiting the sea area or frequency range for performing image acquisition or reception processing of the signal based on the signal received by the aircraft, improve the observation requirement or data processing efficiency. The program according to claim 13 for further causing the same to be executed.

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