JP6410445B2 - Radar equipment - Google Patents

Description

  The present invention relates to a radar apparatus that performs target detection by integrating received signals.

  In the conventional radar apparatus, as shown in FIG. 10 (c), the received signal received during the observation time is equally divided and integrated, and then the target candidate is detected, and the result is cumulatively detected. Thus, target detection was performed (see, for example, Non-Patent Document 1). In this radar apparatus, since a plurality of integration results are cumulatively detected, improvement in target detection performance can be expected.

Merrill I. Skolnik, “Radar Handbook, Second Edition,” 2.9, MacGraw-Hill companies., 1990.

  However, in the conventional radar apparatus as disclosed in Non-Patent Document 1, as shown in FIG. 10A, the signal-to-noise ratio (SNR) of the received signal is divided during the divided observation time. When it changes, there exists a subject that SNR after integration deteriorates. As shown in FIG. 10B, when the target motion changes regardless of the target distance, there is a problem that the integration performance deteriorates and the target detection performance deteriorates.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a radar apparatus that can improve target detection performance.

A radar apparatus according to the present invention includes a signal transmission unit that radiates a transmission signal to space, a signal reception unit that receives a transmission signal radiated by the signal transmission unit and reflected by a target as a reception signal, and an assumed target motion The integration time is calculated as the integration time of the received signal received by the signal receiving means by shortening the integration time when the change in the target motion is small, and shortening the integration time when the change in the target motion is large. Based on the integration time calculated by the calculation means, the integration time calculation means, a frequency domain conversion means for performing frequency domain conversion on the received signal received by the signal reception means, and frequency domain conversion by the frequency domain conversion means. Based on the received signal strength, target candidate detecting means for detecting target candidates and target candidates detected by the target candidate detecting means are assumed. Is obtained by a cumulative detection means for performing cumulative detection based on motion of a target.

The radar apparatus according to the present invention includes a signal transmission unit that radiates a transmission signal to space, a signal reception unit that receives a transmission signal radiated by the signal transmission unit and reflected by the target as a reception signal, and an assumed target. Phase compensation means for performing phase compensation so that the received signal received by the signal receiving means becomes coherent based on the motion of the signal, and phase compensation so that the cumulative detection probability shows the maximum based on the assumed target motion Integration time calculating means for calculating the integration time of the received signal phase-compensated by the means, and frequency domain conversion is performed on the received signal received by the signal receiving means based on the integration time calculated by the integration time calculating means. A target candidate detection unit for detecting a target candidate based on the frequency domain conversion unit to be performed and the intensity of the reception signal frequency domain converted by the frequency domain conversion unit. Means and is obtained by a cumulative detection means for performing cumulative detected based on the motion of the target to assume the target candidate target detected by the detection means candidate.

  According to this invention, since it comprised as mentioned above, target detection performance can be improved.

It is a figure which shows the structure of the radar apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement of the radar apparatus which concerns on Embodiment 1 of this invention. It is a figure explaining operation | movement of the radar apparatus which concerns on Embodiment 1 of this invention, (a) It is a figure which shows the time change of SNR of a received signal, (b) It is a figure which shows the time change of a target relative speed. (C) It is a figure which shows the integration time of a received signal. It is a figure explaining the effect by the integration time calculation means in Embodiment 1 of this invention, (a) It is a figure which shows the integration result at the time of making integration time into equal intervals, (b) According to the change of a target exercise | movement. It is a figure which shows the integration result when integration time is set. It is a figure explaining operation | movement of the accumulation detection means in Embodiment 1 of this invention. It is a figure which shows the structure of the radar apparatus which concerns on Embodiment 2 of this invention. It is a figure explaining operation | movement of the radar apparatus which concerns on Embodiment 2 of this invention, (a) It is a figure which shows the time change of SNR of a received signal, (b) It is a figure which shows the time change of target relative speed. (C) It is a figure which shows the integration time of a received signal. It is a figure which shows the structure of the radar apparatus based on Embodiment 3 of this invention. It is a figure explaining the combination method by the integration time calculation means in Embodiment 3 of this invention (when a division | segmentation number candidate is 2). It is a figure explaining operation | movement of the conventional radar apparatus, (a) It is a figure which shows the time change of SNR of a received signal, (b) It is a figure which shows the time change of a target relative velocity, (c) It is a figure which shows integration time.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1 FIG.
1 is a diagram showing a configuration of a radar apparatus according to Embodiment 1 of the present invention.
As shown in FIG. 1, the radar apparatus includes an antenna 1, a transmission unit 2, a transmission / reception switching unit 3, a reception unit 4, a signal processor 5, and a display 6.

