JP4679500B2 - ADS-B ground station - Google Patents

Description

  The present invention relates to a broadcast-type automatic dependent monitoring (ADS-B) ground station that acquires monitoring information of these aircraft on the ground based on a broadcast-type automatic dependent monitoring (ADS-B) signal emitted from an aircraft in flight.

  Aircraft in flight regularly transmits its own location information, etc., and the ground side receives and decodes this information to monitor the aircraft in real time and continuously. (Automatic Dependent Surveillance-Broadcast, Hereinafter, it is expressed as ADS-B) (for example, see Non-Patent Document 1). This ADS-B is a collective term for so-called ADS data including identification information of its own aircraft, position information acquired by GPS, navigation information such as courses and speeds acquired by various on-board navigation equipment from the aircraft side. Data is periodically transmitted as an ADS-B signal using a broadcast-type data communication means. On the ground side, it is necessary to monitor an aircraft in flight simply by receiving and decoding the ADS-B signal. Various information such as accurate location information is acquired.

  As broadcast-type data communication means used for transmitting ADS-B signals from the aircraft, systems such as an extended squitter, VDL-4 (VHF Digital Link mode 4), and UAT (Universal Access Transceiver) have been internationally proposed. However, the extended squitter method is particularly promising (see Non-Patent Document 2, for example). This is because the extended squitter method uses the same frequency and signal format as the SSR (Secondary Surveillance Radar) mode S. By adding a function to the mode S transponder already installed in a large aircraft, this mode S This is because the transponder can be shared.

  Therefore, there is a possibility that the aircraft side uses a mode S transponder corresponding to the extended squitter method, and the ground station side can realize the same operation as a conventional air traffic control radar with a relatively simple equipment configuration for reception and decoding. Since it is expected, the system using ADS-B is being developed and evaluated as one of the monitoring systems for dealing with the increasing air traffic volume and enhancing the safety of navigation.

  FIG. 6 shows an example of an ADS-B ground station that receives and decodes an ADS-B signal from an aircraft on the ground side. FIG. 6 is a block diagram showing an example of the configuration of a conventional ADS-B ground station.

  In the example shown in FIG. 6, the ADS-B ground station includes an omnidirectional antenna 61 that receives an ADS-B signal from an aircraft, a receiving unit 62 that receives and processes the received ADS-B signal, A signal processing unit 63 that decodes ADS-B data from the signal and outputs the result as an ADS-B message, assembles and edits these ADS-B messages into a predetermined format, and creates an ADS-B report as monitoring information. The message processing unit 64 is configured. The ADS-B signal transmitted from the aircraft is received by this ADS-B ground station, and after undergoing a series of signal processing such as reception processing and decoding processing, it is assembled into a monitoring ADS-B report. The data is displayed on a display device (not shown) or sent to a subsequent device. An example of such a conventional ADS-B ground station is disclosed in, for example, Patent Document 1.

  In addition, this Patent Document 1 also describes an example of an ADS-B ground station having a multilateration function that has been developed recently. In multilateration, signals from an aircraft are simultaneously received by three or more ground stations, and position information of the aircraft is calculated from a difference in reception time at each station. Therefore, the ADS-B ground station with the multilateration function monitors not only the above-mentioned ADS-B report but also the position information of the aircraft independently calculated on the ground side without relying on data from the aircraft. Added to the information.

In addition, the investigation / examination regarding multilateration is shown in Non-Patent Document 3, for example.
Radio Technical Commission for Aeronautics (RTCA), 'Minimum Operational Performance Standards for 1090Mhz Automatic Dependent Surveillance-3, BroadDOA2 International Civil Aviation Organization (ICAO), Aeronautical telecommunication ANNEX10 Volume 4, July 1998 Eurocontrol, NLR-CR-2004-472 Wide Area Multilation Report on EATMP TRS 131/04 Version 1.1, August 2005 JP 2006-162324 A (page 12, FIG. 10)

  By the way, in the conventional ADS-B ground station configured as shown in FIG. 6, all information input for monitoring relies on the ADS-B signal transmitted from the aircraft through the broadcast data link. In addition, all received ADS-B signals are processed as signals originating from an aircraft in flight.

