JP6139210B2 - Aircraft monitoring system - Google Patents

Description

  Embodiments described herein relate generally to an aircraft monitoring system and an aircraft monitoring method that detect all aircraft flying in a monitoring area.

  Aircraft monitoring systems that use the multi-lateration positioning principle have begun to be used for airport surface monitoring as MLAT, but because the monitoring targets are only Mode S transponder-equipped devices (hereinafter referred to as Mode S aircraft), transmission from aircraft The radio wave is a signal including a mode S address unique to each aircraft. In this case, it is very easy to extract only the response signals of the same aircraft from the response signals from a plurality of aircraft, and a high detection rate can be ensured.

Electronic Navigation Research Institute Research Presentation (10th June 2010) “Fundamental Experiment Results of Wide Area Multilateration”

  On the other hand, WAM (Wide Area Multilateration) is required to detect all aircraft flying in the monitored airspace, and transmitted from conventional ATC transponder-equipped machines (hereinafter referred to as ATCRBS machines) in addition to Mode S aircraft It is necessary to receive and decode the ATCRBS response signal and perform correlation and positioning processing.

  However, since there is no identification information assigned to the aircraft body corresponding to the mode S address in the transmission signal from the ATCRBS aircraft, it is generally difficult to extract only the signals transmitted from the same aircraft.

  An object of the present invention is to provide an aircraft monitoring system and an aircraft monitoring method that can extract only a response signal output from the same aircraft regardless of what type of aircraft enters the monitoring area.

  According to the embodiment, the aircraft monitoring system targets an aircraft monitoring system that monitors an aircraft that enters a predetermined monitoring area, and includes a plurality of receiving devices and a management device. The plurality of receiving devices have signal receiving means for receiving signals output from the aircraft, and are installed at geographically separated positions. The management device is connected to a plurality of receiving devices via a network. The management apparatus includes pattern information generation means, storage means, correlation detection means, and target processing means. The pattern information generating means receives signals output from the plurality of receiving apparatuses, and obtains a set of the plurality of received signals as pattern information. The storage means stores the output of the pattern information generation means. The correlation detecting means obtains a correlation by shifting the time axis and comparing the pattern information stored in the storage means and the output of the pattern information generating means by shifting the time axis every time a signal is obtained from the aircraft. The target processing means extracts only the response signal of the same aircraft existing in the monitoring area from the detection result of the correlation detection means.

The figure which shows the whole structure of the aircraft monitoring system in this embodiment. The block diagram which shows the connection structure of the some receiving apparatus and management center in this embodiment. In this embodiment, the figure which shows typically the response sequence when the mode A response from the ATC transponder mounted in the aircraft (A) is received by each receiving device, corresponding to the TOA on the time axis. The conceptual diagram about the correlation of a TOA pattern and the tracking of a pattern in this embodiment. The figure which shows typically the received power level Pn when the same response signal from an aircraft (A) is received by each receiver in this embodiment corresponding to TOA on a time axis. The figure which shows the whole structure of the aircraft monitoring system in the 1st modification of this embodiment. The figure which shows the whole structure of the aircraft monitoring system in the 2nd modification of this embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of an aircraft monitoring system in the present embodiment. As shown in FIG. 1, the management center 10 and a plurality of receiving devices 12-1 to 12-5 are connected to each other via a network NW. In the aircraft monitoring system in the present embodiment, each of the receiving devices 12-1 to 12-5 receives radio waves radiated from the aircraft AP that has entered the monitoring coverage area, and each of the receiving devices 12-1 to 12-12 of the received radio waves. Multilateration positioning that identifies the position of the aircraft AP based on the difference in arrival time to −5 is used.

  FIG. 2 is a block diagram illustrating a connection configuration between the receiving apparatuses 12-1 to 12-5 and the management center 10. Here, the connection configuration between the receiving device 12-1 and the management center 10 will be described as a representative. The reception device 12-1 is provided with a time acquisition unit 21 and a radio wave reception unit 22. The time acquisition unit 21 receives a radio wave from a GPS satellite (not shown), and generates time information from the received signal. The radio wave receiver 22 receives a response signal from the aircraft AP, adds the time information from the time acquisition unit 21 to the response signal, and outputs the response signal to the management center 10. In addition, the radio wave reception unit 22 measures the received power level when the response signal from the aircraft AP is received by the power measurement unit 23, adds the measurement result to the response signal, and outputs the response signal to the management center 10. The receiving devices 12-2 to 12-5 are configured in the same manner as the receiving device 12-1.

  The management center 10 includes a pattern file generation unit 24, a storage unit 25, a correlation detection unit 26, and a target processing unit 27. The pattern file generation unit 24 receives response signals with time information from the plurality of reception devices 12-1 to 12-5, and calculates the arrival time difference of received radio waves based on the time information for each of the sets of two reception devices. . The set of arrival time differences is stored in the storage unit 25 as a pattern file and is output to the correlation detection unit 26.

  The correlation detection unit 26 obtains a correlation between the pattern file stored in the storage unit 25 and the output of the pattern file generation unit 24, and the correlation detection result is supplied to the target processing unit 27. The target processing unit 27 determines the aircraft AP from the correlation detection result, and extracts only the response signal from the aircraft AP.