  The antenna 1 radiates a transmission RF signal (transmission signal) from the transmission / reception switching unit 3 into the air and receives a reflected RF signal reflected by the target. The reflected RF signal received by the antenna 1 is output to the transmission / reception switching means 3 as a reception RF signal (reception signal).

  The transmission means 2 generates a local oscillation signal having a constant frequency and a transmission RF signal obtained by performing pulse modulation on the local oscillation signal. The local oscillation signal generated by the transmission unit 2 is output to the reception unit 4, and the transmission RF signal is output to the transmission / reception switching unit 3.

  The transmission / reception switching unit 3 outputs a transmission RF signal from the transmission unit 2 to the antenna 1 and outputs a reception RF signal from the antenna 1 to the reception unit 4.

  The reception unit 4 down-converts the received RF signal from the transmission / reception switching unit 3 using the local oscillation signal from the transmission unit 2 and performs amplification and phase detection to generate a CW (Continuous Wave) signal. Is. The CW signal generated by the receiving means 4 is output to the signal processor 5 as a received video signal.

  The signal processor 5 processes the received video signal from the receiving means 4 to obtain an accumulated detection probability. The signal processor 5 is executed by program processing using a CPU based on software. A signal indicating the cumulative detection probability obtained by the signal processor 5 is output to the display 6. The configuration of the signal processor 5 will be described later.

  The display 6 displays the cumulative detection probability that is the processing result of the signal processor 5 on the screen.

  The antenna 1, the transmission unit 2, and the transmission / reception switching unit 3 correspond to the “signal transmission unit that radiates a transmission signal to the space” of the present invention, and the antenna 1, the transmission / reception switching unit 3 and the reception unit 4 of the present invention. It corresponds to “a signal receiving means for receiving a transmission signal emitted from the signal transmission means and reflected by a target as a reception signal”.

Next, the configuration of the signal processor 5 will be described.
As shown in FIG. 1, the signal processor 5 includes an integration time calculation unit 51, a frequency domain conversion unit 52, a target candidate detection unit 53, and an accumulation detection unit 54.

  The integration time calculation unit 51 calculates a time (coherent integration time) for coherent integration of the received video signal from the reception unit 4 based on an assumed target motion. A signal indicating the coherent integration time (integration time) calculated by the integration time calculation unit 51 is output to the frequency domain conversion unit 52.

  Based on the coherent integration time calculated by the integration time calculating unit 51, the frequency domain converting unit 52 performs frequency domain conversion as coherent integration on the received video signal from the receiving unit 4, and receives the received video signal in the frequency domain. Is generated. The received video signal in the frequency domain generated by the frequency domain converting unit 52 is output to the target candidate detecting unit 53.

  The target candidate detecting unit 53 detects a target candidate based on the intensity of the received video signal in the frequency domain from the frequency domain converting unit 52. A signal indicating the target candidate detected by the target candidate detecting unit 53 is output to the cumulative detecting unit 54.

  The cumulative detection means 54 performs target cumulative detection based on the target candidates detected by the target candidate detection means 53 and the assumed target motion. A signal indicating the cumulative detection probability as a cumulative detection result by the cumulative detection means 54 is output to the display 6.

