JP3477133B2 - Radar equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar apparatus having a plurality of antennas that simultaneously emits transmission pulses toward moving targets in clutter for different coverage areas and uses radio waves reflected from the targets as reception signals. It is about.

[0002]

2. Description of the Related Art A conventional radar device will be described with reference to the drawings. FIG. 8 shows, for example, Japanese Patent Laid-Open No. 09-3045.
It is a block diagram which shows the structure of the conventional radar apparatus shown by the 21st publication.

In FIG. 8, a conventional radar device is composed of a plurality (three) antennas 1, a plurality of transmitters / receivers 2 connected to the antenna 1 for transmitting and receiving radio waves, and a transmitter / receiver 2. A plurality of signal processing devices 3 that perform processing such as clutter suppression and target detection for an input video signal, and perform prediction and speed detection of the future position of the target from position information of the target detected by the signal processing device 3 and the like. A PRF (Pulse R) is generated from a plurality of tracking calculation devices 4 that generate tracking target specifications and manage them for each target, and tracking target specifications output by the tracking calculation device 4.
beam control apparatus 5 for calculating beam parameters such as the emission frequency, the pulse width, and the number of hits.

Further, in the figure, the beam control device 5
Is not suppressed by the beam parameter calculation device 6 that calculates the parameters of the beam to be emitted to the tracking target based on the tracking target parameters that are input information from the tracking calculation device 4, and the Doppler frequency spectrum MTI process of the tracking target. Usable division PRF range calculation device 8 for obtaining the PRF range, common stagger reference PRF selection device 9 for selecting a reference PRF from the PRF range obtained by the use division PRF range calculation device 8, and common stagger reference PRF Target response determination device 10 that determines whether the error range of the target tracking speed is allowable when the PRF obtained by the selection device 9 is used
And a multi-target speed adaptive stagger calculation device 11 for obtaining a PRF required to increase all frequency responses within the error range of the target tracking speed.

Next, the operation of the above-described conventional radar device will be described with reference to the drawings.

FIG. 9 is a diagram showing the operation of the MTI processing of the conventional radar device. Further, FIG. 10 is a diagram showing the characteristics of the MTI processing of the conventional radar device. In addition, FIG.
FIG. 6 is a diagram showing an usable divided PRF range image in a conventional radar device. Further, FIG. 12 is a diagram showing an example of stagger reference PRF selection in a conventional radar device.

Before explaining the operation of the radar apparatus configured as described above, first, MTI (Mo) which is a typical process for suppressing clutter which is a reflected signal from other than the target.
Ving Target Indicator) processing will be described with reference to FIG.

The MTI processing is a function of suppressing a fixed target and clutter and detecting and displaying only a moving target, and operates on the following principle.

When the input video signal to the MTI processing is E ₁ , the following complex signal (ω is the Doppler angular frequency) is input. E ₁ = Ae ^jωdt

Assuming that the above complex signal is input to the delay circuit 12, the output of the subtractor 13 is as follows. E ₂ = Ae ^jωdt (e ^−jωdT −1)

Therefore, the Doppler response of the single eraser is expressed as: | E ₂ / E ₁ | = 2 | sin (ω _d T / 2) |

Here, the relationship between the Doppler angular frequency ω _d and the target speed v _d is as follows. In addition, λ is a transmission / reception wavelength. ω _d = 4πv _d / λ

Therefore, it can be expressed as follows. │E ₂ / E ₁ │ = 2│sin (2πv _d T / λ) │

FIG. 10 shows the characteristics of MTI processing. According to this, the clutter usually has a velocity close to zero and can be eliminated. However, on the other hand, when the target speed v _d is as follows, the target is also erroneously erased (this is called blind speed). Note that n is a natural number. v _d = (λ / 2T) · n

In order to avoid this, a staggered PRF processing method is generally adopted in which the PRF is changed at a predetermined ratio for each transmission pulse and the blind speed for each PRF is compensated by the synthesized wave. is there.

In the conventional radar device shown in FIG. 8, first of all, a usable divided PRF range calculation device 8 is provided for each system of each antenna 1.
PR calculated by the beam specification calculation device 6 in
F (PRFin), upper limit of usable PRF determined by the system (PRFmax), usable PRF
From the lower limit value (PRFmin), the target Doppler frequency, etc., the tracking target Doppler frequency does not become the blind speed P
Find the RF range.

FIG. 11 is an image diagram of the usable divided PRF range, in which the vertical axis represents PRF and the horizontal axis represents the Doppler frequency. In the figure, 14 is a blind velocity region, and 15 and 16 are usable division PRFs 1 and 2.

In FIG. 11, the blind velocity region 14 is PR
It is shown that the PRF range exists in the vicinity of an integral multiple of F, and the PRF range in which the Doppler frequency spectrum of the tracking target is likely to be detected (hereinafter referred to as a clear region) can be driven.

