Radar signal processing device and radar signal processing method

Abstract

A radar signal processing device (50, 52, 53, 54) comprises: a range compression unit (500) that generates range data by range-compressing an interference signal between a transmission signal transmitted from transmission antennas (400-1 to 400-N) and a reflection signal resulting from reflection of the transmission signal by a target; a range Doppler map generation unit (530) that generates a range Doppler map on the basis of the range data generated by the range compression unit (500) and a plurality of assumed accelerations including a first acceleration and a second acceleration assumed to be the acceleration of the target; an acceleration selection unit (540) that selects, from among the first acceleration and the second acceleration, the acceleration having lower image entropy in the range Doppler map generated by the range Doppler map generation unit (530); and a detection unit (550) that detects the target on the basis of the acceleration selected by the acceleration selection unit (540).

Description

Radar signal processing device and radar signal processing method

[0001] The present disclosure relates to a radar signal processing device and a radar signal processing method.

[0002] High-frequency surface wave radar (HF-SWR) is a commonly known radar that detects targets outside the linear line of sight by utilizing the characteristics of high-frequency (HF) radio waves propagating over the ocean surface as surface waves. While HF surface wave radar is primarily used for vessel detection, it is necessary to extend the coherent integration time to extend the detection range. When the coherent integration time is extended, even if the target's motion is a constant linear motion, the effect of velocity changes in the line-of-sight direction increases, causing the target's motion to appear as accelerated motion with a non-zero acceleration, resulting in an integration loss in the coherent integration results.

[0003] Conventionally, radar devices for detecting targets undergoing accelerated motion have been disclosed (see, for example, Patent Document 1). The radar device described in Patent Document 1 integrates a received signal based on a wave reflected from a target undergoing accelerated motion, and therefore suppresses a decrease in the integral gain of the received signal by exponentiating the sampling number of the received signal with the order of the high-order components contained in the received signal as an exponent.

[0004] Patent No. 7262692

[0005] Generally, a radar device may receive reflected signals from multiple targets with different accelerations at the same time. In such a case, if an attempt is made to detect each of these multiple targets, the problem is that the increased number of data points can easily result in false alarm plots.

[0006] An object of the present disclosure is to provide a radar signal processing device and a radar signal processing method that can suppress the occurrence of false alarm plots.

[0007] The radar signal processing device according to the present disclosure is characterized by including: a range compression unit that generates range data by range-compressing a signal reflected by a target of a transmission signal transmitted from a transmitting antenna and an interference signal between the transmission signal; a range Doppler map generation unit that generates a range Doppler map based on the range data generated by the range compression unit and a plurality of assumed accelerations including a first acceleration and a second acceleration that are assumed as accelerations of the target; an acceleration selection unit that selects, from the range Doppler map generated by the range Doppler map generation unit, an acceleration having a smaller image entropy from the first acceleration and the second acceleration; and a detection unit that detects the target based on the acceleration selected by the acceleration selection unit.

[0008] A radar signal processing device according to the present disclosure can suppress the occurrence of false alarm plots.

[0009] 1 is a block diagram showing a schematic configuration of a radar device according to a first embodiment; FIG. 2 is a block diagram showing an example of a hardware configuration of a radar signal processing device according to the first embodiment; FIG. 3 is a flowchart showing processing of the radar device according to the first embodiment; FIG. 4 is a block diagram showing a configuration of an acceleration selection unit according to the first embodiment; FIG. 5 is a schematic diagram explaining the contents of calculations performed by the acceleration selection unit according to the first embodiment; FIG. 6 is a block diagram showing a schematic configuration of a radar device according to a second embodiment; FIG. 7 is a block diagram showing a schematic configuration of a radar device according to a third embodiment; and FIG. 8 is a block diagram showing a schematic configuration of a radar device according to a fourth embodiment.

[0010] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Embodiment 1. First, a radar device 1 according to embodiment 1 will be described with reference to Fig. 1. Fig. 1 is a block diagram showing a schematic configuration of the radar device according to embodiment 1. As shown in Fig. 1, the radar device 1 according to embodiment 1 includes a signal generating unit 20, a transmitting / receiving unit 30, an antenna unit 40, and a radar signal processing device 50.

[0011] The antenna unit 40 is configured as an array antenna having a plurality of antennas. For example, the antenna unit 40 includes transmitting antennas 400-1, 400-2, ..., 400-N and receiving antennas 410-1, 410-2, ..., 410-M. In the first embodiment, N is an integer of 2 or more indicating the number of transmitting antennas, and M is an integer of 2 or more indicating the number of receiving antennas.

