JP2022018769A - Radar device - Google Patents

Abstract

To provide a radar device that can detect a target position and confirm a surrounding situation, without transmission by its own device, by using a transmission signal transmitted by a target and a transmission signal transmitted by another radar device.SOLUTION: A radar device of an embodiment includes: an antenna unit that includes a plurality of antenna elements and receives reception signals; an extraction unit that extracts one of the plurality of reception signals as a reference function; a first detection unit that performs a pulse compression process on the received signals using the reference function and detects a first target; an angle measuring unit that generates a sum signal and a difference signal using the reception signals received from the first target and uses the sum signal and the difference signal to calculate an azimuth angle of the first target; and a first calculation unit that uses the azimuth angle to calculate distance to the first target.SELECTED DRAWING: Figure 2

Description

Embodiments of the present invention relate to radar devices, especially passive radar.

The reverse probe device is a device that receives a transmission signal from a radar device mounted on a ship and analyzes the direction of the transmission source and the type of the radar device. The reverse probe cannot determine the distance to the source, and thus cannot determine the location of the source.

The passive radar can measure the distance to the target by using the time difference between the indirect wave reflected by the transmission signal (direct wave) transmitted by the other radar device and the direct wave of the other radar device. However, it is premised that the positions of other radar devices are known, and this cannot be measured.

Japanese Unexamined Patent Publication No. 2016-166825

The problem to be solved by the present invention is to provide a radar device capable of detecting a target position and confirming an ambient situation by using a transmission signal transmitted by a target and a transmission signal transmitted by another radar device without transmitting by itself. It is to be.

The radar device according to the embodiment includes an antenna unit that includes a plurality of antenna elements and receives a received signal, an extraction unit that extracts one of the plurality of received signals as a reference function, and a reception signal using the reference function. A sum signal and a difference signal are generated using the first detection unit that performs pulse compression processing and detects the first target and the received signal received from the first target, and the sum signal and the difference signal are used to generate the sum signal and the difference signal. It includes an angle measuring unit that calculates the azimuth angle of the first target, and a first calculation unit that calculates the distance to the first target using the azimuth angle.

FIG. 1 is a schematic diagram illustrating a schematic configuration of a radar device 10 according to a first embodiment. FIG. 2 is a block diagram of the radar device 10 shown in FIG. FIG. 3 is a block diagram showing an example of the hardware configuration of the signal processing device 17 shown in FIG. FIG. 4 is a flowchart illustrating the direct wave processing operation of the radar device 10. FIG. 5 is a schematic diagram illustrating a target angle measurement process. FIG. 6 is a flowchart illustrating the passive radar processing operation of the radar device 10. FIG. 7 is a schematic diagram illustrating an operation of calculating the distance to the target by passive radar processing. FIG. 8 is a flowchart illustrating the display data generation operation of the radar device 10. FIG. 9 is a schematic diagram illustrating a plurality of detection positions and a plurality of video signal flows. FIG. 10 is a diagram illustrating an example of display data. FIG. 11 is a block diagram of the radar device 10 according to the second embodiment. FIG. 12 is a flowchart illustrating a direct wave processing operation of the radar device 10 according to the second embodiment. FIG. 13 is a block diagram of the radar device 10 according to the third embodiment. FIG. 14 is a flowchart illustrating an operation of calculating a moving direction of a target in the radar device 10 according to the third embodiment.

Hereinafter, embodiments will be described with reference to the drawings. Some embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is specified by the shape, structure, arrangement, etc. of the components. It is not something that will be done. Each functional block can be realized as a combination of hardware and software, or both. It is not essential that each functional block be distinguished as in the example below. For example, some functions may be executed by a functional block different from the exemplary functional block. Further, the exemplary functional block may be subdivided into finer functional subblocks. In the following description, elements having the same function and configuration are designated by the same reference numerals, and duplicate description will be omitted.

[1] First Embodiment [1-1] Configuration of Radar Device 10 FIG. 1 is a schematic diagram illustrating a schematic configuration of a radar device 10 according to the first embodiment. The radar device 10 is mounted on the moving body 1. The mobile body 1 is composed of an aircraft, a ship, or the like.

The radar device 10 uses an antenna to form a multi-receive beam. The radar device 10 receives the transmission signal transmitted from the target 2, and performs arithmetic processing on the received reception signal. Goal 2 includes moving objects (including aircraft and ships) or fixed objects. Fixed object means an object fixed to the ground. Fixed objects also include artificially created objects, as well as terrain such as islands and mountains.