なお、ｆ₀は送信周波数、Ｔ_Lは送信信号の送信時間、φ₀は初期位相、Ａ_Lは局部発振信号Ｌ₀（ｔ）の振幅を表す。この送信手段２により生成された局部発振信号Ｌ₀（ｔ）は、受信手段４に出力される。 Next, the operation of the radar apparatus configured as described above will be described with reference to FIGS.
In the operation of the radar apparatus, as shown in FIG. 2, first, the transmission means 2 generates a local oscillation signal L ₀ (t) having a constant frequency (step ST1). Here, the local oscillation signal L ₀ (t) is expressed by the following expression (1).

Here, f ₀ represents the transmission frequency, T _L represents the transmission time of the transmission signal, φ ₀ represents the initial phase, and A _L represents the amplitude of the local oscillation signal L ₀ (t). The local oscillation signal L ₀ (t) generated by the transmission unit 2 is output to the reception unit 4.

なお、Ｔ_priはパルス繰り返し周期（ＰＲＩ：Ｐｕｌｓｅ Ｒｅｐｅｔｉｔｉｏｎ Ｉｎｔｅｒｖａｌ）、Ｔ_pは送信信号のパルス幅、ｎ’はヒット番号、Ｎ’はヒット数を表す。この送信手段２により生成された送信ＲＦ信号Ｔｘ（ｔ）は、送受切替手段３に出力される。 The transmission unit 2 generates a transmission RF signal Tx (t) obtained by performing pulse modulation on the local oscillation signal L ₀ (t) (step ST2). Here, the transmission RF signal Tx (t) is expressed by the following equation (2).

T _pri represents a pulse repetition period (PRI), T _p represents a pulse width of a transmission signal, n ′ represents a hit number, and N ′ represents a hit number. The transmission RF signal Tx (t) generated by the transmission unit 2 is output to the transmission / reception switching unit 3.

  Next, the transmission / reception switching unit 3 outputs the transmission RF signal Tx (t) from the transmission unit 2 to the antenna 1, and the antenna 1 radiates the transmission RF signal Tx (t) into the air (step ST3). Thereafter, the transmission RF signal Tx (t) radiated into the air is reflected by the target and enters the antenna 1 as a reflected RF signal.

なお、ｃは光速を表す。また、目標との相対距離Ｒ（ｎ’，ｔ）は下式（４）で表される。

なお、ｖ（ｔ）は時刻ｔにおける目標相対速度を表す。 Next, the antenna 1 receives the incident reflected RF signal and outputs it as a received RF signal to the transmission / reception switching means 3, and the transmission / reception switching means 3 outputs the received RF signal to the reception means 4 (step ST4). Here, when the transmission RF signal Tx (t) represented by Expression (2) is reflected by a target at a relative distance R (n ′, t) with respect to the radar apparatus, the reflected RF signal (reception RF signal) ) Rx (n ′, t) is expressed by the following formula (3).

C represents the speed of light. Further, the relative distance R (n ′, t) to the target is expressed by the following expression (4).

Note that v (t) represents the target relative speed at time t.

なお、＊は複素共役、ｎは受信ビデオ信号のサンプル番号、Ｎは受信ビデオ信号のサンプル数を表す。また、サンプル番号ｎの距離Ｒ（ｎ）は下式（６）で表される。

なお、ｖ（ｎ）はサンプル番号ｎの目標相対速度、Ｔ_sは受信ビデオ信号のサンプル間隔である。 Next, the reception unit 4 down-converts the reception RF signal Rx (n ′, t) from the transmission / reception switching unit 3 using the local oscillation signal L ₀ (t) from the transmission unit 2 to perform amplification and phase detection. To generate a CW signal (step ST5). The CW signal generated by the receiving means 4 is output to the signal processor 5 as a received video signal V (n). Here, the received video signal V (n) is expressed by the following equation (5).

Note that * represents a complex conjugate, n represents a sample number of the received video signal, and N represents the number of samples of the received video signal. Further, the distance R (n) of the sample number n is expressed by the following formula (6).

