JP3165580B2 - Secondary radar system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary radar system in which an interrogator and a transponder are used opposite to each other in an air traffic control system, an ally identification system, a vehicle identification system, and the like. The present invention relates to a secondary radar system capable of identifying the presence or absence of a response signal from a desired target body among a plurality of aircraft, vehicles, ships, and the like, or the type of the response signal.

[0002]

2. Description of the Related Art Generally, a secondary radar system using an interrogator and a transponder facing each other is also used for an air traffic control system, an enemy / friend identification system, and the like. The secondary radar system radiates a high-frequency interrogation signal from an interrogator to an object via an antenna. The transponder mounted on the target receives the high-frequency interrogation signal via the antenna, and emits the high-frequency response signal from the antenna when it is determined that the interrogation signal is a predetermined interrogation signal. The high-frequency response signal is received by the interrogator, and is subjected to decoding / evaluation processing of the response signal to determine whether or not the response signal is predetermined, including the presence or absence of the response signal. Judge the content.

Generally, in a conventional secondary radar, an interrogator transmits an interrogation signal in a SUM pattern (sum) of a directional antenna, and transmits an SLS signal to a DI of the directional antenna.
Transmit in FF pattern (difference). The transponder side receiving the interrogation signal is configured to return the response signal only when the difference between the received electric field strengths of both is equal to or more than a predetermined value (for example, 6 dB or more). Here, the SU of the antenna
The M pattern refers to a directional antenna pattern having a main lobe in the direction of the target body, and an interrogation signal is transmitted via an antenna having the SUM pattern.

The DIFF pattern is an antenna pattern having a zero point (zero gain) in the main lobe direction of the SUM pattern, and an SLS signal (sidelobe suppression signal) is transmitted via an antenna having the DIFF pattern. . Incidentally, in place of the DIFF pattern, an omnidirectional antenna pattern having a uniform gain in all directions may be used. The SUM pattern and the DIFF pattern generally use one electronically controlled antenna such as a phased array antenna, and each is synchronized with the signal transmission timing.
SUM or DIFF pattern control is performed.

[0005] Such a technique is used for a transponder or the like.
In the next radar, it is a well-known means.

In addition, since the interrogator emits an interrogation signal only to a transponder located in a specific direction when viewed from the interrogator, a relatively directional antenna such as a parabolic antenna or a phased array antenna similar thereto is used. Although there is a method of using an antenna having a high height, there is a problem that the antenna shape becomes large in this case.

FIGS. 8 and 9 show a case where an interrogation signal is transmitted via a directional antenna. FIG.
As shown in the figure, the interrogator mounted on the car A and the cars B and C
In the secondary radar system including the transponders mounted on each of the car and the car D, when the car A (interrogator) identifies the car B (translator), the directional antenna of the car A (interrogator) The high-frequency interrogation signal is radiated toward the car B (the transponder) in the directional antenna SUM pattern shown by the dotted line in FIG. However, as shown, when the car C and the car D are also located in the directional antenna pattern for the interrogator,
Since the high-frequency interrogation signal from the car A is also received by the cars B, C, and D, it is impossible to identify only the car B. That is,
Opposition of the interrogator and the transponder as shown in FIG.
-C and A-D. As a result, as shown in FIG. 10, the cars C and D also generate respective high-frequency response signals to the high-frequency interrogation signal. As a result, car A becomes B
The high-frequency response signals of the car, car C and car D are received almost simultaneously, and among the mixed reception signals from car B, car C and car D, the response signal from car B alone is obtained. There was a problem that it was difficult to extract reliably.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is directed to a plurality of aircraft, vehicles, ships, and the like located in close proximity to one interrogation device. An object of the present invention is to provide a secondary radar system capable of independently obtaining only a response signal from a desired response device in response to an inquiry signal from an interrogation device from among a plurality of mounted response devices.