Next, the common stagger reference PRF selecting device 9 selects one reference PRF from the usable divided PRF range obtained by the usable divided PRF range calculating device 8.

This selection method will be described with reference to FIG. First, the appearance range of the tracking target Doppler frequency is calculated as a percentage with respect to each usable divided PRF range.

Next, from all the usable divided PRF ranges, the used divided PRF range including the value closest to 50% is selected. If the values are the same in a plurality of usable divided PRF ranges, the one with the higher PRF is selected.

Next, within the selected usable divided PRF range, a PRF in which the multiple target Doppler frequencies of all antenna systems are closest to 50% of the PRF is selected, and this is set as the stagger reference PRF.

Further, in the target response determination device 10, when the common stagger reference PRF obtained by the common stagger reference PRF selection device 9 is used, the range of a plurality of target speed errors determined by the performance of the tracking filter etc. is cleared to what extent. It is determined whether the region area can be covered, and if there is an area that cannot be covered, the Doppler frequency area is also obtained.

In the plural target speed adaptive stagger calculation device 11, a plurality of target speed error ranges cannot be included from the inclusion possible determination result and the inclusion impossible region of the plurality of target speed error ranges obtained by the target response determination device 10. When the frequency region exists, a PRF covering the region is newly obtained.

[0025]

However, the radar apparatus constructed by a plurality of antennas having different coverage areas as described above has the following problems.

A method for calculating a common stagger PRF having a plurality of antennas in the procedure of the conventional apparatus as shown in FIGS. 11 and 12 is to drive a plurality of target Doppler frequencies to the clear region in common for each antenna system. In order to avoid blind velocity, each antenna must have the same PRF to avoid radio interference with each other, while the target Doppler frequency of the target is different in each antenna system, so It was very difficult to avoid blind speed in the system of antenna.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a radar system capable of avoiding the blind speed regardless of the target moving speed of each antenna system. To do.

[0028]

A radar apparatus according to claim 1 of the present invention emits a transmission pulse toward a moving target and receives a radio wave reflected from the moving target; A plurality of transmitters / receivers for frequency-converting and amplifying the received signal, and a plurality of signal processing devices for obtaining the position information of the moving target from the received video signal which is the output of the transmitter / receiver and for eliminating clutter components, A plurality of tracking calculation devices for predicting the future position of the moving target and velocity detection from the position information to generate tracking target specifications, and a plurality of beam specifications for beam irradiation from the tracking target specifications A beam parameter calculation device; and a plurality of transmission frequency calculation devices that calculate the transmission frequency so that the Doppler frequency of the moving target is a predetermined ratio of PRF based on the beam parameters. Transmission and receiver, the transmit time for each transmission frequency determined by the transmission frequency calculation unit is configured to receive the reflected waves from the moving target.

The radar device according to claim 2 of the present invention is
A plurality of antennas that emit a transmission pulse toward a moving target and receive the radio waves reflected from the moving target, and a plurality of transmitters / receivers that frequency-convert and amplify the transmission and reception signals,
A plurality of first hit-to-hit phase difference correctors for correcting the hit-to-hit phase difference of the received video signal output from the transmitter / receiver, and the received video signal corrected by the first hit-to-hit phase difference corrector A plurality of MTI processors for detecting only the moving target, and a plurality of MTI processors for performing a correction for canceling the inter-hit phase difference corrected by the first inter-hit phase difference corrector for the video signal detected by the MTI processor. The second hit-to-hit phase difference corrector and the second hit-to-hit phase difference corrector output the target position information to predict the target future position and detect the speed to generate tracking target specifications, which are the targets. A plurality of tracking calculation devices managed for each, a plurality of beam specification calculation devices for calculating beam specifications for beam irradiation from the tracking target specifications, and a predetermined ratio of PRF based on the beam specifications. It becomes the Doppler frequency Hit-to-hit phase-difference correction used in the first and second hit-to-hit phase-difference correctors for calculating the hit-to-hit phase difference of the audio signal and shifting and canceling the current target Doppler frequency to a predetermined ratio of PRF It is provided with a plurality of inter-hit phase difference correction amount calculation devices for calculating the amount.

The radar device according to claim 3 of the present invention is
A plurality of antennas that emit a transmission pulse toward a moving target and receive the radio waves reflected from the moving target, and a plurality of transmitters / receivers that frequency-convert and amplify the transmission and reception signals,
A plurality of MTI processors that detect only moving targets from the video signals received by the transmitter / receiver, and a plurality of Cs that combine the video signals detected by the MTI processors with the same target.
A plurality of tracking calculation devices that generate tracking target specifications by predicting the future position of the target and detecting the speed from the position information of the target output by the inter-PI synthesizer and the CPI synthesizer, and manage this for each target And a beam controller that selects one of the systems of each antenna to select a PRF that can avoid the blind velocity and sequentially change the selected PRF for each CPI.

