JP6351341B2 - Information discrimination device - Google Patents

Description

  The present invention relates to an information discriminating apparatus that discriminates the authenticity of transmission information obtained by demodulating a radio signal that has arrived via a navigation surveillance automatic broadcasting system.

  AIS (Automatic Identification System) devices are being installed in many ships to improve safety and convenience in navigation, as they are being made cheaper, smaller, with lower power consumption and higher functionality as technology advances. .

  In addition, such an AIS device is suitable for ships that have a gross tonnage of 300 tons or more for ships that sail internationally, ships that have a total tonnage of 500 tons or more for ships that travel only in the territorial waters, and passenger ships that sail internationally. The loading obligation is imposed on all. In addition, many simple AIS devices that can be operated even if there are no radio workers are being installed in ships that do not have the obligation to install them.

FIG. 6 is a diagram illustrating a configuration example of the AIS apparatus.
In the figure, the feeding points of the antennas 31AIS and 31GPS are respectively connected to the first antenna terminal and the second antenna terminal of the transponder 40, and the digital input / output port of the transponder 40 is connected to the cascaded collector / distributor 50 and An operation display unit 60 is connected. A desired external device or sensor (none of which is shown) is connected to the collector / distributor 50.

The transponder 40 includes the following elements.
(1) A switch (SW) 41 which is a single pole double throw and whose common contact is connected to the first antenna terminal.
(2) Hybrid (H) 42 having a first terminal connected to the make (break) contact of switch 41

(3) TDMA receivers 43-1 and 43-2 and DSC receiver 44 connected to the second to fourth terminals of the hybrid 42, respectively.
(4) Modulator / demodulator 45 having first to third demodulation inputs connected to the outputs of these TDMA receivers 43-1, 43-2 and DSC receiver 44, respectively.

(5) A transmitter 46 having a modulation input connected to the modulation output of the modem 45 and having an output connected to a break (make) contact of the switch 41
(6) GPS receiver 47 having an input connected to the second antenna terminal

(7) A control unit 48 having a digital input / output port connected to the above described collector / distributor 50 in addition to an input / output port connected to the input / output port of the modem 45 and the output of the GPS receiver 47, respectively.

  In the AIS apparatus having such a configuration, the switch 41 and the TDMA receiving units 43-1 and 43-2 operate under the control of the control unit 48, and provide the modulation / demodulation unit 45 with a received wave that has arrived at the antenna 31AIS from another ship.

  The modem unit 45 demodulates the received wave to obtain transmission information arranged in each field of the message in the format shown in FIG. Such transmission information includes, for example, identification information of other ships, heading, ship position, course, speed, etc. (hereinafter referred to as “notification information”). The control unit 48 converts the notification information obtained in this way into information of a predetermined format and content, and delivers it to the operation display unit 60 via the collector / distributor 50. The operation display unit 60 displays information delivered from the control unit 48 via the collector / distributor 50, thereby notifying personnel involved in the navigation of the ship.

  On the other hand, the collector / distributor 50 is linked to the above-described external devices and sensors under the control of the control unit 48, thereby identifying the ship's identification information, heading, ship position, course, speed, etc. (hereinafter referred to as "notification information"). ) Are collected and given to the control unit 48.

  The GPS receiving unit 47 applies a predetermined satellite navigation to a radio signal arriving at the antenna 31 GPS from a GPS satellite (not shown), so that the time (based on the multiple access performed by the TDMA receiving units 43-1 and 43-2 and the like) And the position of the ship (antenna 31GPS), and the position is handed over to the control unit 48 as information that can be incorporated into the notification information of the ship.

  The control unit 48 converts these pieces of information into a predetermined format and gives the information to the modem unit 45. The modem unit 45 generates a transmission wave modulated with such information in the form of a control unit 48. The transmission unit 46 transmits the transmission wave to other ships and land stations via the switch 41 and the antenna 31AIS under the control of the control unit 48.

