Radar signal processing apparatus and radar signal processing method

Abstract

The radar signal processing apparatuses (50, 52, 53, 54) include a range compression unit (500) that generates range data by range-compressing an interference signal between a reflected signal due to a target of a transmission signal transmitted from transmission antennas (400-1 to 400-N) and the transmission signal, range data generated by the range compression unit (500), and a plurality of assumed accelerations including a first acceleration and a second acceleration assumed as the acceleration of the target, a range Doppler map generation unit (530) that generates a range Doppler map based on these, an acceleration selection unit (540) that selects an acceleration with small image entropy in the range Doppler map generated by the range Doppler map generation unit (530) from among the first acceleration and the second acceleration, and a detection unit (550) that detects a target based on the acceleration selected by the acceleration selection unit (540).

Description

Technical Field

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

Background Art

[0002] Generally, a high-frequency (HF) band surface wave radar (HF-SWR) that utilizes the characteristic that radio waves in the HF band propagate on the sea surface as surface waves to detect targets outside the linearly visible range is known. The HF band surface wave radar is mainly used for ship detection, but in order to extend the detection range, it is necessary to extend the coherent integration time. When the coherent integration time is extended, even if the target's motion is a uniform linear motion, the influence of the velocity change in the line-of-sight direction becomes large, so that the target's motion appears to be an accelerated motion with a non-zero acceleration, and an integration loss occurs in the coherent integration result.

[0003] Conventionally, a radar device for detecting a target performing an accelerated motion has been disclosed (see, for example, Patent Document 1). The radar device described in Patent Document 1 integrates the received signal based on the reflected wave from the target performing the accelerated motion, and therefore suppresses the decrease in the integration gain of the received signal by raising the sampling number of the received signal to the power with the order of the higher-order component included in the received signal as the power exponent.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Generally, in a radar device, reflected signals from a plurality of targets with different accelerations may be input simultaneously. However, when attempting to detect each of these multiple targets in such a case, there is a problem that false alarm plots are likely to occur due to an increase in the number of data points.

[0006] An object of the present disclosure is to provide a radar signal processing apparatus and a radar signal processing method capable of suppressing the occurrence of false alarm plots.

Means for Solving the Problems

[0007] The radar signal processing apparatus according to the present disclosure includes a range compression unit that generates range data by range-compressing an interference signal between a reflected signal from a target of a transmission signal transmitted from a transmission antenna and the transmission signal, range data generated by the range compression unit, A plurality of of the target Each a range Doppler map generation unit that generates a range Doppler map based on a plurality of assumed accelerations including a first acceleration and a second acceleration assumed as the acceleration of the target, and in the range Doppler map generated by the range Doppler map generation unit, an acceleration selection unit that selects an acceleration with a small image entropy among the first acceleration and the second acceleration, and a detection unit that detects a target based on the acceleration selected by the acceleration selection unit.

Effects of the Invention

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

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Embodiment 1. First, with reference to FIG. 1, the radar device 1 according to Embodiment 1 will be described. FIG. 1 is a block diagram showing the 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 generation unit 20, a transmission / reception 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 transmission antennas 400-1, 400-2, ···, 400-N, and reception antennas 410-1, 410-2, ···, 410-M. In Embodiment 1, N is an integer of 2 or more indicating the number of transmission antennas, and M is an integer of 2 or more indicating the number of reception antennas.

[0012] The radar signal processing device 50 includes a range compression unit 500, a digital beam forming (hereinafter also referred to as "DBF") unit 510, an acceleration correction unit 520, an inter-sweep integration unit 530, an acceleration selection unit 540, and a detection unit 550.

[0013] Next, with reference to FIG. 2, the hardware configuration of the radar signal processing apparatus 50 will be described. FIG. 2 is a block diagram showing an example of the hardware configuration of the radar signal processing apparatus 50 according to the first embodiment. For example, as shown in FIG. 2, the radar signal processing apparatus 50 is configured as a computer having a processor 601 such as a CPU and a memory 602, and the processor 601 reads and executes a program for achieving the functions of the radar signal processing apparatus 50 stored in the memory 602. The memory 602 is constituted by, for example, RAM (Random Access Memory), ROM (Read Only Memory), flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), or the like.

