JPS6336176A - Radar target detector - Google Patents

Abstract

PURPOSE:To suppress a crack and a dummy target by carrying out an adaptive receiving process within a specific adaptive prediction area having a detection prediction position in the center corresponding to a reception level in pursuit of a target acquired and detected by a radar. CONSTITUTION:A radar target detector 6 receives the reflected wave of a transmitted ratio wave from the radar or a response signal transmitted through a transponder and detects the target from the received signal. A target position predicting circuit 9 in pursuit of the target detected by a radar target detector 6 predicts the future position of the target in a next scan on the basis of the tracking result. An adaptive control circuit 10 is equipped with an optimum gain calculator 101 and an adder 102 and performs adaptive control over the reception gain of the radar over a preset distance and azimuth display range centering on the future position in correspondence to a target detection prediction level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radar target detection device, and in particular, the reception gain in the vicinity of the next indicator positioning 1 of the target in the secondary and secondary radars is used to predict the detection of the target. The present invention relates to a radar target detection device that performs adaptive control depending on the level.

[Conventional technology]

The primary radar uses the reflected waves of the transmitted waves to display the final ball, or the secondary radar uses the transmitted radio waves as an interrogation signal and uses the response signal from the target station to display the signal. Usually 5TC (Sensitive
y Time Control) gate or Ranze Azimutb
) gate or a combination of both gates performs i[r control of the radar reception gain. Among these gates, the level of the reflected wave received by the STC gate corresponds to the time, that is, the distance R, and for the primary radar, the level of the reflected wave corresponds to 1/
The secondary radar has a spherical dispersion characteristic that decreases by 17R2, and therefore the level becomes stronger as it gets closer to the radar transmitter, and decreases rapidly as it moves away, causing an imbalance on the target detection 2 display. The purpose is to correct the In other words, the level of reflected waves increases rapidly as it gets closer to the radar, so the reflected waves from near the radar are subject to unnecessary and strong racking due to terrain, buildings, etc., so this should be minimized from the detection signal. It is to be excluded.

On the other hand, Range Azimuth Gate uses partially fixed reflected waves from specific terrain and buildings included in the radar search coverage area.
Alternatively, it is an attempt to eliminate the influence of so-called vertical roving, which is the variation of the partial detection level based on the interference of either the sum or the difference between the direct wave on the vertical plane of radio wave emission and the ground reflected wave.

Of the two gates mentioned above, the S 'f' C gate performs gain control such that the reception gain reaches a steady state as the distance increases, while the range azimuth gate performs gain control such that the reception gain reaches a steady state as the distance increases. Control is performed such as reducing the reception gain over the range (distance) and azimuth (azimuth) of the radar, and the content of reception gain control at any gate is set in advance taking into account the operating conditions of the radar, the environment, etc. .

FIG. 2 is a block diagram showing the basic configuration of a conventional radar target detection device, in which antennas 1. Transmission/reception branch circuit 2. Transmitter 3. Receiver 4, STC gate generator 5. Target detector 6. It is composed of a tracking/water landing processing device 7, a display device 8, etc.

A transmission signal output from the transmitter 3 is supplied to the antenna 1 via a transmission/reception branch circuit 2 using a circulator or the like, and is radiated as a transmission radio wave.

The antenna 11, which performs a predetermined movement by a driving rotation mechanism (not shown), captures the reflected wave to the transmitted radio wave or the response signal from the transbonder, and supplies this to the receiver 4 via the transmitting/receiving circuit 2. be done.

The receiver 4 performs reception processing to convert the input received signal into a video signal and output it, but in this case, the received signal is processed by the aforementioned STC gate, range azimuth gate, or a combination of these two gates. Added. In the case of FIG. 2, S'PC gate generator 5 generates S
The case where a TC gate is applied and a video signal is output is taken as an example.

The 8TC gate generator 5 receives a transmission synchronization pulse from the transmitter 3, and starts at the timing when the receiver 4 is switched to the reception state based on this transmission synchronization pulse.
Output the r c gate signal to the receiver 4 and add S to the received signal.
Apply the TC gate.