  However, the received signal may include an ADS-B signal that does not originate from an actual aircraft. That is, since the specifications of the above-mentioned broadcast type data link are internationally standardized and publicly disclosed, an erroneous ADS-B signal including, for example, false broadcasting (spoofing) is generated and received / decoded. There was inherent danger of processing.

  If such an erroneous ADS-B signal is processed, the erroneous target and the actual target are mixed, and it is expected that the air traffic control business will be greatly disrupted and damaged. For this reason, it has been desired to further improve the reliability of the ADS-B monitoring information acquired on the ground station side.

  On the other hand, by providing a multilateration function, as described above, it is also possible to acquire monitoring information without relying on data from the machine as a whole. However, in this case, it is essential to configure at least three ADS-B ground stations, and in addition, real-time processing based on accurate time synchronization between the stations, high-quality communication lines, and the like are also required. . For this reason, as the number of stations increases, the overall facility scale increases and the cost burden increases, and it is expected that the configuration will be complicated within each ground station single station. It was difficult to realize a ground station.

  The present invention has been made in consideration of the above-described circumstances, and an object thereof is to provide an ADS-B ground station in which the reliability of acquired ADS-B monitoring information is improved while suppressing an increase in apparatus scale. And

  In order to achieve the above object, the ADS-B ground station of the present invention receives a broadcast-type automatic dependent surveillance (hereinafter referred to as ADS-B) signal from an aircraft on the ground. In the ADS-B ground station that acquires monitoring information for the aircraft from the received ADS-B signal, the ADS-B receives the ADS-B signal from the aircraft and includes the identification information and position information of the aircraft based on the decoding result. Based on this ADS-B report creation means for creating a B report and new entry information to the monitored coverage area of its own station, track information including time-series position information is created based on this ADS-B report While updating the track information of the aircraft created for each aircraft, Track information management means for determining whether or not the transmission execution time of the mode S individual question transmitted from the own station has been reached for the aircraft including the approaching aircraft for which track information has been created, and the track information management means As a result of the determination, if there is a corresponding machine that has reached the transmission execution time, a predetermined mode S individual question is created for the corresponding machine based on the track information of the corresponding machine and transmitted at a predetermined transmission timing. Mode S question transmission means for receiving a response from the corresponding machine to the mode S individual question within a predetermined time width after the transmission of the question to obtain a mode S response message, and its reception timing and transmission timing Mode S response processing means for obtaining the distance information of the corresponding machine based on the track information, the track information of the corresponding machine from the track information management means, Comparing with the mode S response message of the corresponding machine from the mode S response processing means and its distance information, and comparing and judging means for rejecting the track information of the corresponding machine when both do not match under a predetermined condition It is characterized by that.

  ADVANTAGE OF THE INVENTION According to this invention, the ADS-B ground station which improved the reliability of ADS-B monitoring information can be obtained, suppressing the increase in an apparatus scale.

  The best mode for carrying out the ADS-B ground station according to the present invention will be described below with reference to FIGS.

  FIG. 1 is a block diagram showing a configuration of a first embodiment of an ADS-B ground station according to the present invention. In the present embodiment, the operation when there is an aircraft newly entering the monitored coverage area of the own station will be mainly described. As illustrated in FIG. 1, the ADS-B ground station includes an antenna unit 11, a circulator 12, a receiving unit 13, an ADS-B signal processing unit 14, a mode S signal processing unit 15, a message processing unit 16, and track information management. The unit 17 includes a mode S question creation unit 18, a transmission timing control unit 19, a transmission unit 20, and a comparison determination unit 21.

  The antenna unit 11 is, for example, an omnidirectional antenna, and exchanges an ADS-B signal, a mode S individual inquiry signal, and a response signal with a high-frequency signal having a predetermined frequency. The circulator 12 allows the signal received by the antenna unit 11 to pass through the receiver unit 13 and allows the transmission signal from the transmitter unit 20 to pass through the antenna unit 11.