[0012] The radar signal processing device 50 includes a range compressor 500, a digital beam forming (DBF) unit 510, an acceleration corrector 520, an inter-sweep integrator 530, an acceleration selector 540, and a detector 550.

[0013] Next, the hardware configuration of the radar signal processing device 50 will be described with reference to Fig. 2. Fig. 2 is a block diagram showing an example of the hardware configuration of the radar signal processing device 50 according to the first embodiment. For example, as shown in Fig. 2, the radar signal processing device 50 is configured as a computer having a processor 601 such as a CPU and a memory 602, and is configured so that the processor 601 reads and executes a program for achieving the functions of the radar signal processing device 50, which is stored in the memory 602. The memory 602 is configured by, for example, a random access memory (RAM), a read only memory (ROM), a flash memory, a hard disk drive (HDD), a solid state drive (SSD), etc.

[0014] The radar signal processing device 50 may be configured as a computer having a dedicated hardware processing circuit (not shown) instead of the processor 601. For example, the radar signal processing device may have a processing circuit configured as a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof, and the processing circuit is configured to execute a program. The hardware configuration of the radar signal processing device is not limited to the above-described one, and the radar signal processing device may also have hardware other than those described above, such as a hardware timer.

[0015] Next, the radar device 1 according to the first embodiment will be described in detail with reference to Fig. 1 and Fig. 3 to Fig. 5. Fig. 3 is a flowchart showing the processing performed by the radar device 1 according to the first embodiment. Note that, in the following description, the radar device 1 will be described using an FMCW (Frequency Modulated Continuous Wave) system as an example, but the radar device is not limited to this and may be any pulse compression radar that performs pulse compression processing, such as one that performs pulse compression processing using a linear chirp signal.

[0016] First, when the radar device 1 starts processing, the radar signal generating unit 200 generates an FMCW radar signal (step ST10).

[0017] After the radar signal generating unit 200 performs the processing of step ST10, the transmission signal generating unit 300 generates a transmission signal, which is a radio frequency (RF) signal, by frequency-converting the radar signal generated by the radar signal generating unit 200, and transmits (radiates) the transmission signal into space from the transmitting antennas 400-1 to 400-N (step ST20).

[0018] When the transmission signal generation unit 300 performs the process of step ST20, the receiving antennas 410-1 to 410-M receive the reflected signals from the target and output the received reflected signals to the signal receiving unit 310 (step ST30).

[0019] After the receiving antennas 410-1 to 410-M perform the process of step ST30, the signal receiving unit 310 converts the frequency of the reflected signal received by the receiving antennas 410-1 to 410-M using information on the transmission signal generated by the transmission signal generating unit 300 (step ST40). For example, in this process, the signal receiving unit 310 converts the frequency of the reflected signal by generating an interference signal between the reflected signal received by the receiving antennas 410-1 to 410-M and the transmission signal output from the transmission signal generating unit 300. Also, in this process, the signal receiving unit 310 A / D (Analog to Digital) converts the frequency-converted signal and outputs a video signal, which is the signal obtained by A / D conversion, to the radar signal processing device 50. In addition, in embodiment 1, the signal receiving unit 310 constitutes an interference signal generating unit that generates an interference signal between the reflected signal received by the receiving antennas 410-1 to 410-M and the transmission signal generated by the transmission signal generating unit 300.

[0020] After the signal receiving unit 310 performs the process of step ST40, the range compression unit 500 performs a fast Fourier transform (FFT) on the video signal to generate range data, which is data obtained by the range compression (step ST50). In other words, in this process, the range compression unit 500 performs range compression on the signals reflected by a target of the transmission signals transmitted from the transmitting antennas 400-1 to 400-N and the interference signals between the transmission signals, to generate range data. Specifically, in this process, the range compression unit 500 performs a Fourier transform on the video signal to generate range data (beat spectrum).

[0021] After the range compression unit 500 performs the processing of step ST50, the DBF unit 510 performs digital beamforming on the range data based on the array data of each of the receiving antennas 410-1 to 410-M, and converts the range data into data that directs beams in each direction (step ST60).

