JPH02173587A - Electronic scanning type secondary monitoring radar equipment - Google Patents

Abstract

PURPOSE:To obtain the equipment which can suppress the generation of a false image even against an aircraft positioned in a long distance by switching a question signal consisting of two pulses and a transponder suppressing signal for suppressing the receiving sensitivity, based on a transmission switching control signal. CONSTITUTION:A question signal generator 12 generates a question signal consisting of two pulses. A transponder suppressing signal generator 13 generates a transponder suppressing signal for bringing the receiving sensitivity of the transponder to suppression control. A transmitter 10 inputs the question signal and the transponder suppressing signal, switches the question signal and the transponder suppressing signal, based on a transmission switching control signal, generates a transmitting signal and outputs it to an electronic scanning antenna 9. In this state, when a main beam of the antenna 9 emits a transmitting signal of a first pulse question signal toward the azimuth direction of a current reflecting object which becomes a factor for generating a false image, a controller 15 executes a beam scanning control so as to turn the main beam in the azimuth direction of an aircraft for receiving a reflected wave reflected by a radio wave reflecting object, and also, executes a transmission switching control so as to emit a transmitting signal of the transponder suppressing signal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a secondary surveillance radar device (5
econdary 5urveillance Rad
ar (hereinafter referred to as SSR), and particularly relates to an electronic scanning secondary surveillance radar device that can suppress the generation of false images caused by radio wave reflecting objects such as buildings.

(Prior art) SSR uses an interrogation antenna whose main beam has a sharp directivity pattern in the horizontal plane.
nLenna (hereinafter referred to as INT antenna),
A sidelobe suppression antenna (Si-de L) with a nearly omnidirectional pattern that covers the sidelobes of the INT antenna
As shown in Fig. 4, an interrogation signal consisting of a first pulse and a third pulse (two pulses, a P+ pulse and a P3 pulse) is transmitted from the INT antenna. A pulse signal) is emitted into space, and an SLS control signal (P2 pulse signal) consisting of a second pulse is emitted into space from the SLS antenna. The aircraft transponder receives and decodes the interrogation signal and emits a corresponding response signal, but it does not emit a response signal to the snow signal emitted by the side lobe of the INT antenna, so ni, P
Compare the reception levels of the 1 pulse and the P2 pulse, and if the level of the P2 pulse is higher than the level of the Pl pulse,
That is, when an interrogation signal emitted by the side lobe of the INT antenna is received, reception sensitivity is suppressed for 35 μs after the reception timing of the P2 pulse, and reception of the P pulse is prohibited.

By inhibiting the reception of P3 pulses, the transponder does not respond to the interrogation signal; thus, the SSR
Interrogation sidelobe suppression is a function that prevents the transponder from responding to interrogation signals emitted from the sidelobes of the T antenna.
5ide Lobe 5uppression: Below,
It has a function (described as ISLS).

However, if the main beam of the INT antenna is oriented in the direction of a radio wave reflecting object such as a building, and the interrogation signal emitted from the main beam is reflected by the radio wave reflecting object, the INT antenna An aircraft transponder existing in the sidelobe range may receive not only the direct wave interrogation signal emitted from the side lobe but also the reflected wave interrogation signal emitted from the main beam. In this case, if the reception level of the interrogation signal from the side lobe is small and below a predetermined value, the transponder will naturally not respond to the interrogation signal, but since the transponder's l5LSlfi function will also not operate, the transponder will receive the interrogation signal from the main beam. and emit a response signal in response to the interrogation signal. As a result, a false image appears as if an aircraft were present in the direction in which the main beam is facing. This l5
In order to improve the problem of LS (i.e. suppress the generation of artifacts), improved question sidelobe suppression (Improved question sidelobe suppression)
Inter-errogation 5ide Lobe
An SSR has been proposed and is in use. l
In the SSR having l5LS1fi capability, as shown in Fig. 5, the SLS control signal emitted from the SLS antenna is not a pulse signal of one P2 pulse, but two pulse signals of a pt pulse and a P2 pulse (P+ pulse level ≦
P2 pulse level).

As can be seen from Fig. 7, the reflected wave path where the false image occurs is 6 longer than the direct wave path, so the S L S L4j control signal (pt pulse and P2 pulse) of the direct wave emitted from the SLS antenna is It reaches the aircraft earlier than the reflected wave interrogation signals (Pi pulse and P3 pulse) emitted from the antenna. Therefore, the transponder detects P, pulse and P of the SLS control signal that arrived first.
By comparing the levels of the two pulses, it is possible to suppress the reception sensitivity for f&35 μs from the reception timing of the P2 pulse, thereby prohibiting reception of the interrogation signal of the reflected wave that arrived later.