Here, v (n) is the target relative speed of sample number n, and T _s is the sample interval of the received video signal.

  Next, the integration time calculation means 51 of the signal processor 5 calculates the time (coherent integration time) for coherent integration with respect to the received video signal V (n) from the reception means 4 based on the assumed target motion. (Step ST6).

For example, as shown in FIG. 3B, based on the target motion, the time that the received video signal V (n) can be regarded as coherent, that is, the time that can be regarded as constant-velocity linear motion is defined as a coherent integration time T _C (n _C ). calculate. Here, n _C represents an integration time number, and N _C represents an integration time number.
In FIG. 3B, since the change in the target motion is small in the section A, the integration time is set long. On the other hand, in the section B, since the change in the target motion is large, the integration time is set short.

なお、ｖ₀（ｎ_C）は積分時間番号ｎ_Cの初期相対速度、Δｖ_C，_Tはコヒーレント積分時間終了条件の速度変化量を表す。 Specifically, first, the integration time calculation means 51 calculates a speed change amount Δv _C (n _C ) based on the target motion according to the following equation (7), using the following equation (8) as an integration time end condition.

Note that v ₀ (n _C ) represents the initial relative speed of the integration time number n _C , and Δv _C , _T represents the speed change amount of the coherent integration time end condition.

Then, the integration time calculation means 51 calculates n ′ in the equation (7) by one by one, and calculates n ′ when the equation (8) is satisfied as the coherent integration time T _C (n _C ). .

The integration time calculation unit 51 can calculate the optimum coherent integration time, and the coherent integration by the frequency domain conversion unit 52 described later can be efficiently performed. FIG. 4 (a) shows the result of coherent integration of a conventional received signal divided at equal intervals. It can be seen that efficient integration is not possible when the target motion changes during the integration time. On the other hand, as shown in FIG. 4B, the integration time can be efficiently integrated by calculating the integration time in which the target motion does not change during the integration time by the integration time calculation means 51 according to the target motion. .
A signal indicating the coherent integration time T _C (n _C ) calculated by the integration time calculation unit 51 is output to the frequency domain conversion unit 52.

なお、ｋは周波数領域のサンプリング番号、Ｎ_FFTはＦＦＴ点数、Ｍ_C（ｎ_C）はコヒーレント積分時間Ｔ_C（ｎ_C）のサンプリング点数を表す。ただし、Ｎ_FFT＞Ｍ_C（ｎ_C）の場合にはV（ｎ）に０を代入する。 Next, the frequency domain transforming unit 52 performs coherent integration on the received video signal V (n) from the receiving unit 4 based on the coherent integration time T _C (n _C ) calculated by the integration time calculating unit 51. Frequency domain conversion is performed to generate a received video signal F (n _C , k) in the frequency domain (step ST7). Here, the frequency domain transforming unit 52 performs Fast Fourier Transform (FFT) represented by the following formula (9) as the frequency domain transform.

Note that k represents a sampling number in the frequency domain, N _FFT represents the number of FFT points, and M _C (n _C ) represents the number of sampling points for the coherent integration time T _C (n _C ). However, if N _FFT > M _C (n _C ), 0 is substituted for V (n).

Then, the frequency domain conversion means 52 performs frequency domain conversion with an FFT point number N _FFT larger than the pulse number N, whereby the received video signal F (n _C , k) in the frequency domain is highly sampled, and a highly accurate Doppler is obtained. It is possible to calculate the frequency, that is, the target relative speed. Further, when suppressing the side lobe of the clutter, the frequency domain transforming unit 52 performs window function processing on the received video signal before the frequency domain transform. For example, the side lobe of the signal after the frequency domain can be suppressed by multiplying by the Blackman window.
The frequency domain received video signal F (n _C , k) generated by the frequency domain converting means 52 is output to the target candidate detecting means 53.