  The receiving unit 13 performs reception processing such as amplification, frequency conversion, and detection on the ADS-B signal and the mode S individual response signal from the aircraft received by the antenna unit 11. Note that when the ADS-B signal is an extended squitter system, the ADS-B signal and the mode S individual response signal have the same frequency and signal format. The reception processing can be commonly performed by the unit 13.

  The ADS-B signal processing unit 14 decodes the ADS-B data from the ADS-B signal after the reception processing, and outputs the result as an ADS-B message. Further, the mode S signal processing unit 15 decodes the mode S individual response signal after reception processing and outputs the result as a mode S response message. In addition, based on the transmission timing of the mode S individual question signal and the reception timing of the mode S individual response signal as a response thereto, range information is acquired as distance information between the own station and the target device. When the mode S individual response signal is not received within a predetermined time after the transmission of the question, the contents of the mode S response message and the range information indicate that.

  The message processing unit 16 assembles and edits the ADS message from the ADS-B signal processing unit 14 into a predetermined format, and creates an ADS report. An example of the created ADS-B report is shown in FIG. In the example shown in FIG. 2, one ADS report includes a reception time when an ADS-B signal is received, a discrete beacon code (hereinafter referred to as DBC) as an aircraft identification information, a mode, It is composed of an S address, latitude, longitude, altitude, flight direction, and flight speed as position information (three-dimensional).

  The track information management unit 17 creates or updates the track information of the corresponding machine based on the ADS-B report from the message processing unit 16. The track information is created for each aircraft and held in the track information management unit 17. When an ADS-B report of an aircraft that does not hold track information is received, the aircraft is newly created as a new approaching aircraft to the monitored coverage area of its own station, and track information for this aircraft is newly created.

  In this track information, position information for each aircraft is stored in time series, an example of which is shown in FIG. In the example shown in FIG. 3, the track information 30 is composed of a header portion 31 and a track portion 32. The header section 31 associates the aircraft mode S address and DBC with the track number for identifying each track information, and indicates the transmission execution time of the mode S individual question transmitted from the own station to the aircraft. The mode S individual question execution time is included. In the track unit 32, a plurality of reception times and position information in the ADS-B report are stored in chronological order.

  Further, the track information management unit 17 determines the mode S individual question execution time in the header portion 31 of each track information, and if there is an aircraft that has reached the execution time of the question transmission, the track information is indicated as the mode S question. In addition to notifying the creation unit 18 and the comparison determination unit 21, the mode S individual question execution time is updated after the notification. In the present embodiment, it is determined that an approaching aircraft that has newly created the track information described above has reached the transmission execution time of the mode S individual question immediately after the creation. Further, the track information management unit 17 rejects the corresponding track information from the track information held based on the determination result from the comparison determination unit 21 described later.

  The mode S question creation unit 18 creates a predetermined mode S individual question for the target aircraft based on the track information notified from the track information management unit 17. In this embodiment, as the mode S individual question, an individual question (UF = 5) requesting DBC as identification information of the target machine is created according to a predetermined question format. The transmission timing control unit 19 performs transmission scheduling of the mode S individual question, sends it to the transmission unit 20 at a predetermined transmission timing, and notifies the mode S signal processing unit 15 of the transmission timing. The transmission unit 20 converts this into a high-frequency transmission signal and sends it to the antenna unit 11 via the circulator 12.

  The comparison determination unit 21 receives the track information of the aircraft that has reached the mode S individual question transmission time from the track information management unit 17 and the mode S response message and range information of this aircraft from the mode S signal processing unit 15. Compare the two. Then, it is determined whether or not both match under a predetermined condition, and the result is notified to the track information management unit 17. In this embodiment, the condition for determining that both are the same is that the DBC in the track information header section 31 matches the DBC in the mode S response message, and the latest position information in the track section 32 is used. The difference between the distance information to the target aircraft calculated based on the range information from the mode S signal processing unit 15 is within an observation error, for example.