  Note that such transmission waves conform to a predetermined time division multiplexing system under the synchronization control performed by the TDMA receiving units 43-1 and 43-2 to receive the above-described received waves under the control unit 48. It is generated as a burst wave during the transmission time slot (reserved under the control of the control unit 48 or assigned to the ship).

  That is, the AIS device automatically notifies the ship's notification information to surrounding ships and land stations, obtains notification information notified in the same manner from other ships, and performs predetermined processing to obtain the ship. It is used to support collision control, cargo information, navigation management operations, maritime security operations, operation control at ports, etc.

  As prior arts related to the present invention, there are Patent Documents 1 to 5 listed below.

(1) “Ship position information extracting means that receives a ship identification signal transmitted from a ship and extracts at least position information of the ship from the ship identification signal; and captures the position of a target from radar detection data; Target capturing / tracking means for tracking, a first mark indicating the position or speed vector of the ship obtained by the ship position information extracting means, and the position or speed vector of the target obtained by the target capturing / tracking means Control means for displaying the first mark in preference to the second mark at the display position of the first mark or in the vicinity thereof. "The table when displaying the mark of another ship by the automatic vessel identification device (AIS) and the mark of the target by the automatic collision prevention assistance device (ARPA) on the same display screen. The ship display device is characterized in that it eliminates the complexity of the displayed contents and makes it possible to effectively use the capabilities of ARPA.

(2) “Detecting means for detecting other ship information including at least position information of other ships, and the importance of the other ship information detected by the detecting means is determined according to a predetermined condition, and the importance of a preset range is determined. By providing other ship information extracting means for extracting other ship information and a display control means for graphically displaying the position of the other ship corresponding to the extracted other ship information, When displaying the relative position relationship between other ships and own ship or between other ships in graphic form, it prevents the display from becoming complicated when the number of other ships increases and improves visibility. '' Other ship display device with ... Patent Document 2

(3) “The AIS device of the ship with the ARPA radar device is connected to the ARPA radar device via the interface, and the dynamic information of the nearby vessel to be received and the radar symbol information acquired from the ARPA radar device are compared every moment. , Radar symbol information without dynamic information for which a predetermined match is recognized is set as transmission stop warning information, dynamic information without radar symbol information with a predetermined match is set as intangible notification warning information, and the warning information is displayed. By displaying on the device and prompting the operator to be vigilant, and converting the alert information into a report and transmitting it to a nearby vessel, the “transmission AIS device does not stop transmission or the dynamic information without the entity, transmission information By receiving AIS devices and prompting vigilance, the environment where the deterrence effect against unauthorized information transmission is realized is realized. Reliability method AIS transceiver information characterized by the reliability improved "point location ... Patent Document 3

(4) “A ship's navigation support system that is installed in a ship and supports navigation, an AIS (automatic ship identification) device that receives target ship information transmitted from the target ship, and a target ship captured from the radar signal of the radar. ARPA (Automatic Collision Prevention Assistance) device for tracking the ship, own ship position information specifying means for specifying the ship position, and relative to the ship of the target ship from the received target ship position information and the specified ship position information Target relative position calculating means for calculating the position, and the same target determining means for specifying the same target ship that is being tracked by the ARPA device from the relative position of the target ship calculated by the target relative position calculating means And AIS information monitoring means for monitoring the accuracy of the target ship information received by the AIS device and determining whether the target ship information received by the AIS device is incorrect. When the AIS information monitoring means determines that the target ship information is incorrect, it outputs an abnormal signal. By using the characteristics of the AIS device and the ARPA device, the ARPA device complements the AIS device. And improve the reliability of the target ship information received by the AIS device ".

