JP2013140049A - Radar link system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radar link system capable of acquiring positional information on an aircraft from an information source other than an air-traffic control station.SOLUTION: In a radar link system 10, a plurality of interrogation signals transmitted by an SSR transmitter-receiver 12 are received by using a first receiving apparatus 21 to generate an interrogation data set having a time stamp of a reception time of the interrogation signals, and a plurality of response signals outputted in response to the interrogation signals by a transponder 19 of an aircraft are received by using a second receiving apparatus 40 to generate a response data set having a time stamp of reception time of the response signals. Then, interrogation data and response data corresponding to each other are paired on the basis of the reception time, and based on the respective reception time and the like of the paired interrogation data and response data, an elliptical sphere is identified where the aircraft can be positioned. Further, an aircraft position in the elliptical sphere is obtained from a flight altitude extracted from the response signals, and from a direction of an antenna 12A of the SSR transmitter-receiver 12 that is identified on the basis of a change in reception intensity of the interrogation signals.

Description

  The present invention relates to a radar link system for detecting the position of an airplane, helicopter or other aircraft.

  In general, the flight position of an aircraft is monitored by an air station of the Ministry of Land, Infrastructure, Transport and Tourism (hereinafter simply referred to as “air station”) by a primary monitoring radar or a secondary monitoring radar installed at an airfield (see Patent Document 1).

Japanese Patent Application Laid-Open No. 08-179039 (paragraphs [0001], [0002])

  By the way, in order to investigate the noise of an aircraft, it is necessary to know the flight position of the aircraft. However, in recent years, with the increase in the number of aircraft, it has become difficult to obtain position information of each aircraft from an air station for purposes unrelated to aircraft operation management. Also, for example, the location information of other aircraft in the sky from other than the air station in order for the SDF and the news agency aircraft that are urgently dispatched immediately after the occurrence of a major disaster such as an earthquake, or a doctor helicopter to fly more safely. There is a need to get.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radar link system that can acquire position information of an aircraft from other than an air station.

  In order to achieve the above object, a radar link system according to the first aspect of the present invention comprises an A interrogation signal and a C signal transmitted a plurality of times while the antenna of the radar transmitter of the secondary monitoring radar system rotates once. A first receiver that receives the interrogation signal and generates interrogation data for each interrogation signal, and a transponder installed in an airplane, helicopter or other aircraft with a certain delay in response to the interrogation signal transmitted by the radar transmitter The second receiving device that receives the answer signal output after time and generates the answer data, the time measuring means for ticking the time, and the first receiving device are provided at the time by the time measuring means each time the question signal is received. A first time stamp means for measuring the reception time and including it in the question data, and a time provided by the second receiving device each time the answer signal is received. A second time stamp means for measuring the reception time based on the response time and including it in the answer data; a flight altitude extracting means for extracting information on the flight altitude of the aircraft contained in the answer signal received by the second receiver; and the first receiver The antenna direction calculation means for calculating in which direction the antenna is directed at the reception time of each question data based on the change in the reception strength of the question signal received by the receiver, the question from the first receiver and the second receiver Data group and answer data group are acquired, and each answer data is paired with the question data of the reception time within a predetermined time before the time obtained by subtracting the response delay time from the reception time of each answer data. The ellipsoidal sphere on which the aircraft can be located is identified from the pairing means for ringing, the reception time of each of the paired answer data and question data, the response delay time, and the speed of light. , Characterized in was a position calculating means for calculating a position of the aircraft on the ellipsoid from an antenna orientation computed at altitude and antenna direction calculation means extracted in altitude extracting means.

  According to a second aspect of the present invention, in the radar link system according to the first aspect, when the first receiving device is arranged at a position where the interrogation signals of a plurality of radar transmitters can be received, The present invention is characterized in that there is provided a sorting means for sorting the question data for each radar transmitter based on the difference in the shape of the received waveform of the question signal.

  According to a third aspect of the present invention, in the radar link system according to the first or second aspect, the trajectory of the aircraft that can be calculated based on the answer data and the question data generated while the antenna of the radar transmitter rotates once, Drawing a curved line segment that is part of an ellipse, and a plurality of line segments as an aircraft trajectory that can be calculated based on answer data and question data obtained while the radar transmitter antenna rotates multiple times, It has a feature in that it includes data reliability determination means for determining whether or not the calculation result of the position of the aircraft is correct depending on whether or not a plurality of concentric elliptical line segments are configured.

  A radar link system according to a fourth aspect of the present invention receives a search pulse wave transmitted a plurality of times while the antenna of the radar transmitter of the primary monitoring radar system makes one rotation, and searches for each search pulse wave. A first receiving device for generating data; a second receiving device for generating reflected data by receiving a reflected pulse wave of a search pulse wave reflected by an airplane, helicopter or other aircraft; and a time measuring means for ticking time A first time stamp means provided in the first receiving apparatus, which measures the reception time based on the time by the time measuring means every time a search pulse wave is received, and is provided in the second receiving apparatus. Each time the reflected pulse wave is received, the reception time is measured based on the time by the time measuring means, and the second time stamp means included in the reflected data and the first receiving device receive Based on a change in the reception intensity of the search pulse wave, antenna direction calculation means for calculating which direction the antenna is facing at the reception time of each search data, and search data from the first receiver and the second receiver A pairing means for acquiring a group and a reflection data group, and pairing each reflection data with search data at a reception time within a predetermined time before the reception time of each reflection data; The ellipsoidal sphere on which the aircraft can be located is identified from the received time and the light velocity of the reflected data and the search data, and the estimated value of the flight altitude of the aircraft set in advance and the antenna calculated by the antenna direction calculation means It has a feature in that it is provided with position calculating means for calculating the position of the aircraft on the elliptic sphere from the direction.

  According to a fifth aspect of the present invention, in the radar link system according to any one of the first to fifth aspects, the first receiving device and the second receiving device are separately provided, and the same time is recorded in synchronization with each other. It is characterized in that each of the first receiving device and the second receiving device is provided with a synchronous clock as time measuring means.

  The invention according to claim 6 is characterized in that, in the radar link system according to claim 5, the synchronous timepiece is configured to keep time based on time information from a GPS satellite acquired from a GPS module.

  According to a seventh aspect of the present invention, in the radar link system according to the fifth or sixth aspect, the position calculating means acquires data from one or both of the first receiving device and the second receiving device using a communication line network. However, it has characteristics.

