JPH03131785A - Method and device for radar tracking - Google Patents

Abstract

PURPOSE:To stabilize the tracking state and to expand effective area by adding detection signal processing pertaining to target search beam scanning, a signal processing indicating circuit for switching them, and a target position analyzer. CONSTITUTION:A data processor 13 calculates the distance, speed, angle, and tracking position of a target by a target tracking filter 14 and the target position analyzer 15 according to a target signal detection position obtained as a result of the search signal processing for obtaining a target image and sends out the detection data and target image to a display device 16. The display device 16 displays the position and size (detection range and shape) of the target as a symbol and an image. Further, the data processor 13 sends angle data of the target data to an antenna 2 and speed data is used to find a pulse repetitive frequency.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention uses a pulse Doppler method and a mono-pulse tracking method to determine the shape of a target with a large effective area or a target at a short distance. -Relates to a tracking radar method and device for indicating the size and target tracking position.

[Conventional technology]

Figure 7 is a configuration diagram of a conventional tracking radar device. In the figure, (1) is a transmitter, (2) is a transmitter that radiates the transmitted signal from the transmitter (1) into space, and receives a reflected signal from the target. The receiving antenna (3) receives the reflected signal received by the above antenna (2), and performs amplification, frequency conversion, phase detection, analog/
Receiver for digital conversion, (4) is the above receiver (3)
(6) is a signal processor that performs various signal processing on the received signal digitized by the receiver (3); (7) is a buffer memory that holds the received signal digitized by the receiver (3);
is a frequency analysis circuit that analyzes the frequency of the digital received signal held in the buffer memory (6), and (8) detects the maximum distance gate and detects the distance discriminator based on the frequency analysis result of the frequency analysis circuit (7). (9) is a target frequency detection circuit that performs maximum amplitude frequency bin detection/frequency discriminator formation and frequency error detection. (10) is an angular error that detects monopulse angle error. Detection circuit (13) is the target distance detection circuit (8) and target frequency detection circuit (9)
, a data processor that performs tracking processing and radar operation control using distance information, frequency information, and angle information output from the angle error detection circuit (10); (14) is located in the data processor; A tracking filter that estimates or predicts the position, speed, etc. of the target and outputs target data. (16) is a display that displays the target data.

Next, the operation will be explained. The transmission signal generated by the transmitter (1) is sent to the antenna (2).
is emitted from the target towards the target. This transmitted signal is reflected by the target, received by the antenna (2) again, and then received by the receiver (3).
), and after being subjected to amplification, phase detection, and analog/digital conversion, it is sent to a signal processor (4). In the signal processor (4), the digital received signal sampled according to the pulse repetition frequency is input to the buffer memory (6).

After fast Fourier transform and amplitude detection are performed in the frequency analysis circuit (7), the target distance detection circuit (8) uses the output to perform maximum amplitude distance gate detection, distance discriminator formation, and distance error detection. Target frequency detection circuit (9
) performs signal processing such as maximum amplitude frequency bin/frequency discriminator formation and frequency error detection, and the angle error detection circuit performs signal processing such as monopulse angle error detection, and calculates the distance gate number and distance error 8 frequency bin number regarding the target for each pulse repetition frequency. 1 frequency error and angle error are calculated and sent to the data processor (13) as target data every signal processing period. The target data from the signal processor (4) is input to the tracking filter (14) to be estimated or predicted, and the distance, speed, and angle of the target are determined. Of these data, the angle data is used as antenna directional angle data. sent to antenna (2). The speed data is also used to determine the pulse repetition frequency. Further, the distance and angle data are sent to a display (16) to be displayed as a target tracking position or an antenna beam pointing position.

[Problem to be solved by the invention]

Conventional tracking radar methods and devices use two or more methods, so the tracking distance, angle, and speed of the target are determined by the maximum amplitude value detected based on the strength of the signal received from the target. Furthermore, since the tracking position is determined from the reflected signal from the target, if the tracking state is reached when a target with a large effective area or a target at a very close range is constantly maneuvering, It is difficult to determine which part of the target the beam is directed at.
, when instructing a fire control device about the aiming position, a phenomenon may occur in which the indicated position is not fixed and constantly fluctuates.