(5) “Target ship information receiving means for receiving target ship position information transmitted from the target ship or a third party in a ship navigation support apparatus that is mounted on a ship and supports navigation, and identifies the ship position. The target ship position information specifying means, the target ship position information calculating means for calculating the relative position of the target ship to the ship from the received target ship position information and the specified ship position information, and the radar signal of the radar The target ship capture and tracking means for providing the movement information of the target ship from the history, the target ship relative position calculated by the target relative position calculation means and the target ship capture and tracking means being tracked The same target determination that identifies the target ship that has obtained the target ship position information by the target ship information receiving means, which is the same as the target ship that is being tracked by the target ship capturing and tracking means, by comparing the relative position of the target ship. Means and equipment The same target determination means is further provided with the same target determination period limiting means for limiting the period during which the same determination is performed. A ship navigation support apparatus characterized by “complementing by utilizing each characteristic of the target ship information received and efficiently integrating information on the target ship”. Patent Document 5

JP 2002-372583 A JP 2003-048595 A JP 2005-141656 A JP 2005-181078 A JP 2005-182539 A

  By the way, in the above-mentioned conventional examples and patent documents, the authenticity of the position notified from a non-existing ship or the like is not positively discriminated, or the radio navigation that requires a complicated and large processing amount is used in combination. Has been realized.

  The present invention accurately and efficiently discriminates the authenticity and reliability of received transmission information without drastically changing the basic configuration of the navigation monitoring automatic broadcasting system, the existing multiple access method and the communication procedure. It is an object of the present invention to provide an information discriminating apparatus that can perform such operations.

In the first aspect of the present invention, the obtaining means obtains transmission information that is transmitted via the wireless transmission path of the navigation monitoring automatic broadcast system and includes an identifier of a desired wireless station. The discriminating unit extracts the communication state included in the transmission information acquired by the acquiring unit , stores the communication state in correspondence with the identifier in time series, and refers to the stored column of the communication state in the time series. Then, the authenticity of the wireless station or the transmission information is determined by performing a determination process consisting of a combination of processes determined by a determination criterion for the value of the Communication State or the item included in the Communication State .

  That is, the authenticity of transmission information that is difficult for non-regular radio stations to handle either authenticity between the radio stations facing each other via the radio transmission path of the navigation monitoring automatic broadcasting system and the radio information transmitted from the radio stations Determined with strict confirmation of content.

  According to the present invention, a radio station that may have illegally accessed the navigation surveillance automatic broadcast system can be used without significantly changing the basic configuration, multiple access method, and communication procedure of the navigation surveillance automatic broadcast system. It is discriminated easily.

  In addition, according to the present invention, there is a possibility that the navigation monitoring automatic broadcast system may be illegally accessed without drastically changing the basic configuration, multiple access method and communication procedure of the navigation monitoring automatic broadcast system. The speed of the station discrimination can be increased.

  Furthermore, the mobile object equipped with the navigation information generating device according to the present invention is more accurate and efficient in determining whether the mobile device is not equipped with such a navigation information generating device. To be realized.

  Therefore, according to the navigation monitoring automatic broadcast system to which the present invention is applied, the safety and convenience of navigation are enhanced at a low cost, in addition to reliability and performance, and are maintained stably.

It is a figure which shows 1st thru | or 3rd embodiment of this invention. It is an operation | movement flowchart of the control part in 1st embodiment of this invention. It is a figure explaining operation | movement of 1st embodiment of this invention. It is an operation | movement flowchart of the control part in 2nd embodiment of this invention. It is an operation | movement flowchart of the control part in 3rd embodiment of this invention. It is a figure which shows the structural example of an AIS apparatus. It is a figure which shows the structure of the message transmitted by radio | wireless via AIS.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[First embodiment]
FIG. 1 is a diagram showing first to third embodiments of the present invention.
In the figure, components having the same functions and configurations as those shown in FIG. 8 are given the same reference numerals, and descriptions thereof are omitted here.

  The configuration of this embodiment is different from the conventional example shown in FIG. 8 in that a control unit 11 is provided instead of the control unit 48.