FIG. 2 is a block diagram of the radar device 10 shown in FIG. The radar device 10 includes an antenna unit 11, a receiving unit 13, an A / D conversion unit 15, a signal processing device 17, and a display unit 23.

The antenna portion 11 is attached to the exterior of the moving body 1. The antenna unit 11 is composed of, for example, a phased array antenna. The antenna unit 11 includes a plurality of antenna elements 12-1 to 12-m. m is an integer of 2 or more. In the present specification, the description of the reference code without the branch number is common to the description of the reference code with the branch number.

The receiving unit 13 amplifies the reception level of the received signal received by the antenna unit 11 and determines the received signal. The receiving unit 13 includes a plurality of receiving circuits (Rx) 14-1 to 14-m. The receiving circuit 14 is provided for each antenna element 12.

The receiving circuit 14 performs analog signal processing on the received signal received by the corresponding antenna element 12. Specifically, the receiving circuit 14 amplifies the received signal with low noise and controls the phase of the received signal. Then, the receiving unit 13 forms a receiving beam in an arbitrary direction by performing phase control and synthesizing a plurality of received signals received by the plurality of antenna elements 12.

The A / D conversion unit 15 includes a plurality of A / D conversion circuits 16-1 to 16-m. The A / D conversion circuit 16 is provided for each antenna element 12. The A / D conversion circuit 16 converts the received signal input from the corresponding receiving circuit 14 from an analog signal to a digital signal. Specifically, the A / D conversion circuit 16 converts an analog signal into an orthogonal digital signal having an I component (In-Phase signal component) and a Q component (Quadrature signal component). Orthogonal digital signals (also referred to as IQ data) include amplitude and phase information of the received signal.

The display unit 23 displays the display data sent from the signal processing device 17 on its own screen. The display unit 23 is composed of, for example, a liquid crystal display device.

The signal processing device 17 processes a plurality of digital signals corresponding to the plurality of received signals received by the antenna elements 12-1 to 12-m. The signal processing device 17 includes a data transfer unit 18, a direct wave processing unit 19, a passive radar processing unit 20, a display data generation unit 21, and a storage unit 22.

The data transfer unit 18 transfers a plurality of received signals output from the A / D conversion unit 15 to the storage unit 22. The storage unit 22 stores a plurality of received signals transferred from the data transfer unit 18. Further, the data transfer unit 18 transfers a plurality of received signals stored in the storage unit 22 to the direct wave processing unit 19 and the passive radar processing unit 20. With such a configuration of the data transfer unit 18, the signal processing device 17 can arbitrarily process a plurality of received signals received in the past in addition to the plurality of received signals currently received.

The direct wave processing unit 19 includes a reference function extraction unit 19A, a target detection unit 19B, an angle measurement unit 19C, and a distance calculation unit 19D.

The reference function extraction unit 19A extracts a received signal presumed to be a direct wave from a plurality of received signals.

The target detection unit 19B uses the received signal extracted by the reference function extraction unit 19A as a reference function to perform pulse compression processing on the received signal to detect the target.

The angle measuring unit 19C calculates the azimuth angle of the target using the received signal received from the target.

The distance calculation unit 19D calculates the distance to the target using the azimuth angle calculated by the angle measurement unit 19C.

The passive radar processing unit 20 includes an indirect wave detection unit 20A, a position calculation unit 20B, and a video signal generation unit 20C.

The indirect wave detection unit 20A performs correlation processing between the direct wave detected by the direct wave processing unit 19 and the received signal, and detects the indirect wave having a correlation with the direct wave.

The position calculation unit 20B calculates the target position using the direct wave detected by the direct wave processing unit 19 and the indirect wave detected by the indirect wave detection unit 20A.

The video signal generation unit 20C generates a target video signal by using a plurality of indirect waves.

The display data generation unit 21 acquires a plurality of detection positions related to the plurality of direct waves from the direct wave processing unit 19. Further, the display data generation unit 21 acquires a plurality of video signals from the passive radar processing unit 20. Then, the display data generation unit 21 superimposes a plurality of detection positions and a plurality of video signals to generate display data.

FIG. 3 is a block diagram showing an example of the hardware configuration of the signal processing device 17 shown in FIG. The signal processing device 17 includes a processor 30, a memory 31, an input interface unit (input I / F) 32, an output interface unit (output I / F) 33, and a bus 34. The processor 30, the memory 31, the input interface unit 32, and the output interface unit 33 transmit and receive data to and from each other via the bus 34.