This invention was made to solve these problems, and it maintains a stable tracking state, as well as the tracking position for a target with a large effective area or a target at a very close distance, as well as the shape and size of the target. The purpose of this is to provide instructions to the fire control system by using information about the situation.

[Means to solve the problem]

In order to achieve the above object, the tracking radar method and device according to the present invention utilize the tracking radar method and device based on the conventional mono-pulse method and tracking filter, and detect the target which is the output of the tracking filter. A function that directs a single pointed beam to the estimated or predicted position of the target and processes the signal. Target search beam scanning and target detection using the narrow beam width over the canyon coverage area centered on the target's estimated or predicted position. Target tracking position (distance, angle), speed, target signal reflection range (target size 9) obtained by signal processing or target search beam scanning and target image detection processing using a wide beam width A function is added to display the information (shape) on the display by symbol display or image display, and to instruct the firearm device with the above information.

[Effect]

With this invention, it is possible to realize a more stable tracking state during tracking, and at the same time, information indicating the size and shape of the target is displayed as a symbol or an image, at the same time as a symbol indicating the tracking position, thereby increasing the effective area. This makes it possible to provide information on the tracking state of a large target or when the target is at a very close range.

Furthermore, when performing fire control control based on this information, it becomes an effective means for determining the aim position of the target.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings. FIG. 1 shows the configuration of a radar device according to the present invention. In the figure (1) to (4), (6) to (10), (13
).

(14) and (16) are the same devices or parts as the conventional radar device described above. In this invention, (5) is a signal processing instruction circuit, (11) is an amplitude detection circuit, (12)
is a target detection circuit, and (15) is a target position analyzer.

FIG. 2(a) is a conceptual diagram of a scanning pattern in target search beam scanning centered on the tracked target estimation or predicted position according to the present invention. In the figure, (17) represents the antenna beam, and (1g) represents the target. Figure 2(b) shows the second
FIG. 3 is a conceptual diagram of a target detection circuit obtained as a result of processing using the scanning pattern shown in FIG. In the figure, (27) represents the target detection state, and (2g) represents the target non-detection state. FIG. 3 is a conceptual diagram of a display in a state where a target is being tracked according to the present invention. In the figure, (19) is a symbol that indicates the target tracking position, that is, the single peak beam pointing position determined based on the tracking filter output, in terms of azimuth angle and elevation angle, (2G) lt[l[symbol that indicates distance, (
21) is a symbol indicating the position (range) where a target is detected as a result of the target search beam scanning process in terms of azimuth angle and elevation angle.

Next, y of the radar device according to the present invention will be explained. The transmission signal generated by the transmitter 0) is sent to the antenna (2). At the antenna (2), the data processor (13)
A single peaked beam is directed toward the estimated or predicted location of the target, and a transmitted signal is emitted toward the target. This transmitted signal is reflected by the target, received by the antenna (2) again, inputted to the receiver (3), and after amplification, phase detection, and analog/digital conversion are performed, it is sent to the signal processor (4). It will be done. In the signal processor (4), first, the signal processing indicator (
5) directs a conventional tracking operation with a single pointed beam;
The digital reception signal sampled according to the pulse repetition frequency from the receiver (3) is input to the buffer memory (6). After fast Fourier transform and amplitude detection are performed in the frequency analysis circuit (7), the target distance detection circuit (8) uses the output to perform maximum amplitude distance gate detection, distance discriminator formation, and distance error detection. The target frequency detection circuit (9) performs signal processing such as maximum amplitude frequency bin/frequency discriminator formation and frequency error detection, and the angular error detection circuit performs signal processing such as monopulse angle error detection, and calculates the distance gate number regarding the target for each pulse repetition frequency.