[0009]

For this reason, the secondary radar system of the present invention comprises an interrogator and a responder having the following means. (1) The interrogator was equipped with the following means.

Laser irradiation means capable of irradiating a laser signal to a desired one of the plurality of response devices provided opposite to each other; and interrogating a plurality of response devices including the desired one after the laser signal irradiation. (2) The responding device includes the following means: (1) a responding device that can receive a response signal from a responding device that has emitted the interrogating signal;

A laser detecting means capable of detecting a laser signal emitted from the interrogation device; a response signal to the interrogation signal radiated from the interrogation device based on a detection signal of the laser signal reception from the laser detecting means. The reply means for transmitting, and the secondary radar system of the present invention further include the following means in addition to the above-mentioned means (1) and (2). (3) The receiving means of the interrogating device receives only the response signal emitted from the replying means of the desired responding device, which is irradiated with the laser signal of the plurality of responding devices.

[0012]

According to the present invention, there are provided the above-mentioned means (1) and (2) of the present invention.
In the next radar system, (1) Even if a plurality of response devices provided facing one interrogation device are arranged close to each other, the interrogation signal radiated from the interrogation device is transmitted only to the desired response device. Is decoded and a response signal is transmitted, so that the interrogator can obtain only the response signal from the desired responder alone.

[0013] Further, the secondary radar system comprising the above-mentioned means (3) according to the present invention is characterized in that, in addition to the above-mentioned (1), (2) the interrogation device has specified by laser irradiation before emitting the interrogation signal. Since only the response signal from the reply means of the desired response device is received, the interference signal is eliminated, and only the response signal from the desired response device can be reliably obtained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the secondary radar system according to the present invention will be described below with reference to the drawings. FIG.
It is a schematic configuration diagram showing an embodiment of a next radar system,
FIG. 2 is an operation conceptual diagram of the embodiment shown in FIG.

As shown in FIG. 1, the secondary radar system of this embodiment is an interrogator 1 equipped with an interrogation signal radiating means mounted on a car A and a directional antenna 5 as a receiving means.
And an interrogator A that combines a laser telemeter 2 as a laser irradiating unit, a transponder 3 equipped with an omnidirectional antenna 6 as a returning unit mounted on a car B, and a laser detecting unit as a laser detecting unit. A basic one-way system is constituted by the response device B coupled with the laser detector 4.

For the sake of simplicity, an example is shown in which only the interrogation device A is mounted on the vehicle A and only the response device B is mounted on the vehicle B. A vehicle employing the secondary radar system according to the present embodiment includes an interrogating device A and a responding device B as a pair, and the interrogating vehicle side or the answering vehicle side depends on the situation. To function as.

Then, the laser telemeter 2 of the interrogator A is used.
The distance to the target body is measured by irradiating a desired vehicle with a laser that emits more. Since the laser irradiated on the target body is partially reflected and reaches the interrogation device A,
The distance to the target can be determined from the round trip time of the laser. Therefore, when the interrogation device A detects the reflection of the laser,
Based on the distance measurement information, the timing of generating a time gate for receiving a response signal from the target is calculated, and the interrogator 1 is triggered. Thereafter, a high-frequency interrogation signal is radiated from the directional antenna for interrogator 5 after Tμs from the laser irradiation. On the other hand, in the responding device B that has been irradiated with the laser, the laser detector 4 detects the laser signal and applies a laser detection trigger to the transponder 3. Reception becomes possible, and the interrogation signal radiated T μs after the laser irradiation is received from the omnidirectional antenna 6, after which the transponder 3 radiates a high frequency response signal to the interrogation signal from the omnidirectional antenna 6. .

That is, the interrogator 1 receives the radiated laser signal from the target by the laser distance measuring device 2 and applies a laser reception trigger to the interrogator 1. A response gate for extracting a response signal from the transponder 3 is generated, so that only a response signal from the transponder B that desires the response is extracted.