A radar device according to a fourth aspect of the present invention is
A plurality of antennas that emit a transmission pulse toward a moving target and receive the radio waves reflected from the moving target, and a plurality of transmitters / receivers that frequency-convert and amplify the transmission and reception signals,
A plurality of coherent integration processors for generating an FFT filter bank from the video signal received by the transmitter / receiver, and a plurality of clutters rejected by the coherent integration processor among the clutter discriminated by the coherent integration processor and the target Doppler frequency A target detector and a plurality of tracking calculation devices that generate tracking target specifications by performing prediction and speed detection of the target future position from the position information of the target output by the target detector, and managing this for each target, Any one of the systems of each antenna is provided with a beam control device that selects a PRF that can avoid a blind velocity and sequentially changes the selected PRF for each CPI.

The radar device according to claim 5 of the present invention is
A plurality of coherent integration number calculation devices for calculating the number of integrations of the coherent integration processor from the target Doppler frequency input from the tracking calculation device to the radar device according to claim 4, and providing the calculated integration number to the coherent integration processor. Is further provided.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. A radar device according to Embodiment 1 of the present invention will be described with reference to the drawings. 1 is a block diagram showing the configuration of a radar device according to Embodiment 1 of the present invention. In each figure, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, antenna 1 to tracking calculation device 4
Is the same as the above conventional device, and 5A is a beam control device.

Further, in the figure, 6 is the same beam specification detecting device as the conventional device constituting the beam control device 5A, 7
Is a transmission frequency calculation device that calculates the transmission frequency from the target velocity (beam specifications) in the system of each antenna 1 so that the target Doppler frequency is 50% of PRF.

Next, the operation of the radar device according to the first embodiment will be described with reference to the drawings. Figure 2
FIG. 4 is a diagram showing characteristics of MTI processing for three transmission frequencies of the radar device according to the first embodiment of the present invention.

The signals received by the three antennas 1 are input to the transmitter / receiver 2. Each transmitter / receiver 2 performs frequency conversion and amplification, and outputs a received video signal to the signal processing device 3 corresponding to each transmission frequency.

The signal processing device 3 performs processing such as clutter suppression and target detection on the input received video signal.

The tracking calculation device 4 predicts the future position of the target from the detected position information of the target and detects the speed to generate tracking specifications, which are managed for each target.

Further, the beam parameter calculation device 6 constituting the beam control device 5A calculates the parameter (PRF) of the beam with which the tracking target is irradiated, based on the beam tracking parameters.

Here, the PRFs output from the beam parameter calculation device 6 must be selected as common PRFs so that radio waves do not interfere with each other in each antenna system. FIG. 2 shows target frequency characteristics of the provisionally set common PRF. The target Doppler frequency of each antenna 1 system is shown in FIG.
In some cases, as shown in (a), (b), and (c), they are independent, and it is impossible to avoid all the coping objectives of the system of each antenna 1 from the blind speed by the common PRF adjustment.

On the other hand, the target Doppler frequency is calculated by the above equation v
_{As shown by d} = (λ / 2T) · n (v _d : target speed, λ: transmission / reception wavelength, n: natural number), it depends on the wavelength of the transmission pulse, that is, the transmission frequency.

Therefore, in the transmission frequency calculation device 7 which constitutes the beam control device 5A, rather than adjusting the common PRF, the transmission frequency is appropriately selected, that is, the transmission / reception wavelength λ of the above equation is appropriately selected. , Move the target Doppler frequency to any position.

As a result, of the video signals received from the transmitter / receiver 2, the clutter that does not depend on the transmission frequency has the same Doppler response, and the target Doppler frequency is shown in FIGS. 2 (a) to 2 (c). Thus, it is possible to shift to 50% of PRF.

As described above, in the first embodiment, since the blind frequency depends on the transmission frequency, the transmission frequency device 7 for calculating the transmission frequencies for transmitting and receiving at different frequencies at the same time is provided. There is an effect that blind speed can be avoided in the system of all antennas.

That is, the radar device according to the first embodiment is a radar device for detecting a moving target in clutter, and three beam parameters for calculating parameters for beam irradiation from the parameters of the input target. The original calculation device 6, three transmission frequency calculation devices 7 for obtaining transmission frequencies that can avoid the target Doppler frequency from the blind speed, and the transmission frequency obtained by the transmission frequency calculation device 7 are transmitted at the same time,
Three transmitters / receivers 2 for receiving the reflected waves from the target, three signal processing devices 3 connected to the rear stage of the transmitter / receiver 2 for canceling clutter components from the received video, and the above signal processing A device including three tracking calculation devices 4 for predicting the future position of the target, detecting the speed, and the like from the position information of the target detected by the device 3 to generate tracking target specifications, and managing the specifications for each target. Is.