[0022] After the DBF unit 510 performs the process of step ST60, the acceleration correction unit 520 corrects the data of each beam using a plurality of assumed accelerations (step ST70). In other words, in this process, the acceleration correction unit 520 corrects the data (signals) of each beam obtained by digital beamforming by the DBF unit 510 using a plurality of accelerations including a first acceleration and a second acceleration assumed as the acceleration of the target. These multiple accelerations may be set at equal intervals of a predetermined number between the minimum acceleration and the maximum acceleration assumed as the acceleration of the target, or may be set in unit acceleration increments from the minimum acceleration to the maximum acceleration assumed as the acceleration of the target, or may be a partial acceleration extracted from the multiple accelerations set in this manner.

[0023] After acceleration correction unit 520 performs the process of step ST70, sweep-to-sweep integrator 530 integrates, between sweeps, the acceleration-corrected signal, which is the signal whose acceleration has been corrected by acceleration correction unit 520 (step ST80). In other words, sweep-to-sweep integrator 530 performs a Fourier transform in the sweep direction on the acceleration-corrected signal, which is the signal whose acceleration has been corrected by acceleration correction unit 520, and performs sweep-to-sweep integration to calculate a range-Doppler map. In the first embodiment, sweep-to-sweep integrator 530 constitutes a range-Doppler map generator that generates a range-Doppler map based on the range data generated by range compressor 500 and a plurality of assumed accelerations, including a first acceleration and a second acceleration, which are assumed as the acceleration of the target.

[0024] After the sweep-to-sweep integrator 530 performs the process of step ST80, the acceleration selector 540 calculates image entropy based on the range-Doppler map generated by the sweep-to-sweep integrator 530 and selects, from the multiple accelerations, an acceleration that suppresses image entropy as an estimated acceleration (step ST90). In other words, in this process, the acceleration selector 540 calculates image entropy based on the range-Doppler map generated by the sweep-to-sweep integrator 530 and selects, from the multiple accelerations, an acceleration with the smallest image entropy as an estimated acceleration. For example, in this process, the acceleration selector 540 selects, from the multiple accelerations, an acceleration that minimizes image entropy as an estimated acceleration. The acceleration selector 540 outputs the range-Doppler map of the estimated acceleration to the detector 550. Details of the process performed by the acceleration selector 540 will be described later.

[0025] After the acceleration selection unit 540 performs the process of step ST90, the detection unit 550 performs a target detection process (step ST100) to detect a target based on the estimated acceleration selected by the acceleration selection unit 540. For example, the detection unit 550 performs the target detection process using a Constant False Alarm Rate (CFAR) based on the estimated acceleration selected by the acceleration selection unit 540.

[0026] In the first embodiment, the radar device 1 includes transmitting antennas 400-1 to 400-N that transmit signals and receiving antennas 410-1 to 410-M that receive signals, but is not limited to this. The radar device only needs to include antennas that are capable of transmitting and receiving signals. For example, the radar device may be configured as a monostatic radar that includes antennas that transmit and receive signals. Furthermore, the transmitting antennas and receiving antennas may each be configured as subarray antennas having a plurality of element antennas.

[0027] Next, details of the processing performed by the acceleration selection unit 540 of the radar signal processing device 50 will be described with reference to Figures 4 and 5. Figure 4 is a block diagram showing the configuration of the acceleration selection unit 540 according to embodiment 1. As shown in Figure 4, the acceleration selection unit 540 has a calculation range setting unit 540-1, a histogram calculation unit 540-2, an image entropy calculation unit 540-3, and an estimated acceleration data output unit 540-4.

[0028] The calculation range setting unit 540-1 sets the calculation range (Doppler range) when the histogram calculation unit 540-2 calculates the histogram.

[0029] 5 is a schematic diagram illustrating the processing performed by the acceleration selection unit 540 according to the first embodiment. As shown in FIG. 5, for example, the calculation range setting unit 540-1 selects a Doppler number l that precedes the target Doppler data (target Doppler bin) corresponding to the target Doppler number l. ｓｔｒ From the Doppler data (Doppler bin) corresponding to ｅｎｄ For example, the calculation range setting unit 540-1 sets the calculation range based on the expected acceleration and signal processing time. Specifically, the calculation range setting unit 540-1 sets the calculation range up to the Doppler data corresponding to Doppler number l ｓｔｒ and Doppler number l ｅｎｄ The calculation range is set so that the difference between is the maximum Doppler velocity range that is assumed to be variable within the integration time.