FIG. 2 is an operation flowchart of the control unit in the first embodiment of the present invention.
FIG. 3 is a diagram for explaining the operation of the first embodiment of the present invention.
Hereinafter, the operation of this embodiment will be described with reference to FIGS. 1, 2, 3, and 7.

In the present embodiment, the control unit 11 functions as the control unit 48 illustrated in FIG. 6 and appropriately performs processing described later.
The control unit 11 performs the following processing at a predetermined frequency (cycle) or according to a predetermined trigger.

(1) Among the ships whose positions are notified via the AIS, the identifier IDd of a specific ship that should be the target of true / false determination of the position is identified (step S1, FIG. 3 (1) in FIG. 2).
(2) An “inquiry” (message 15) (FIG. 7B) including the following items is generated (step S2 in FIG. 2, FIG. 3 (2)).

・ MMSI number = own ship identifier IDs
-Destination ID1 = identifier IDd of the specific ship
Message Id = the number of a message that has a high possibility that a ship that pretends the above position cannot respond (for example, corresponds to “1”, “2”... “Class A position information”).
The offset number of the slot to be used for transmission of the answer (may be obtained or updated as appropriate by the control unit 11).

(3) This “inquiry” is transmitted to the specific ship via the modem 45, the transmitter 46, the switch 41 and the antenna 31AIS (step S3 in FIG. 2, FIG. 3 (3)).
(4) At this time, a timer having a predetermined length is started (step S4 in FIG. 2), and the following processing is performed during the period (FIG. 3 (4)) until the time measurement by the timer is completed.

(4-1) By linking with the TDMA receiving units 43-1 and 43-2 and the modem unit 45, the message (FIG. 7 (a)) included in the received wave arriving at the antenna 31AIS is appropriately fetched (step in FIG. 2). S5, FIG. 3 (5)).

(4-2) It is determined whether or not the message is a regular response to the “inquiry” (step S6 in FIG. 2, FIG. 3 (6)).

(5) Binary information indicating whether or not a response to the “inquiry” has been identified within the period is delivered to the operation display unit 60 through the collector 50 together with the previously described “notification information c” (FIG. 2). Step S7, FIG. 3 (7)).

Here, for the regular response described above, for example, it is desirable to satisfy all of the following requirements.
Received via a slot (hereinafter referred to as “response slot”) corresponding to the offset number of the slot described above.
・ Message number = 1
MMSI number = specific ship identifier IDd
Latitude / longitude = There is a predetermined correlation with the latitude / longitude notified in advance from the specific ship.

  The operation display unit 60 notifies the personnel involved in the navigation of the ship by displaying the binary information delivered in this way and the notification information c described above (FIG. 3 (8)).

In other words, according to the present embodiment, it is determined whether or not the desired ship is a “fake ship that has a false position, or is not equipped with a regular AIS transponder” under the preferred configurations listed below. Is realized with high accuracy, and the result of the determination is displayed on the display screen of the operation display unit 60.
(1) Wireless navigation and satellite navigation that require a complicated and large amount of processing are not applied.
(2) No fundamental changes are made to existing multiple access methods or communication procedures.
(3) The configuration of the AIS transponder is not changed except for software.

  Therefore, the information notified from the non-existent ship via the AIS is identified at low cost and with high accuracy, the result of the determination is provided for navigation support, and unnecessary hindrance to navigation by the fake ship is avoided.

  In the present embodiment, the time T required for receiving a “regular response” from a specific ship via a response slot in response to an “inquiry” in the current AIS system is as follows: The shortening may be achieved by any configuration of (4).

(1) A binary broadcast message (message 8) is transmitted instead of the “regular response” by an AIS transponder mounted on a specific ship, and the binary broadcast message is received and identified by the AIS transponder according to the present embodiment. Is called. Here, the binary broadcast message is at least a response to the “inquiry” and needs to satisfy a requirement that can be regarded as equivalent to a “regular response” with a desired accuracy.

(2) The contents of the “inquiry” (for example, “priority specification”, “priority setting condition”) so that the time required for receiving the “regular response” is as short as possible. Etc.) is set.