The input interface unit 32 is connected to an external circuit and performs data input processing with the external circuit. In the present embodiment, the input interface unit 32 receives the data input from the A / D conversion unit 15.

The processor 30 is a CPU (Central Processing Unit) that collectively controls the operation of the signal processing device 17. The processor 30 executes various programs stored in the memory 31.

The memory 31 is a non-volatile memory that non-volatilely stores various programs for realizing the signal processing of the present embodiment and various data necessary for executing the signal processing, and is generated when the signal processing is executed. Includes volatile memory for temporarily storing various data and tables. The memory 31 includes a ROM (Read Only Memory), an SDRAM (Synchronous Dynamic Random Access Memory), and the like.

The output interface unit 33 is connected to an external circuit and performs data output processing with the external circuit. In the present embodiment, the output interface unit 33 outputs data to the display unit 23.

[1-2] Operation The operation of the radar device 10 configured as described above will be described.

[1-2-1] Direct wave processing operation First, the direct wave processing operation will be described. FIG. 4 is a flowchart illustrating the direct wave processing operation of the radar device 10. The direct wave is a transmission signal directly transmitted by the target.

The receiving unit 13 forms a reception multi-beam by DBF (Digital Beam Forming) over the entire circumference of the moving body 1 and receives radio waves all around the moving body 1 (step S100). The entire circumference of the moving body 1 means a three-dimensional direction including an azimuth direction and an altitude direction.

Subsequently, the A / D conversion circuit 16 converts the received signal from the analog signal to the digital signal for each antenna element 12 (step S101). This digital signal is an orthogonal digital signal including an I component and a Q component.

Subsequently, the data transfer unit 18 stores the digital signal transmitted from the A / D conversion unit 15 in the storage unit 22 for each antenna element 12 (step S102). Further, the data transfer unit 18 stores the digital signal in the storage unit 22 each time the reception unit 13 receives the reception signal. The data transfer unit 18 transfers the digital signal stored in the storage unit 22 to the direct wave processing unit 19 and the passive radar processing unit 20.

Subsequently, the reference function extraction unit 19A extracts a received signal presumed to be a direct wave from the plurality of received signals (step S103). The transmitted signal (direct wave) directly transmitted by the target has a large amplitude. When the amplitude (reception level) of the received signal is equal to or greater than the threshold value, the reference function extraction unit 19A determines that the received signal is a direct wave. Further, when the pulse of the received signal is repeated in a predetermined cycle, the received signal may be determined to be a direct wave.

Subsequently, the target detection unit 19B uses the received signal extracted in step S103 as a reference function to perform pulse compression processing on the received signal to detect the target (step S104). In the pulse compression process, the target detection unit 19B determines the correlation between the reference function for pulse compression and an arbitrary received signal. When there is a correlation between the reference function and the received signal, the amplitude of the received signal is increased and detected. Then, it is determined that the received signal that correlates with the reference function is a direct wave transmitted from the target.

Further, when the transmission signal characteristics (including frequency, pulse width, and pulse interval) are different, the target detection unit 19B detects a plurality of transmission signals having different characteristics as different targets. Then, the target detection unit 19B executes the detection process for each target.

Subsequently, the direct wave processing unit 19 calculates the position of the target detected in step S104. Specifically, the angle measuring unit 19C calculates the azimuth angle of the target using the received signal received from the target (step S105).

FIG. 5 is a schematic diagram illustrating a target angle measurement process. The angle measuring unit 19C calculates a sum signal (Σ signal) and a difference signal (Δ signal) in the directional direction using a plurality of received signals received by the plurality of antenna elements 12. The sum signal is calculated by summing the signals received by all the antenna elements 12. The difference signal is calculated by the difference between the sum of the signals in the right half region and the sum of the signals in the left half region of the array consisting of all the antenna elements 12. The angular error voltage ε is a numerical value obtained by normalizing the difference signal with a sum signal, that is, calculated by ε = Δ / Σ. FIG. 5A is a diagram showing the relationship between the azimuth angle and the amplitude (reception level) in the sum signal and the difference signal, and FIG. 5B is a diagram showing the relationship between the azimuth angle and the angle error voltage. be.

The angle measuring unit 19C calculates the angle error voltage ε using an angle measuring table or the like within the range where the angle error voltage ε is ± 1, and calculates the target azimuth angle. That is, the angle measuring unit 19C calculates the azimuth angle corresponding to ε = 0.