Distance error 1 frequency bin number 1 frequency error and angle error are calculated and sent to the data processor (13) as target data for each signal processing cycle. The data processor (13) converts the target data from the signal processor (4) into a tracking filter (
I4) and estimates or predicts the target distance.
Find velocity and angle. Next, the data processor (13) instructs the antenna (2) to perform target search beam scanning as shown in FIG. For 5),
Instruct target search signal processing. This allows the antenna (2
) performs target beam scanning around the predicted position, and a transmission signal is emitted toward the target. This transmitted signal is reflected by the target and received by the antenna (2) again, inputted to the receiver (3), where it is amplified, phase detected, and analog/digital converted, and then sent to the signal processor (4). Sent. The signal processor (4) stores the digital reception signal sampled according to the pulse repetition frequency from the receiver (3) in a buffer memory in accordance with the target search signal processing instruction of the data processor (13). (6) Manpower. After fast Fourier transform and amplitude detection are performed in the frequency analysis circuit (7), the amplitude detection circuit (11) detects the target amplitude for each pulse repetition frequency and sends it to the target detector (12). The target detector (12) holds the target detection results until the end of one scan in the azimuth direction and one scan in the elevation direction, and sends the target detection results for each scan of the target search beam to the data processor (13). Data processor (1
3) is obtained as a result of the above conventional tracking signal processing. Target data such as distance gate number, distance error 9 frequency bin number 2 frequency error and angle error regarding the target for each pulse repetition frequency, and target signal detection obtained as a result of search signal processing performed around the target estimation or predicted position. Target tracking filter (14) based on the position (range)
Then, the target position analyzer (15) calculates the distance, speed, angle, and tracking position of the target and sends them to the display (I6). On the display (16), as illustrated in FIG.
Displays the target position and size (detection range) using symbols. Further, among the target data calculated by the data processor (13), the angle data is sent to the antenna (2) as the directivity angle data of the antenna, and the velocity data is used to determine the pulse repetition frequency.

In the process of determining the target signal detection position described above, the resolution in the elevation direction and azimuth direction is determined by the antenna beam width and scan width in each direction.

In order to keep these resolutions constant, a data processor (15) performs control to keep the scan rate constant in each direction and beam stabilization control in response to the movement of the aircraft.
In FIG. 2(b), the target detection state (27
) and the range representing the target undetected state (28) will be determined by the above resolution.

FIG. 4 shows the configuration of a radar device showing another embodiment of the present invention. In the figure (1) to (4), (6) to
(10), (13), (14), and (16) are the same devices or parts as the conventional radar device described above. In this invention, (5) is a signal processing instruction circuit; (22)
is an amplitude detection circuit (24) is an image conversion processing circuit, (15
) is the target position analyzer. FIG. 5(a) is a conceptual diagram of a scanning pattern in target search beam scanning centered on the estimated or predicted position of the tracked target according to the present invention. In the figure, (25) represents the antenna beam, and (1g) represents the target. FIG. 5(b) is a conceptual diagram of the target detection result obtained as a result of processing using the scanning pattern of FIG. 5(a). In the figure, (27) represents the target detection state, and (28) represents the target non-detection state. FIG. 6 is a conceptual diagram of a display in a state where a target is being tracked according to the present invention. In the figure (
19) is a symbol that indicates the target tracking position determined based on the tracking filter output, that is, the single peak beam pointing position in terms of azimuth angle and elevation angle, (20) is a symbol that indicates the target distance, and (26) is the target This is an image showing the position (range) and shape of the target where the target was detected as a result of the search beam scanning process.

Next, the operation of the radar device according to the present invention will be explained. The transmission signal generated by the transmitter (1) is sent to the antenna (2).
) will be sent to. At the antenna (2), the data processor (1
3) directs a single peaked beam toward the estimated or predicted position of the target, and a transmitted signal is emitted toward the target; This transmitted signal is reflected by the target, received again by the antenna (2), and inputted to the receiving fi (3).
After amplification, phase detection, and analog/digital conversion, the signal is sent to a signal processor (4). In the signal processor (4), first, in accordance with the instruction from the data processor (13), the signal processing indicator (5) instructs a conventional tracking operation using a single peak beam, and the pulse from the receiver (3) is Buffers the digital received signal sampled according to the repetition frequency.