  In FIG. 1, the antenna unit 11, the circulator 12, the receiving unit 13, the ADS-B signal processing unit 14, and the message processing unit 16 correspond to the ADS-B report creation means. The track information management unit 17 corresponds to the track information management means. The mode S question transmission means corresponds to the mode S question creation unit 18, the transmission timing control unit 19, the transmission unit 20, the circulator 12, and the antenna unit 11. The antenna unit 11, the circulator 12, the receiving unit 13, and the mode S signal processing unit 15 correspond to the mode S response processing means. The comparison determination unit corresponds to the comparison determination unit 21 and the track information management unit 17.

  Next, the operation of the ADS-B ground station of the present embodiment configured as described above will be described with reference to the flowcharts of FIGS. 1 to 3 and FIG. In the following explanation, the operation when there is a new approaching aircraft to the monitored coverage area of the own station is mainly taken up.

  FIG. 4 is a flowchart for explaining the operation of this embodiment. First, when an ADS-B signal is transmitted from an aircraft (ST401), the ADS-B signal is received by the antenna unit 11 and sent to the receiving unit 13 via the circulator 12. The reception unit 13 performs reception processing such as amplification, frequency conversion, and detection on the ADS-B signal. The signal after reception processing is sent to ADS-B signal processing section 14 (ST402).

  The ADS-B signal processing unit 14 decodes the ADS-B signal after the reception processing and sends the result to the message processing unit 16 as an ADS-B message. The message processing unit 16 edits this and illustrated in FIG. Create an ADS-B report. The created ADS-B report is sent to the track information management unit 17 (ST403).

  When receiving the ADS-B report, the track information management unit 17 verifies whether or not the track information having the mode S address and DBC in the received ADS-B report is already held (ST404). As a result, if it is held, it is determined that this ADS-B report is not from a new approaching aircraft (N in ST404), and the track information 30 already held in the format illustrated in FIG. The corresponding track information is updated by adding predetermined contents to the track section 32, and this ADS-B report is output to the subsequent stage (ST405).

  On the other hand, if the ADS-B report is not held, it is determined that the ADS-B report is from an aircraft that has newly entered the surveillance coverage area of its own station (Y in ST404), and based on this ADS-B report, FIG. New track information 30 of the exemplified format is created. That is, the new track information has a new track number in the header section 31, and the mode S address and DBC, and the corresponding contents in the ADS-B report are written in the track section 32 (ST406).

  Further, the track information management unit 17 directs the aircraft from this station to this aircraft, for example, by setting the current time as the mode S individual question execution time in the header unit 31 for such a new approaching aircraft. By setting a time at which it can be determined that the transmission execution time of the mode S individual question has been reached, it is determined that the execution time has been reached by itself, and the mode S individual question is executed. Then, the track information of the target aircraft (in this case, a new approach aircraft) is notified to the mode S question creation unit 18 and also to the comparison determination unit 21 in preparation for later determination (S407). .

  When the track information is notified from the track information management unit 17, the mode S question creating unit 18 requests the mode S individual question (UF) for requesting the DBC to the aircraft having the mode S address held in the track information. = 5) is created according to a predetermined question format (ST408). The created individual question is sent to the transmission timing control unit 19 and scheduled for transmission, and then is transmitted from the antenna unit 11 as a high-frequency mode S individual question signal from the transmission unit 20 at a predetermined timing (ST409). ).

  Thereafter, a mode S individual response signal is transmitted from the target machine that has received the mode S individual question signal (S410). This mode S individual response signal is received by the antenna unit 11, received in the receiving unit 13 in the same manner as in step ST402, and sent to the mode S signal processing unit 15 (ST411). The mode S signal processing unit 15 first performs the next signal processing after determining that the mode S individual response signal is a response within a predetermined time including the question transmission retry time (Y in ST412).