Embodiment 2. A radar apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings.
FIG. 3 is a block diagram showing the configuration of the radar device according to the second embodiment of the present invention.

In FIG. 3, the beam control device 5B includes the same beam parameter calculation device 6 as in the first embodiment, and a hit-to-hit phase difference correction amount calculation device 21 at the subsequent stage.

Further, in the figure, the signal processing device 3A
Is a video signal from the A / D converter 17 for converting the analog video signal from the transmitter / receiver 2 into a digital video signal, and the correction amount obtained by the inter-hit phase difference correction amount calculation device 21 of the beam control device 5B. The first inter-hit phase difference corrector 18 for correction, the MTI processor 19 for suppressing clutter which is a reflection signal from other than the target, and the correction amount corrected by the first inter-hit phase difference corrector 18 The second inter-hit phase difference corrector 20 is provided for canceling.

The other configurations are the same as those in the first embodiment.
Since it is the same as the device according to the first embodiment, its description is omitted here.

Next, the operation of the radar device according to the second embodiment will be described with reference to the drawings.

Similar to the first embodiment, the beam specification calculation device 6 of the beam control device 5B outputs the target Doppler frequency and PRF. This Doppler frequency is MT
In the input video signal of the I processor 19, it appears as a phase rotation angle between hits. That is, when the target moving speed is constant, the phase difference of the video signal between hits is constant,
In the case of a fixed target, the phase difference of the video signal between hits becomes zero.

Therefore, the inter-hit phase difference correction amount calculation device 2
At 1, the inter-hit phase difference of the video signal having the Doppler frequency of 50% of the PRF is calculated, and the inter-hit phase difference correction amount for shifting the current target Doppler frequency to 50% of the PRF is calculated.

In the first inter-hit phase difference correction unit 18 of the signal processing apparatus 3A, the inter-hit phase difference correction amount calculation apparatus 2 is used.
The target Doppler frequency can be pseudo-shifted to 50% of PRF by multiplying the video signal by the calculation result of 1, that is, the hit phase difference correction amount.

The target Doppler frequency is set to P by multiplying the video signal before MTI processing by the phase difference correction between hits.
Shifting to 50% of RF leads to avoiding blind velocities.

The video signal before MTI processing includes reflected waves from the fixed target and clutter in addition to the moving target. However, since these doppler frequencies are zero, the phase difference between hits is zero. Therefore, even if it is multiplied by the inter-hit phase difference correction amount, it remains zero and is suppressed by the MTI processor 19.

The output signal from the MTI processor 19 that avoids the blind speed and suppresses only the fixed target and clutter is the target Doppler frequency, and the hit-to-hit phase difference correction amount calculated by the hit-to-hit phase difference correction amount calculation device 21 is calculated. Although it is multiplied by the amount and is not the true target Doppler frequency, the true target Doppler frequency is required in the tracking calculation device 4 in the subsequent stage.

Therefore, a second inter-hit phase difference corrector 20 is provided at the subsequent stage of the MTI processor 19, so as to cancel the inter-hit phase difference corrected by the first inter-hit phase difference corrector 18. to correct. As a result, the target Doppler frequency, that is, the target speed input to the tracking calculation device 4 in the subsequent stage becomes a true value.

As described above, in the radar device according to the second embodiment, the beam control device 5B includes the inter-hit phase difference correction amount calculation device 21, and the radar device according to the second embodiment is provided with the first and second stages before and after the MTI processor 19 of the signal processing device 3A. By providing the one-hit phase difference corrector 18 and the second-hit phase difference corrector 20,
Since the hit-to-hit correction is performed before and after the MTI processing so that only the target Doppler frequency is frequency-shifted to 50% of PRF, the blind speed can be avoided.

That is, the radar apparatus according to the second embodiment is a radar apparatus for detecting a moving target in clutter, and three beam specifications for calculating specifications for beam irradiation from specifications of the input target. Source calculation device 6 and target Doppler frequency can be avoided from blind speed 3
The inter-hit phase difference correction amount calculation device 21 and three transmitters / receivers 2 that simultaneously transmit and receive the reflected wave from the target.
And three first inter-hit phase difference correctors 18, which are connected to the subsequent stage of the transmitter / receiver 2 and correct the inter-hit phase difference calculated by the inter-hit phase difference correction amount calculation device 21, Three MTI processors 19 for detecting only a moving target from the video signal corrected by one hit-to-hit phase difference corrector 18,
Three second inter-hit phase difference correctors 20 for performing correction to cancel the correction amount corrected by the first inter-hit phase difference corrector 18 for the video signal detected by the MTI processor 19.
Then, from the position information of the target output from the second hit-to-hit phase difference corrector 20, prediction of the future position of the target, speed detection, etc. are performed to generate tracking target specifications, which are managed for each target 3 The tracking calculation device 4 is provided.