Therefore, as shown in FIG. 2, a secondary radar comprising an interrogation device A mounted on vehicle A and response devices B mounted on vehicles B, C, D and E, respectively. In the system, when the cars B, C, and D are close to each other in the directional antenna pattern for the interrogator, for example, the responder B of the target car B, the interrogator A of the car A, If the laser telemeter 2 is aimed and the laser is irradiated, and then the interrogation signal is transmitted, only the transponder 3 of the car B can receive the interrogation signal, and only the transponder 3 of the car B can receive the interrogation signal. , The car A can obtain only the response signal from the car B.

Further, when an interference signal is emitted from the vehicle E shown in FIG. 3, for example, the interrogator 1 of the vehicle A receives the interference signal together with the response signal from the transponder 3 of the vehicle B. But based on the reflected laser signal from car B,
Since the response signal from the car B is received with a time (distance) correlation with the response gate, the interrogator 1 of the car A can receive only the response signal of the car B as a normal reception signal.

Next, the interrogator A and the responder B
A specific configuration example and an operation example will be described.

FIG. 4 is a block diagram showing an example of the internal configuration of the inquiry device A. As described above, the interrogator 1 constituting the interrogator A together with the directional antenna 5 for interrogator and the laser telemeter 2 includes the duplexers 8, 9 connected to the directional antenna 5 for interrogator, Duplexer 8, 9
And the receivers 10 and 11 connected to the
1; a response decoding circuit 13 connected to the video processing circuit 12; a response evaluation circuit 14 connected to the response decoding circuit 13; A timing circuit 15 connected to the decoding circuit 13; an interrogation pulse generation circuit 16 connected to the timing circuit 15;
6 and an RF switch 18 connected to the transmitter 17 and the duplexers 8 and 9. The RF switch 18 is a switch for switching and supplying the output of the transmitter 17 to one of the duplexers 8 and 9, and supplies an interrogation signal to the duplexer 8.
, And an SLS signal to the DIFF pattern antenna via the duplexer 9.

FIG. 5 is a block diagram showing an example of the internal configuration of the response device B. As described above, together with the omnidirectional antenna 6 for the transponder and the laser detector 4, the transponder B
The transponder 3 comprises a duplexer 19 connected to the omnidirectional antenna 6 for a transponder, a receiver 20 connected to the duplexer 19, and a video processing circuit 21 connected to the receiver 20. , The video processing circuit 21
, A question decoding circuit 22 connected to the laser detector 4, a response pulse generation circuit 23 connected to the question decoding circuit 22, and a response pulse generation circuit 23 connected to the response pulse generation circuit 23. And a transmitter 24 connected to the duplexer 19.

Next, the internal operation of the interrogator A and the responder B will be described. Here, as described above, A
A case where the vehicle B is operated as a target body by the vehicle interrogation device A will be described.

First, the laser telemeter 2 of the interrogation device A of the car A
, The irradiation operation is performed with the car B as the target body, and an identification request signal is applied to the timing circuit 15 of the interrogator 1. This timing circuit 15 generates a distance measurement request signal and causes the laser distance measuring device 2 to transmit a laser. The laser telemeter 2 irradiates a laser signal to the car B and returns a transmission trigger synchronized with the laser transmission to the timing circuit 15 of the interrogator 1. The timing circuit 15 calculates Tμs from this transmission trigger.
After ec, the interrogation pulse generation circuit 16 is driven so as to generate an interrogation pulse. This interrogation pulse is applied to the transmitter 17 and converted into a high-frequency interrogation signal.
Power is supplied to the SUM channel or the DIFF channel of the directional antenna for interrogator 5 via the duplexer 8 and the duplexers 8 and 9. As a result, the SU of the directional antenna 5
A high-frequency interrogation signal is emitted from the M channel, and a high-frequency SLS signal is emitted from the DIFF channel in the direction of the B vehicle.