(3) The content of the “inquiry” is set so that the “regular response” or the information replacing it is replaced by the earliest message transmitted (received) from a specific ship.

(4) The content of the “inquiry” is set so that a “regular response” or information replacing it can be included in a message transmitted (received) earliest from a specific ship.

  The selection of any of the above items (1) to (4), or the “priority” and the setting conditions thereof are appropriately determined according to the designation given by the operator via the operation display unit 60, for example. It may be configured to be able to set and change.

  Furthermore, in this embodiment, for example, the “inquiry” (message 15) and the regular response to “inquiry” may be replaced by any of the message pairs listed below.

(1) Pair of message 6 and message 7
(2) Pair of two binary broadcast messages (Message 8)
(3) Pair of message 10 and message 11
(4) Pair of message 16 and message 17

(5) A group assignment report (message 23) and a response message from the ship to this
(6) Of the information fields included in the desired message, it is formed by the bit steal method without affecting the apparent multiple access method and communication procedure, and the transmission speed is secured high enough to be practical. A pair of messages delivered to each other via a channel (which may be formed utilizing the desired spare field)

In the present embodiment, the “inquiry” includes the offset number of the slot.
However, such an offset number may not be included in the “inquiry” as long as it is possible to identify that a specific ship is a fake ship.

Furthermore, in the present embodiment, any item listed below may be set in any way as long as it is possible to determine whether or not a specific ship is a fake ship.
(1) Combination and content of information that should be included in “inquiries”
(2) Criteria to be applied to discriminating legitimate responses to “inquiries”

(3) A pair of messages that should be delivered between the “inquiry” and a specific ship as a legitimate response to it.
(4) Configuration mode to be acted on to shorten the time T described above

  Further, such a setting form may be set manually or automatically based on a predetermined algorithm.

[Second Embodiment]
As shown in FIG. 1, the configuration of the present embodiment is different from the configuration of the first embodiment described above in that a control unit 11A is provided instead of the control unit 11.

FIG. 4 is an operation flowchart of the control unit in the second embodiment of the present invention.
Hereinafter, the operation of this embodiment will be described with reference to FIGS. 1, 4, and 7.

In the present embodiment, the control unit 11A functions as the control unit 48 illustrated in FIG. 6 and appropriately performs processing described later.
The control unit 11A performs the following processing at a predetermined frequency (cycle) or according to a predetermined trigger.

(1) The ship etc. which transmitted the message notified via AIS is memorize | stored suitably (FIG. 4 step S1), and the specific ship which should be the object of discrimination | determination whether it is a fake ship among these ships Is identified (step S2 in FIG. 4).

(2) The Communication State (FIG. 7 (c) i) included in the message notified from the specific ship and stored (hereinafter referred to as “specific message”) is extracted, and the identifier IDd is in chronological order. (Step S3 in FIG. 4). The Communication State generally includes the following items.

Slot time-out (FIG. 7 (c) ii): 3-bit binary number (= 0 to 7), where “0” means the last transmission in the corresponding slot, and “1” to “ “7” means an ascending number indicating the number of individual frames transmitted in the corresponding slot (the number of remaining frames to be transmitted in the corresponding slot). )

Sub message (FIG. 7 (c) iii): A 14-bit message in which information corresponding to the value of the Slot time-out is arranged as listed below. Note that the Sub message in the case where the value of Slot time-out is “0”, “3”, “5”, “7” is not referred to in the present embodiment, so the description thereof is omitted here.

[When Slot time-out = 1]
Coordinated Universal Time (UTC) hour and minute values [when Slot time-out = 2, 4, 6]
“Slot number” indicating the slot used to send the message

  Further, in the present embodiment, a security class SC indicating a determination criterion to be applied in the process of “determination processing” to be described later (meaning the degree of severity with which a fake ship should be identified) is given in advance. Alternatively, it is given by the operator via the operation display unit 60.