Next, the target candidate detecting unit 53 detects a target candidate based on the intensity of the received video signal F (n _C , k) in the frequency domain from the frequency domain converting unit 52 (step ST8). Here, the target candidate detection means 53 detects a target candidate for the received video signal F (n _C , k) by processing based on signal power (for example, CFAR (Constant False Alarm Rate) processing). A signal indicating the target candidate detected by the target candidate detecting unit 53 is output to the cumulative detecting unit 54.

なお、Ｐ_d（ｉ）は各積分後の検出確率である。 Next, the cumulative detection means 54 performs target cumulative detection based on the target candidates detected by the target candidate detection means 53 and the assumed target motion (see FIG. 5) (step ST9).
In FIG. 5, the broken line indicates the target relative speed of the integration time number calculated from the assumed target motion, and the solid line indicates the signal after integration. Further, the probability (cumulative detection probability) P _C (n _C ) of detecting the target at least once from the integration result of the integration time number n _C times is expressed by the following equation (10).

Note that P _d (i) is a detection probability after each integration.

In the first embodiment, since the integration time is changed according to the target motion (when the coherent integration is possible, the integration time is increased), the target detection probability is improved and the cumulative detection probability is improved. A signal indicating the cumulative detection probability P _C (n _C ) that is the cumulative detection result by the cumulative detection means 54 is output to the display 6.

Next, the display 6 displays the cumulative detection probability P _C (n _C ), which is the processing result by the signal processor 5, on the screen (step ST10).

  As described above, according to the first embodiment, the integration time calculation unit 51 calculates the coherent integration time according to the assumed target motion, and the frequency domain conversion unit 52 performs the coherent integration. Coherent integration according to the target motion becomes possible, and even when the target motion changes during the divided observation time, the SNR of the received video signal in the frequency domain after the coherent integration is improved, and the target detection performance is improved. . Further, since the cumulative detection means 54 cumulatively detects target candidates of received video signals in a plurality of frequency regions, the cumulative detection performance is improved.

Embodiment 2. FIG.
FIG. 6 is a diagram showing a configuration of a radar apparatus according to Embodiment 2 of the present invention. The radar apparatus according to Embodiment 2 shown in FIG. 6 is obtained by changing the signal processor 5 of the radar apparatus according to Embodiment 1 shown in FIG. 1 to a signal processor 5b. The signal processor 5b in the second embodiment is obtained by changing the integration time calculating unit 51 of the signal processor 5 in the first embodiment to an integration time calculating unit 51b. Other configurations are the same, and the same reference numerals are given and description thereof is omitted.

  The integration time calculation unit 51b calculates a coherent integration time (coherent integration time) for the received video signal from the receiving unit 4 based on the assumed target motion and the SNR of the assumed received video signal (received signal). To do. A signal indicating the coherent integration time (integration time) calculated by the integration time calculation unit 51 b is output to the frequency domain conversion unit 52.

That is, the integration time calculation unit 51b calculates the coherent integration time T _C (n _C ) according to the equations (7) and (8) according to the target motion, as with the integration time calculation unit 51. However, as shown in FIG. 7, the SNR may change greatly even during the time that can be regarded as coherent. If there are many signals with low SNR, the SNR after coherent integration may not be efficiently integrated.

ここで、σ_noiseは雑音の分散、ａｂｓ（Ｖ’（ｎ））は想定する目標信号の電力を表す。図７（ａ）において、Ｃの区間では、ＳＮＲの変化が小さいため積分時間を長く設定する。一方、Ｄの区間では、ＳＮＲの変化が大きいため積分時間を短く設定する。また、Ｅ，Ｆの区間では、ＳＮＲと目標運動に基づき、積分時間を変化させて、積分効率を向上させる。
なお、分割した信号のコヒーレント積分後のＳＮＲが両方向上する必要はない。 Therefore, the integration time calculation unit 51b further divides the integration time according to the following equation (11) so that the SNR _FFT after the coherent integration is improved.