  That is, the mode S individual response signal is encoded in a predetermined format, and the mode S signal processing unit 15 decodes the mode S individual response signal after reception processing from the reception unit 13 to obtain a mode S response message. . In this embodiment, the mode S individual question (UF = 5) for requesting the DBC is made to the target machine, and the response signal (DF = 5) is processed. Includes the DBC of the target machine. In addition, based on the time difference between the transmission timing of the mode S individual question signal from the transmission timing control unit 19 and the reception timing of the mode S individual response signal, range information between the own station and the target device is acquired. Then, the mode S response message including the DBC and the range information are sent to the comparison determination unit 21 (ST413).

  The comparison / determination unit 21 compares the mode S response message and range information from the mode S signal processing unit 15 with the track information notified from the track information management unit 17 in step ST407, and whether or not they match. Determine whether. That is, by this determination, it is determined whether or not the aircraft that issued the ADS-B signal that is the source for creating new track information and the aircraft that responded to the mode S individual question are the same actual target. .

  In this embodiment, in making this determination, first, the DBC in the mode S response message is compared with the DBC in the header portion 31 of the track information to determine whether or not they match. Next, based on the latest aircraft position information stored in the track section 32 of the track information, the distance from the own station to this aircraft is calculated, and the calculation result and the range information from the mode S signal processing section 15 are calculated. For example, it is determined whether or not they match with a difference within a predetermined range to the extent that is caused by the processing time and the observation error. (ST414).

  As a result of these two determinations, if both are true, it is assumed that the above two match. That is, it is determined that the aircraft that issued the ADS-B signal and the aircraft that responded to the mode S individual question are the same actual target. Then, the determination result is notified from the comparison / determination unit 21 to the track information management unit 17 (Y in ST414).

  Upon receipt of the notification from the comparison / determination unit 21, the track information management unit 17 assumes that the track information newly created in step ST406 is that of the new approaching aircraft determined to be the actual target. Are kept inside for preparation for updating, and the ADS-B report is output to the subsequent device or the like (ST415). After that, the mode S individual question in the header section 31 of the track information is issued so that the mode S individual question is issued to the aircraft at a predetermined time interval of, for example, several minutes. The execution time is updated (ST416).

  On the other hand, if one of the results of the two determinations in step ST414 is not true, it is not determined that an actual target exists (N in ST414). In addition, when there is no response to the mode S individual question signal from the own station within a predetermined time including the case of no response (N in ST412), it is not determined that an actual target exists. Therefore, when the track information management unit 17 receives these determination results from the comparison determination unit 21, the track information management unit 17 rejects the track information newly created in step ST406 and the ADS-B report (ST417).

  The track information and the ADS-B report acquired in this way are displayed as monitoring information on, for example, a display device (not shown) in the own station or sent to a subsequent device. The series of operations described above continues until an instruction to end the operation is given (ST418).

  As described above, in this embodiment, a mode S individual question for requesting DBC is made immediately after the creation of the track information, with respect to the aircraft in which the track information is newly created based on the received ADS-B signal. After receiving and decoding the response signal, it is determined whether or not the DBC and the distance information in the newly created track information and the mode S individual response match. If they match, it is assumed that the aircraft that issued the ADS-B signal and the aircraft that responded to the mode S individual question are the same aircraft, and this is treated as an actual target. And the newly created track information is continuously held. On the other hand, if they do not match, it is determined as an erroneous target, and the newly created track information and ADS-B report are rejected.

  Therefore, in acquiring the ADS-B monitoring information of the approaching aircraft to the monitored coverage area of the local station, the ADS-B monitoring information determined to be from the actual target is discontinued and the ADS-B monitoring information determined to be from the actual target is continued. Therefore, the mixture of erroneous targets can be reduced, and the reliability and safety of the acquired ADS-B monitoring information can be improved.