[0014] Note that the radar signal processing apparatus 50 may be configured as a computer having a processing circuit (not shown) which is dedicated hardware instead of the processor 601. For example, the radar signal processing apparatus has a processing circuit composed of 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. Note that the hardware configuration of the radar signal processing apparatus is not limited to that described above, and for example, it may have hardware other than that described above, such as a hardware timer.

[0015] Next, with reference to FIGS. 1, 3 to 5, the details of the radar device 1 according to Embodiment 1 will be described. FIG. 3 is a flowchart showing the processing of the radar device 1 according to Embodiment 1. In the following description, the radar device 1 of the FMCW (Frequency Modulated Continuos Wave) method will be described as an example. However, the radar device is not limited to this, and any radar device that performs pulse compression processing may be used. For example, a radar device that performs pulse compression processing using a linear chirp signal may be used.

[0016] First, when the radar device 1 starts processing, the radar signal generation unit 200 generates a radar signal of the FMCW method (step ST10).

[0017] When the radar signal generation unit 200 performs the processing of step ST10, the transmission signal generation unit 300 generates a transmission signal, which is a high-frequency (RF; Radio Frequency) signal, by frequency-converting the radar signal generated by the radar signal generation unit 200, and transmits (radiates) it into space from the transmission antennas 400-1 to 400-N (step ST20).

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

[0019] When the reception antennas 410-1 to 410-M perform the process of step ST30, the signal reception unit 310 uses the information of the transmission signal generated by the transmission signal generation unit 300 to convert the frequency of the reflected signal received by the reception antennas 410-1 to 410-M (step ST40). For example, in this process, the signal reception unit 310 generates an interference signal between the reflected signal received by the reception antennas 410-1 to 410-M and the transmission signal output from the transmission signal generation unit 300, thereby converting the frequency of the reflected signal. Also, in this process, the signal reception unit 310 performs A / D (Analog to Digital) conversion on the frequency-converted signal, and outputs the video signal, which is the signal obtained by the A / D conversion, to the radar signal processing device 50. Note that in Embodiment 1, the signal reception unit 310 constitutes an interference signal generation unit that generates an interference signal between the reflected signal received by the reception antennas 410-1 to 410-M and the transmission signal generated by the transmission signal generation unit 300.

[0020] When the signal reception unit 310 performs the process of step ST40, the range compression unit 500 performs range compression on the video signal by fast Fourier transform (FFT; Fast Fourier Transform), and generates range data, which is the data obtained by the range compression (step ST50). In other words, in this process, the range compression unit 500 performs range compression on the interference signal between the reflected signal of the transmission signal transmitted from the transmission antennas 400-1 to 400-N and the transmission signal according to the target, and generates range data. Specifically, in this process, the range compression unit 500 generates range data (beat spectrum) by performing Fourier transform on the video signal.

[0021] When the range compression unit 500 performs the process of step ST50, the DBF unit 510 performs digital beamforming on the range data based on the array data of each of the reception antennas 410-1 to 410-M, and converts the range data into data with the beam directed in each direction (step ST60).

[0022] When 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 (signal) of each beam using a plurality of accelerations including a first acceleration and a second acceleration assumed as the target acceleration, for the signal digitally beamformed by the DBF unit 510. These plurality of accelerations may be set at equal intervals by a preset number between, for example, the minimum acceleration and the maximum acceleration assumed as the target acceleration, or may be set one unit acceleration at a time from the minimum acceleration to the maximum acceleration assumed as the target acceleration, or may be a partial extraction from the plurality of accelerations set in this way.

[0023] When the acceleration correction unit 520 performs the process of step ST70, the inter-sweep integration unit 530 integrates the post-acceleration correction signal, which is the signal whose acceleration has been corrected by the acceleration correction unit 520, between sweeps (step ST80). In other words, the inter-sweep integration unit 530 performs inter-sweep integration that Fourier-transforms the post-acceleration correction signal, which is the signal whose acceleration has been corrected by the acceleration correction unit 520, in the sweep direction and calculates a range-doppler map. Note that, in Embodiment 1, the inter-sweep integration unit 530 constitutes a range-doppler map generation unit 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 assumed as the target acceleration.