Next, the configuration and operation of a conventional secondary surveillance radar device with ll5LS function will be explained.

Figure 3 is a configuration diagram of a conventional secondary monitoring radar device with ll5LS function.
22 pulse generator, 3 is P, pulse generator, 4 is PI pulse generator 1 output P, pulse and P, PI/P3 synthesizer that synthesizes P3 pulse of pulse generator 3 output, 5 is P11
A Pl/P2 synthesizer that combines the P1 pulse output from the pulse generator 1 and the 22 pulses output from the P22 pulse generator 2, 6 a transmitter that generates a transmission signal (interrogation signal and SLS control signal), 7 an INT antenna, 8 is an SLS antenna.

The P1 pulse output from the P1 pulse generator 1 is input to a PI/P3 combiner 4 and a PL/P2 combiner 5. The P2 pulse output from the P22 pulse generator 2 is input to the P+/Pz combiner 5. P, P3 pulse of pulse generator 3 output is PI
/P3 is input to the synthesizer 4. The output signal of the P1/P3 combiner 4 is input to the transmitter 6, and a transmission signal for the interrogation signal is generated and output to the INT antenna 7. P1/P2
The output signal of combiner 5 is transmitted v! 16 and SLS
A transmission signal for a control signal is generated and output to the SLS antenna 8.

The ll5LSI function described above can suppress the generation of false images caused by radio wave reflecting objects such as buildings.

(Problem to be solved by the invention) However, in the conventional secondary surveillance radar device with ll5LS function, the SL has a pattern close to omnidirectional.
The antenna gain of the S antenna is low, larger than the sidelobe gain of the INT antenna, but much smaller than the main beam gain (e.g., about 20 dB smaller), so the SLS control signal emitted from the SLS antenna Aircraft that can receive SSR are those that exist within a limited range of a predetermined distance from the SSR installation location, and that
Aircraft located far away from the SR installation and outside its limited range cannot receive SLS control signals, i.e. transponders of aircraft located close to the SSR installation cannot have the ll5LS function. It works, but the ll5LS@ function does not work on the transponders of aircraft located far away, so there is a drawback that it is not possible to suppress the generation of false images for aircraft located far away from the SSR installation location. .

An object of the present invention is to provide an electronic scanning antenna capable of electronically scanning a main beam in an azimuth plane and directing it to a predetermined azimuth direction, in order to solve the problem of assembly point between the above-mentioned conventional techniques. When an interrogation signal is emitted with the main beam pointing in the azimuth direction where there is a radio wave reflecting object, the main beam is directed in the azimuth direction of the aircraft that will receive the reflected waves reflected by the radio wave reflecting object to increase the reception sensitivity of the transponder. By having a means for emitting a transponder suppression signal for suppressing control, the generation of false images can be suppressed not only for aircraft located close to the SSR installation location but also for aircraft located far away. An object of the present invention is to provide a secondary monitoring radar device that can perform the following tasks.

(Means for Solving the Problems) In order to achieve the above object, the present invention has the following means configuration.

That is, the electronic scanning type secondary surveillance radar device of the present invention has the following features:
an electronic scanning antenna capable of electronically scanning the main beam in an azimuth plane and directing the main beam in a predetermined azimuth direction based on a beam scanning control signal; an interrogation signal consisting of a first pulse and a third pulse; interrogation signal generation means for generating; transponder suppression signal generation means for generating a transponder suppression signal for suppression control of reception sensitivity of the transponder; interrogation signal output from the interrogation signal generation means; a transmitter that receives a transponder suppression signal as an input, switches between the interrogation signal and the transponder suppression signal based on a transmission switching control signal, generates a transmission signal, and outputs the transmission signal to the electronic scanning antenna; When the main beam emits the transmission signal of the first pulse interrogation signal in the direction of the radio wave reflecting object that causes false images, the direction of the aircraft that receives the reflected wave reflected by the radio wave reflecting object. outputting the beam scanning control signal for controlling beam scanning so as to direct the main beam in a direction to the electronic scanning antenna; and outputting the transmission switching control signal for controlling transmission switching to emit a transmission signal of the transponder suppression signal; outputting the beam scanning control signal to the transmitting means and further outputting the beam scanning control signal to the electronic scanning antenna for controlling beam scanning so that the main beam is directed in the azimuth direction when the transmitting signal of the first pulse interrogation signal is emitted; , a control means for outputting the transmission switching control signal to the transmission means for controlling transmission switching so that the transmission signal of the third pulse interrogation signal is emitted.