[0030] The histogram calculation unit 540-2 calculates a histogram of power within the calculation range set by the calculation range setting unit 540-1. For example, the histogram calculation unit 540-2 sets the gradation of the histogram to M (m=1, 2, ..., M) and calculates the histogram within the calculation range (l ｅｎｄ -l ｓｔｒ +1) histogram is normalized.

[0031] The image entropy calculation unit 540-3 calculates the image entropy ε from the histogram normalized by the histogram calculation unit 540-2 using the following equation (1): ｋ、ｌ、ｂIn the formula (1), k is the range number, b is the beam number, a is the acceleration number which is the acceleration bin number, p ｋ、ｌ、ｂ、ｍ [a] shows the histogram normalized by the histogram calculation unit 540-2.

[0032] The estimated acceleration data output unit 540-4 selects the acceleration that minimizes the image entropy calculated by the image entropy calculation unit 540-3 using the following formula (2). In this way, the acceleration selection unit 540 reduces the number of dimensions of the data to be processed (dimensional reduction). In the first embodiment, the symbol "^" above a, which indicates an estimated value, is also written as "hat_a", and in formula (2), hat_a ｋ、ｌ、ｂ indicates the estimated acceleration number.

[0033] The estimated acceleration data output unit 540-4 outputs the Doppler number l and the estimated acceleration number hat_a based on the selected acceleration. ｋ、ｌ、ｂ x[k, l, b, hat_a ｋ、ｌ、ｂ ] to the detection unit 550. The acceleration selection unit 540 performs the above process for each of the preset range numbers, Doppler numbers, and beam numbers.

[0034] As described above, the radar signal processing device 50 according to the first embodiment includes a range compression unit 500 that generates range data by range-compressing signals of signals transmitted from the transmitting antennas 400-1 to 400-N, the signals being reflected by a target, and interference signals between the transmitted signals; an inter-sweep integration unit 530 that generates a range-Doppler map based on the range data generated by the range compression unit 500 and a plurality of assumed accelerations including a first acceleration and a second acceleration that are assumed as accelerations of the target; an acceleration selection unit 540 that selects, from the first acceleration and the second acceleration, an acceleration that has a small image entropy in the range-Doppler map generated by the inter-sweep integration unit 530; and a detection unit 550 that detects a target based on the acceleration selected by the acceleration selection unit 540.

[0035] With this configuration, even when reflected signals from multiple targets with different accelerations are input, the radar signal processing device according to the first embodiment detects the multiple targets based on a specific acceleration among multiple assumed accelerations assumed for these multiple targets, thereby reducing the number of data points used in processing and the occurrence of false alarm plots.

[0036] Furthermore, image entropy is a measure of disorder and does not depend on power but on the probability density distribution (normalized histogram) of the Doppler profile. By using such image entropy as an evaluation index, the radar signal processing device 50 according to the first embodiment detects targets based on accelerations that improve the signal-to-noise ratio based on the variability of the entire Doppler profile, rather than detecting targets based on the accelerations that maximize the signal-to-noise ratio of a single target that exhibits peak power. This makes it possible to suppress integration loss over the entire Doppler range of interest and improve the signal-to-noise ratio when detecting targets.

[0037] Second Embodiment Next, a radar device 2 according to a second embodiment will be described with reference to Fig. 6. The radar device 2 according to the second embodiment differs from the radar device 1 according to the first embodiment in that it includes an element space (hereinafter also referred to as "ES") unwanted wave suppression unit instead of the DBF unit. However, the other configurations are the same, and the same components as those in the first embodiment are denoted by the same names and symbols as those in the first embodiment, and the description thereof will be omitted.

[0038] As shown in FIG. 6 , the radar device 2 according to the second embodiment includes a signal generating unit 20 , a transmitting / receiving unit 30 , an antenna unit 40 , and a radar signal processing device 52 .

[0039] The radar signal processing device 52 includes a range compressor 500 , an ES unwanted wave suppressor 560 , an acceleration corrector 520 , an inter-sweep integrator 530 , an acceleration selector 540 , and a detector 550 .

[0040] Generally, radar devices receive unwanted waves such as reflected waves from sources other than targets, called clutter, and interference waves transmitted from and received by other wireless devices. The ES unwanted wave suppression unit 560 according to the second embodiment suppresses the unwanted waves. For example, the ES unwanted wave suppression unit 560 suppresses the unwanted waves using array signal processing. For example, the ES unwanted wave suppression unit 560 uses the processing described in Non-Patent Document 1 shown below as the array signal processing.