[0024] When the inter-sweep integration unit 530 performs the process of step ST80, the acceleration selection unit 540 calculates the image entropy based on the range-Doppler map generated by the inter-sweep integration unit 530, and selects, as the estimated acceleration, the acceleration among a plurality of accelerations in which the image entropy is suppressed (step ST90). In other words, in this process, the acceleration selection unit 540 calculates the image entropy based on the range-Doppler map generated by the inter-sweep integration unit 530, and selects, as the estimated acceleration, the acceleration with a smaller image entropy among the first acceleration and the second acceleration included in the plurality of accelerations. For example, in this process, the acceleration selection unit 540 selects, as the estimated acceleration, the acceleration that minimizes the image entropy among the plurality of accelerations. The acceleration selection unit 540 outputs the range-Doppler map of the estimated acceleration to the detection unit 550. Details of the process performed by the acceleration selection unit 540 will be described later.

[0025] When the acceleration selection unit 540 performs the process of step ST90, the detection unit 550 performs a target detection process for detecting a target based on the estimated acceleration selected by the acceleration selection unit 540 (step ST100). For example, the detection unit 550 executes the target detection process by CFAR (Constant False Aram Rate) based on the estimated acceleration selected by the acceleration selection unit 540.

[0026] Note that in the first embodiment, the radar device 1 includes the transmission antennas 400-1 to 400-N that transmit signals and the reception antennas 410-1 to 410-M that receive signals, but is not limited thereto. The radar device only needs to include an antenna capable of transmitting and receiving signals. For example, the radar device may be configured as a monostatic radar including an antenna capable of transmitting and receiving signals. Also, the transmission antenna and the reception antenna may each be configured as a sub-array antenna having a plurality of element antennas.

[0027] Next, with reference to FIGS. 4 and 5, the details of the processing performed by the acceleration selection unit 540 of the radar signal processing apparatus 50 will be described. FIG. 4 is a block diagram showing the configuration of the acceleration selection unit 540 according to Embodiment 1. As shown in FIG. 4, the acceleration selection unit 540 includes 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] FIG. 5 is a schematic diagram for explaining the content of the processing performed by the acceleration selection unit 540 according to Embodiment 1. As shown in FIG. 5, for example, the calculation range setting unit 540-1 is the Doppler number l corresponding to the Doppler data of interest (Doppler bin) for the Doppler number l of interest. str From the Doppler data (Doppler bin) corresponding to the Doppler number l before the Doppler number l of interest, to the Doppler data corresponding to the Doppler number l end after the Doppler data of interest is set as the calculation range. For example, the calculation range setting unit 540-1 sets the calculation range based on the assumed acceleration and signal processing time. Specifically, the calculation range setting unit 540-1 is the Doppler number l str and the Doppler number l end so that the difference between them is within the maximum Doppler speed range that can change within the integration time, the calculation range is set.

[0030] The histogram calculation unit 540-2 calculates the power histogram 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 as M (m = 1, 2, ···, M), and 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 according to the following formula (1). k、l、b [a] is calculated. In formula (1), k is the range number, b is the beam number, a is the acceleration number which is the number of the acceleration bin, and p k、l、b、m [a] represents the histogram normalized by the histogram calculation unit 540-2. TIFF0007686170000001.tif15166

[0032] The estimated acceleration data output unit 540-4 selects the acceleration at which the image entropy calculated by the image entropy calculation unit 540-3 is minimized according to the following formula (2). Thereby, the acceleration selection unit 540 reduces the number of dimensions (dimensional reduction) of the data for which the process is performed. In the first embodiment, the symbol with “^” meaning the estimated value above a is also described as “hat_a”. In formula (2), hat_a k、l、b represents the estimated acceleration number. TIFF0007686170000002.tif10166

[0033] The estimated acceleration data output unit 540-4 outputs the range-Doppler map x[k, l, b, hat_a k、l、b corresponding to the Doppler number l and the estimated acceleration number hat_a k、l、b being focused on to the detection unit 550. The acceleration selection unit 540 performs the above process for each of the range number, Doppler number, and beam number set in advance.

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

[0035] Configured in this way, the radar signal processing apparatus according to Embodiment 1 can, for example, detect a plurality of targets based on a specific acceleration among a plurality of assumed accelerations assumed for these plurality of targets even when reflected signals from a plurality of targets with different accelerations are input, so that the number of data points used in the processing can be suppressed, and the occurrence of false alarm plots can be suppressed.