  In this embodiment, since the question and response process using the mode S is performed, a transmission / reception system and an antenna system are required for this, but only the mode S individual question and its response are used. For this reason, a large directional antenna, a sidelobe suppression transmission system, etc. like a mode S radar are not required, for example. Furthermore, by using the extended squitter method, the ADS-B signal reception process and the mode S response signal reception process can be shared, so that the apparatus configuration is relatively simple without increasing the scale of the apparatus. Can be realized.

  FIG. 5 is a flowchart for explaining the operation of the second embodiment of the ADS-B ground station of the present invention. In the second embodiment, the same parts as those in the first embodiment shown in FIGS. 1 to 4 are denoted by the same reference numerals, and the description thereof is omitted. The difference between the second embodiment and the first embodiment is that the track information management unit 17 manages the track information. In contrast to the aircraft in which track information has been newly created and the question transmission timing immediately after the creation of track information, the second embodiment targets aircraft in which track information has already been created. The mode S individual question is transmitted at a predetermined time interval. Hereinafter, only the difference will be described with reference to FIGS.

  Similarly to the first embodiment, the ADS-B ground station of the second embodiment is also configured by the block diagram illustrated in FIG.

  Next, the operation will be described with reference to the flowchart of FIG. First, corresponding track information is updated in time series by an ADS-B signal from an aircraft, and an ADS-B report is output to a subsequent device or the like. This operation is, for example, the same as the series of operations in steps ST401 to ST405 in FIG. 4 of the first embodiment (ST51). The track information management unit 17 refers to the mode S individual question execution time in each created track information held inside (ST52), and determines whether there is an aircraft that has reached the execution time of the question transmission. Determine (ST53).

  As a result of the determination, if there is no corresponding aircraft, the operation from step ST51 is repeated (N in ST53). On the other hand, when there is an aircraft that has reached the execution time, the track information management unit 17 notifies the mode S question creation unit 18 and the comparison determination unit 21 of the track information of the target aircraft (Y in ST53).

  Thereafter, a series of operations similar to those in steps ST408 to ST414 in FIG. 4 are performed. That is, a mode S individual question (UF = 5) requesting DBC is generated and transmitted to the target machine, and a mode S individual response signal (DF = 5) is received from the target machine within a predetermined response time width. The mode S message and range information are obtained (ST408 to ST413).

  Subsequently, the comparison / determination unit 21 compares the mode S message and range information with the track information notified from the track information management unit 17 in step Y of ST53, and determines whether or not they match. judge. In this embodiment, DBC matching is determined in the same manner as in the first embodiment, and the distance information includes the latest distance information calculated from the track information and the range information obtained in step ST413. However, it is determined whether or not they coincide with each other within a predetermined range that is caused by the difference between the time when these are calculated and acquired and the observation error (ST54).

  If these two determinations are both true, it is assumed that the corresponding track information matches the mode S response and range information. That is, in this step, it is determined that there is an actual target corresponding to the track information to be compared and is moving, and the determination result is notified to the track information management unit 17 (Y in ST54).

  Upon receipt of the notification from the comparison / determination unit 21, the track information management unit 17 continues to hold the corresponding track information as corresponding to the actual target, and thereafter continues to the aircraft at a predetermined time interval. The mode S individual question execution time in the header part 31 of the track information is updated so that the mode S individual question is issued, and the ADS-B report is output to a subsequent device or the like (ST55).

  On the other hand, if one of the results of the two determinations in step ST54 is not true, and if there is no response within a predetermined time to the mode S individual question signal in step ST411, the corresponding track information is displayed. It is not determined that the corresponding real target exists (N in ST54 and N in ST411). Therefore, when receiving such a determination result from the comparison determination unit 21, the track information management unit 17 stops holding the corresponding track information and rejects it together with the ADS-B report. Notification is made (ST56).

  As described above, in the present embodiment, a mode S individual question for requesting DBC at a predetermined time interval is made to an aircraft for which track information has been created based on the received ADS-B signal, and the response signal is sent. After receiving and decoding, it is determined whether or not the DBC and the distance information in the track information and the mode S individual response match. If they match, the target aircraft is handled as a moving target, the track information is continuously held, and the execution time of the mode S individual question is updated. On the other hand, if these do not match, the target is wrong and the corresponding track information is rejected.