  The invention according to claim 8 is the radar link system according to any one of claims 5 to 7, wherein a plurality of second receiving devices are provided for one radar transmitter, and the position calculation means is The present invention is characterized in that when the aircraft is positioned on a vertical plane including a straight line connecting the second receiver and the radar transmitter, the position of the aircraft is calculated using another second receiver.

  The radar link system according to the invention of claim 9 generates the transmission time data by acquiring the transmission time of the transmission source signal through the communication network every time the radar transmitter of the surveillance radar system transmits the transmission source signal. Receives a reply source signal that is returned or reflected from an airplane, helicopter or other aircraft in response to a transmission source signal transmitted from a transmission time data generator and a radar transmitter, and includes the reception time each time a reply source signal is received. A plurality of reception time data generation devices that generate reception time data and are arranged at different positions, and a transmission time and a reception time from a reception time data group and a transmission time data group for each reception time data generation device. A pairing means for pairing transmission time data and reception time data before a predetermined time within a predetermined time, and a reception time data generation device A plurality of elliptic spheres where the aircraft can be located are identified from the time difference between the transmission time data and the reply time data paired every time and the light speed, and the intersection between the elliptic spheres and the preset estimated flight altitude Alternatively, the present invention is characterized in that it includes position calculation means for calculating the position of the aircraft from the flight altitude included in the return source signal.

  In the radar link system according to the invention of claim 10, every time the radar transmitter of the monitoring radar system transmits a transmission source signal, the transmission time of the transmission source signal and the direction of the antenna of the radar transmitter are transmitted through the communication network. A transmission time data generator that generates and acquires transmission time data including information on the transmission time and antenna direction, and answers or reflections from airplanes, helicopters, and other aircraft with respect to the transmission source signal transmitted by the radar transmitter A reception time data generator, receiving time data including the reception time each time a reply source signal is received, and arranged at different positions, a reception time data group, and transmission time data The transmission time data and the reception time data before a certain time within a predetermined time difference between the transmission time and the reception time are paired with each other. The elliptical sphere on which the aircraft can be located is identified from the time difference between the paired transmission means and the paired transmission time data and reply time data and the light velocity, and is included in the preset estimated flight altitude or the reply source signal It has a feature in that it is provided with position calculating means for calculating the position of the aircraft from the flight altitude and the antenna orientation information.

[Invention of Claim 1]
In the radar link system according to claim 1, a plurality of interrogation signals transmitted from the radar transmitter are received by the first receiver, and a question data group in which the reception times are time-stamped is generated. The aircraft transponder receives a plurality of response signals output in response to the question signal, and generates a response data group in which the reception times are time-stamped. Thereby, the question data and the answer data corresponding to each other can be paired based on the reception time from the question data group and the answer data group. The ellipsoidal sphere where the aircraft can be located can be specified based on the reception time of the paired answer data and question data, etc., and the flight altitude that can be extracted from the answer signal and the change in the reception strength of the question signal The position of the aircraft in the ellipsoidal sphere can be obtained from the direction of the antenna of the radar transmitter that can be specified based on the orientation. That is, according to the radar link system of the present invention, the position of the aircraft can be obtained by linking to the secondary monitoring radar system, and the position information of the aircraft from other than the air station can be acquired.

[Invention of claim 2]
According to the radar link system of claim 2, the position of the aircraft can be obtained even in an area where interrogation signals from a plurality of radar transmitters are mixed.

[Invention of claim 3]
According to the configuration of the third aspect, since the data reliability determination unit verifies whether or not the calculation result of the aircraft position is correct, the reliability of the detection result of the aircraft position is improved.

[Invention of claim 4]
In the radar link system according to claim 4, a plurality of search pulse waves transmitted from the radar transmitter are received by the first receiver, and a search data group in which the reception times are time-stamped is generated, and the second The receiving device receives the reflected pulse wave of the search pulse wave reflected by the aircraft, and generates a reflection data group in which the reception times are time stamped. As a result, the search data and the reflection data corresponding to each other can be paired based on the reception time from the search data group and the reflection data group. Then, it is possible to identify an elliptical sphere on which the aircraft can be located based on the reception time of the paired reflection data and search data, etc., and the flight altitude that can be estimated and set in advance and the change in reception intensity of the interrogation signal The position of the aircraft on the elliptic sphere can be obtained from the direction of the antenna of the radar transmitter that can be specified based on That is, according to the radar link system of the present invention, the position of the aircraft can be obtained by linking to the primary monitoring radar system, and the position information of the aircraft from other than the air station can be acquired.

[Invention of claim 5]
According to the configuration of the fifth aspect, since the first timepiece and the second timepiece are each provided with a synchronous clock that clocks the same time in synchronism with each other, Even if they are provided separately and arranged at different positions, pairing of question data and answer data or pairing of search data and reflection data can be performed.
[Invention of claim 6]
According to the configuration of the sixth aspect, a plurality of synchronous watches can be easily synchronized by using the GPS module.

[Invention of Claim 7]
According to the configuration of the seventh aspect, since the position calculation means acquires one or both of the question data and the answer data using the communication line network, the position of the aircraft can be quickly obtained.

[Invention of Claim 8]
Although the position of the aircraft cannot be detected when the aircraft is positioned on the vertical plane including the straight line connecting the radar transmitter and the second receiver, the configuration according to claim 8 can be applied to one radar transmitter. A plurality of second receiving devices, and when the aircraft is positioned on a vertical plane including a straight line connecting the one second receiving device and the previous radar transmitter, the other second receiving device is used to make the aircraft Can be calculated.

[Invention of claim 9]
According to the configuration of claim 9, the position information of the aircraft cannot be acquired from the air station, but the position of the aircraft is obtained when the radar transmitter of the monitoring radar system can acquire the transmission time for transmitting the transmission source signal. be able to. That is, each time the radar transmitter of the monitoring radar system transmits a transmission source signal, the transmission time data generation unit generates the transmission time data by acquiring the transmission time of the transmission source signal through the communication network, and at different positions. A plurality of arranged reception time data generation devices receive a response source signal that is answered or reflected from the aircraft with respect to the transmission source signal transmitted by the radar transmitter, and generates reception time data including the reception time. . As a result, the transmission time data and the reception time data before a predetermined time within a predetermined time difference between the transmission time and the reception time are selected from the reception time data group and the transmission time data group for each reception time data generation device. Pairing is possible. And while specifying a plurality of elliptic spheres where the aircraft can be located from the time difference between the transmission time data and the reply time data paired for each reception time data generation device and the light speed, the intersection line between the elliptic spheres, The position of the aircraft can be obtained from the preset estimated flight altitude or the flight altitude included in the return source signal. That is, according to the radar link system of the present invention, the position of the aircraft can be obtained by linking to the primary monitoring radar system, and the position information of the aircraft from other than the air station can be acquired.