  Furthermore, in parallel with the above-described processing (steps S1 to S3 in FIG. 2), the control unit 11A displays the sequence of Communication State stored in association with each identifier IDd in the course of these processing in the time series t. By sequentially referring to them, a “determination process” including a combination of processes determined by the security class SC among the following processes (1) to (5) is appropriately performed.

  In the following, the communication state corresponding to the identifier IDd and the time series t is expressed as CS (IDd, t), and the slot time-out and sub message included in the CS (IDd, t) are as follows. They are written as STO (IDd, t) and SM (IDd, t), respectively.

(1) Even if there is no apparent irregularity in CS (IDd, t), the ship (indicated by identifier IDd) that is the sending end of the message containing that CS (IDd, t) This is not regarded as a regular ship (step S10 in FIG. 4).

(2) It is determined whether or not there is any difference in the values of the plurality of communication states (..., CS (IDd, (t-1)), CS (IDd, t)) accumulated in order of time series t ( In FIG. 4 step S11), if there is a difference, the ship indicated by the corresponding identifier IDd is identified as a fake ship (step S12 in FIG. 4).

(3) It is determined whether or not a plurality of slot time-outs (..., STO (IDd, (t-1)), STO (IDd, t)) accumulated in order of time series are cyclically decremented ( In FIG. 4, step S13), if not decremented, the ship indicated by the corresponding identifier IDd is identified as a fake ship (step S14 in FIG. 4).

(4) The value of SM (IDd, t) included in the Communication State where the value of STO (IDd, t) is “1” (meaning the hour / minute value in Coordinated Universal Time) is the current time. It is determined whether or not they match with a predetermined accuracy (step S15 in FIG. 4). If they do not match, the ship indicated by the corresponding identifier IDd is identified as a fake ship.

(5) The value of SM (IDd, t) included in the Communication State in which the values of STO (IDd, t) are “2”, “4”, and “6” (meaning the aforementioned “slot number”). ) Matches the slot number of the corresponding slot (step S17 in FIG. 4). If not, the ship indicated by the corresponding identifier IDd is identified as a fake ship (FIG. 4). Step S18).

  The control unit 11A appropriately delivers the identifier IDd of the ship thus identified as a fake ship and the notification information c described above to the operation display unit 60 (step S19 in FIG. 4).

  The operation display unit 60 displays these identifiers IDd and the above-described notification information c, thereby notifying personnel involved in the navigation of the ship.

  In other words, according to the present embodiment, it is determined whether or not the desired ship is a “fake ship that has a false position, or is not equipped with a regular AIS transponder” under the preferred configurations listed below. Is realized with high accuracy, and the result of the determination is displayed on the display screen of the operation display unit 60.

(1) Wireless navigation and satellite navigation that require a complicated and large amount of processing are not applied.
(2) The Communication State, which is not fundamentally changed to existing multiple access methods and communication procedures and cannot be easily altered by persons or devices that plan fake ships, etc., is the standard for identifying `` fake ships ''. Referenced.
(3) The configuration of the AIS transponder is not changed except for software.

  Therefore, the information notified via the AIS from the non-existent ship is identified inexpensively and with high accuracy, and the result of the determination is provided for navigation support, thereby avoiding unnecessary hindrance to navigation by the fake ship. .

  In the present embodiment, as described above, the software executed by the control unit 11A is incorporated as a coprocessor or package linked with the control unit 48 (11), for example, so that a conventional AIS transponder or other The AIS transponder may be configured as a device that increases the accuracy of identification of a fake ship.

  Further, in the present embodiment, both of the above-described aspects of the security class SC and the “determination process” procedure adapted to these security classes SC may be set to a form suitable for any of the following. .