Subsequently, the distance calculation unit 19D calculates the distance to the target using the azimuth angle calculated in step S105 (step S106). For example, since the radar of a ship is received at a fixed cycle, the distance is calculated by the following equation (1) from the elapsed time and the angle changed during the elapsed time.

R = VT / Δθ ・ ・ ・ (1)
R: Distance to the target (m)
V: Own speed component (m / s) orthogonal to the target direction
T: Elapsed time (s)
Δθ: Azimuth change amount (rad)
The elapsed time T is the time from the reception of the first received signal to the next reception of the second received signal from the target. The own speed component V is the speed in the direction orthogonal to the target direction in the moving body 1 equipped with the radar device 10. The amount of change in azimuth Δθ is the azimuth angle changed during the elapsed time T.

Based on the target direction and distance calculated in the above process, each target is tracked.

[1-2-2] Passive radar processing operation Next, the passive radar processing operation will be described. FIG. 6 is a flowchart illustrating the passive radar processing operation of the radar device 10. Passive radar is a method in which the direct wave transmitted from the transmitter receives the indirect wave reflected by the target, and the target position is calculated from the delay time between the direct wave and the indirect wave and the arrival direction of the indirect wave. ..

The passive radar processing is performed after the processing for detecting the direct wave by the direct wave processing unit 19. That is, the direct wave processing unit 19 calculates the position information of the target transmitting the transmission signal as a direct wave. The passive radar processing unit 20 acquires direct wave information from the direct wave processing unit 19 (step S200).

Subsequently, the indirect wave detection unit 20A performs correlation processing between the direct wave acquired in step S200 and the received signal, and detects the indirect wave correlated with the direct wave (step S201).

Subsequently, the position calculation unit 20B calculates the target position using the direct wave acquired in step S200 and the indirect wave detected in step S201 (step S202).

FIG. 7 is a schematic diagram illustrating an operation of calculating the distance to the target by passive radar processing. In FIG. 7, the transmitter 3 and the target 4 that directly transmit waves. The distance R1 between the transmitter 3 and the moving body 1, the distance R2 between the transmitter 3 and the target 4, the distance R3 between the moving body 1 and the target 4, the delay time τ between the direct wave and the indirect wave, and the speed of light c. be. The distances R1 to R3 have the relationship of the following equation (2).

R2 + R3 = c ・ τ + R1 ・ ・ ・ (2)
The position calculation unit 20B calculates the azimuth angle θ between the arrival direction of the direct wave and the arrival direction of the indirect wave. Then, the position calculation unit 20B calculates the distance to the target 4 by using the equation (2) and the azimuth angle θ.

Subsequently, the video signal generation unit 20C generates a target video signal using a plurality of indirect waves (step S203). Multiple indirect waves include clutter. A clutter is an indirect wave reflected by a fixed object (such as terrain) around the target, and is a received echo with a low reception level. A video signal is a signal relating to an image. Images included in video signals include moving objects (including ships, etc.) and fixed objects (islands, waves, etc.). The video signal generation process is performed for each target detected by the direct wave processing unit 19.

[1-2-3] Display data generation operation Next, the display data generation operation will be described. FIG. 8 is a flowchart illustrating the display data generation operation of the radar device 10.

The display data generation unit 21 acquires a plurality of detection positions related to the plurality of direct waves from the direct wave processing unit 19 (step S300).

Subsequently, the display data generation unit 21 acquires a plurality of video signals from the passive radar processing unit 20 (step S301).

FIG. 9 is a schematic diagram illustrating a plurality of detection positions and a plurality of video signal flows. The direct wave processing unit 19 executes a plurality of direct wave detection processes # 1 to #N and generates a plurality of detection positions # 1 to #N. Further, the information related to the plurality of direct waves # 1 to #N is sent to the passive radar processing unit 20. The passive radar processing unit 20 executes a plurality of passive radar processes # 1 to #N and generates a plurality of video signals # 1 to #N. Each of the plurality of video signals # 1 to #N is generated by using the plurality of direct waves # 1 to # N. The display data generation unit 21 acquires a plurality of detection positions # 1 to #N and a plurality of video signals # 1 to #N.

Subsequently, the display data generation unit 21 superimposes a plurality of detection positions and a plurality of video signals to generate display data (step S302).

Subsequently, the display data generation unit 21 displays the display data generated in step S302 on the display unit 23 (step S303).