  The pattern file generation unit 24 receives response signals with reception power level information from the plurality of reception devices 12-1 to 12-5, and stores a set of these reception signals in the storage unit 25 as a pattern file.

  By the way, in the positioning by multilateration, as shown in FIG. 1, a 1090 MHz transmission signal transmitted at the same time from an ATC transponder mounted on an aircraft AP is sent to a plurality of receiving devices 12-1 to 12-5 installed on the ground. The time (TOA: Time Of Arrival) when the transmission signal of the ATC transponder of the aircraft AP arrives at each receiving device 12-1 to 12-5 is measured, and the difference in TOA (TDOA: Time Difference Of Arrival) ) Is a method of drawing a hyperbola with a constant value and calculating the position of the aircraft from the intersection of the hyperbola.

  At this time, it is necessary to extract the transmission signal of the ATC transponder of the same aircraft AP and perform the processing of TDOA. Conventionally, it is included in the signal transmitted by the mode S aircraft and is different for each aircraft. Using the “address” as a key, response data obtained by decoding the response signal is grouped by correlation processing for positioning.

  However, there are only two types of ATCRBS machine identification: mode A response (ID response) and mode C response (barometric altitude response). In addition, there are 4096 mode A responses and the same mode A code is assigned at the same time in the case of instrument flight, except for some exceptions.

  However, in the case of a visual flight aircraft, a mode A code called a “family beacon code” assigned to multiple aircraft with the last two digits of the mode A code indicated by four digits in octal display as “00” (eg, 1200) 1400), there may be a plurality of ATCRBS machines that transmit the same mode A code in the WAM monitoring coverage area. In such a case, it is difficult to extract only the response of the same aircraft. .

  Therefore, in the present embodiment, a pattern in which TOAs are generated based on the relative positional relationship between the aircraft AP to be subjected to multi-lateration positioning and a plurality of ground receiving devices 12-1 to 12-5 (transmitted from the ATC transponder of the same aircraft). Group of absolute time when the same received signal reaches a plurality of receiving devices 12-1 to 12-5 placed on the ground) and reception of response signals received by the receiving devices 12-1 to 12-5 Using the power level pattern, as the response of the ATC transponder of the same aircraft AP, the correlation is determined from the received signals of the responses of many ATC transponders, and the response of a specific ATCRBS machine is extracted.

  Next, the operation in the above configuration will be described with reference to FIGS.

  FIG. 3 schematically shows a response sequence when the mode A responses from the ATC transponders mounted on the aircraft AP (A) are received by the receiving apparatuses 12-1 to 12-5, corresponding to the TOA on the time axis. It is shown as an example. In the figure, a group of response signals enclosed by an ellipse is referred to as a TOA group at the corresponding position of the aircraft AP (A). The elements of the set of individual TOA differences in this TOA group have the property of changing depending on the relative relationship between the target aircraft AP (A) and the plurality of receiving devices 12-1 to 12-5 placed on the ground. . By capturing the set of TOA differences at a certain moment as a pattern, it is possible to extract only the response from the aircraft AP (A) by rejecting the ATCRBS response that does not match the pattern as being uncorrelated It becomes.

  FIG. 4 is a conceptual diagram showing TOA pattern correlation and pattern tracking. In general, the target aircraft AP moves at high speed, but the response from the first aircraft AP (A) is captured by the plurality of receiving devices 12-1 to 12-5 and the pattern of the next aircraft AP (A). The TOA pattern obtained by capturing the above response by the plurality of receiving apparatuses 12-1 to 12-5 has a very high correlation. This is because the repetition period of the response signal is smaller than the moving speed of the aircraft AP.

  That is, if the TOA group patterns of response signals received and decoded by the plurality of receiving devices 12-1 to 12-5 on which the response signals of the aircraft AP (A) are placed on the ground are sequentially tracked in time series, the aircraft AP (A ) Since the pattern at each response timing of the aircraft AP can be predicted even if there is a change in the pattern of the TOA group accompanying the movement of), the response of the mode A code of the aircraft AP (A) is continued by taking the pattern correlation. Can be detected.

  In this case, it goes without saying that the mode A code is first correlated.

  In FIG. 5, the reception power level Pn when the same response signal from the aircraft AP (A) is received by each of the receiving devices 12-1 to 12-5 is arranged on the time axis in association with the TOA as described above. Is. The reception power level of each of the reception devices 12-1 to 12-5 for the response signal of the aircraft AP (A) is also unique corresponding to the relative relationship between the aircraft AP (A) and the ground reception devices 12-1 to 12-5. Pattern.

  Using this feature, by creating a new pattern profile that adds the received power level pattern to the TOA pattern, the response from the aircraft AP (A) when the aircraft AP (A) is at a specific position can be correlated. When extracting, it is an additional element that improves accuracy.

  When the response of the ATC transponder is a mode C code, FIGS. 3 to 5 can be detected similarly by replacing the mode C code with the mode C code.