[0041] https: / / apmc-mwe.org / MicrowaveExhibition2010 / program / tutorial2009 / TL03-01.pdf (Accessed March 6, 2024) Nobuyoshi Kikuma, Fundamentals of Array Antennas, Microwave Exhibition 2010, Basic Lecture 03, December 8-10, Pacifico Yokohama.

[0042] In addition, the ES unwanted wave suppression unit 560 applies, for example, array signal processing before or after Doppler processing (before or after sweep-to-sweep integration), element space processing (before DBF), or beam space processing (after DBF), as described in Non-Patent Document 2.

[0043] James Ward, Space-time Adaptive Processing for airborne radar, International Conference on Acoustics, Speech, and Signal Processing, 1995.

[0044] The radar signal processing device 52 according to the second embodiment is configured by adding element-space unwanted wave suppression processing to the radar signal processing device 50 according to the first embodiment. Examples of such unwanted wave suppression processing include DCMP (Directionally Constrained Minimization of Power) described in Non-Patent Document 1. With this configuration, the radar signal processing device 52 according to the second embodiment can suppress unwanted waves while taking advantage of the advantages of the radar signal processing device 50 according to the first embodiment.

[0045] Third Embodiment Next, a radar device 3 according to a third embodiment will be described with reference to Fig. 7. The radar device 3 according to the third embodiment differs from the radar device 1 according to the first embodiment in that it includes a beam space (hereinafter also referred to as "BS") unnecessary wave suppression unit, but the other configurations are the same. The same components as those in the first embodiment are given the same names and symbols as those in the first embodiment, and the description thereof will be omitted.

[0046] As shown in FIG. 7, the radar device 3 according to the third embodiment includes a signal generating unit 20, a transmitting / receiving unit 30, an antenna unit 40, and a radar signal processing device 53.

[0047] The radar signal processing device 53 includes a range compressor 500 , a DBF unit 510 , an acceleration corrector 520 , an inter-sweep integrator 530 , a BS unwanted wave suppressor 570 , an acceleration selector 540 , and a detector 550 .

[0048] The BS unwanted wave suppression unit 570 performs unwanted wave suppression processing to suppress unwanted waves in beam space. Examples of unwanted wave suppression processing include DCMP, which is described in Non-Patent Document 1. With this configuration, the radar signal processing device 53 according to embodiment 3 can suppress unwanted waves while taking advantage of the advantages of the radar signal processing device 50 according to embodiment 1. Furthermore, by performing the unwanted wave suppression processing in beam space, the radar signal processing device 53 according to embodiment 3 can select whether or not to perform the unwanted wave suppression processing (turn it on or off) depending on the beam number.

[0049] Fourth Embodiment Next, a radar device 4 according to a fourth embodiment will be described with reference to Fig. 8. The radar device 3 according to the fourth embodiment differs from the radar device 2 according to the second embodiment in that it includes two inter-sweep integrating units and an inverse inter-sweep integrating unit, but the other configurations are the same. The same components as those in the second embodiment are denoted by the same names and reference numerals as those in the second embodiment, and the description thereof will be omitted.

[0050] As shown in FIG. 8, the radar device 4 according to the fourth embodiment includes a signal generating unit 20, a transmitting / receiving unit 30, an antenna unit 40, and a radar signal processing device 54.

[0051] The radar signal processing device 54 includes a range compressor 500 , an ES unwanted wave suppressor 560 , an inverse sweep integration unit 580 , an acceleration corrector 520 , two sweep integration units 530 , an acceleration selector 540 , and a detector 550 .

[0052] The inverse sweep-to-sweep integrator 580 performs an inverse Fourier transform on the input signal converted into the Doppler axis by the sweep-to-sweep integrator 530, and converts the input signal converted into the Doppler axis by the sweep-to-sweep integrator 530 into time axis (sweep axis in the FMCW system) data. For example, the inverse sweep-to-sweep integrator 580 converts the data in which unwanted waves have been suppressed by the element space unwanted wave suppressor into time axis data by performing an inverse Fourier transform.

[0053] Thereafter, the radar signal processing device 53 performs processing from the acceleration correction unit 520 to the acceleration selection unit 540. With this configuration, the radar signal processing device 54 according to embodiment 4 can suppress unwanted waves while making use of the advantages of the radar signal processing device 50 according to embodiment 1. Furthermore, by performing the unwanted wave suppression processing after sweep integration, the radar signal processing device 54 according to embodiment 4 can select whether or not to perform the unwanted wave suppression processing (turn on / off) depending on the Doppler number.