[Claim 10]
According to the configuration of claim 10, the position of the aircraft cannot be acquired from the air station, but the position of the aircraft is obtained when the radar transmitter of the monitoring radar system can acquire the transmission time for transmitting the transmission source signal. be able to. That is, every time the radar transmitter of the monitoring radar system transmits the transmission source signal, the transmission time data generation unit acquires the transmission time of the transmission source signal and the antenna direction information through the communication network and transmits the transmission time data. The reception time data generation device receives a reply source signal that is answered or reflected from the aircraft with respect to the transmission source signal transmitted by the radar transmitter, and generates reception time data including the reception time. Thereby, it is possible to pair the transmission time data and the reception time data before a predetermined time within a predetermined time difference between the transmission time and the reception time from the reception time data group and the transmission time data group. Then, the elliptical sphere on which the aircraft can be located is identified from the time difference between the paired transmission time data and reply time data and the light velocity, and the flight altitude and antenna included in the preset estimated flight altitude or the reply source signal The position of the aircraft can be obtained from the direction of the aircraft. That is, according to the radar link system of the present invention, the position of the aircraft can be obtained by linking to the primary monitoring radar system, and the position information of the aircraft from other than the air station can be acquired.

The conceptual diagram of the radar link system which concerns on 1st Embodiment of this invention. (A) Conceptual diagram of question signal group output by SSR transceiver, (B) Conceptual diagram of A question signal, (C) Conceptual diagram of C question signal Conceptual diagram showing the relationship between the reception strength of the SSR pulse wave and the direction of the antenna (A) Conceptual diagram showing a change in received intensity when a first receiver receives an interrogation signal group of one SSR transceiver, (B) reception of interrogation signal groups of two SSR transceivers by the first receiver Conceptual diagram showing changes in received strength Conceptual diagram showing the difference in the shape of the pulse waveform Conceptual diagram showing the configuration of the entire radar link system The block diagram which showed the structure of the signal processing circuit of a 1st receiver. The block diagram which showed the structure of the signal processing circuit of a 2nd receiver Block diagram showing the configuration of the signal processing circuit of the position calculation device Conceptual diagram of question data and answer data Conceptual diagram showing the principle of aircraft position detection Conceptual diagram showing the principle of determining data reliability The conceptual diagram which showed the structure of the whole radar link system of 2nd Embodiment. The block diagram which showed the structure of the signal processing circuit of a 1st receiver. The block diagram which showed the structure of the signal processing circuit of a 2nd receiver Block diagram showing the configuration of the signal processing circuit of the position calculation device The conceptual diagram which showed the structure of the whole radar link system of 3rd Embodiment.

[First Embodiment]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. Reference numeral 10 in FIG. 1 is a general radar transmission tower provided in an air station of an airfield, and includes an antenna 11A for transmission / reception of a PSR (Primary Surveillance Radar) transmitter / receiver 11 and an SSR (Secondary Surveillance Radar) transceiver. 12 transmission / reception antennas 12 </ b> A and a transmission antenna 13 </ b> A of an SLS (Side Robot Suppression) transmitter 13 attached to the SSR. There are airfields with only one radar transmission tower 10R and airfields with two radar transmission towers 10R. The SSR transceiver 12 has a stagger trigger specification and a normal specification.

  The antenna 12A of the SSR transmitter / receiver 12 rotates at a cycle of, for example, 4 seconds per rotation. In the SSR transmitter / receiver 12 of the normal specification, as shown in FIG. An interrogation signal or a C interrogation signal is transmitted. The SSR transceiver 12 of the stagger trigger specification and the normal specification has an interval for transmitting the A question signal or the C question signal of 5 ± Δt [msec] (Δt is a random value of 0.5 [msec] or less). Only random points differ from normal specifications

  The transmission pattern of the A question signal and the C question signal by the SSR transceiver 12 includes a pattern of alternately transmitting the A question and the C question, a pattern of “A question / A question / C question”, and a pattern of “A question / C question”. There are a plurality of patterns such as the “question / C question” pattern, and in an airfield equipped with two radar transmission towers 10R, 10R, the A question signal by the SSR transceivers 12, 12 of both radar transmission towers 10R, 10R is usually provided. And the transmission pattern of the C interrogation signal is different.

  As shown in FIG. 2B, the A interrogation signal is composed of two pulse waves with an interval of 8 [μsec], and the C interrogation signal is 21 [μsec] as shown in FIG. ] Are formed with two pulse waves spaced apart from each other. Then, the SSR transceiver 12 modulates each pulse wave constituting the A interrogation signal and the C interrogation signal with a carrier wave of 1030 [MHz] and outputs it with an output intensity of 1.0 [kw]. Hereinafter, the pulse wave output from the SSR transceiver 12 is appropriately referred to as “SSR pulse wave”. In the above example, the normal specification SSR transceiver 12 that transmits the A interrogation signal or the C interrogation signal at a fixed frequency of 5 [msec] is illustrated, but two normal specification SSR transceivers 12 and 12 are provided. In general, the periods at which the two SSR transceivers 12 and 12 transmit the A interrogation signal and the C interrogation signal are different. That is, the pulse repetition frequencies of the two SSR transceivers 12 and 12 are different.

  Here, FIG. 3 shows the received intensity when the SSR pulse wave is received by a receiver installed at a fixed distance from the SSR transceiver 12 and the rotational position of the antenna 12A of the SSR transceiver 12. The relationship is shown schematically. In the figure, the position at which the antenna 12A of the SSR transceiver 12 faces the receiver is set as the rotation angle origin, and the reception intensity at each rotation angle when the antenna 12A of the SSR transceiver 12 is rotated therefrom is shown in FIG. The distance from the origin P1 is shown. As shown in the figure, the reception intensity of the SSR pulse wave becomes the largest when the antenna 12A of the SSR transceiver 12 is located at the rotation angle origin, but the antenna 12A of the SSR transceiver 12 is oriented in any direction. Even the SSR pulse wave radiated from the SSR transceiver 12 is received by the receiver. For this reason, because only the SSR pulse wave from the SSR transmitter / receiver 12 is away from the SSR transmitter / receiver 12, the receiver has low reception strength of the SSR pulse wave or is not directly facing the SSR transmitter / receiver 12. It cannot be determined whether the reception strength of the SSR pulse wave is low.