[0036] Also, image entropy is a measure of clutter and depends not 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 apparatus 50 according to Embodiment 1 detects a target not based on an acceleration that maximizes the signal-to-noise ratio of a single target indicating peak power, but based on an acceleration that improves the signal-to-noise ratio based on the variation of the entire Doppler profile. Therefore, the integration loss within the entire Doppler range of interest can be suppressed, and the signal-to-noise ratio when detecting a target can be improved.

[0037] Embodiment 2. Next, with reference to FIG. 6, the radar device 2 according to Embodiment 2 will be described. The radar device 2 according to Embodiment 2 is different from the radar device 1 according to Embodiment 1 in that it includes an element space (hereinafter also referred to as "ES") unnecessary wave suppression unit instead of the DBF unit. For other configurations, they are the same. For the same configurations as those in Embodiment 1, the same names and reference numerals as those in Embodiment 1 are given, and the description thereof is omitted.

[0038] As shown in FIG. 6, the radar device 2 according to Embodiment 2 includes a signal generation unit 20, a transmission / reception unit 30, an antenna unit 40, and a radar signal processing device 52.

[0039] The radar signal processing device 52 includes a range compression unit 500, an ES unnecessary wave suppression unit 560, an acceleration correction unit 520, an inter-sweep integration unit 530, an acceleration selection unit 540, and a detection unit 550.

[0040] Generally, a radar device receives unnecessary waves such as reflected waves from sources other than targets called clutter and interference waves transmitted and received from other wireless devices. The ES unnecessary wave suppression unit 560 according to Embodiment 2 suppresses unnecessary waves. For example, the ES unnecessary wave suppression unit 560 suppresses unnecessary waves using array signal processing. The ES unnecessary wave suppression unit 560 uses, for example, the processing described in Non-Patent Document 1 shown below as array signal processing.

[0041]

Non-Patent Document 1

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

[0043]

Non-Patent Document 2

[0044] The radar signal processing device 52 according to Embodiment 2 is obtained by adding unnecessary wave suppression processing in the element space to the radar signal processing device 50 according to Embodiment 1. Such unnecessary wave suppression processing includes, for example, DCMP (Directionally Constrained Minimization of Power) described in Non-Patent Document 1. With such a configuration, the radar signal processing device 52 according to Embodiment 2 can suppress unnecessary waves while taking advantage of the radar signal processing device 50 according to Embodiment 1.

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

[0046] As shown in FIG. 7, the radar device 3 according to Embodiment 3 includes a signal generation unit 20, a transmission / reception unit 30, an antenna unit 40, and a radar signal processing device 53.

[0047] The radar signal processing device 53 includes a range compression unit 500, a DBF unit 510, an acceleration correction unit 520, an inter-sweep integration unit 530, a BS unwanted wave suppression unit 570, an acceleration selection unit 540, and a detection unit 550.

[0048] The BS unwanted wave suppression unit 570 performs an unwanted wave suppression process for suppressing unwanted waves in the beam space. Examples of the unwanted wave suppression process include DCMP 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 radar signal processing device 50 according to Embodiment 1. Furthermore, the radar signal processing device 53 according to Embodiment 3 can select (turn on / off) whether to perform the unwanted wave suppression process depending on the beam number by performing the unwanted wave suppression process in the beam space.

[0049] Embodiment 4. Next, with reference to FIG. 8, the radar device 4 according to Embodiment 4 will be described. The radar device 3 according to Embodiment 4 is different from the radar device 2 according to Embodiment 2 in that it includes two inter-sweep integration units and an inverse inter-sweep integration unit, but the other configurations are the same. For the same configurations as those in Embodiment 2, the same names and reference numerals as those in Embodiment 2 are given and the description thereof is omitted.

[0050] As shown in FIG. 8, the radar device 4 according to Embodiment 4 includes a signal generation unit 20, a transceiver unit 30, an antenna unit 40, and a radar signal processing device 54.

[0051] The radar signal processing device 54 includes a range compression unit 500, an ES unwanted wave suppression unit 560, an inverse inter-sweep integration unit 580, an acceleration correction unit 520, two inter-sweep integration units 530, an acceleration selection unit 540, and a detection unit 550.