FIG. 3 is an STC gate characteristic diagram showing an example of control of reception gain using an STC gate signal. Figure 3 shows S'l
' This shows the gain control characteristic C when the reception gain is controlled by the C gate and the gain increases over time according to the four glands of 几2 or R4. Here, R2 is the characteristic of the secondary radar, and trench 4 is the characteristic of the primary radar. By performing such gain control on the receiver 4, the effect of the air propagation loss of the transmitted radio waves is compensated for, and a receiving sensitivity pattern 1 that is uniform in distance and near is achieved.
It is possible to hold the standard and relatively suppress the strong rack near the radar. In Figure 3, s ′r c
Although an example has been shown in which the gate characteristic increases at 2 or 4, this characteristic can be set arbitrarily, taking into account all aspects such as the operational purpose of the radar.

In this way, the receiver 4 outputs a video signal while receiving gain control by the STC gate, and supplies this to the target detection device 6.

The target detector 6 performs target detection processing such as comparing the input video signal with a preset target determination threshold, and supplies the output to the tracking/display processing device 7.

The tracking/display processing device 7 tracks and records the position data and level of the moving target, converts it into display data in a predetermined format, and supplies it to the display device 8 for video display.

[Problems to be Solved by the Invention] The conventional radar target detection device described above is aimed at controlling the reception gain of the STC gate or range azimuth gate, and the characteristics of each location where the radar is operated. Therefore, it is effective in eliminating clutter, etc. caused by the radar installation environment, but at the same time,
This also imposes unnecessary gain restrictions on the target. Originally, radar target detection was based on vertical roving.

Changes in the reflection cross section due to target motion, and in the case of secondary radar interrogating the ground station from the aircraft, there is also a change in the aircraft antenna gain due to aircraft oscillation, and a decrease in detection probability is unavoidable, resulting in an STC gate.

There is a problem in that the range azimuth gate further exacerbates this tendency, and even makes it impossible to detect the target. Also, if you try to solve this problem by increasing the sensitivity and gain of the receiver, you will encounter clutter,
There is a problem in that an increase in undesired inputs, such as an increase in multipath reception, is unavoidable.

An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a radar target that can significantly improve target detection probability by providing means for adaptively controlling the reception gain in the vicinity of the target's predicted position in response to the predicted reception level of the target. The object of the present invention is to provide a detection device.

[Failure to solve the problem]

The radar target detection device of the present invention includes a radar target detection means for receiving a reflected wave of a radar transmission radio wave or a response signal transmitted via a transbonder and detecting a target from the received signal; a target position prediction means that tracks the detected target and predicts the future position 1σ of the target in the next scan based on the tracking result; and a target detection prediction level over a preset distance and direction display range centered on the future position. and reception gain adaptive control means for adaptively controlling the reception gain of the radar in response to 1u.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. The embodiment shown in FIG. 1 includes an antenna 1, a transmitting/receiving branch circuit 2. Transmitter 3. Receiver 4. STC gate generator5. Target detector 69 display device 8. Target position prediction circuit 9. Adaptive control circuit 1
0, etc., and the adaptive control circuit 10 includes an optimum gain calculator 101 and an adder 102.

Among the components of the embodiment shown in FIG. 1, antenna 1. Transmission/reception branch circuit 2. Transmitter 3. Receiver 4. STC gate generator5. The target detector 62, display device 8, etc. have the same reference numerals as shown in FIG. 2, so a detailed description thereof will be omitted.

The received signal supplied to the receiver from the antenna 1 through all the transmitting/receiving branch circuits 2 is supplied as a video signal to the target detector 6 after receiving processing, and the target detected thereby is supplied to the target position prediction circuit 9. Ru.

However, in this processing flow, the receiver 4 receives the adaptive '! output from the adaptive control circuit 10, which will be described later. II Go S'PC
An adaptively controlled STC gate is applied to the gate signal to increase and maintain the receiving gain at a predetermined level over an adaptive control region that corresponds to the predicted level of the target and is centered on the predicted position of the target.