  Therefore, in order to enable the receiver to determine whether the antenna 12A of the SSR transceiver 12 has received the SSR pulse wave output at the rotation angle origin or the SSR pulse wave output at a position other than the rotation angle origin. 2 (B) and 2 (C), 2 [μsec] after the output timing of the first SSR pulse wave of the A interrogation signal, and the output of the first SSR pulse wave of the C interrogation signal After 2 [μsec] from the timing, the SLS transmitter 13 modulates a pulse wave (hereinafter referred to as “SLS pulse wave” as appropriate) with a carrier wave of 1030 [MHz], which is the same as that of the SSR transmitter / receiver 12, and is omnidirectional. Is output.

  Further, the output intensity of the SLS pulse wave by the SLS transmitter 13 is smaller than the output intensity (1.0 [kw]) of the SSR pulse wave by the SSR transceiver 12. Specifically, the SSR pulse wave has a higher receiving intensity than the SLS pulse wave within a range of several degrees from the rotation angle origin at which the SSR transceiver 12 and the receiver face each other (hereinafter referred to as “facing range”). Thus, outside the facing range, the output intensity of the SLS transmitter 13 is set so that the SSR pulse wave has a lower reception intensity than the SLS pulse wave. Since the SSR transmitter / receiver 12 rotates once in 4 seconds, the facing range described above corresponds to several tens [msec] in terms of time.

  The stagger trigger SSR transmitter / receiver 12 also outputs the SLS pulse wave 2 [μsec] after the output timing of the first SSR pulse wave of the interrogation signal in the same manner as the normal SSR transmitter / receiver 12.

  In general, an aircraft (for example, an airplane, a helicopter, an airship, a balloon) is equipped with a transponder 19 (see FIG. 1) for responding to an A question signal and a C question signal from the SSR transceiver 12. When the transponder 19 receives two pulse waves at a frequency of 1030 [MHz], the ratio of the reception intensity of the previous pulse wave to the subsequent pulse wave (hereinafter referred to as “two-pulse reception intensity ratio”). Is sent and received only when the predetermined reference ratio matches with a predetermined allowable error range. Specifically, when the transponder 19 receives the A interrogation signal, the transponder 19 receives the “A interrogation signal” at the timing after the response delay time determined in advance from the timing at which the last SSR pulse wave constituting the A interrogation signal is received. In addition to outputting the response signal of “ID number” and receiving the C question signal, the aircraft is sent at the timing after the response delay time from the timing of receiving the last directly-facing SSR pulse wave constituting the C question signal. Outputs a response signal for "flying altitude". The response signals of “ID number” and “flight altitude” are composed of a plurality of pulse waves, and the transponder 19 modulates these pulse waves with a carrier wave of 1090 [MHz] and outputs them. Then, these answer signals are received by the SSR transceiver 12 installed in the airfield, so that the air station can detect and manage which ID number of the aircraft is flying in which position. It has become.

  Note that the antenna 11A of the PSR transceiver 11 rotates integrally with the antenna 12A of the SSR transceiver 12. Also, the PSR transceiver 11 modulates a search pulse wave (hereinafter referred to as “PSR pulse wave”) with a cycle of 2.5 [msec] with a carrier wave of 2.8 [GHz], for example, 30 [kw]. ] Is output. Then, the reflected wave when the PSR pulse wave is reflected by the aircraft is received by the PSR transceiver 11 installed in the site of the airfield, so that the air station has the aircraft or the transponder 19 in which the transponder 19 has failed. It is possible to detect and manage the position of the aircraft that does not.

  As shown in FIG. 1, the radar link system 10 of the present embodiment is separated from a plurality of first receiving devices 21 arranged, for example, in the vicinity of a plurality of airfields (for example, within 5 km), and the airfield. A plurality of second receiving devices 40 distributed in a remote location (for example, a position 10 to 100 km away from the airport), the plurality of first receiving devices 21 and the plurality of second receiving devices. And a position calculation device 60 connected to the network 40 via an Internet line.

  As shown in FIG. 6, the first receiving device 21 includes a receiving circuit 22, a GPS module 23, an A / D converter 24, a signal processing circuit 25, a WiMAX terminal 26, a monitor 27, and an operation unit 28. It has. The first receiving device 21 is connected to the position calculation device 60 via a wireless communication line network by the WiMAX terminal 26 and the Internet line network.

  The GPS module 23 gives position information and GPS time information calculated based on time information acquired from a plurality of GPS satellites to the signal processing circuit 25. The receiving circuit 22 receives and demodulates a radio wave having an output frequency (1030 [MHz]) of the SSR transceiver 12. Then, the analog reception signal demodulated by the reception circuit 22 is converted into a digital reception signal at a constant sampling period of, for example, 0.1 to 0.3 [μsec] by the A / D converter 24. Are taken into the signal processing circuit 25.

  The signal processing circuit 25 includes a CPU 25A, a RAM 25B, a ROM 25C, and a flash memory 25D. When the first receiving device 21 is activated, the CPU 25A executes the initial setting program stored in the ROM 25C, and informs the operator of the installation position data of the radar transmission tower 10R and each pulse of the SSR transceiver 12 and the SLS transmitter 13. Determine the repetition frequency (PPS) input. Here, the position of the radar transmission tower 10R can be known on a map, and the specification data of the pulse repetition frequency of the SSR transmitter / receiver 12 and the SLS transmitter 13 can be separately measured and known. Therefore, the operator inputs the position data of one radar transmission tower 10R at an airfield equipped with one radar transmission tower 10R and specifications of the pulse repetition frequencies of the SSR transceiver 12 and the SLS transmitter 13. Enter the data. Further, in an airfield equipped with two radar transmission towers 10R, position data for each radar transmission tower 10R and specification data of pulse repetition frequency for each SSR transceiver 12 and each SLS transmitter 13 are input. Then, when the CPU 25A writes the input data to the flash memory 25D and the antenna 12A of the SSR transceiver 12 faces the first receiver 21 based on the position data and the position information from the GPS module 23 described above. , That is, origin direction data for specifying the direction at the rotation angle origin of the antenna 12A of the SSR transceiver 12 is calculated. Then, the device identification number of the first receiving device 21 itself, the position data of each radar transmission tower 10R, and the origin direction data of the antenna 12A of the SSR transceiver 12 included in each radar transmission tower 10R are transmitted to the position calculation device 60. Exit the initial setting program.