(Function) Below, the function of the electronic scanning type secondary surveillance radar device of the present invention having the above-mentioned means configuration will be explained.

An interrogation signal consisting of two pulses, a first pulse (P1 pulse) and a third pulse (P3 pulse), is generated in the interrogation signal generation means and input to the transmission means. The transponder suppression signal generation means generates a transponder suppression signal for suppressing the reception sensitivity of the transponder, and outputs the signal to the transmission means. The transponder suppression signal is a signal consisting of two pulses having similar characteristics to the SLS control signal of the conventional ll5LS (a signal consisting of two pulses, a Pl pulse and a P2 pulse), and the P! of the interrogation signal! P is the signal generated within the time between the pulses. The transmitting means switches between the interrogation signal and the transponder suppression signal based on the transmission switching control signal, generates a transmission signal, and outputs the transmission signal to the electronic scanning antenna. An electronically scanned antenna is an antenna whose main beam can be electronically scanned in an azimuth plane and whose main beam can be directed in a predetermined azimuth direction based on a beam scanning control signal. When the main beam of the electronic scanning antenna is directed in the azimuth direction of the radio wave reflecting object that causes false images, and the transmission signal of the first pulse interrogation signal (P+ pulse) is emitted, the control means is directed to the direction of the radio wave reflecting object that causes false images. A beam scanning control signal is output to the electronic scanning antenna to perform beam scanning control so as to direct the main beam in the azimuth direction of the aircraft that receives the reflected reflected wave. The control means outputs to the transmission means a transmission switching control signal for controlling transmission switching so that the transmission signal of the transponder suppression signal is emitted when the main beam is directed in the direction of the aircraft receiving the reflected wave. Next, the control means outputs a beam scanning control signal to the electronic scanning antenna to control beam scanning so that the main beam is directed in the azimuth direction when the transmission signal of the first pulse interrogation signal (Pl pulse) was emitted. When the beam is directed in the azimuth direction, a transmission switching control signal is output to the transmitting means to control transmission switching so that a transmission signal of the third pulse interrogation signal (P3 pulse) is emitted.

As a result of the above action, it is possible to emit a transponder suppression signal using a main beam with a large antenna gain toward an aircraft that receives reflected waves that are not reflected by a radio wave reflecting object, and therefore to transmit a transponder suppression signal to an aircraft located at a long distance. However, the reception sensitivity of the transponder can be suppressed to prevent the reflected wave from responding to the interrogation signal, thereby suppressing the generation of false images.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of an electronic scanning type secondary monitoring radar device according to an embodiment of the present invention. 8 is an SLS antenna that emits the SLS flilJ control signal, 9 is an electronic scanning antenna that can electronically scan the main beam in the azimuth plane and emits an interrogation signal and a transponder suppression signal, and 10 is an interrogation signal. The transmitter (1), 11 switches the transmission signal for the interrogation signal and the transponder suppression signal to generate the transmission signal for the interrogation signal and the transmission signal for the transponder suppression signal, and outputs the transmission signal to the electronic scanning antenna 9. A transmitter a (
2J, 12 are the first pulse (Pt pulse) and the third pulse (
An interrogation signal generator 13 generates an interrogation signal consisting of a P3 pulse) and outputs the interrogation signal to a transmitter il+ 10, and an interrogation signal generator 13 generates a transponder suppression signal for suppression control of the reception sensitivity of the transponder, and transmits the transponder suppression signal. A transponder suppression signal generator outputs to the transponder fi+ 10, 14 is an SLS consisting of a second pulse (Pa pulse)
Generate control signal and send SLS control signal to transmitter +2111
The SLS control signal generator 15 outputs to the electronic scanning antenna 9 a beam scanning control signal +01 that controls the main beam of the electronic scanning antenna 9 to direct in a predetermined azimuth direction, and generates an interrogation signal and a transponder suppression signal. This is a controller that outputs a transmission switching control signal +02 for switching control to a transmitter +1110.

The operation of the embodiment of the present invention will be explained below.