Here, σ _noise represents the variance of noise, and abs (V ′ (n)) represents the power of the assumed target signal. In FIG. 7A, in the section C, since the change in SNR is small, the integration time is set long. On the other hand, in the section D, since the change in SNR is large, the integration time is set short. In the section of E and F, the integration efficiency is improved by changing the integration time based on the SNR and the target motion.
Note that it is not necessary to improve both the SNR after coherent integration of the divided signals.

  As described above, according to the second embodiment, the integration time calculation unit 51b is configured to calculate the coherent integration time so that the SNR after the coherent integration is improved in addition to the assumed target motion. In addition to the effects of the first embodiment, even when the SNR changes, the SNR of the received video signal in the frequency domain after coherent integration is improved, and the target detection performance is improved.

Embodiment 3 FIG.
FIG. 8 is a diagram showing a configuration of a radar apparatus according to Embodiment 3 of the present invention. The radar apparatus according to Embodiment 3 shown in FIG. 8 is obtained by changing the signal processor 5 of the radar apparatus according to Embodiment 1 shown in FIG. 1 to a signal processor 5c. The signal processor 5c in the second embodiment is obtained by adding a phase compensation means 55 to the signal processor 5 in the first embodiment and changing the integration time calculation means 51 to the integration time calculation means 51c. Other configurations are the same, and the same reference numerals are given and description thereof is omitted.

この位相補償手段５５により生成された位相補償後の受信ビデオ信号Ｖ_cor（ｎ）は積分時間算出手段５１ｃに出力される。 The phase compensation unit 55 performs phase compensation on the received video signal from the receiving unit 4 so as to be coherent based on an assumed target motion. Here, the phase compensation means 55 performs phase compensation according to the received video signal V (n) according to the following equation (12) using the phase compensation amount φ (n) corresponding to the assumed target motion, and after phase compensation. The received video signal V _cor (n) is generated.

The phase-compensated received video signal V _cor (n) generated by the phase compensation means 55 is output to the integration time calculation means 51c.

The integration time calculation means 51c calculates the time (coherent integration time) for coherent integration of the received video signal from the phase compensation means 55 based on the assumed target motion. Here, the integration time calculation means 51c calculates the SNR after coherent integration for the received video signal at each observation time in a brute force combination using the division number candidate and the coherent integration time candidate, and the SNR after the coherent integration is calculated. The corresponding detection probability P _d (n _C ) is calculated, and finally the cumulative detection probability P _C (n _C ) is calculated according to equation (10). Then, the integration time calculation means 51c, as a result of the brute force combination, shows the number of divisions with the maximum cumulative detection probability P _C (n _C ), the number of divisions of the integration time candidate, the coherent integration time T _C (n _C To the frequency domain conversion means 52.

An example of a brute force combination of a division number candidate and a coherent integration time candidate is shown.
FIG. 9 shows a case where the number of division candidates is 2, and FIG. 9A shows that the first integration time candidate T _C ″ (0) is subjected to FFT, and the subsequent integration time candidate T _C ″ (1 ) Is performed to calculate the cumulative detection probability. FIG. 9B shows a case where the order of the integration time candidates is reversed. In addition, when there are other integration time candidates, the cumulative detection probability is calculated by brute force. The same process is performed when there are other division number candidates. A combination indicating the cumulative detection probability is defined as the number of divisions and coherent integration time.

  As described above, according to the third embodiment, the phase compensation means 55 performs phase compensation on the received video signal in a coherent manner, enables coherent integration, improves the SNR of the signal after coherent integration, and further integrates the integration time. Since the calculation unit 51c is configured to calculate the combination having the maximum cumulative detection probability among the division number candidates and the coherent integration time candidates and calculate the coherent integration time, the cumulative detection probability is higher than that of the first embodiment. Further improve.

  In the above, the case where the phase compensation unit 55 is applied to the configuration of the first embodiment has been described. However, the phase compensation unit 55 may be applied to the configuration of the second embodiment, and the same effect can be obtained. Can be obtained.