[0054] In any of the above-described embodiments, the radar signal processing device may include some or all of the other components of the radar device, or some of the components of the radar signal processing device may be provided in another device that is communicatively connected to the radar device.

[0055] In addition, the present disclosure allows for free combination of the respective embodiments, modification of any of the components of the respective embodiments, or omission of any of the components of the respective embodiments.

[0056] A radar signal processing device according to the present disclosure can be used, for example, in a radar device for detecting the direction and distance of a target.

[0057] 1 radar device, 2 radar device, 3 radar device, 4 radar device, 20 signal generation unit, 30 transmission / reception unit, 40 antenna unit, 50 radar signal processing device, 52 radar signal processing device, 53 radar signal processing device, 54 radar signal processing device, 200 radar signal generation unit, 300 transmission signal generation unit, 310 signal reception unit (interference signal generation unit), 400-1 transmission antenna, 400-2 transmission antenna, 400-N transmission antenna, 410-1 reception antenna, 410-2 reception antenna, 410-M reception antenna, 500 range compression unit, 510 digital beam forming unit, 520 acceleration correction unit, 530 sweep integration unit (range Doppler map generation unit), 540 acceleration selection unit, 540-1 calculation range setting unit, 540-2 histogram calculation unit, 540-3 Image entropy calculation unit, 540-4 estimated acceleration data output unit, 550 detection unit, 560 element space unwanted wave suppression unit, 570 beam space unwanted wave suppression unit, 580 inverse sweep-to-sweep integration unit (inverse Fourier transform unit), 601 processor, 602 memory.

Claims

1. A radar signal processing device comprising: a range compression unit that generates range data by range-compressing a signal reflected by a target of a transmission signal transmitted from a transmitting antenna and an interference signal between the transmission signal transmitted from the transmitting antenna; a range Doppler map generation unit that generates a range Doppler map based on the range data generated by the range compression unit and a plurality of assumed accelerations including a first acceleration and a second acceleration that are assumed to be accelerations of the target; an acceleration selection unit that selects, from the first acceleration and the second acceleration, an acceleration that has a small image entropy in the range Doppler map generated by the range Doppler map generation unit; and a detection unit that detects the target based on the acceleration selected by the acceleration selection unit.

2. The radar signal processing device according to claim 1, wherein the acceleration selection unit sets the calculation range of the image entropy based on the expected acceleration and signal processing time.

3. A radar signal processing device according to claim 1 or 2, characterized in that it comprises an element space unwanted wave suppression unit that performs unwanted wave suppression processing in element spaces.

4. A radar signal processing device according to any one of claims 1 to 3, characterized in that it comprises a beam space unwanted wave suppression unit that performs unwanted wave suppression processing in the beam space.

5. A radar signal processing device according to claim 1 or 2, characterized in that it comprises: an element space unwanted wave suppression unit that suppresses unwanted waves in element space in the Doppler axis data of the range-Doppler map generated by said range-Doppler map generation unit; and an inverse Fourier transform unit that performs an inverse Fourier transform on the data from which unwanted waves have been suppressed by said element space unwanted wave suppression unit to convert it into time axis data.

6. A radar device comprising: a radar signal processing device according to any one of claims 1 to 5; a transmission signal generation unit that generates a transmission signal; a transmission antenna that transmits the transmission signal generated by the transmission signal generation unit into space; a receiving antenna that receives a signal reflected by the target; and an interference signal generation unit that generates an interference signal between the reflected signal received by the receiving antenna and the transmission signal generated by the transmission signal generation unit.

7. A radar signal processing method comprising a range compression unit, a range-Doppler map generation unit, an acceleration selection unit, and a detection unit, comprising: a step in which the range compression unit generates range data by range-compressing a signal reflected by a target of a transmission signal transmitted from a transmission antenna and an interference signal of the transmission signal; a step in which the range-Doppler map generation unit generates a range-Doppler map based on the range data generated by the range compression unit and a plurality of assumed accelerations including a first acceleration and a second acceleration that are assumed to be accelerations of the target; a step in which the acceleration selection unit selects, from the first acceleration and the second acceleration, an acceleration that has a small image entropy in the range-Doppler map generated by the range-Doppler map generation unit; and a step in which the detection unit detects the target based on the acceleration selected by the acceleration selection unit.

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