In addition, SLS antenna 8, transmission fl! ! +2111 and 5LSf9Jall signal generator 14 are conventional I
These are component devices for the SLS function, and operational explanations regarding these component devices will be omitted.

In the interrogation signal generator 12, the P1 pulse and P.

An interrogation signal consisting of pulses is generated. This interrogation signal is the same as the interrogation signal of the prior art.

The transponder suppression signal generator 13 generates a transponder suppression signal to suppress and control the receiving sensitivity of the transponder. This transponder suppression signal is a signal consisting of two pulses having similar characteristics to the SLS control signal (signal consisting of two pulses, P+ pulse and P2 pulse) used for the ll5LS function of the conventional technology. It is.

The interrogation signal at the output of the interrogation signal generator 12 and the transponder suppression signal at the output of the transponder suppression signal generator 13 are input to the transmitter fil 10. The transmitter +1110 switches between the interrogation signal and the transponder suppression signal based on the transmission switching control signal +02 from the controller 15, generates a transmission signal, and outputs the transmission signal to the electronic scanning antenna 9.

The main beam of the electronic scanning antenna 9 electronically scans within the azimuth plane based on the beam scanning control signal 101 from the controller 15, and emits the interrogation signal transmission signal from the transmitter fil 10. The first pulse interrogation signal (Pt
When a pulse (pulse) transmission signal is emitted, the main beam is directed in the direction of the aircraft that will receive the reflected wave reflected by the radio wave reflecting object. This beam scanning control is performed by a beam scanning control signal 101.

Then, the controller 15 transmits a transmission switching control signal 102 that controls the transmitter (1) 10 to switch from the interrogation signal to the transponder suppression signal when the main beam is directed in the direction of the aircraft receiving the reflected wave. Output to machine il+10. Transmitter (1) 10 outputs a transponder suppression signal transmission signal to electronic scanning antenna 9. The electronic scanning antenna 9 emits a transponder suppression signal transmission signal from a main beam oriented in the azimuth direction of the aircraft that receives the reflected waves.

Since the transponder suppression signal is emitted from the main beam with a large antenna gain, the transponder suppression signal can be received even by an aircraft located far away from the SSR installation site.

In the transponder of the aircraft that received the transponder suppression signal, the transponder suppression signal is ll5LS.
Since the signal is composed of two pulses having characteristics similar to the SLS control signal used for the FI function, the electronic scanning antenna 9 The main beam is redirected in the direction of the radio wave reflecting object that emitted the interrogation signal (Pr pulse).

This beam scanning control is performed under the control of a beam scanning control signal 101. Then, the controller 15 controls the transmitter (11
10, from the transponder suppression signal to the interrogation signal (
It outputs a transmission switching control signal 102 that controls switching to Pt pulse). The transmitter il+10 sends an interrogation signal (
The transmission signal for Pt pulse) is output to the electronic scanning antenna 9, and the electronic scanning antenna 9 emits the interrogation signal (Pt pulse) from the main beam pointing in the same azimuth as the interrogation signal (Pt pulse). do. Before the interrogation signal (Pt pulse) reflected by a radio wave reflecting object reaches the aircraft, the transponder of the aircraft receives a transponder suppression signal and the receiving sensitivity is suppressed, so that the interrogation signal <Pt pulse) Reception is prohibited, and as a result, no response signal is emitted, so no false image is generated.

The above operation will be explained in more detail with reference to FIGS. 2(a) and 2(b). First, the ↓ beam of the electronic scanning antenna 9 is directed toward the direction (θ1) of the radio wave reflecting object. The data of the beam scanning control signal 101 at this time is “
"A" is data corresponding to the direction (θ1). Further, the transmission switching control signal 102 has a logic level of "0", and the transmitter +1110 has an interrogation signal (
Pt pulse) is selected.

Next, the beam scanning control signal! 0! data changes to "B", and the transmission switching control signal 102 changes to logic level "1". rB is data corresponding to the direction (θ2).

As a result, the main beam of the electronic scanning antenna 9 is directed in the direction (θ2
), the transmitter +1110 selects the transponder suppression signal, and the transponder suppression signal is emitted in the direction of the azimuth (θ2) of the #1 aircraft.

Furthermore, if the #2 aircraft in the direction of azimuth (θ3) also exists in a position where it receives reflected waves, the beam scanning control signal 101
data changes to "C". "C" is data corresponding to the direction (θ3). At this time, the transmission signal for transponder suppression signal is output from the transmission fi+1110 to the electronic scanning antenna 9 again.