(1) Attributes of manufacturer, model, etc. of AIS transponder mounted on a specific ship
(2) Nominal position of a particular ship, weather conditions and other attributes at that position
(3) Other information that can be specified based on received messages

In each of the above-described embodiments, the specific ship may be any of the following ships.
(1) A ship designated by an operator who operates the operation display unit 60
(2) Ships whose location was notified (most recently)

[Third embodiment]
The configuration of the present embodiment is different from the configuration of the first embodiment described above in that a control unit 11B is provided instead of the control unit 11 as shown in FIG.

FIG. 5 is an operation flowchart of the control unit in the third embodiment of the present invention.
Hereinafter, the operation of the present embodiment will be described with reference to FIG. 1, FIG. 5, and FIG.

In the present embodiment, the control unit 11B functions as the control unit 48 illustrated in FIG. 6 and appropriately performs processing described later.
Each time the control unit 11B receives any of the messages listed below, the control unit 11B performs processes (1) and (2) described later.

・ Location report (Message 1, 2, 3)
・ Base station report (Message 4)
・ SAR aircraft position report (Message 9)
・ Standard position report (Message 18)
・ Extended position report (Message 19)
・ Navigation assistance equipment report (Message 21)

(1) A 6-bit time stamp value (hereinafter referred to as “T”) that is included in the corresponding message and indicates the Coordinated Universal Time (UTC) second value (0 to 59), and the message The number (hereinafter referred to as “S”) (0 ≦ S ≦ 2249) of the time slot (FIG. 7 (d) iv) used for wireless transmission is extracted (step S1 in FIG. 5). Here, T means the time when the GPS receiving unit obtains the result of the positioning calculation in the AIS transponder which is the transmission end of the corresponding message, and the value is “0” at the beginning of the frame including the time slot. When the transition from the end of the 2250th slot at the end of the frame to the start of the subsequent frame is made, the value exceeds “59” and becomes “0”. Therefore, the values of T and S are known pairs for each column of 37.5 (= 2250/60) slots that are consecutive in time series.

(2) It is determined whether or not the following inequality holds between T and S (step S2 in FIG. 5). If not, the ship corresponding to the transmission end of the corresponding message is regarded as a fake ship. Identify (step S3 in FIG. 5).
(S / 37.5) ≦ T ≦ (S / 37.5) +1

  The control unit 11B appropriately delivers the identifier IDd of the ship identified as a fake ship and the notification information c described above to the operation display unit 60 as appropriate.

  The operation display unit 60 displays the identifier IDd and the notification information c described above, thereby notifying personnel involved in the navigation of the ship.

  In other words, according to the present embodiment, it is determined whether or not the desired ship is a “fake ship that has a false position, or is not equipped with a regular AIS transponder” under the preferred configurations listed below. Is realized with high accuracy, and the determination result is displayed on the display image of the operation display unit 60.

(1) Wireless navigation and satellite navigation that require a complicated and large amount of processing are not applied.
(2) Timestamp values that are not fundamentally altered by existing multiple access methods and communication procedures and cannot be easily tampered by those who plan fake ships are referred to as the criteria for identifying `` fake ships '' Is done.
(3) The configuration of the AIS transponder is not changed except for software.

  Therefore, the information notified via the AIS from the non-existent ship is identified inexpensively and with high accuracy, and the result of the determination is provided for navigation support, thereby avoiding unnecessary hindrance to navigation by the fake ship. .

  In the present embodiment, as described above, the software executed by the control unit 11B is incorporated as, for example, a coprocessor or package linked with the control unit 48 (11), so that a conventional AIS transponder or other The AIS transponder may be configured as a device that increases the accuracy of identification of a fake ship.

  In the present embodiment, the determination as to whether the above-described inequality is satisfied may be replaced by any combination of the determinations listed below.

(a) Judgment whether or not T matches the value of the second of the clock giving Coordinated Universal Time (UTC) with a predetermined accuracy

(b) Determining whether the interval at which T is updated (in modulo 60) in the order of time series is below an allowable upper limit (determination that T does not correspond to any of the values listed below)
60: This means that the time stamp S cannot be used.
61: Indicates that the positioning system is in manual input mode.
62: Means that the positioning system is in dead reckoning mode.
• 63: Indicates that the positioning system is disabled.