  When the initial setting program ends, the CPU 25A, for example, stores a plurality of programs including a time measurement program stored in the ROM 25C, a time stamp program, a pulse sorting program, an origin marking program, and an A / C question sorting program. The processes are executed in parallel at a cycle (for example, 0.05 [μsec]). Thus, the CPU 25A functions as the GPS synchronous clock 30, the time stamp unit 31, the pulse sorting unit 32, the origin marking unit 33, and the A / C question sorting unit 34 shown in FIG.

  The GPS synchronous clock 30 is a clock that clocks time with an accuracy of, for example, 0.01 [μsec] based on GPS time information. In addition, the time stamp unit 31 obtains the reception time of the received signal by the GPS synchronous clock 30 for each sampling period of the A / D converter 24, and generates time / intensity data in which the reception time and the reception intensity are associated with each other. .

  The pulse sorting unit 32 performs a pulse extraction process for extracting a plurality of pulse waves included in the received signal from the time / intensity data. Specifically, a pulse wave is extracted when the reception intensity is a value equal to or greater than a threshold value over a predetermined time. Then, the extracted pulse wave group is classified into an SSR pulse wave and an SLS pulse wave based on the specification data of the pulse repetition frequency stored in the flash memory 25D, and each of the two SSR transmission / receptions When the specification data of the pulse repetition frequency of the transmitter 12 and the two SLS transmitters 13 is stored in the flash memory 25D, the first SSR pulse wave, the second SSR pulse wave, the first SLS And the second SLS pulse wave.

  Here, since the pulse wave group included in the received signal is densely or superimposed, the above-described classification may not be performed with the specification data of the pulse repetition frequency. In such a case, the group of pulse waves is classified based on the shape of the pulse wave unique to each transceiver. Specifically, even if the SSR transceivers 12 and 12 have the same structure, the shapes of the pulse waves are different due to variations in the radio wave propagation path of each SSR transceiver 12. The same is true between the two SLS transmitters 13 and 13, and the same is true between the SSR transmitter / receiver 12 and the SLS transmitter 13. Therefore, for example, if the pulse wave groups extracted by the first receiving device 21 installed in the vicinity of an airfield including two radar transmission towers 10R are of the same type, as shown in FIG. In addition, it can be classified into four types of pulse waves.

  Therefore, for example, the pulse sorting unit 32 outputs a pulse wave having the same number of vertices included in the pulse wave, a time difference between the vertices, and a reception intensity difference between the vertices from the same transmitter. Assuming the same group of pulse waves, the first SSR pulse wave, the second SSR pulse wave, the first SLS pulse wave, the second SLS pulse wave, etc. A group is classified for each transmitter. And for each pulse wave included in each type of pulse wave group, it corresponds to the reception time of the rising timing, the maximum value of the received intensity of the pulse wave, and the transmitter identification number for distinguishing the transmission source Generate attached pulse wave data.

  The origin marking unit 33 detects, from the SSR pulse wave data group, the time when the SSR transmitter / receiver 12 estimated as the transmission source and the first receiving device 21 face each other. Specifically, as shown in FIG. 4A, the reception intensity of the pulse wave data group of the SSR pulse wave gradually increases in a sinusoidal manner once every 4 seconds and then gradually decreases. To change. Then, the origin marking unit 33 determines that the SSR transmitter / receiver 12 faces the first receiving device 21 at the reception time of the pulse wave data at the peak point where the reception intensity changes in a sine wave shape, and determines the reception time. An origin mark for specifying the rotation angle origin is added to the transmitter identification number of the pulse wave data.

  When the first receiving device 21 is installed in the vicinity of an airfield equipped with two radar transmission towers 10R, as shown in FIG. 4B, it corresponds to the two SSR transceivers 12 and 12. The peak point of the reception intensity occurs twice in 4 seconds. The origin marking unit 33 applies the origin mark to the first SSR pulse wave data and the origin mark to the second SSR pulse wave data. Do both.

  The A / C question separation unit 34 combines the SLS pulse wave data group corresponding to the SSR transmitter / receiver 12 and the SLS transmitter 13 of the same radar transmission tower 10R and the SSR pulse wave data group, and these pulse wave data groups are combined. Grouping into pulse wave groups for one interrogation signal of A interrogation signal and C interrogation signal. Corresponds to the reception time of the rising timing of the last pulse in the pulse wave group for each question signal, question type information indicating whether the question signal is an A question or a C question, and the presence or absence of an origin mark The attached question data (see reference numerals 101 and 102 in FIG. 10) is generated. Then, the question data is collectively transmitted to the position calculation device 60, for example, every 40 [msec]. Here, the question data is collectively transmitted every 40 [msec] because the SSR transmitter / receiver 12 can transmit the SSR pulse wave in front of the aircraft in the tens of [msec] as described above. This is because, for every long period including several tens of [msec] (that is, 40 [msec]), the query data is collected and transmitted to the position calculation device 60 to detect the position of the aircraft.

  As shown in FIG. 6, the second receiving device 40 includes a receiving circuit 42, a GPS module 43, an A / D converter 44, a signal processing circuit 45, a WiMAX terminal 46, a monitor 47, and an operation unit 48. It has. The second receiving device 40 is connected to the position calculation device 60 via a wireless communication line network by the WiMAX terminal 46 and an Internet line network. Also in the second receiving device 40, as in the case of the first receiving device 21, the GPS module 43 gives position information and GPS time information to the signal processing circuit 45. The receiving circuit 42 receives and demodulates a radio wave having an output frequency (for example, 1090 [MHz]) of the transponder, and the demodulated analog reception signal is, for example, 0.1 by the A / D converter 44. It is converted into a digital received signal at a constant sampling period of .about.0.3 [.mu.sec] and is taken into the signal processing circuit 45.

  The signal processing circuit 45 includes a CPU 45A, a RAM 45B, a ROM 45C, and a flash memory 45D. When the second receiver 40 is activated, the CPU 45A executes the initial setting program stored in the ROM 45C, and sends the position information from the GPS module 43 and the device identification number of the second receiver 40 to the position calculator 60. Send to finish the initial setting program.