As a result, the main beam of the electronic scanning antenna 9 is directed in the direction (θ3
), and a transponder suppression signal is emitted in the direction of the azimuth (θ3) of the #2 aircraft.

After that, the data of the beam scanning control signal 101 changes to "A", the main beam is directed to the direction (θl) again, and the transmission switching control signal 102 returns to the logic level "0", and the transmitter (1110 Select the signal (P3 pulse).

As a result, the direction in which the interrogation signal (P+pulse) was emitted (
An interrogation signal (Ps pulse) is emitted in the same direction as θ1).

By the above operation, it is possible to emit a transponder suppression signal using a main beam with a large antenna gain to an aircraft receiving reflected waves, and it is possible to suppress the generation of false images.

In addition, in the above-mentioned embodiment, I SL is used as SLS.
Although we have shown an example using S, it is clear that 115LS can also be used.

(Effects of the Invention) As explained above, in the electronic scanning type secondary surveillance radar device according to the present invention, the main beam with a large antenna gain is directed in the azimuth direction of the aircraft where false images are expected to occur, and the transponder suppression signal is transmitted. Can be fired. the result,
The transponder suppression signal can be received not only by an aircraft located close to the SSR installation site but also by an aircraft located far away, and the reception sensitivity of the transponder can be suppressed. Therefore, there is an effect that generation of false images can be suppressed by targeting aircraft within the SSR coverage area.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an electronic scanning type secondary surveillance radar device according to an embodiment of the present invention, Fig. 2 is a diagram of the operation of suppressing the generation of false images by a transponder suppression signal, and Fig. 3 is a diagram of the conventional 22 with 11SLS function.
4 is a transmission signal waveform diagram for ISLS, 5 is a transmission signal waveform diagram for 115LS, 6 is a transponder response state diagram, and 7 is a configuration diagram of the monitoring radar device.
The figure is a diagram showing a state in which false images occur due to radio wave reflecting objects. 1...P1 pulse generator, 2...P
2 pulse generator, 3...P33 pulse generator,
4...Ps/Ps combiner, 5...P
s/P2 combiner, 6... transmitter, 7...
...INT antenna, 8...SLS antenna, 9...electronic scanning antenna, 10...
・Transmitter (1), 11... Transmission 81 (21
, 12...question signal generator, 13...
・Transponder suppression signal generator, 14...
・SLS flil+ 1:n signal generator, 15
...controller. ,〉To 2 shots 1 month kan 2) proboscis; IL type 2 inspector, ib-data installation structure diagram No. 1 Agent Patent attorney Yoshi Yahata Extract drawing P4 Harires P,) Long form drawing of the Haruka Izai in the case of 5LS, I I SLS /) Eaves Jh22χ Monitoring - Da Uba Shi [
Diagram F

Claims (1)

[Claims] In a secondary surveillance radar device used for air traffic control, an electronic scanning antenna that can electronically scan the main beam in the azimuth plane and direct the main beam in a predetermined azimuth direction based on a beam scanning control signal. and; 1st pulse and 3rd pulse
interrogation signal generation means for generating an interrogation signal consisting of pulses; transponder suppression signal generation means for generating a transponder suppression signal for suppressing reception sensitivity of the transponder; an interrogation signal output from the interrogation signal generation means and the transponder suppression Transmitting means that receives the transponder suppression signal output from the signal generation means as an input, switches between the interrogation signal and the transponder suppression signal based on a transmission switching control signal, generates a transmission signal, and outputs the transmission signal to the electronic scanning antenna; When the main beam of the electronic scanning antenna emits the transmission signal of the first pulse interrogation signal in the direction of the radio wave reflecting object that causes false images, the reflected wave reflected by the radio wave reflecting object is emitted. The beam scanning control signal for controlling beam scanning so as to direct the main beam in the azimuth direction of the receiving aircraft is output to the electronic scanning antenna, and the transmission switching control is performed so as to emit the transmission signal of the transponder suppression signal. A transmission switching control signal is output to the transmitting means, and the beam scanning control signal for controlling the beam scanning so that the main beam is directed in the azimuth direction when the transmission signal of the first pulse interrogation signal is emitted is transmitted to the electronic scanning. and control means for outputting the transmission switching control signal to the transmission means for controlling transmission switching so as to output the transmission signal of the third pulse interrogation signal to the antenna. Type secondary monitoring radar device.