JP3015502B2 - Secondary surveillance radar equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a monopulse antenna for forming a sum and difference radiation patterns, radiates first and third pulses in a sum pattern, respectively,
The present invention relates to a secondary surveillance radar device which emits pulses in a difference pattern to obtain aircraft identification, altitude information, and the like.

[0002]

2. Description of the Related Art As is well known, a secondary surveillance radar device is
This is a device that sends an interrogation signal to a transponder on an aircraft, receives and decodes a response signal from the transponder, and obtains aircraft identification and altitude information. A monopulse antenna is used, the first and third pulses are radiated as an interrogation signal in a sum pattern, and the second pulse is converted into a difference pattern (SLS (Side Lobe Sup) for sidelobe suppression.
pressor (including the pattern).

[0003] By the way, when detecting each aircraft approaching the parallel runway at the same time, for example, two aircraft approaching each other in the azimuth plane are detected.
In some cases, it is necessary to accurately separate and detect more than two aircraft.

[0004] However, when the above-mentioned detection is performed by the conventional secondary surveillance radar device, the detection is limited by the horizontal beam width of the sum pattern. For example, two aircraft are at the same distance from the antenna and are close in the azimuth plane,
If both are within the horizontal beam width of the sum pattern, the responses from each aircraft overlap, and it is not possible to separate and detect each aircraft. In other words, unless each aircraft is separated by more than the horizontal beam width of the sum pattern, it cannot be detected as two aircraft.

Although the azimuth resolution limit can be slightly improved by the monopulse angle measuring technique, it is not sufficient for monitoring with high accuracy, and the problem of garble (a phenomenon of overlapping responses) remains as before. ing. In order to improve the azimuth resolution, the horizontal beam width may be narrowed, but this is not a good idea because the mechanical dimensions of the antenna are increased.

[0006]

As described above, the conventional secondary surveillance radar device cannot accurately separate and detect two or more aircraft close to each other in the azimuth plane.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem.
An object of the present invention is to provide a secondary surveillance radar device capable of accurately separating and detecting more than two aircraft.

[0008]

In order to achieve the above object, a secondary surveillance radar device according to the present invention uses a monopulse electronic scanning antenna for forming sum and difference radiation patterns, and uses a first and second electronic scanning antennas. 3 pulses were respectively radiation patterns of the sum, the second pulse to a device for emitting a pattern of said difference, radiation collector of said first and third pulses
A first power regulating device for regulating the force, and the first power regulating device;
The radiation power of the second pulse independently of the adjustment of the regulating device
And a second power adjusting device for adjusting the power .

[0009]

The secondary surveillance radar device having the above configuration utilizes a difference pattern that is used only during normal reception, and further utilizes the response characteristics of the transponder on the aircraft side.
Radiated power of first and third pulses and radiation of second pulse
Power can be adjusted independently of each other , lowering the difference pattern against the level of the sum pattern, lowering the level of the sum pattern against the level of the difference pattern,
Alternatively, by lowering the level of the sum pattern and raising the level of the difference pattern, the transponder response region in the sum beam is narrowed, and the horizontal beam width of the sum pattern is narrowed equivalently. Here, the transmission pulse
Reducing the launch power reduces the transponder's reception gain.
Especially in distant aircraft,
It is difficult to detect the difference between the pattern level and the difference pattern level.
Become. Therefore, lower the level of the sum pattern and
If you use an adjustment method that raises the
Since the receiving gain of the spawner can be maintained,
The difference can be accurately determined.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 3 shows the overall configuration of the secondary monitoring radar apparatus. The transmitting / receiving apparatus 11 generates first to third pulses P1 to P3 shown in FIGS. And the third pulse P 1, P 3 is a Σ (sum) signal, and the second pulse P
2 is supplied to the electronic scanning antenna 12 for monopulse together with a beam control signal as a Δ (difference) signal. This antenna 12 is connected to the target aircraft A,
A beam having a sum pattern and a difference pattern is formed toward B, and a Σ (sum) signal and a Δ (difference) signal are transmitted. Although the second pulse P2 is also provided to the SLS, it is not directly related to the present invention, so that the details are omitted.

The aircrafts A and B each have a transponder (not shown). The transponder is the first
When the third to third pulses P1 to P3 are received, the respective reception levels are compared, and the levels of P1 and P3 are 9 times higher than those of P2.
If it is larger than dB, it responds 90% or more, and P2 becomes P1, P
It has the characteristic that it does not respond when it is equal to or greater than 3.

When a response signal emitted from each of the transponders of the aircrafts A and B is captured by the antenna 12, the transmission / reception device 11 decodes the data from the received signal and sends it to the data processing device 13 as target data. The data processing device 13 identifies and decodes the aircraft, altitude information, and the like from the target data, and displays the information on the display device 14 as appropriate.

FIG. 1 shows the internal configuration of the transmission / reception device 11. The transmission / reception device 11 includes first and second transmitters 111 and 112. The first transmitter 111 generates first and third pulses P1 and P3, and the second transmitter 1
12 generates a second pulse P2. Each transmitter 111,
The output pulses P1, P3, and P2 of 112 are supplied to the power adjusters 113 and 114, and the circulators 116 and 117, respectively.
Are sent to the antenna 12 as a sum signal Σ and a difference signal Δ. Note that the second pulse P2 is sent to the antenna 12 as the SLS control signal Ω via the power adjusting device 115 and the circulator 118.