Input into memory (6). And frequency analysis circuit (7)
After performing fast Fourier transform and amplitude detection, the target distance detection circuit (8) uses the output to perform maximum amplitude distance gate detection, distance discriminator formation, distance error detection, and target frequency detection circuit (9). Then, the maximum amplitude frequency bin
The frequency discriminator formation, frequency error detection, and angle error detection circuit performs signal processing such as monopulse angle error detection, and calculates the distance gate number regarding the target for each pulse repetition frequency.

Distance error 9 Frequency bin number 2 Frequency error and angle error are calculated and sent to the data processor (13) as target data for each signal processing cycle. The data processor (13) converts the target data from the signal processor (4) into a tracking filter (
14) and performs estimation or prediction processing to determine the distance, speed, and angle of the target. Next, the data processor (13)
The beam shape controller (24) is instructed to switch from a single peaked beam to a single wide beam, and the antenna (2)
In contrast, the fifth tracking target estimation or the predicted position is
Instruct target search beam scanning using a wide antenna beam (25) in the azimuth direction as shown in Figure (a). Further, the signal processing instruction device (5) is instructed to perform target search signal processing to obtain an image showing the shape of the target from the target reflected wave. As a result, the antenna (2) performs target beam scanning around the predicted position, and the transmission signal is radiated toward the target. This transmitted signal is reflected by the target, received again by the antenna (2), inputted to the receiver (3), subjected to amplification, phase detection, and analog/digital conversion, and then sent to the signal processor (4). It will be done. Signal processor (4
) inputs the digital reception signal sampled according to the pulse repetition frequency from the receiver (3) to the buffer memory (6) in response to the instruction of the target search signal processing of the data processor (13). do. After the frequency analysis circuit (7) performs phase correction, Brissum filter processing, and fast Fourier transform, the amplitude detection circuit (22) detects the target amplitude for each pulse repetition frequency. ). Image conversion processing circuit (2
In 3), the target detection results up to the end of one scan in the elevation direction are held, converted to a brightness signal, that is, the brightness levels are assigned, and the target detection results for each scan are sent to the data processor (13). . The data processor (I3) is obtained as a result of the conventional tracking signal processing described above. Target data such as distance gate number, distance error 1 frequency bin number 1 frequency error and angle error regarding the target for each pulse repetition frequency, and search signal processing to obtain a target image centered on the target estimated or predicted position. Based on the target signal detection position (range) obtained as a result, the target tracking filter (14) and target position analyzer (15) calculate and display the target distance, speed, angle, and tracking position m (16) The above-mentioned detection data and target image are respectively sent to the target image. The display device (16) displays the position and size (detection range and shape) of the target using symbols and images, as illustrated in FIG. Among the target data calculated in the data processor (13), the angle data is the antenna (2) as the directivity angle data of the antenna.
) and the velocity data is used to determine the pulse repetition frequency.

In the process of obtaining the target image above, the resolution in the elevation direction is
It is determined by the beam width and scan width. In the azimuth direction, the Doppler frequency difference due to the speed difference of the target within the antenna beam width irradiating the target is separated by a narrow band filter to obtain 9 resolution. The relationship between Doppler frequency difference and azimuth angular resolution is shown below. Δf = fd, -rd, = -Δθ・sinθAz-c
osθEL (3) λ Δf: Doppler frequency difference 80: Angular resolution (angular difference between two points) θAz: Antenna pointing azimuth angle θEL: Antenna pointing azimuth angle V: Own aircraft speed λ: Transmission wavelength Obtained from equation (3) The resulting Doppler frequency difference is related to the bandwidth of the Doppler filter, and the relationship expressed by equation (4) holds true.