The transponder B of the car B first receives the laser signal from the car A by the laser detector 4, and then transmits the subsequent high-frequency interrogation signal and high-frequency SLS signal to the non-directional antenna 6 for the transponder. Receive. The received high frequency signal is
The video signal is applied to the receiver 20 via the duplexer 19, is subjected to video processing by the video processing circuit 21, and is supplied to the question decoding circuit 22. The question decoding circuit 22 decodes the question signal only when there is a laser detection trigger input from the laser detector 4 and recognizes that the question is a legitimate question.
The response pulse generation circuit 23 is triggered and the omnidirectional antenna 6 for the transponder is transmitted via the transmitter 24 and the duplexer 19.
Radiates a high frequency response signal from the

Next, the high frequency response signal of the car B is transmitted to the SUM channel of the directional antenna 5 for
Received on the IFF channel and each duplexer 8,
9. Video processing circuit 12 via receivers 10 and 11
, And the reception response video is processed. The processed response video is applied to the response decoding circuit 13. On the other hand, prior to this, the laser emitted from the car A and reflected by the car B is received by the laser telemeter 2,
A reception trigger signal is generated, and the reception trigger signal is applied to the timing circuit 15 of the interrogator 1 to generate a response gate. This response gate functions as a time gate for decoding only a signal received at a predetermined time, and is set based on the distance to the target vehicle B and the propagation time between the inquiry signal and the response signal. Things. As a result, B
Only the response signal from the car is decoded by the response decoding circuit 13 described above. The response evaluation circuit 14 evaluates the decoded response signal of the car B and determines the identification information of the car B.

FIG. 6 shows a timing chart of a response operation between the interrogation device A of the vehicle A and the response layer B of the vehicle B. Here, the timing chart shown in FIG. 6 will be briefly described. In the laser telemeter 2, when the laser for distance measurement is fired simultaneously with the generation of the transmission trigger,
After reaching the target body r hours later, the reflected component arrives at the laser telemeter (Car A) after the elapse of the same time r, and serves as a reception trigger. That is, in the figure, R is the time required for the laser beam to be reflected by the target object and return to the laser telemeter, where R = 2r. The interrogator 1 transmits an interrogation signal (RF) after a required time T from the laser emission. This time T takes into account the time required to detect the distance measuring laser at the target body, generate a laser detection trigger, and start up the transponder.

On the other hand, in the responding device B which receives the above laser and the following interrogation signal, a trigger is first generated in accordance with the laser detection, the subsequent interrogation signal is received, a video signal is generated, and the interrogation signal is generated in advance. If it is determined, a response signal (RF) is emitted. The response signal (RF) is received by the interrogator of the car A after the elapse of the time r and demodulated into a response video. If the signal is a predetermined signal, the target body has a function of responding to the inquiry signal. A discrimination output is generated to indicate that the item has been received.

In the response devices B of the vehicles C and D, which have not been irradiated with the laser from the interrogation device A of the vehicle A, the laser detection trigger of the laser detector 4 is not applied and the interrogation signal is decoded. And does not generate high frequency signals. Therefore, the interrogation device A of the vehicle A can receive only the response signal from the response device B of the vehicle B.

FIG. 7 shows a timing chart of the operation between the interrogating device A of the car A and the responding device B of the car C and the car D which is not irradiated with the laser. The timing chart shown in FIG. 7 is basically the same as that shown in FIG. 6, except that the car C and the car D are not irradiated with the laser for distance measurement as described above. No response signal (RF) is generated. In this way, if only the target irradiated with the laser is configured to transmit the response signal, it is possible to accurately identify whether the specific target is capable of responding to the interrogation signal. Can be.

Further, when there is an interference signal from the vehicle E shown in FIG. 3, the interrogation device A of the vehicle A receives the interference signal together with the response signal of the vehicle B. Since the (distance) correlation can be always taken, the interrogation device A of the car A can regard only the response of the car B as a normal reception signal.