Embodiment 3. A radar apparatus according to Embodiment 3 of the present invention will be described with reference to the drawings.
FIG. 4 is a block diagram showing the configuration of the radar device according to the third embodiment of the present invention.

In FIG. 4, the signal processing device 3B is
An A / D converter 17 for converting an analog video signal from the receiver 2 into a digital video signal, an MTI processor 19 for suppressing clutter, which is a reflected signal from other than the target, and an output video signal of the MTI processor 19. To CPI (Coh
erent Processing Interva
l), and an inter-CPI combiner 22 that integrates the outputs of the MTI processor 19 for the same target.

Further, in the figure, in the radar device according to the third embodiment, one of the systems of each antenna selects a PRF that can avoid the blind speed, and the PRF to be selected is sequentially changed for each CPI. Beam control device 5C
Equipped with.

The rest of the configuration is the same as that of the above-mentioned conventional device, and therefore its explanation is omitted here.

Next, the operation of the radar apparatus according to the third embodiment will be described with reference to the drawings.

Similar to the conventional example, the analog video signal is input to the signal processing device 3B, converted into a digital video signal by the A / D converter 17, and then the MTI processor 19 is inputted.
This suppresses fixed targets and clutter. At this time,
The Doppler frequency is different because the coping objectives of each antenna 1 system are different. Therefore, it becomes difficult to shift the target Doppler frequency to 50% of PRF in all systems.

Therefore, first, in the beam control device 5C, a PRF in which the target Doppler frequency of any one of the systems of each antenna 1 is 50% of PRF is selected. In the system selected by the beam controller 5C, the reflected signal transmitted from and received by the PRF can avoid the blind speed by the MTI processor 19 and suppress clutter other than the target. However, in other systems there may be blind velocities.

Next, in the beam controller 5C, the target Doppler frequency of the system other than the system selected first is PRF.
Select a PRF that is 50% of Similarly, this PRF
In the system in which is selected, the MTI processor 19 avoids the blind speed and suppresses clutter other than the target, but in other systems, the blind speed cannot be avoided.

Next, in the beam control device 5C, the target Doppler frequency of the remaining system is set to 50% of PRF.
Select F.

As described above, the beam control device 5C selects a PRF that avoids the blind speed only in any one of the systems, and selects the PRF while sequentially changing the target system.

Then, in the signal processing device 3B, the MTI
In the inter-CPI synthesizer 22 located after the processor 19,
The outputs of the MTI processor 19 at the three PRFs are accumulated and integrated for each CPI. This integrates the outputs of the MTI processor 19 in the three PRFs to compensate the blind velocities of the PRFs with each other, and the blind velocities of the PRFs are three.
The aim is to increase to the least common multiple of.

As described above, in the radar apparatus according to the third embodiment, the PRF is sequentially changed for each CPI and the MTI processing output for each CPI is integrated, so that the blind speed can be avoided. There is an effect.

That is, the radar apparatus according to the third embodiment is a radar apparatus for detecting a moving target in clutter, and at the same time as a beam control apparatus 5C for controlling the beam irradiation from the specifications of the input target. Three transmitters / receivers 2 for transmitting and receiving a reflected wave from the target, and three MTI processors 19 connected to the subsequent stage of the transmitter / receiver 2 for detecting only the moving target from the video signal. , Above MTI
Three inter-CPI synthesizers 22 for synthesizing the video signals detected by the processor 19 with the same target, and the inter-CPI synthesizer 2
2 has three tracking calculation devices 4 for predicting the future position of the target, speed detection, etc. from the position information of the target output to generate tracking target specifications, and managing this for each target. is there.

Fourth Embodiment A radar apparatus according to Embodiment 4 of the present invention will be described with reference to the drawings.
FIG. 5 is a block diagram showing the configuration of the radar device according to the fourth embodiment of the present invention.

In FIG. 5, the signal processing device 3C sends and receives signals.
A / D converter 17 for converting an analog video signal from the receiver 2 into a digital video signal, and the A / D converter 1
The output video signal of No. 7 is FFT (Fast Fourier).
r Transform: Fast Fourier Transform) to form a filter bank, and a coherent integration processor 23 for discriminating between a target and clutter, and a video signal for each filter bank output from the coherent integration processor 23. A target detector 24 that rejects a video signal of a filter bank (# 0 filter bank) having a frequency of zero and detects a target.

In the figure, the radar apparatus according to the fourth embodiment determines the common PRF from the target target Doppler frequency of the system of each antenna 1 selected from the output of the target detector 24 through the tracking calculation apparatus 4. A beam control device 5D for calculating is provided.

The other configurations are the same as those of the third embodiment.
Since it is the same as the radar device according to the present invention, its description is omitted here.

Next, the operation of the radar apparatus according to the fourth embodiment will be described with reference to the drawings. Figure 6
FIG. 6 is a diagram showing a coherent integral response of the radar device according to the fourth embodiment of the present invention.