  Further, in the present embodiment, among the determination of whether or not the above-described inequality is satisfied and the alternative determinations (a) and (b), the determination form and combination to be adopted are the message transmission It may be determined as appropriate based on the attribute of the ship corresponding to the end, or may be specified by an operator who operates the operation display unit 60.

  In addition, such “determination of the presence or absence of other ships and their accuracy” can be achieved by, for example, combining the invention according to the application on the same day as the present application and all or a part of each of the above-described embodiments with higher accuracy. It may be realized.

  Further, in each of the above-described embodiments, the transmitting end of the incoming received wave is not limited to the ship station, but may be an AIS transponder mounted on a land station, a buoy or the like.

Moreover, in each embodiment mentioned above, this invention is applied to AIS applied to a ship station or a land station.
However, the present invention is not limited to such an AIS, and can be similarly applied to any system or apparatus described below.

(1) “Artificial Satellite AIS” that can monitor the navigational status of ships on the ocean that are more than 80 kilometers away from the coast by installing an AIS receiver in an artificial satellite orbiting in a low orbit.

(2) AIS transponders mounted on aircraft that search and monitor at sea
(3) Broadcast Dependent Surveillance-Broadcast (ADS-B): An aircraft constantly reports its position and altitude to other aircraft and ground stations.

  Furthermore, the configuration of each embodiment described above is not limited to the configuration illustrated in FIG. 1, and the hardware configuration may be any as long as the characteristic processing and functions of the present invention are realized. In addition, the function of each unit and the form of load distribution may be any.

  The present invention is not limited to the above-described embodiments, and various configurations can be made within the scope of the present invention, and any improvements may be made to all or some of the components.

  Hereinafter, among the inventions disclosed in the present application, the configurations, operations, and effects of the invention that were not described in the “Claims” will be described as “Claims”, “Means for Solving the Problems”, “ List them in a format according to the description in each column of “Effect”.

[1] In the information discrimination device according to claim 1,
Said criteria are:
An information discriminating apparatus characterized by conforming to the attribute of the wireless station in combination with the multiple access method and / or the communication procedure.

  In the information discriminating apparatus having such a configuration, in the information discriminating apparatus according to claim 1, the reference is an attribute of the radio station in addition to the multiple access method and / or the communication procedure. Fits.

  In other words, both of the regular radio stations facing each other through the radio transmission path of the navigation monitoring automatic broadcast system and the transmission information wirelessly transmitted from the radio station are used for unauthorized access to the navigation monitoring automatic broadcast system. Is strictly discriminated under a standard in which the attributes of the corresponding radio station are added to all or part of the contents of the inquiry, the multiple access method, the communication procedure, and the corresponding transmission information that are difficult to handle.

  Therefore, the navigation surveillance automatic broadcasting system to which the present invention is applied can be flexibly adapted to radio stations having various attributes in addition to reliability.

11, 11A, 11B, 48 Control unit 31AIS, 31GPS antenna 40 Transponder 41 (SW) Switch 42 (H) Hybrid 43 TDMA reception unit 44 DSC reception unit 45 Modulation / demodulation unit 46 Transmission unit 47 GPS reception unit 50 Concentrator / distributor 60 Operation display unit

Claims (1)

Acquisition means for acquiring transmission information transmitted through a wireless transmission path of the navigation monitoring automatic broadcast system and including an identifier of a desired wireless station;
The Communication State included in the transmission information acquired by the acquisition unit is extracted, stored in correspondence with the identifier in time series, the stored Communication State column is referenced in time series, and the Communication State is referred to. And a determination means for determining the authenticity of the wireless station or the transmission information by performing a determination process consisting of a combination of processes determined by a determination criterion for the value included in the communication state or the item included in the Communication State. A characteristic information discrimination device.