While the embodiment of the present invention has been described in detail above, the present invention is not limited to this embodiment, and various modifications can be made.

For example, the laser telemeter may have only a function of emitting a laser and not have a distance measuring function, or a laser telemeter for a sight such as a cannon or a missile may be used. It may be used. Also, as an alternative to lasers, similar to lasers, communication media with sharp beam directivity, for example, ultrasound with sharp beams,
Ultraviolet rays, infrared rays, microwaves and the like may be used.

In the above embodiment, the interrogation signal is decoded only when the laser irradiation is detected.
Not limited to this, regardless of whether laser irradiation is detected,
The interrogation of the interrogation signal may be performed to control the generation of the reception trigger signal.

[0036]

As described above, according to the present invention, a laser signal is emitted from an interrogator to a responder desiring a response.
Only the transponder that has received the laser signal can decode the interrogation signal from the interrogation, and based on the reflected laser signal from the transponder that was able to decipher the interrogation signal, responds from the transponder that desires the response. Since only the signal can be decoded by the interrogation device, the interrogation device can be selected from a plurality of adjacent vehicles, ships, aircraft, etc. Can be reliably obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram as an embodiment of a secondary radar system of the present invention,

FIG. 2 is an operation conceptual diagram of the embodiment shown in FIG. 1;

FIG. 3 is a timing chart of an operation signal including a case where there is an interference signal from another response device that does not want a response;

FIG. 4 is a block diagram showing the internal configuration of the interrogator shown in FIG. 1;

FIG. 5 is a block diagram showing the internal configuration of the response device shown in FIG. 1;

FIG. 6 is a timing chart of an operation signal between an interrogator and a response device that desires a response;

FIG. 7 is a timing chart of an operation signal between the interrogator and the responder not desiring a response;

FIG. 8 is an operation conceptual diagram of a conventional secondary radar system,

9 is a schematic configuration diagram of the secondary radar system shown in FIG.

10 is a timing chart of operation signals in the secondary radar system shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 interrogator 2 laser telemeter 3 transponder 4 laser detector 5 directional antenna for interrogator 6 omnidirectional antenna for transponder 8, 9, 19 duplexer 10, 11, 20 receiver 12, 21 video processing circuit 13 Response decoding circuit 14 Response evaluation circuit 15 Timing circuit 16 Interrogation pulse generation circuit 17, 24 Transmitter 18 RF switch 22 Interrogation decoding circuit 23 Response pulse generation circuit A Interrogation device B Interrogation device

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroyuki Suzuki 3000 Tana, Sagamihara-shi, Kanagawa Prefecture Mitsubishi Heavy Industries, Ltd.Sagamihara Works (72) Inventor Masashi Oyasu 3000, Tana, Sagamihara-shi, Kanagawa Mitsubishi Heavy Industries, Ltd. (56) References JP-A-2-141689 (JP, A) JP-A-5-203735 (JP, A) JP-A-5-333145 (JP, A) JP-A-6-68330 (JP, A) A) Japanese Utility Model Showa 57-159183 (JP, U) Japanese Patent Publication No. 58-19993 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01S ⁷ /00-17/88 H04B 9 / 00

Claims (2)

(57) [Claims] 1. A secondary radar system in which a plurality of response devices are provided to face one interrogation device, and the response device outputs a response signal in response to an interrogation signal from the interrogation device. Laser irradiating means for irradiating a laser signal to the responding device that desires a response signal, interrogating signal emitting means for emitting an interrogating signal after the irradiation of the laser signal, and receiving means for receiving a response signal from the responding device. The response device, a laser detection means for detecting a laser signal emitted from the interrogation device, and a reply means for transmitting a response signal to the interrogation signal from the interrogation device by a detection signal from the laser detection means A secondary radar system, comprising: 2. The secondary radar system according to claim 1, wherein the receiving means of the interrogation device receives only a response signal from the response device that has irradiated the laser signal.