  When the initial setting program is terminated, the CPU 45A executes a plurality of programs including a time measurement program, a time stamp program, a pulse extraction program, and an A / C answer determination program stored in the ROM 45C in parallel at a predetermined cycle, for example. Thus, it functions as the GPS synchronous clock 50, the time stamp unit 51, the pulse extraction unit 52, and the A / C answer sorting unit 53 shown in FIG.

  The GPS synchronous clock 50 and the time stamp unit 51 are the same as the GPS synchronous clock 30 and the time stamp unit 31 of the first receiving device 21. The pulse extraction unit 52 extracts a plurality of pulse waves included in the reception signal from the time / intensity data generated by the time stamp unit 51, similarly to the pulse classification unit 32 of the first reception device 21. Then, the A / C answer classification unit 53 divides the pulse wave group into a pulse wave group of an answer signal for the A question signal and a pulse wave group of an answer signal for the C question signal. In addition, the A / C answer classification unit 53 determines the reception time of the rising timing of the first pulse in the pulse wave group for each answer signal and the flight altitude of the aircraft or the aircraft ID number specified from the answer signal. Corresponding response data (see reference numerals 201 and 202 in FIG. 10) is generated. Then, the answer data is collectively transmitted every 40 [msec] to the position calculation device 60.

  As shown in FIG. 6, the position calculation device 60 includes a signal processing circuit 61, a monitor 62, and an operation unit 63. The signal processing circuit 61 includes a CPU 61A, a RAM 61B, a ROM 61C, and a flash memory 61D. The CPU 61A executes, for example, a plurality of programs including an initial registration program, a data pairing program, a position calculation program, and a data reliability determination program stored in the ROM 61C in parallel at a predetermined cycle, as shown in FIG. It functions as an initial registration unit 65, a data pairing unit 66, a position calculation unit 67, and a data reliability determination unit 68.

  When initial setting data is transmitted from the first receiving device 21, the initial registration unit 65 includes the device identification number of the first receiving device 21 included in the transmitted data, and (one or two) radar transmission towers. The position data of 10R and the stable origin direction data of the SSR transmitter / receiver 12 included in each radar transmission tower 10R are written in the flash memory 61D. Further, when initial setting data is transmitted from the second receiving device 40, the initial registration unit 65 writes the position information and device identification number of the second receiving device 40 included in the transmission data in the flash memory 61D.

  The data pairing unit 66 takes in a response data group for 40 [msec] transmitted from the second receiver 40, and subtracts the response delay time of the transponder 19 from the reception time of each response data, thereby reaching the radar arrival time. Convert to Next, the data pairing unit 66 compares the radar arrival time possessed by each answer data with the radar emission time as the reception time possessed by each question data already captured from the plurality of first receiving devices 21. Answer data and question data having a relationship that the radar emission time is within a predetermined period (for example, 50 [μsec]) with respect to the arrival time are selected, and the selected question data and answer data are both When "A question / A answer" or "C question / C answer" is supported, the question data and the answer data are paired. Then, the data pairing unit 66 identifies the question data group having the largest number of question data paired with the answer data, and the origin direction data of the antenna 12A of the SSR transceiver 12 that is the transmission source of the question data group The position information of the radar transmission tower 10R is fetched from the flash memory 61D.

  The position calculation unit 67 multiplies the difference between the radar arrival time and the radar emission time of the paired answer data and question data by the speed of light, so that the linear distance from the SSR transceiver 12 to the aircraft and the aircraft To the second receiving device 40 is obtained as a pulse transmission distance which is the sum of the linear distance. Then, as shown in FIG. 11A, “A”, which is the installation position of the radar transmission tower 10R, and “B”, which is the installation position of the second receiving device 40, are set as the focal points A and B, and the focal point A , B and the elliptical sphere 90 in which the sum of the distances from the arbitrary point becomes the pulse transmission distance is specified as a range where the aircraft can be located.

  Next, the position calculation unit 67 determines the difference between the radar emission time of the question data and the radar emission time of the question data with the origin mark in the question data group to which the question data belongs, and the antenna 12A of the SSR transceiver 12. From the origin direction data, the direction of the antenna 12A of the SSR transceiver 12 at the radar emission time of the question data paired with the answer data, that is, the turning angle θ from the rotation origin is calculated. Then, as shown in FIG. 11B, a vertical plane 91 including a vertical axis passing through the focal point A and rotated by the turning angle θ from the rotation origin is specified, and the position of the aircraft is set to the vertical position of the ellipsoid 90 It narrows down on the intersection line 91A with the surface 91.

  Further, the position calculation unit 67 specifies a horizontal plane 92 that horizontally crosses the elliptic sphere 90 as shown in FIG. 11C from the “flight altitude” of the answer to the C question included in the answer data group, and the horizontal plane An intersection point P94 between the intersection line 92A between the elliptical sphere 90 and the intersection line 91A between the elliptical sphere 90 and the vertical plane 91 is specified as the position of the aircraft. Then, the same processing is performed for all the paired answer data and question data, the position and locus of the ellipsoid sphere 90 are obtained, the position of the aircraft is displayed on the monitor 62, or via the Internet as requested. It transmits to the 2nd receiver 40 grade | etc.,.

  By the way, as shown in FIG. 12, each time the antenna 12A of the SSR transceiver 12 makes one rotation, the position of the aircraft can be specified by a plurality of points. Then, when the trajectory is obtained by connecting the positions of these aircraft, the trajectory constitutes a part of a segment of the ellipse. And the locus | trajectory of the aircraft for every rotation of the SSR transceiver 12 forms a plurality of concentric elliptical line segments. In view of this point, the data reliability determination unit 68 determines that when the plurality of aircraft trajectories obtained by the position calculation unit 67 constitute a part of a plurality of ellipses and the plurality of ellipses are concentric. The data is judged to be highly reliable. Otherwise, the data is judged to be unreliable and a warning to that effect is given to prompt the correction of the initial setting data. Is replaced with another SSR transmitter / receiver 12 to recalculate the position of the aircraft, and the reliability of the data is determined again.

  In the present embodiment, a plurality of the second receiving devices 40 described above are arranged at different positions, and the position calculation device 60 calculates the position of the aircraft and does not find a solution or an abnormal value is obtained. Is determined that the aircraft is located on a vertical plane including a straight line connecting one second receiving device 40 and the radar link system 10, and the response data of the other second receiving device 40 is used to determine the aircraft. The position is calculated.