[0052] The inter-sweep integration unit 580 performs an inverse Fourier transform on the input signal converted to the Doppler axis by the inter-sweep integration unit 530, and converts the input signal converted to the Doppler axis by the inter-sweep integration unit 530 into data on the time axis (sweep axis in the FMCW method). For example, the inter-sweep integration unit 580 converts the data with unnecessary waves suppressed by the element space unnecessary wave suppression unit into data on the time axis 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. Configured in this way, the radar signal processing device 54 according to the fourth embodiment can suppress unnecessary waves while taking advantage of the radar signal processing device 50 according to the first embodiment. Furthermore, the radar signal processing device 54 according to the fourth embodiment can select (turn on / off) whether to perform unnecessary wave suppression processing according to the Doppler number by performing unnecessary wave suppression processing after sweep integration.

[0054] In any of the above-described embodiments, the radar signal processing device may include part or all of other configurations of the radar device, or part of the configuration of the radar signal processing device may be provided in another device communicably connected to the radar device.

[0055] Note that in the present disclosure, free combinations of the respective embodiments, modifications of any constituent elements of the respective embodiments, or omissions of any constituent elements in the respective embodiments are possible.

Industrial Applicability

[0056] The 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.

Explanation of Signs

[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 beamforming unit, 520 Acceleration correction unit, 530 Inter-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 inter-sweep integration unit (inverse Fourier transform unit), 601 Processor, 602 Memory.

Claims

1. a range compression unit that generates range data by compressing the range of a reflected signal of a transmission signal transmitted from a transmission antenna by a target and an interference signal of the transmission signal transmitted from the transmission antenna; a range-Doppler map generating unit that generates a plurality of range-Doppler maps based on the range data generated by the range compression unit and a plurality of assumed accelerations that include a minimum acceleration and a maximum acceleration assumed as the acceleration of each of the plurality of targets and further include an acceleration between the minimum acceleration and the maximum acceleration; an acceleration selection unit that calculates an image entropy for each of the plurality of range Doppler maps generated by the range Doppler map generation unit in response to the plurality of set assumed accelerations, and selects, from the plurality of assumed accelerations, the assumed acceleration corresponding to the range Doppler map in which the image entropy is minimum, as an estimated acceleration; a detection unit that detects the plurality of targets based on the range-Doppler map corresponding to the estimated acceleration selected by the acceleration selection unit; 4. A radar signal processing device comprising:

2. The acceleration selection unit sets a calculation range of image entropy based on an expected acceleration and a signal processing time.

2. The radar signal processing device according to claim 1.

3. Equipped with an element space unnecessary wave suppression section that performs unnecessary wave suppression processing in the element space 2. The radar signal processing device according to claim 1.

4. Equipped with a beam space unwanted wave suppression unit that performs unwanted wave suppression processing in the beam space 2. The radar signal processing device according to claim 1.

5. an element space unwanted wave suppression unit that suppresses unwanted waves in element space in data on the Doppler axis of the range Doppler map generated by the range Doppler map generation unit; an inverse Fourier transform unit that converts the data in which the unwanted waves have been suppressed by the element space unwanted wave suppression unit into data on a time axis by performing an inverse Fourier transform thereon; 2. The radar signal processing device according to claim 1.

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

7. A radar signal processing method including a range compression unit, a range Doppler map generation unit, an acceleration selection unit, and a detection unit, a step of generating range data by compressing a range of a reflected signal of a transmission signal transmitted from a transmission antenna by a target and an interference signal of the transmission signal by the range compression unit; a step of the range-Doppler map generating unit generating a plurality of range-Doppler maps based on the range data generated by the range compression unit and a plurality of assumed accelerations set including a minimum acceleration and a maximum acceleration assumed as accelerations of each of the plurality of targets, and further including an acceleration between the minimum acceleration and the maximum acceleration; the acceleration selection unit calculating an image entropy for each of the plurality of range Doppler maps generated by the range Doppler map generation unit in response to the plurality of set assumed accelerations, and selecting, from among the plurality of assumed accelerations, the assumed acceleration corresponding to the range Doppler map in which the image entropy is minimum, as an estimated acceleration; The detection unit detects a plurality of targets based on the range-Doppler map corresponding to the estimated acceleration selected by the acceleration selection unit.

2. A radar signal processing method comprising:

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