FIG. 10 is a diagram illustrating an example of display data. The direct wave processing unit 19 generates the detection positions # 1 and # 2, and the passive radar processing unit 20 generates the video signals # 1 and # 2. The detection positions # 1 and # 2 are represented by black dots. The video signals # 1 and # 2 are represented by, for example, a terrain having a region (for example, an island). In the video signals # 1 and # 2, a ship or the like that does not transmit the transmission signal may be represented by a black dot or the like. The video signals # 1 and # 2, respectively, are generated using the direct waves # 1 and # 2, respectively.

The display data generation unit 21 superimposes the detection positions # 1 and # 2 and the video signals # 1 and # 2 and displays them on the display unit 23.

[1-3] Effect of First Embodiment As described in detail above, in the first embodiment, the reference function extraction unit 19A extracts one of a plurality of received signals as a reference function. The target detection unit 19B performs pulse compression processing on the received signal using the reference function to detect the target. The angle measuring unit 19C generates a sum signal (Σ signal) and a difference signal (Δ signal) using the received signal received from the target, and calculates the azimuth angle of the target using the sum signal and the difference signal. The distance calculation unit 19D calculates the distance to the target using the azimuth angle calculated by the angle measurement unit 19C.

Therefore, according to the first embodiment, the target for transmitting the transmission signal as a direct wave can be detected, and the azimuth angle of the target and the distance to the target can be calculated. This makes it possible to calculate a more accurate position of the target. That is, it is possible to realize a radar device 10 capable of detecting the position of the target using the transmission signal transmitted by the target.

Further, if the direction and distance of the source of the direct wave can be calculated, the passive radar processing can be performed using the indirect wave that the direct wave is reflected by the terrain or another ship and received by the radar device 10. can. This allows it to generate a video signal around the target.

In addition, by superimposing all the passive radar processing results on the detection results of multiple direct waves and the indirect waves that use them as the transmission source, it is possible to grasp the topographical conditions and the positions of vessels that are not transmitting. Will be.

Further, by displaying the passive radar processing result of the indirect wave only for a specific transmission source, it is possible to infer the state of the radar scope seen from the ship or the like of the transmission source.

Further, since the direct wave has a smaller distance attenuation than the indirect wave, it is possible to detect the direct wave even at a distance from the transmission source. In addition, it is possible to check the situation around the transmission source by using indirect waves.

[2] Second Embodiment The second embodiment is another embodiment for calculating the distance to the target for transmitting the direct wave. In the second embodiment, the distance to the target is calculated by using the information regarding the characteristics of the transmission signal of the ship or the like that is managed in advance.

[2-1] Configuration of Radar Device 10 FIG. 11 is a block diagram of the radar device 10 according to the second embodiment. The signal processing device 17 includes a transmission signal information storage unit 24. The transmission signal information storage unit 24 stores, for example, a correspondence between a ship as a target and characteristics of the transmission signal (including frequency, pulse width, pulse interval, and the like).

The direct wave processing unit 19 includes a transmission signal determination unit 19E and a distance calculation unit 19D.

The transmission signal determination unit 19E compares the characteristics of the received signal received from the target with the information stored in the transmission signal information storage unit 24, and identifies the transmission signal transmitted by the target.

The distance calculation unit 19D calculates the distance to the target by using the information of the transmission signal stored in the transmission signal information storage unit 24 and the reception level of the actually received reception signal.

[2-2] Operation FIG. 12 is a flowchart illustrating a direct wave processing operation of the radar device 10 according to the second embodiment. The operation of steps S100 to S104 is the same as that of the first embodiment.

Subsequently, the transmission signal determination unit 19E compares the characteristics of the received signal received from the target detected in step S104 with the information stored in the transmission signal information storage unit 24, and identifies the transmission signal transmitted by the target. (Step S400).

Subsequently, the distance calculation unit 19D calculates the distance to the target using the signal strength information of the transmission signal stored in the transmission signal information storage unit 24 and the reception level of the actually received reception signal (step). S401). That is, the distance calculation unit 19D calculates the distance to the target by using the attenuation level of the signal. The distance R to the target is calculated by the following equation (3).

_IT : Direct wave signal strength _GR : Antenna gain (dB)
_PR : Reception level (W)
λ: Wavelength (m)
The signal strength _IT is represented by “ _PT × _GT ” where the transmission power _PT and the transmission gain _GT are taken.

The subsequent operation of the passive radar processing unit 20 to generate a video signal is the same as that of the first embodiment.

[2-3] Effect of the Second Embodiment In the second embodiment, the distance to the target can be calculated by using the information regarding the characteristics of the transmission signal of a ship or the like that is managed in advance.

Other effects are the same as in the first embodiment.