  To summarize the present embodiment described above, in the radar link system 10 of the present embodiment, a plurality of interrogation signals transmitted by the SSR transceiver 12 are received by the first receiver 21 and their reception times are time stamped. And a plurality of response signals output by the aircraft transponder 19 in response to the question signal are received by the second receiver 40, and a response data group in which the reception times are time-stamped is generated. To do. Thereby, the question data and the answer data corresponding to each other can be paired based on the reception time from the question data group and the answer data group. The ellipsoidal sphere 90 where the aircraft can be located can be specified based on the reception time of the paired answer data and question data, etc., and the flight altitude extracted from the answer signal and the change in the reception intensity of the question signal The position of the aircraft in the ellipsoidal sphere 90 can be obtained from the direction of the antenna 12A of the SSR transceiver 12 specified based on the above. That is, according to the radar link system 10 of the present embodiment, the position of the aircraft can be obtained by linking to the secondary monitoring radar system, and the position information of the aircraft from other than the air station can be acquired.

[Second Embodiment]
The radar link system 10V of the present embodiment is shown in FIGS. 13 to 16, and uses the search pulse wave (hereinafter referred to as “PSR pulse wave”) transmitted by the PSR transceiver 11 as the first. Different from the embodiment. That is, the overall hardware configuration of the radar link system 10 of the present embodiment is the same as that of the radar link system 10 of the first embodiment shown in FIG. 6, and the first receiving device 21 and the second receiving device. 40 and a position calculation device 60. The receiving circuits 22V and 42V of the first receiving device 21 and the second receiving device 40 respectively receive a signal of 2.8 [GHz] for the PSR transceiver 11, and the first receiving device 21 and the second receiving device. The programs executed by the CPUs 25A, 45A, 61A of the device 40 and the position calculation device 60 are different from those of the first embodiment.

  As illustrated in FIG. 14, the CPU 25 </ b> A of the first receiving device 21 functions as a GPS synchronous clock 30, a time stamp unit 31, a pulse sorting unit 32 </ b> V, and an origin marking unit 33 by executing a predetermined program. In the pulse sorting unit 32V of the present embodiment, the pulse wave group is extracted from the time / intensity data pulse wave group, and extracted when the specification data of the two PSR transceivers 11 are stored in the flash memory 25D. The pulse group is classified into a pulse wave of the first PSR and a pulse wave of the second PSR. And for each pulse wave included in each type of pulse wave group, it corresponds to the reception time of the rising timing, the maximum value of the received intensity of the pulse wave, and the transmitter identification number for distinguishing the transmission source The attached search data (corresponding to the “pulse wave data” of the first embodiment) is generated. Then, an origin mark is given to a part of the search data by the origin marking unit 33, and the search data group is transmitted to the position calculation device 60 via the Internet.

  As shown in FIG. 15, the CPU 45A of the second receiving device 40 functions as a GPS synchronous clock 50, a time stamp unit 51V, and a pulse extraction unit 52 by executing a predetermined program. In the pulse extraction unit 52 of this embodiment, a pulse wave group is extracted from the time / intensity data pulse wave group, and for each pulse wave included in the pulse wave group, reflection data including the reception time of the rising timing is obtained. Generate.

  As illustrated in FIG. 16, the CPU 61A of the position calculation device 60 functions as an initial registration unit 65, a data pairing unit 66, a position calculation unit 67V, and a data reliability determination unit 68 by executing a predetermined program. Further, the flash memory 61D of the position calculation device 60 stores an estimated value of the flight altitude of the aircraft. And the position calculation part 67V of this embodiment pairs each reflection data and the search data of the reception time before the predetermined time predetermined with respect to the reception time of the reflection data, and it was paired An elliptical sphere in which the aircraft can be located is specified from each reception time and reflection speed of the reflection data and search data. Then, the position of the aircraft on the elliptic sphere is calculated from the estimated value of the flight altitude and the direction of the antenna. Since other configurations are the same as those in the first embodiment, a duplicate description is omitted.

[Third Embodiment]
The radar link system 10W of this embodiment is shown in FIG. 17, and includes a position calculation device 60W and a plurality of second reception devices 40W connected to the secondary monitoring radar system via the Internet. The CPU 61A of the position calculation device 60W executes a predetermined program, so that each time the SSR transceiver 12 of the secondary monitoring radar system transmits the interrogation signal as the “transmission source signal” of the present invention, It functions as a transmission time data generation unit that acquires transmission time through a communication network (Internet) and generates transmission time data including the transmission time.

  In addition, the CPU 45A of each second receiving device 40W executes a predetermined program, so that the reply signal transmitted by the aircraft in response to the transmission source signal transmitted by the SSR transceiver 12 is a “reply source signal” according to the present invention. The signal processing circuit 45 generates reception time data including the reception time each time the reply source signal is received.

  Similarly to the first embodiment, the position calculation device 60W pairs the reception time data and the transmission time data for each second reception device 40W, and returns the response time data paired for each second reception device 40W. A plurality of elliptical spheres on which the aircraft can be located are specified from the time difference from the transmission time data and the speed of light, and the position of the aircraft is calculated from the intersection line between the elliptical spheres and the flight altitude. According to the configuration of the present embodiment, the position information of the aircraft cannot be acquired from the air station, but the position of the aircraft can be acquired when the radar transmitter of the secondary monitoring radar system can acquire the transmission time at which the transmission source signal is transmitted. Can be requested.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

(1) In the first embodiment, the first receiving device 21, the second receiving device 40, and the position calculating device 60 are separately provided and connected via a communication network such as the Internet. The device 60 may be configured to be integrated with either the first receiving device 21 or the second receiving device 40, or the first receiving device 21, the second receiving device 40, and the position calculation device 60 may be integrated. You may make the structure provided.

(2) In the third embodiment, the transmission time data is acquired from the secondary monitoring radar system having the SSR transceiver. However, the transmission time data is acquired from the primary monitoring radar system having the PSR transceiver. It may be.

(3) As a modified example of the third embodiment, antenna direction data may be acquired together with the transmission time from the monitoring radar system and used for detecting the position of the aircraft.