Similar to the conventional example, an analog video signal is input to the signal processing device 3C, converted into a digital video signal by the A / D converter 17, and FFT is performed by the coherent integration processor 23 to form a filter bank. To do. When FFT is performed by the coherent integration processor 23,
As shown in FIG. 6, the PRF can be divided into filter banks, and the larger the number of FFT points (m), the higher the frequency resolution can be.

As shown in the figure, the target Doppler frequency is P
Even if it is not around 50% of RF, if the number of FFT points is large to some extent, discrimination from clutter can be easily performed. Further, the target detector 24 rejects the output of the # 0 filter having clutter, so that clutter can be suppressed at the same time.

Therefore, in the latter stage beam control device 5D,
It is not necessary to set the target Doppler frequency to 50% of the PRF, and it is sufficient to calculate the common PRF so that the target Doppler frequency of each system does not reach the blind speed.

As described above, since the radar apparatus according to the fourth embodiment is configured to reject the coherent integration processing for generating the FFT filter bank and the # 0 filter regardless of the MTI processing, the target tracking performance is reduced. And the clutter suppression performance can be maintained.

That is, in the radar device according to the fourth embodiment, in the radar device for detecting the moving target in the clutter, the beam control device 5D for controlling the beam irradiation from the specifications of the input target and the beam control device 5D are simultaneously provided. Three transmitters / receivers 2 for transmitting and receiving a reflected wave from the target, three coherent integration processors 23 connected to the latter stage of the transmitter / receiver 2 for generating the FFT filter bank, Of the clutter discriminated by the coherent integration processor 23 and the target Doppler frequency, the three target detectors 24 that reject the clutter and the target position information output from the target detector 24, etc. It is provided with three tracking calculation devices 4 that generate tracking target specifications by performing prediction and speed detection, and manage these specifications for each target.

Embodiment 5. A radar apparatus according to Embodiment 5 of the present invention will be described with reference to the drawings.
FIG. 7 is a block diagram showing the configuration of the radar device according to the fifth embodiment of the present invention.

In FIG. 7, the radar device according to the fifth embodiment includes a coherent integration number calculation device 25 at the subsequent stage of the tracking calculation device 4.

Note that other configurations, that is, antennas 1 to 1
Since the beam control device 5D is the same as the device according to the fourth embodiment, the description thereof is omitted here.

Next, the operation of the radar device according to the fifth embodiment will be described with reference to the drawings.

Similar to the fourth embodiment, an analog video signal is input to the signal processing device 3C, converted into a digital video signal by the A / D converter 17, FFT is performed by the coherent integration processor 23, and the filter bank is used. To form. At this time, the number of FFT points needs to be selected so that the target Doppler frequency and the clutter enter different filter banks.

The coherent integration number calculation device 25 uses the target Doppler frequency input from the tracking calculation device 4 to form the coherent integration processor 23 constituting the signal processing device 3C.
Is calculated. At this time, a lower limit value of the number of integrals is selected so that the clutter and the target Doppler frequency are discriminated in different FFT filter banks. The following operation is the same as that of the fourth embodiment.

As described above, the radar apparatus according to the fifth embodiment selects the lower limit value of the coherent integration number for discriminating the FFT filter banks in which the clutter and the target Doppler frequency are different from each other. This has the effect of shortening the

That is, the radar apparatus according to the fifth embodiment is a radar apparatus for detecting a moving target in clutter, and three coherent integration number lower limit values for calculating the coherent integration lower limit value capable of discriminating the Doppler frequencies of the clutter and the target. An integral number calculating device 25, three transmitters / receivers 2 that simultaneously transmit and receive a reflected wave from a target, and three transmitters / receivers 2 that are connected to the rear stage of the transmitter / receiver 2 and that generate the FFT filter bank. Of the coherent integration processor 23, the clutter discriminated by the coherent integration processor 23, and the three target detectors 24 that reject the clutter among the target Doppler frequencies, and the target position output by the target detector 24. It is provided with three tracking calculation devices 4 for predicting the future position of the target from the information, detecting the speed, generating the tracking target specifications, and managing the specifications for each target. It is intended.

[0092]

As described above, the radar apparatus according to the first aspect of the present invention emits a transmission pulse toward a moving target and transmits a plurality of antennas for receiving radio waves reflected from the moving target, and a transmission line. And a plurality of transmitters / receivers for frequency-converting and amplifying the received signals, and a plurality of signal processing devices for obtaining the position information of the moving target from the received video signals output from the transmitters / receivers and eliminating clutter components. , A plurality of tracking calculation devices for predicting the future position of the moving target and speed detection from the position information to generate tracking target specifications, and a plurality of calculating beam specifications for beam irradiation from the tracking target specifications Beam specification calculation device, and a plurality of transmission frequency calculation devices that calculate the transmission frequency so that the Doppler frequency of the moving target is a predetermined ratio of PRF based on the beam specifications, Note that the plurality of transmitters / receivers simultaneously transmit at each transmission frequency obtained by each transmission frequency calculation device, and receive the reflected wave from the moving target, so that it does not depend on the moving speed of the target of the system of each antenna. Thus, it is possible to avoid the blind speed.