The direct wave detection process of the first embodiment and the direct wave detection process of the second embodiment may be performed in parallel. Then, a highly accurate detection result may be used.

[3] Third Embodiment In the third embodiment, the moving direction of the target is calculated.

FIG. 13 is a block diagram of the radar device 10 according to the third embodiment.

The direct wave processing unit 19 includes a moving direction calculation unit 19F. The moving direction calculation unit 19F calculates the moving direction of the target by using the information about the direct wave.

FIG. 14 is a flowchart illustrating an operation of calculating a moving direction of a target in the radar device 10 according to the third embodiment. It is assumed that the direct wave of the target has already been detected. The operation of calculating the moving direction of the target can be performed at any timing after the direct wave of the target is detected.

The moving direction calculation unit 19F receives a plurality of received signals related to the direct wave from the data transfer unit 18 (step S500).

Subsequently, the moving direction calculation unit 19F calculates the Doppler frequency using the plurality of received signals (step S501). That is, the moving direction calculation unit 19F calculates the frequencies of the plurality of received signals. Then, the moving direction calculation unit 19F calculates the Doppler frequency by calculating the difference in frequency.

Subsequently, the movement direction calculation unit 19F calculates the target movement direction using the Doppler frequency (step S502).

According to the third embodiment, the moving direction of the target can be determined with respect to the moving body 1. Therefore, it is possible to confirm whether the target is approaching or moving away from the moving body 1.

In each of the above embodiments, the measurement angle at the time of detecting the target is described as the azimuth angle direction, but the elevation angle direction may be used. Further, these may be combined to calculate the angle over the azimuth direction and the elevation angle direction.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... mobile body, 2 ... target, 3 ... transmitter, 4 ... target, 10 ... radar device, 11 ... antenna unit, 12 ... antenna element, 13 ... receiver unit, 14 ... receiver circuit, 15 ... A / D converter unit , 16 ... A / D conversion circuit, 17 ... signal processing device, 18 ... data transfer unit, 19 ... direct wave processing unit, 19A ... reference function extraction unit, 19B ... target detection unit, 19C ... angle measuring unit, 19D ... distance Calculation unit, 19E ... Transmit signal determination unit, 19F ... Movement direction calculation unit, 20 ... Passive radar processing unit, 20A ... Indirect wave detection unit, 20B ... Position calculation unit, 20C ... Video signal generation unit, 21 ... Display data generation unit , 22 ... storage unit, 23 ... display unit, 24 ... transmission signal information storage unit, 30 ... processor, 31 ... memory, 32 ... input interface unit, 33 ... output interface unit, 34 ... bus.

Claims (10)

An antenna unit that includes multiple antenna elements and receives received signals,
An extractor that extracts one of multiple received signals as a reference function,
A first detection unit that performs pulse compression processing on the received signal using the reference function to detect the first target, and
An angle measuring unit that generates a sum signal and a difference signal using the received signal received from the first target and calculates the azimuth angle of the first target using the sum signal and the difference signal.
The first calculation unit that calculates the distance to the first target using the azimuth, and
A radar device equipped with. The radar device according to claim 1, wherein the extraction unit extracts the first received signal as the reference function when the amplitude of the first received signal is equal to or larger than a threshold value. The radar device according to claim 1, wherein the extraction unit extracts the first received signal as the reference function when the pulse of the first received signal is repeated in a predetermined cycle. The radar device according to any one of claims 1 to 3, wherein the first calculation unit calculates the distance by using the elapsed time and the amount of change in azimuth angle changed during the elapsed time. A conversion unit that converts the plurality of received signals received by the antenna unit into a plurality of digital signals, respectively.
The radar device according to any one of claims 1 to 4, further comprising a storage unit for storing the plurality of digital signals. The radar device according to claim 5, further comprising a transfer unit that transfers a plurality of digital signals stored in the storage unit to the extraction unit and the first detection unit. A second detection unit that detects an indirect wave in which the direct wave transmitted by the first target is reflected by the second target,
The radar according to any one of claims 1 to 6, further comprising a first generation unit that generates a video signal of the second target by using a plurality of indirect waves detected by the second detection unit. Device. The radar device according to claim 7, further comprising a second generation unit that generates display data obtained by superimposing the position of the first target and the video signal. Claims 1 to 8 further include a second calculation unit that calculates a Doppler frequency using a plurality of received signals received from the first target and calculates a moving direction of the first target using the Doppler frequency. The radar device according to any one of the following items. The radar device according to any one of claims 1 to 9, wherein the antenna unit is a phased array antenna.

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