10, 10V, 10W Radar link system 11 PSR transmitter / receiver 12 SSR transmitter / receiver 13 SLS transmitter / receiver 19 Transponder 21 First receiver 23, 43 GPS module 30, 50 GPS synchronous clock 31, 51, 51V Time stamp unit 32, 32V pulse Sorting unit 33 Origin marking unit 40, 40W Second receiving device 60, 60W Position calculating unit 66 Data pairing unit 67, 67V Position calculating unit 68 Data reliability determining unit 90 Elliptic sphere

Claims (10)

A first question signal is generated for each question signal by receiving question signals of the A question signal and the C question signal transmitted a plurality of times while the antenna of the radar transmitter of the secondary monitoring radar system makes one rotation. A receiving device;
A second receiving device for generating response data by receiving a response signal output from a transponder mounted on an airplane, helicopter or other aircraft after a certain response delay time with respect to the inquiry signal transmitted by the radar transmitter;
Time measuring means for ticking time,
A first time stamp means provided in the first receiving device and measuring a reception time based on a time by the time measuring means every time the question signal is received;
A second time stamp means provided in the second receiving device, measuring a reception time based on a time by the time measuring means each time the answer signal is received, and including the received time in the answer data;
A flight altitude extraction means for extracting information on the flight altitude of the aircraft included in the answer signal received by the second receiver;
An antenna direction calculation means for calculating which direction the antenna is facing at the reception time of each question data based on a change in reception strength of the question signal received by the first receiver;
Obtaining the question data group and the answer data group from the first receiving device and the second receiving device, and for each of the answer data and a time obtained by subtracting the response delay time from the reception time of each of the answer data A pairing means for pairing the question data at a reception time within a predetermined time in advance,
The elliptical sphere on which the aircraft can be located is identified from the reception time of the paired answer data and the question data, the response delay time, and the speed of light, and the flight altitude extracted by the flight altitude extracting means And a position calculating means for calculating the position of the aircraft on the elliptic sphere from the antenna direction calculated by the antenna direction calculating means.   When the first receiving device is arranged at a position where the question signals of the plurality of radar transmitters can be received, the radar is based on the difference in the shape of the reception waveform of the question signals from the radar transmitters. The radar link system according to claim 1, further comprising a sorting unit that sorts the question data for each transmitter.   The trajectory of the aircraft that can be calculated based on the answer data and the question data generated while the antenna of the radar transmitter rotates once draws a curved line segment that is a part of an ellipse, and the radar Whether or not the plurality of line segments as the trajectory of the aircraft that can be calculated based on the answer data and the question data obtained while the transmitter antenna rotates a plurality of concentric ellipse lines 3. The radar link system according to claim 1, further comprising data reliability determining means for determining whether the calculation result of the position of the aircraft is correct. A first receiver for receiving search pulse waves transmitted a plurality of times while the antenna of the radar transmitter of the primary monitoring radar system makes one rotation, and generating search data for each of the search pulse waves;
A second receiving device for receiving reflected pulse waves of the search pulse wave reflected by an airplane, helicopter or other aircraft and generating reflected data;
Time measuring means for ticking time,
A first time stamp unit provided in the first receiving device, measuring a reception time based on a time by the time measuring unit each time the search pulse wave is received, and including it in the search data;
A second time stamp unit provided in the second receiving device, measuring a reception time based on a time by the time measuring unit each time the reflected pulse wave is received, and including the second time stamp unit in the reflection data;
An antenna direction calculating means for calculating in which direction the antenna is directed at the reception time of each search data based on a change in reception intensity of the search pulse wave received by the first receiving device;
The search data group and the reflection data group are acquired from the first reception device and the second reception device, and the reflection data and the reception time of the reflection data are within a predetermined time before the reception time. Pairing means for pairing the search data at the reception time of
The ellipsoidal sphere on which the aircraft can be located is identified from the reception time and the light velocity of the paired reflection data and search data, and the estimated value of the flight altitude of the aircraft set in advance and the antenna direction calculation A radar link system comprising: position calculating means for calculating the position of the aircraft on the elliptic sphere from the direction of the antenna calculated by the means.   The first receiving device and the second receiving device are provided separately, and each of the first receiving device and the second receiving device is provided with a synchronous clock that clocks the same time in synchronization with each other as the time measuring means. The radar link system according to any one of claims 1 to 5, wherein:   6. The radar link system according to claim 5, wherein the synchronous clock is configured to keep a time based on time information from a GPS satellite acquired from a GPS module.   The radar link system according to claim 5 or 6, wherein the position calculation means acquires data from one or both of the first receiving device and the second receiving device using a communication network.   A plurality of the second receivers are provided for one radar transmitter, and the position calculating means is configured to position the aircraft on a vertical plane including a straight line connecting the second receiver and the radar transmitter. The radar link system according to any one of claims 5 to 7, wherein the position of the aircraft is calculated using the other second receiving device. A transmission time data generation unit that generates a transmission time data by acquiring a transmission time of the transmission source signal through a communication network each time a radar transmitter of the monitoring radar system transmits the transmission source signal;
Receiving time data including a receiving time each time the reply source signal is received by receiving a reply source signal that is answered or reflected from an airplane, helicopter or other aircraft with respect to the transmission source signal transmitted by the radar transmitter And a plurality of reception time data generating devices arranged at different positions,
For each of the reception time data generation devices, the transmission time data before a predetermined time within a predetermined time difference between the transmission time and the reception time from the reception time data group and the transmission time data group; and A pairing means for pairing the reception time data;
A plurality of elliptical spheres on which the aircraft can be located are specified from the time difference and the light speed of the transmission time data and the reply time data paired for each reception time data generation device, and the elliptical spheres are interchanged. A radar link system comprising: a line; and a position calculation means for calculating a position of the aircraft from a preset estimated flight altitude or a flight altitude included in the return source signal. Each time the radar transmitter of the monitoring radar system transmits a transmission source signal, the transmission time of the transmission source signal and the direction of the antenna of the radar transmitter are acquired through a communication network, and the transmission time and the direction of the antenna are obtained. A transmission time data generation unit that generates transmission time data including the information of
Receives a reply source signal that is answered or reflected from an airplane, helicopter or other aircraft with respect to the transmission source signal transmitted by the radar transmitter, and receives reception time data including the reception time each time the reply source signal is received. A reception time data generation device that is generated and arranged at different positions;
A pair for pairing the transmission time data and the reception time data within a predetermined time within a predetermined time difference between the transmission time and the reception time from the reception time data group and the transmission time data group Ring means;
The elliptical sphere on which the aircraft can be located is identified from the time difference between the paired transmission time data and the reply time data and the speed of light, and the flight included in the preset estimated flight altitude or the return source signal A radar link system comprising: position calculation means for calculating the position of the aircraft from altitude and information on the direction of the antenna.