  As described above, in the above-described embodiment, the pattern file generation unit 24 is based on a set of reception signals with time information or reception power levels respectively output from the plurality of reception devices 12-1 to 12-5 installed in the monitoring coverage area. Then, a pattern file is generated and stored in the storage unit 25, and the correlation detection unit 26 performs a correlation comparison with a pattern file that is a set of received signals obtained from the aircraft AP, and shifts the time axis. By superimposing, the same pattern location has the greatest correlation, and the same aircraft has moved, thereby rejecting ATCRBS responses that do not fit in the pattern and extracting only the response signals from the same aircraft AP it can.

(First modification)
In the first modification, by adding the arrival direction information of each response signal to the response signal of the aircraft that transmits the same mode A code, a plurality of aircraft flying in the WAM monitoring coverage area are displayed in the azimuth direction. It is an example which makes it possible to separate using differences.

  The above embodiment is premised on the use of an aerial having directivity in all directions used in a general multilateration system. However, as shown in FIG. An antenna 31 having omnidirectional characteristics composed of a combination of antennas having directivity in the sector direction (sector-divided antenna) is used, and the antenna has directivity as shown in FIG. 6B. By forming a receiving system, it is possible to easily identify and distinguish aircraft having family beacon codes with different flight positions by configuring a ground receiving system that can add approximate direction information of TGT. .

(Second modification)
The second modification is a method of separating a plurality of aircraft AP-1 and AP-2 that transmit the same mode A code by using individual differences in the transmission frequency of the response signal of the TAC transponder.

  FIG. 7 is a schematic configuration diagram showing a second modification. This makes use of the different nature of each ATC transponder within the range allowed by the International Civil Aviation Organization (1090MHz ± 3MHz). Each receiving device 12-1 to 12-5 measures the response frequency of each ATCBRS transponder, generates a response data set to which the transmission frequency information of the transponder is added together with the response data, and transmits the response data set to the management center 10. The management center 10 is further effective to improve the grouping success rate by using it as a correlation condition for grouping.

  As described above, according to the second modified example, it is necessary to add a function of measuring the carrier frequency with high accuracy for each response of the transponder to the receiving devices 12-1 to 12-5. The performance of identification is greatly improved.

  Even when the frequency of the carrier wave of the transponder response signal is the same, the separation performance can be further improved by the combined use with the first modification.

(Other embodiments)
In the first modified example, when a plurality of aircraft existing in the same sector of the same sector antenna are separated, the separation performance can be further improved by using the second modified example together.

  Each process described in the above embodiment can be processed by software by a computer program.

  In addition, the embodiments are not limited to the above-described embodiments as they are, and in the implementation stage, the constituent elements can be modified and embodied without departing from the scope of the invention. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 10 ... Management center, 12-1 to 12-5 ... Receiving device, 21 ... Time acquisition part, 22 ... Radio wave receiving part, 23 ... Electric power measurement part, 24 ... Pattern file generation part, 25 ... Storage part, 26 ... Correlation detection Part, 27 ... target processing part, AP ... aircraft.

Claims (4)

In an aircraft monitoring system that monitors an aircraft entering a predetermined monitoring area,
A plurality of receiving devices each including a signal reception output means for receiving a signal output from the aircraft, adding a reception time to the received signal, and outputting the received signal;
A management device connected to the plurality of receiving devices via a network;
The management device
Receiving reception signals respectively output from the plurality of reception devices, and calculating arrival time differences of reception signals in the plurality of reception devices based on reception times added to the plurality of reception signals, respectively. Pattern information generating means for generating a set of time differences as pattern information;
Storage means for storing the output of the pattern information generation means;
Correlation detecting means for correlating the pattern information stored in the storage means with the output of the pattern information generating means;
An aircraft monitoring system comprising: target processing means for extracting only response signals of the same aircraft existing in the monitoring area from the detection result of the correlation detecting means. In an aircraft monitoring system that monitors an aircraft entering a predetermined monitoring area,
A plurality of receiving devices each including a signal reception output means for receiving a signal output from the aircraft, adding a reception power level information to the reception signal and outputting the received signal;
A management device connected to the plurality of receiving devices via a network;
The management device
Pattern information generating means for receiving reception signals respectively output from the plurality of receiving apparatuses and generating a set of received power levels of received signals in the plurality of receiving apparatuses as pattern information;
Storage means for storing the output of the pattern information generation means;
Correlation detecting means for correlating the pattern information stored in the storage means with the output of the pattern information generating means;
An aircraft monitoring system comprising: target processing means for extracting only response signals of the same aircraft existing in the monitoring area from the detection result of the correlation detecting means. The aircraft monitoring system according to claim 1 or 2 , wherein an antenna having directivity in all directions is used for a receiving device located in the center of the monitoring area among the plurality of receiving devices. The plurality of receiving devices measure the response frequency of the aircraft, add response frequency information to the received signal, and output to the management device,
The pattern information generating means, based on the response frequency information of the received signal at each of said plurality of receiving devices, the aircraft monitoring system as claimed in claim 1 or 2, wherein the generating the pattern information.

Images