The Σ signal, Δ signal, and Ω signal captured by the antenna 12 are circulators 116, 117,
The received signal is transmitted to a multi-channel receiver 119 via 118, where a received signal of a Σ pattern, a Δ pattern, and an Ω pattern is obtained, and necessary data such as a response signal from a transponder is demodulated. It is sent to the processor 1110.

The monopulse processor 1110 detects the azimuth directions of the aircrafts A and B within the beam coverage from the Σ and Δ received signals by monopulse angle measurement. The above data and information such as the azimuth direction are sent to the data processing device 13 as target data. In the configuration described above, a characteristic part of the present invention will be described below with reference to FIG.

First, in the prior art, the pulses P1 to P3 are generated by one transmitter, the levels are adjusted, and then P1, P3 and P2 are adjusted.
And sent to the antenna. Therefore, P1, P3 and P2 were at the same level, and the radiated powers of the Σ pattern and the Δ pattern were almost at the same level as shown in FIG. To ensure that the transponder responds (90% or more), the difference between the levels of P1 and P3 and the level of P2 needs to be 9 dB or more. Therefore, the range A in FIG. B is a transponder uncertain response area, and C is a transponder non-response area.

Here, if the two aircrafts A and B are at the same distance from the antenna, are close in the azimuth plane, and are both within the horizontal beam width of the Σ pattern, the responses from each aircraft overlap. Therefore, each aircraft cannot be separated and detected. In this case, the deterministic response area A may be narrowed to improve the azimuth resolution. However, in order to narrow the area A, if the horizontal beam width of the Σ pattern is reduced, the mechanical This is not a good idea because the target size becomes large.

Therefore, in this embodiment, P1, P3 and P3
2 are mutually independent first and second transmitters 111 and 112
And the level can be individually adjusted by the first and second power adjusting devices 113 and 114. With this configuration, as shown in FIG. 2B, the level of the パ タ ー ン pattern is increased with respect to the level of the Σ pattern, the level of the Σ pattern is reduced with respect to the level of the パ タ ー ン pattern, or the level of the Σ pattern is decreased. It is possible to raise the level of the pattern.

As described above, when a level difference is provided between the Σ pattern and the パ タ ー ン pattern, as is clear from FIG. 2B, the transponder response region A in the Σ beam is narrowed, and equivalently, the Σ pattern Can be reduced in horizontal beam width. As a result, the azimuth resolution is improved, and even if the two aircraft A and B are at the same distance from the antenna and are close in the azimuth plane, one of them is removed from the horizontal beam of the Σ pattern, and Can be separated and detected.

By the way, if a mechanically rotating antenna that rotates at a constant speed as in the prior art is used as an antenna with the horizontal beam width of the Σ pattern narrowed equivalently as described above, the response from the transponder per antenna rotation is as follows. Insufficient numbers reduce data reliability. Therefore, in the above embodiment, in order to prevent a decrease in the number of responses, an electronic scanning antenna capable of directing a beam in an arbitrary direction for an arbitrary time is used.

In the above embodiment, P1 and P3 are generated by the first transmitter 111 and P2 is generated by the second transmitter 112. However, P1 to P1 are generated by one transmitter.
Of course, after P3 is generated, it may be separated and output, and sent to the first and second power adjusting devices 113 and 114. In addition, it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0023]

As described above, according to the present invention, it is possible to provide a secondary surveillance radar device having a simple configuration and capable of accurately separating and detecting two or more aircraft close in an azimuth plane. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a transmission / reception apparatus as one embodiment of a secondary monitoring radar apparatus according to the present invention.

FIG. 2 is a power distribution diagram of Σ and Δ patterns for explaining the operation and effect of the embodiment.

FIG. 3 is a block diagram showing the overall configuration of a secondary monitoring radar device to which the present invention is applied.

FIG. 4 is a timing chart showing an output timing of a pulse used in the secondary monitoring radar device.

[Explanation of symbols]

P1 to P3: pulse, A, B: aircraft, 11: transceiver, 111, 112: transmitter, 113, 114, 115
.., Circulators, 119, multi-channel receivers, 1110, mono-pulse processors, 12, mono-pulse electronic scanning antennas, 13, data processing devices, and 14 display devices.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-68682 (JP, A) JP-A-64-13486 (JP, A) JP-A-61-256272 (JP, A) JP-A-61-256272 11683 (JP, A) JP-A-2-168188 (JP, A) JP-A-2-198381 (JP, A) JP-A 1-136085 (JP, A) (58) Fields investigated (Int. Cl. G01S ⁷ /00-7/64 G01S 13/00-13/95

Claims (1)

(57) [Claims] 1. An electronic scanning antenna for monopulses forming respective radiation patterns of a sum and a difference, wherein first and third pulses are respectively radiated in the pattern of the sum and a second pulse is formed in the pattern of the difference. In the secondary surveillance radar device which radiates at the above, the radiation power of the first and third pulses is adjusted.
A first power adjustment device, and an adjustment of the first power adjustment device.
Adjusting the radiated power of the second pulse independently of the adjustment
A secondary surveillance radar device comprising: a second power conditioning device.