A radar device according to claim 2 of the present invention is
As described above, emitting a transmission pulse toward the moving target, a plurality of antennas that receive the radio waves reflected from the moving target, and a plurality of transmitters and receivers that frequency-convert and amplify the transmission and reception signals, A plurality of first hit-to-hit phase difference correctors for correcting the hit-to-hit phase difference of the received video signal output from the transmitter / receiver, and the received video signal corrected by the first hit-to-hit phase difference corrector A plurality of MTI processors for detecting only the moving target, and a plurality of MTI processors for performing a correction for canceling the inter-hit phase difference corrected by the first inter-hit phase difference corrector for the video signal detected by the MTI processor. The second hit-to-hit phase difference corrector and the second hit-to-hit phase difference corrector output the target position information to predict the target future position and detect the speed to generate tracking target specifications, which are the targets. Multiple to manage for each A tracking computing device, a plurality of beams specification calculating unit for calculating a beam specifications for beam emitted from the tracking target specifications, based on the beam specifications, PR
The phase difference between hits of the video signal having the Doppler frequency of a predetermined ratio of F is calculated, and the current target Doppler frequency is set to P
And a plurality of hit-to-hit phase difference correction amount calculation devices for calculating hit-to-hit phase difference correction amounts used in the first and second hit-to-hit phase difference correctors for shifting and offsetting a predetermined ratio of RF. Therefore, it is possible to avoid the blind speed regardless of the target moving speed of each antenna system.

The radar device according to claim 3 of the present invention is
As described above, emitting a transmission pulse toward the moving target, a plurality of antennas that receive the radio waves reflected from the moving target, and a plurality of transmitters and receivers that frequency-convert and amplify the transmission and reception signals, A plurality of MTI processors that detect only a moving target from the video signals received by the transmitter / receiver, a plurality of inter-CPI combiners that combine the video signals detected by the MTI processor with the same target; Based on the target position information output from the inter-CPI synthesizer, the target future position is predicted and the velocity is detected to generate tracking target specifications, and a plurality of tracking calculation devices that manage these specifications for each target and the system of each antenna Since any one of the systems has a beam control device that selects a PRF that can avoid the blind speed and sequentially changes the PRF that is selected for each CPI, it does not depend on the target moving speed of the system of each antenna. An effect that it is possible to avoid a blind speed.

A radar device according to claim 4 of the present invention is
As described above, emitting a transmission pulse toward the moving target, a plurality of antennas that receive the radio waves reflected from the moving target, and a plurality of transmitters and receivers that frequency-convert and amplify the transmission and reception signals, A plurality of coherent integration processors for generating an FFT filter bank from the video signal received by the transmitter / receiver, and a plurality of clutters rejected by the coherent integration processor among the clutter discriminated by the coherent integration processor and the target Doppler frequency A target detector and a plurality of tracking calculation devices that generate tracking target specifications by performing prediction and speed detection of the target future position from the position information of the target output by the target detector, and managing this for each target, A beam control device is provided, in which any one of the systems of each antenna selects a PRF that can avoid a blind velocity, and sequentially changes the selected PRF for each CPI. Because, without depending on the moving speed of the target systems for each antenna, an effect that it is possible to avoid a blind speed.

A radar device according to claim 5 of the present invention is
As described above, the radar apparatus according to claim 4 calculates the number of integrations of the coherent integration processor from the target Doppler frequency input from the tracking calculation apparatus, and provides it to the coherent integration processor. Since the coherent integration number calculation device is further provided, it is possible to avoid the blind speed without depending on the target moving speed of the system of each antenna.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a radar device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing characteristics of MTI processing for a plurality of transmission frequencies of the radar device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a radar device according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a radar device according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a radar device according to Embodiment 4 of the present invention.

FIG. 6 is a diagram showing a coherent integral response of the radar device according to the fourth embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a radar device according to Embodiment 5 of the present invention.

FIG. 8 is a block diagram showing a configuration of a conventional radar device.

FIG. 9 is a diagram showing a configuration of MTI processing in a conventional radar device.

FIG. 10 is a diagram showing characteristics of MTI processing in a conventional radar device.

FIG. 11: Usable division P in a conventional radar device
It is a figure which shows an RF range image.

FIG. 12: Stagger reference PR in a conventional radar device
It is a figure which shows the example of F selection.