PRP: Pulse hill repetition frequency N = Number of sample points for fast Fourier transform To keep these resolutions constant, control to keep the scan rate in the elevation direction constant, and depending on the aircraft's speed and antenna directivity angle. The data processor (15) is caused to perform a process of changing the pulse repetition frequency. Fifth
In Figure (b), the range representing the target detection state (27) and the target non-detection state (28) is determined by the above-mentioned resolution.

〔Effect of the invention〕

As described above, the present invention adds detection signal processing associated with target search beam scanning, a signal processing instruction circuit and a target position analyzer to switch between them, and adds a tracking filter to the tracking signal processing of a conventional tracking radar device. The size of the target is determined from the target detection range and the target data calculated based on the estimated or predicted position from .

In addition, the present invention uses an antenna that can electrically change the beam shape for tracking signal processing of a tracking radar device to perform beam scanning with a wide beam width and target image detection processing, and a signal processing circuit and a target image detection process to switch between them. A position analyzer is added to determine the size and shape of the target from the target image and the target data calculated based on the estimated or predicted position from the tracking filter, thereby stabilizing the tracking state and detecting a large distance between the effective surfaces. Or detect the tracking position for a very close target.

In this way, by ensuring stable tracking conditions and accurate beam pointing position relative to the target, more accurate information is provided to the operator, and the accuracy of the target aiming position calculated by the fire control system is increased. It has the effect of being able to

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a radar device according to an embodiment of the present invention, FIG. 2(a) is a diagram showing an antenna scan pattern of the present invention, and FIG. 2(b) is a signal processing result. FIG. 3 is a conceptual diagram showing the display content which is the final output of this invention, FIG. 4 is a schematic configuration diagram showing a radar device according to another embodiment of this invention, and FIG. 5(a) is a diagram showing an antenna scan pattern according to another embodiment of the present invention, FIG. 5(b) is a conceptual diagram of the signal processing result, and FIG.
The figure is a conceptual diagram showing the display content which is the final output according to another embodiment of the present invention, and FIG. 7 is a schematic configuration diagram showing a conventional radar device. In the figure, (1) is a transmitter, (2
) is the antenna, (3) is the receiver, (4) is the signal processor,
(5) is a signal processing instruction circuit, (6) is a buffer memory,
(7) is a frequency analyzer, (8) is a target detection circuit, (9)
is a target frequency detection circuit, (10) is an angular error detection circuit, (11) is an amplitude detection circuit, (12) is a target detection circuit,
(13) is a data processor, (14) is a target tracking filter, (15) is a target position analyzer, (16) is a display device,
(17) is the antenna beam, (1g) is the target, (19
) is a symbol that indicates the target tracking position determined based on the tracking filter output, that is, the single peak beam pointing position in terms of azimuth angle and elevation angle, (20) is a symbol that indicates the target distance, and (21) is the symbol that indicates the target search. Symbol indicating the position (range) where the target is detected as a result of beam scanning processing using azimuth angle and elevation angle, (22) is amplitude detection circuit, (23) is image conversion processing circuit, (24) is beam shape controller (25) is the antenna beam, (2
6) is the target image, (27) is the target detection state,
(28) is a target undetected state. In addition, in FIG. 1, the same reference numerals indicate the same or corresponding parts.

Claims (4)