Now, the target position prediction circuit 9 tracks the target data and position provided from the target detector 6, constantly updates and stores a plurality of past samples set in advance in the memory, and stores the position information and movement speed of these data. Based on the above, the future position for the next radar search is predicted and calculated. The number of samples to be stored in the target data is set to the number necessary for this prediction and the required accuracy. Target position prediction circuit 9
The adaptive prediction area is defined as the area centered around the predicted next appearance position of the target and including the predicted fluctuations, and the distance and direction data that represents this area is determined, and this and the past multiple data used for prediction calculation are determined. The sample target level information is supplied to the adaptive control circuit 10 as target prediction data.

The adaptive control circuit 10 uses an optimal gain calculator 101 to calculate the target level to be acquired next time using an extrapolation method based on the target level information of a plurality of past samples of the input target prediction data, and Based on the results, the optimum reception gain to be prepared for the next target is calculated based on the radar operation specifications. The optimal gain calculator 101 determines the level of the STC gate signal to be controlled to the optimal reception gain obtained in this way, and adds this STC gate signal and the data regarding the above-mentioned adaptive prediction region to which this STC gate signal is applied. 102.

The adder 102 thus adds the STC gate signal provided from the STC gate generator 5 and the STC gate signal output from the optimal gain calculator 101, and as a result, the optimal gain calculation is performed for the adaptive prediction region. In addition, in the search area other than the adaptive prediction area, an adaptive control STC gate signal composed of 8TC gate signals output from the STC gate generator 5 is generated, and this is sent to the receiver 4. 8 'I'C control of the receiver 6 is performed.

In this way, once the target is detected, it will be tracked and
In the adaptive prediction domain centered on this goal, the normal S
TC? s'r allows reception at the optimal level, which is set to increase the reception gain by a certain percentage in accordance with the past target reception level than the reception gain by tIIJ control.
c control can be implemented.

That is, reception sensitivity can be adaptively controlled for each detected target, and the increase in pseudo targets and clutter can be greatly suppressed, thereby enabling reception that can significantly improve the target detection probability.

The output of the target detector 6, which is obtained while the reception gain is adaptively controlled by the adaptive control S'll''C gate signal, is supplied to the display processing device 11 via the target position prediction circuit 9, where it is subjected to predetermined display processing. After being converted into a display signal, it is displayed on the display device 8.

The above-mentioned adaptive control of the reception gain is performed using only the control by the S 'l' C gate as an example, but even if this applies to the azimuth range gate, it still cannot be controlled in combination with the azimuth range gate. It is clear that it can be implemented in almost the same way as a target. Furthermore, it is clear that the operation of such adaptive control can be used in combination with conventional control methods, and any of these can be easily implemented without impairing the spirit of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, while tracking the target captured and detected by the next or secondary radar, the target is adapted within a predetermined adaptive prediction area centered around the detected predicted position in accordance with the reception level. By providing means for receiving and processing, it is possible to realize a radar target detection apparatus that can significantly improve the probability of target detection while greatly suppressing the occurrence of ivy and pseudo-targets.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the radar target detection device of the present invention, FIG. 2 is a block diagram showing the basic configuration of a conventional radar target detection device, and FIG. 3 is reception by STC gate signal. FIG. 3 is an STC gate characteristic diagram showing an example of gain control. 1... Antenna, 2... Transmission/reception branch circuit, 3... Transmitter, 4... Receiver, 5...
... STC gate generator, 6 ... Target detector, 7 ... Tracking/display processing device, 8 ...
...Display device, 9...Target position prediction circuit, 10
...Adaptive control circuit, 11...Display processing device, 101...Optimum gain calculator, 102.
...Adder. Agent: Patent Attorney Shinji Uchihara 3

Claims (1)

[Claims] Radar target detection means that receives reflected waves of radio waves transmitted by the radar or response signals transmitted via a transbonder and detects a target from this received signal, and a radar target detection means that tracks and tracks the target detected by the radar target detection means. a target position prediction means for predicting the future position of the target in the next scan based on the result; and adaptive control of the radar in response to the predicted detection level of the target over a preset distance and azimuth display range centered on the future position. What is claimed is: 1. A radar target detection device comprising reception gain adaptive control means for detecting a radar target.