  Therefore, when acquiring the ADS-B monitoring information of the aircraft in the monitored coverage area of the local station, the ADS-B monitoring information determined to be an actual target and moving is rejected while the one determined to be an erroneous target is rejected. Since it is held, the mixture of erroneous targets can be reduced, and the reliability and safety of the ADS-B monitoring information can be improved.

  Further, it can be realized by the same device configuration as that of the first embodiment, and a relatively simple device configuration can be achieved without increasing the scale of the device.

  Note that the present invention is not limited to the above-described embodiments as they are, and can be embodied by variously modifying the components and combinations thereof without departing from the scope of the invention in the implementation stage.

The block diagram which shows the structure of the 1st Example of the ADS-B ground station which concerns on this invention. The figure which shows an example of an ADS report. The figure which shows an example of track information. The flowchart for demonstrating operation | movement of the 1st Example of this invention. The flowchart for demonstrating operation | movement of the 2nd Example of this invention. The block diagram which shows an example of a structure of the conventional ADS-B ground station.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Antenna part 12 Circulator 13 Reception part 14 ADS-B signal processing part 15 Mode S signal processing part 16 Message processing part 17 Track information management part 18 Mode S question preparation part 19 Transmission timing control part 20 Transmission part 21 Comparison determination part 30 Track Information 31 Header part 32 Track part

Claims (5)

ADS-B that receives broadcast-type automatic dependent monitoring (Automatic Dependent Surveillance-Broadcast, hereinafter referred to as ADS-B) signal from the aircraft and acquires monitoring information for the aircraft from the received ADS-B signal In the ground station,
ADS-B report creating means for receiving an ADS-B signal from the aircraft and creating an ADS-B report including identification information and position information of the aircraft based on the decoding result;
Based on this ADS-B report, for the new approaching aircraft to the monitored coverage area of its own station, while creating new track information including time-series position information, the track of the aircraft created for each aircraft Track information management for updating information and determining whether or not the transmission execution time of the mode S individual question transmitted from the own station has been reached with respect to the aircraft including the new approaching aircraft for which track information has been created Means,
As a result of the determination by the track information management means, if there is a corresponding machine that has reached the transmission execution time, a predetermined mode S individual question for the corresponding machine is created based on the track information of the corresponding machine. Mode S question transmission means for transmitting at a predetermined transmission timing;
A response to the mode S individual question from the corresponding machine is received within a predetermined time width after the transmission of the question to obtain a mode S response message, and the distance information of the corresponding machine based on the reception timing and the transmission timing Mode S response processing means for obtaining
The track information of the corresponding machine from the track information management means is compared with the mode S response message and distance information of the relevant machine from the mode S response processing means, and when both do not match under a predetermined condition An ADS-B ground station comprising comparison judgment means for rejecting the track information of the corresponding aircraft.   2. The track information management means determines that an approaching aircraft that has newly created the track information has reached the transmission execution time of the mode S individual question immediately after the creation. ADS-B ground station described in 1.   When the track information management means has reached the transmission execution time of the mode S individual question for each predetermined time interval for the aircraft for which the track information has been created except for a new approaching aircraft, The ADS-B ground station according to claim 1, wherein the ADS-B ground station is determined. The predetermined mode S individual question created in the mode S question transmission means is a question requesting identification information of the corresponding machine,
The predetermined condition in the comparison / determination means is that the identification information in the track information of the corresponding machine matches the identification information in the mode S response message from the corresponding machine, and the latest information in the track information of the corresponding machine. The difference between the distance information from the own station calculated based on the position information of the mobile station and the distance information from the mode S response processing means is within a predetermined range. The ADS-B ground station according to any one of the above.   The ADS-B ground station according to any one of claims 1 to 4, wherein when the track information is updated and rejected, the track information management means outputs the result. .

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