[Claims] (1) Generate a signal with a constant frequency, pulse modulate it with a predetermined pulse width and pulse repetition frequency, radiate the transmitted wave into the air, and use the received target reflected signal to perform frequency analysis, amplitude detection, maximum value detection, Performs signal processing such as discriminator formation and error detection to determine the target distance and speed, uses this target data as observed values to estimate or predict the target position using a tracking filter, and directs a single peaked beam. At the same time, it radiates into the air a transmission wave that is pulse-modulated at a constant frequency with a predetermined pulse width and pulse repetition frequency, and the beam is directed toward a canthus coverage area centered on the estimated target position or predicted position calculated by the tracking filter. Scanning is performed in the azimuth direction and in the elevation direction, amplitude detection is performed using the received target signal, and position information (distance and angle) determined by the maximum reflected signal from the target and total reflected signal from the target are used. A radar tracking method that uses the required position information to obtain information on which part of the beam is directed toward a target with a large effective area or a target at a short distance. (2) a transmitter that generates a signal of a constant frequency and pulse-modulates it with a predetermined pulse width and pulse repetition frequency; an antenna that radiates the transmitted wave from the transmission into space and receives a reflected signal from the target; a receiver that amplifies, frequency converts, phase detects, and analog/digital converts the received signal;
A series of tracking signal processing such as frequency analysis, amplitude detection maximum value detection, discriminator formation and error detection is performed on the above digital signal, and search signal processing such as amplitude detection and signal detection is performed on the above digital signal in a temporal manner. a signal processor that calculates data regarding the distance and speed of the target, and a tracking filter that estimates or predicts the target position using the target data obtained by a series of tracking signal processing of the signal processor; In addition to determining the distance, angle, and speed of the target, the position and size of the target in space are determined using the target data determined by a series of search signal processing by the signal processor, and the angle information is also determined. and a data processor for instructing the single peak beam pointing angle of the antenna and the target search beam scanning position in the canyon area, and a data processor for instructing the single peak beam pointing angle of the antenna and the scanning position of the target search beam in the canyon area, and a data processor for instructing the position and position of the target within the space determined by the data processor.
A tracking radar device characterized by comprising a display device that displays the size and the beam direction position of the antenna. (3) In radar equipment that uses an antenna system that can electronically change the beam shape, a signal of a constant frequency is generated, pulse-modulated with a predetermined pulse width and pulse repetition frequency, and the transmitted wave is radiated into the air and received. The target reflected signal is used to perform signal processing such as frequency analysis, amplitude detection, maximum value detection, discriminatory format, and error detection to determine the distance and speed of the target, and the tracking filter uses this target data as the observed value. The target position is estimated or predicted, and a single peaked beam is directed. At the same time, a transmission wave pulse-modulated at a constant frequency with a predetermined pulse width and pulse repetition frequency is emitted into the air, and the target position calculated by a tracking filter is emitted. The area covered by the estimated or predicted position is scanned in the azimuth direction and the elevation direction with a wide beam width, and the received target signal is used to perform frequency analysis and analysis.
Amplitude detection and signal brightness conversion are performed, and position information (distance and angle) obtained from the maximum reflected signal from the target and target image information obtained from the total reflected signal from the target are used to detect targets with large effective areas and at short distances. A radar tracking method that allows you to obtain information about where the beam is directed to the target, as well as the shape and size of the target. (4) A transmitter that generates a signal of a constant frequency and pulse-modulates it with a predetermined pulse width and pulse repetition frequency, and a transmitter that emits the transmitted wave from the above transmission into space and receives the reflected signal from the target, and an electronic an antenna with a beam controller that can arbitrarily change the beam shape; a receiver that amplifies, frequency converts, phase detects, and analog/digitally converts the received signal; and a receiver that performs frequency analysis and amplitude detection on the digital signal.・Performs a series of tracking signal processing such as maximum value detection discriminator formation and error detection, and search signal processing such as frequency analysis, amplitude detection, signal detection, and signal brightness conversion for the digital signal by temporal switching. The target position is estimated or predicted by a tracking filter using target data obtained by a signal processor that detects data regarding the distance and speed of the target and spatial target image information, and a series of tracking signal processing by the signal processor. In addition to determining the distance, angle, and velocity of the target, the position, shape, and size of the target in space are determined using the target image information determined by a series of search signal processing by the signal processor; A data processor that instructs the antenna's single peak beam pointing angle and canthus coverage target search beam scanning position based on the information, and the position, shape, and size of the target that can be placed in the space determined by the data processor. A tracking radar device characterized by being equipped with an indicator that displays the beam orientation position of the beam and the antenna.