  Further, within the scope of the present invention, the invention of the present application can be freely combined with each embodiment, modified with any component in each embodiment, or omitted with any component in each embodiment. .

  1 antenna, 2 transmission means, 3 transmission / reception switching means, 4 reception means, 5, 5b, 5c signal processor, 6 display, 51, 51b, 51c integration time calculation means, 52 frequency domain conversion means, 53 target candidate detection means 54 accumulation detecting means, 55 phase compensating means.

Claims (7)

A signal transmission means for radiating a transmission signal to space;
A signal receiving means for receiving, as a received signal, a transmission signal radiated by the signal transmitting means and reflected by the target;
Based on the assumed target motion, when the change in the target motion is small, the integration time is lengthened, and when the change in the target motion is large, the integration time is shortened and received by the signal receiving means. Integration time calculating means for calculating the integration time of the signal;
Based on the integration time calculated by the integration time calculation means, frequency domain conversion means for performing frequency domain conversion on the received signal received by the signal reception means;
Target candidate detection means for detecting the target candidate based on the intensity of the received signal frequency domain transformed by the frequency domain transformation means;
A radar apparatus comprising: cumulative detection means for performing cumulative detection based on the target motion assumed to be the target candidate detected by the target candidate detection means. The radar apparatus according to claim 1, wherein the integration time calculation unit calculates an integration time of the reception signal received by the signal reception unit based on an assumed SNR of the reception signal. A signal transmission means for radiating a transmission signal to space;
A signal receiving means for receiving, as a received signal, a transmission signal radiated by the signal transmitting means and reflected by the target;
Based on the assumed target motion, according to the following equation (1), the following equation (2) is used as the integration time end condition to calculate the speed change amount ΔvC (nC) based on the target motion, and n in equation (1) Integration time calculation means for calculating 'by incrementing one by one and calculating n' when Expression (2) is satisfied as the integration time of the received signal received by the signal receiving means;
Based on the integration time calculated by the integration time calculation means, frequency domain conversion means for performing frequency domain conversion on the received signal received by the signal reception means;
Target candidate detection means for detecting the target candidate based on the intensity of the received signal frequency domain transformed by the frequency domain transformation means;
A radar apparatus comprising: cumulative detection means for performing cumulative detection based on the target motion assumed to be the target candidate detected by the target candidate detection means.

(1)

(2)
v ₀ (n _C ) represents the initial relative speed of the integration time number n _C , and Δv _{C, T} represents the speed change amount under the integration time end condition. A signal transmission means for radiating a transmission signal to space;
A signal receiving means for receiving, as a received signal, a transmission signal radiated by the signal transmitting means and reflected by the target;
Phase compensation means for performing phase compensation so that the received signal received by the signal receiving means becomes coherent based on the assumed motion of the target;
Based on the motion of the target assumed, the divided number of candidates and the coherent integration time candidates, calculates the combination of cumulative detection probability is maximized, said phase compensating means integration time of the I Ri position phase compensated received signal to Integration time calculating means for calculating
Based on the integration time calculated by the integration time calculation means, frequency domain conversion means for performing frequency domain conversion on the received signal received by the signal reception means;
Target candidate detection means for detecting the target candidate based on the intensity of the received signal frequency domain transformed by the frequency domain transformation means;
A radar apparatus comprising: cumulative detection means for performing cumulative detection based on the target motion assumed to be the target candidate detected by the target candidate detection means. The radar apparatus according to claim 4, wherein the integration time calculation unit calculates an integration time of the reception signal phase-compensated by the phase compensation unit based on an assumed SNR of the reception signal. The radar apparatus according to claim 1, 3 or 4, wherein the frequency domain transforming means performs frequency domain transform with a score larger than the signal score of the received signal. The radar apparatus according to claim 1, 3 or 4, wherein the frequency domain conversion means performs window function processing on the received signal.

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