[Explanation of symbols]

1 Antenna 2 Transmitter / Receiver 3, 3A, 3B, 3C
Signal processing device, 4 tracking calculation device, 5A, 5B, 5C,
5D beam control device, 6 beam specification calculation device, 7
Transmission frequency calculation device, 17 A / D converter, 18 First hit phase difference corrector, 19 MTI processor, 20
Second hit-to-hit phase difference corrector, 21 Hit-to-hit phase difference correction amount calculation device, 22 CPI inter-combiner, 23 Coherent integration processor, 24 Target detector, 25 Coherent integration number calculation device.

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-9-304521 (JP, A) JP-A-4-265883 (JP, A) JP-A-4-32790 (JP, A) JP-A-9- 257910 (JP, A) JP, 10-186026 (JP, A) Supervised by Takashi Yoshida, Revised radar technology, Japan, The Institute of Electronics, Information and Communication Engineers, October 1, 1996, 72-74 (58) Fields investigated (Int .Cl. ⁷ , DB name) G01S ^7/ 00-7/42 G01S 13/00-13/95

Claims (5)

(57) [Claims] 1. Emitting a transmission pulse toward a moving target,
A plurality of antennas for receiving the radio waves reflected from the moving target, a plurality of transmitters / receivers for frequency-converting and amplifying the transmitting and receiving signals, and the moving target from the received video signal output from the transmitter / receiver. Position information, a plurality of signal processing device for eliminating the clutter component, a plurality of tracking calculation device for predicting the future position of the moving target and speed detection from the position information to generate tracking target specifications, and A plurality of beam parameter calculation devices for calculating beam parameters for beam irradiation from the tracking target parameters, and a transmission frequency so that the Doppler frequency of the moving target becomes a predetermined ratio of PRF based on the beam parameters. A plurality of transmission frequency calculation devices for calculating, the plurality of transmitters / receivers simultaneously transmit at each transmission frequency obtained by each transmission frequency calculation device, and from the moving target. Radar apparatus characterized by receiving a reflected wave. 2. Emitting a transmission pulse toward a moving target,
A plurality of antennas for receiving the radio waves reflected from the moving target, a plurality of transmitters / receivers for frequency-converting and amplifying the transmitted and received signals, and hit intervals of the received video signals output from the transmitters / receivers. A plurality of first hit-to-hit phase difference correctors for correcting the phase difference; a plurality of MTI processors for detecting only a moving target from the received video signal corrected by the first hit-to-hit phase difference corrector; A plurality of second inter-hit phase difference correctors for correcting the video signal detected by the processor by the first inter-hit phase difference corrector to cancel out the inter-hit phase difference; A plurality of tracking calculation devices that generate tracking target specifications by predicting the future position of the target and speed detection from the target position information output by the phase difference corrector, and manage this for each target, and the tracking target specifications Beam irradiation from A plurality of beam specifications calculation device for calculating a fit of beam specifications, based on the beam specifications, calculating the hit phase difference of the video signal which is a predetermined percentage of the Doppler frequency of the PRF,
A plurality of hit-to-hit phase difference corrections for calculating hit-to-hit phase difference correction amounts used in the first and second hit-to-hit phase difference correctors for shifting and canceling the current target Doppler frequency to a predetermined ratio of PRF A radar device comprising a quantity calculation device. 3. Emitting a transmission pulse toward a moving target,
A plurality of antennas that receive the radio waves reflected from the moving target, a plurality of transmitters and receivers that frequency-convert and amplify the transmission and reception signals, and only the moving target from the video signals received by the transmitters and receivers. A plurality of MTI processors for detecting, a plurality of inter-CPI synthesizers for synthesizing the video signals detected by the MTI processor with the same target, and a future position of the target based on target position information output by the inter-CPI synthesizer. , A tracking target specification is generated by performing prediction and velocity detection, and a plurality of tracking calculation devices that manage this for each target, and a PRF that allows one of the systems of each antenna to avoid the blind velocity, A radar device, comprising: a beam control device that sequentially changes a PRF selected for each CPI. 4. Emitting a transmission pulse toward a moving target,
A plurality of antennas for receiving radio waves reflected from the moving target, a plurality of transmitters / receivers for frequency-converting and amplifying transmission and reception signals, and an FFT filter bank from the video signals received by the transmitters / receivers. A plurality of coherent integration processors to generate, among the clutter discriminated by the coherent integration processor and the target Doppler frequency, a plurality of target detectors that reject clutter, and target position information output by the target detector Predict the future position of the target and detect the speed to generate tracking target specifications,
A plurality of tracking calculation devices that manage this for each target and a beam control device that selects a PRF that allows one of the systems of each antenna to avoid the blind speed and sequentially changes the selected PRF for each CPI. A radar device characterized by being provided. 5. A plurality of coherent integration number calculation devices for calculating an integration number of the coherent integration processor from a target Doppler frequency input from the tracking calculation device and providing the calculated integration number to the coherent integration processor. The radar device according to claim 4, characterized in that: