JP2011149816A - Radar false image removing processing device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire an effect equivalent to the case of using a continuous wide band by removing a false image of a target, even when only a discrete band can be used in a radar. <P>SOLUTION: This device includes: a temporary recording part 10 for outputting a reception signal; a correlation function generation part 11 for all bands for outputting a correlation function in an outside continuous band; a processing part 12 for all bands for performing correlation processing between the correlation function and the reception signal, and outputting a first processing signal; a correlation function generation part 13 for a discrete band for outputting a correlation function in the same discrete band as a transmission signal; a processing part 14 for a discrete band for performing correlation processing between the correlation function and the reception signal, and outputting a second processing signal; and a superposition processing part 15 for adopting as an actual target signal, a partial signal of the first processing signal included in the second processing signal by performing superposition processing of the first processing signal and the second processing signal, to thereby perform removal processing of a signal which is a false image of the target signal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a radar false image removal processing device that can remove a false image of a target and obtain an effect equivalent to the case of using a continuous wide band even when a band can be used only discretely in a radar, and Regarding the method.

  A radar is used to detect a target. When detecting a target, a radar false image based on a target other than the target may be included in the received radar signal, and techniques for removing the radar false image have been developed (Patent Documents 1 to 5).

  As shown in FIG. 18, when the radar can transmit and receive a wideband signal S1 having a continuous radar use band B, the target signal T1 with good resolution and no false image can be obtained.

  When realizing a low-frequency radar in Japan, it is necessary to transmit while avoiding the frequency bands of radio stations that exist frequently in the low-frequency band, and transmission / reception signals must be in discrete bands.

JP 2002-168936 A JP 2006-328661 A JP 2009-074917 A JP-A-01-235883 JP 09-090020 A

However, when only the discrete bands B1, B2, B3, B4, and B5 can be used in the radar use band B, the target is set using the signal S2 that uses the discrete bands B1, B2, B3, B4, and B5. When detected, the resolution is good, but as shown in FIG. 19, a large number of signals N1 and N2 that are false images of the target signal T1 are generated depending on how the bands B1, B2, B3, B4, and B5 are used.
When only the discrete bands B1, B2, B3, B4, and B5 can be used, the resolution is poor or a large number of false image signals N1 and N2 are generated, which is fatal performance for the radar. Accordingly, there has been a demand for a technique that can achieve both false image removal and high resolution even when only discrete bands can be used.

  An object of the present invention is to remove a radar false image by removing a false image of a target and obtaining an effect equivalent to the case of using a continuous wide band even when a band can be used only discretely in a radar. It is to provide an apparatus and method.

In order to achieve the above object, a radar false image removal processing device according to the present invention is a radar false image removal processing device that removes a false image of a target signal included in a received signal that has received a reflected wave at a detection target or the like.
A temporary recording unit that records the received signal and outputs the stored received signal, and generates a continuous band correlation function based on the necessary resolution instruction from the outside, and outputs the correlation function A correlation signal generating unit for all bands, a correlation function output from the correlation function generating unit for all bands, and a reception signal output from the temporary recording unit, and a first processing signal by the correlation processing Is generated by a processing unit for all bands that outputs the same, a discrete band correlation function generating unit that generates the same discrete band correlation function as the transmission signal, and a discrete band correlation function generating unit that outputs the correlation function Correlation processing between the correlation function and the reception signal output by the temporary recording unit, and the discrete band processing unit that outputs a second processing signal by the correlation processing, and the all band processing unit performs the correlation processing A first processing signal; and A portion of the first processing signal included in the second processing signal by inputting the second processing signal subjected to correlation processing by the processing unit for spread band and superimposing the processing signals By using the signal as an actual target signal, it has a superimposition processing unit that removes a signal that is a false image of the target signal.

A radar false image removal processing method according to the present invention is a radar false image removal processing method for removing a false image of a target signal included in a reception signal that has received a reflected wave at a detection target or the like.
A first processed signal obtained by multiplying the received signal by a continuous correlation function of a radar use band and a process obtained by multiplying the received signal by a correlation function of the same discrete band as the transmission signal. A signal that is a false image of the target signal by performing a superposition process with the second processed signal and adopting a partial signal of the first processed signal included in the second processed signal as an actual target signal It is characterized by carrying out the removal process.

  According to the present invention, the processing signal obtained by multiplying the received signal by the continuous correlation function of the radar use band and the processing of multiplying the received signal by the correlation function of the same discrete band as the transmission signal are performed. In order to perform superimposition processing with the processed signal, even if the band can only be used discretely in the radar, the false image of the target is removed, and an effect equivalent to the case of using a continuous wide band is obtained. It is something that can be done.

It is a figure explaining the radar false image removal processing method which concerns on embodiment of this invention. It is a block diagram which shows the structure of the radar false image removal processing apparatus which concerns on embodiment of this invention. It is a figure which shows the received signal which the radar false image removal processing apparatus which concerns on embodiment of this invention processes. It is a figure explaining the case where the correlation function production | generation part for all bands in the embodiment of this invention produces | generates a correlation function. It is a figure explaining the case where the process part for all the bands in embodiment of this invention performs a correlation process. It is a figure explaining the case where the correlation function production | generation part for discrete bands in embodiment of this invention produces | generates a correlation function. It is a figure explaining the case where the process part for discrete bands in embodiment of this invention performs a correlation process. It is a figure explaining the case where the superimposition process part in embodiment of this invention performs a superimposition process. In an embodiment of the present invention, it is a figure explaining a case where a false image is included in a processing signal when superposition processing is performed. It is a figure explaining the case where the correlation function production | generation part for discrete bands in embodiment of this invention produces | generates a correlation function when performing a reprocessing. It is a figure explaining the case where the process part for discrete bands in embodiment of this invention performs a correlation process in the case of a reprocessing field. It is a figure explaining the case where superposition processing is performed when the superposition processing part in an embodiment of the present invention performs reprocessing. It is a figure explaining the case where the convergence determination part in embodiment of this invention finally performs a determination process. It is a figure explaining the effect by embodiment of this invention. It is a block diagram which shows the structure which concerns on the example of a change of embodiment of this invention. It is a figure explaining the correlation process in the example of a change of embodiment of this invention. It is a figure explaining the superimposition process in the example of a change of embodiment of this invention. It is a figure explaining the information of the target in the case of transmitting / receiving the broadband signal with a continuous radar use band. It is a figure explaining the information of the target in the case of transmitting / receiving the signal of a discrete band among radar use bands.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, when a target is detected by discretely using the radar usage band B, the received signal is subjected to a process of multiplying the continuous correlation function F1 of the radar usage band B to obtain a resolution. Target signal T1 is obtained, but many signals N1 and N2 which are false images of the target are generated at the same time. This is defined as a processing signal P1.

  As shown in FIG. 1, when a process of multiplying the received signal by the correlation function F2 of the same discrete bands B1, B2, B3, B4, and B4 as the transmission signal is performed, a false image of the target does not occur. A target signal T2 having a low resolution is obtained. This is defined as a processing signal P2.

In the embodiment of the present invention, as shown in FIG. 1, the processing signal P1 and the processing signal P2 are overlapped, and the partial signal (T1) of the processing signal P1 included in the processing signal P2 is By adopting it as the actual target signal T, the target is detected.
Next, the embodiment of the present invention will be described more specifically.

The apparatus that executes the above-described radar false image removal processing method according to the embodiment of the present invention has a common configuration for performing the superimposition processing of the processing signal P1 and the processing signal P2. There are two methods for performing the matching process. One of the devices employs a method that converges false image removal by feedback, and the other device prepares a sufficient number of processing units and correlation function generation units in advance. This method employs a method of removing a false image by the superimposing process.
(Embodiment 1)

  A radar false image removal processing apparatus that employs a method of converging false image removal by feedback will be described as Embodiment 1 of the present invention.

  As shown in FIG. 2, the radar false image removal processing device according to the first embodiment of the present invention includes a temporary recording unit 10, an all-band all-band correlation function generating unit 11, an all-band processing unit 12, and a discrete unit. A band correlation function generation unit 13, a discrete band processing unit 14, an overlay processing unit 15, a convergence determination unit 16, a switching unit 17, and a band selection unit 18 are included.

  The temporary recording unit 10 records a reception signal based on a target received by the reception unit 19 for a certain period of time, and based on the control signal from the convergence determination unit 16, the stored reception signal is processed for the all-band processing unit 12. And output to the discrete band processing unit 14.

  The all-band correlation function generating unit 11 generates a continuous band correlation function F1 based on the necessary resolution instruction D from the outside, and outputs the correlation function F1 to the all-band processing unit 12. .

  The all-band processing unit 12 performs a correlation process between the correlation function F1 output from the all-band correlation function generation unit 11 and the received signal output from the temporary recording unit 10, and a processing signal P1 based on the correlation process. Is output to the overlay processing unit 15 via the switching unit 17.

  The discrete band correlation function generation unit 13 generates a correlation function F2 having the same discrete band as that of the transmission signal, outputs the correlation function F2 to the discrete band processing unit 14, and outputs the correlation function F2 from the band selection unit 18. A partially continuous correlation function F 2 ′ is generated based on the control signal, and the correlation function F 2 ′ is output to the discrete band processing unit 14.

  The discrete band processing unit 14 performs correlation processing between the correlation function F2 or F2 ′ output from the discrete band correlation function generating unit 13 and the received signal output from the temporary recording unit 10, and processing by the correlation processing The signal P2 is output to the overlay processing unit 15.

  The superposition processing unit 15 performs a superposition process on the processing signal P1 output from the all-band processing unit 12 via the switching unit 17 and the processing signal P2 output from the discrete band processing unit 14 to perform processing. The partial signal T1 of the processing signal P1 included in the signal P2 is adopted as the actual target signal T, and is output as the processing signal P3 to the convergence determination unit 16, and the processing signal P2 is also used for determination in the convergence determination unit 16. In parallel, it is output to the convergence determination unit 16.

  The convergence determination unit 16 determines whether the processing signal P3 output from the overlay processing unit 15 includes a target false image. If the target false image is not included, the convergence determination unit 16 directly uses the processing signal P3 as a target. If the target T is output as a signal T and a false image of the target is included, the processing signal P3 is output to the switching unit 17 for reprocessing, and also to the switching unit 17, the band selection unit 18 and the temporary recording unit 10 In contrast, a control signal is output.

  Based on a control signal from the convergence determination unit 16, the switching unit 17 selects either the processing signal P 1 output from the all-band processing unit 12 or the processing signal P 3 output from the convergence determination unit 16 from the superposition. This is output to the processing unit 15.

  Based on the control signal from the convergence determination unit 16, the band selection unit 18 uses, as a band control signal, band information that is used to generate a correlation function in the discrete band correlation function generation unit 13. This is output to the discrete band correlation function generator 13.

  Next, the case where the radar false image removal processing method is executed using the radar false image removal processing apparatus according to the embodiment of the present invention shown in FIG. 1 will be described in detail.

  In executing the radar false image removal processing method according to the first embodiment of the present invention, as shown in FIG. 3, the radar use band B is a frequency f1 to a frequency f0, and within a band from the frequency f0 to the frequency f1. Assume a received signal having discrete occupied bands B1, B2, B3, B4, and B5.

  In FIG. 1, the reception unit 19 outputs a reception signal, and the reception signal is input to the temporary recording unit 10. The temporary recording unit 10 records the received signal for a certain period of time and outputs the received signal to the full band processing unit 12 and the discrete band processing unit 14 based on the control signal from the convergence determination unit 16.

The all-band correlation function generation unit 11 generates a continuous band correlation function F1 according to the occupied frequency band of the received signal based on the necessary resolution instruction D from the outside. When generating the correlation function F1, the all-band correlation function generation unit 11 automatically selects a frequency band that maximizes the total occupied band of the corresponding received signal.
More specifically, as shown in FIG. 4A, the all-band correlation function generator 11 has a frequency in the range of frequency f0 to frequency f1 if a resolution corresponding to the radar use band B is required. A continuous band B correlation function F1 is generated.
As shown in FIG. 4B, the all-band correlation function generation unit 11 needs a resolution corresponding to a band B ′ narrower than the radar use band B, and the range of the frequency f2 to the frequency f0 is the band B. And the discrete band B1 + B2 + B3 + B4 is the maximum in selecting the band B ′ within the range of the frequency f0 to the frequency f1, the continuous band B ′ in the range of the frequency f0 to the frequency f2. The correlation function F1 is generated.
Then, the all-band correlation function generating unit 11 outputs the generated correlation function F1 shown in FIG. 4A or FIG. 4B to the all-band processing unit 11.

  The all-band processing unit 12 performs correlation processing between the correlation function F1 generated by the all-band correlation function generating unit 11 and the reception signal output from the temporary recording unit 10, and outputs a processing signal P1 based on the correlation processing. To do. Since the all-band processing unit 12 performs correlation processing between the correlation function F1 of the continuous band B and the received signal of the discrete band B, as shown in FIG. At the same time, a large number of signals N1 and N2 that are false images of the target signal T1 are generated.

  The discrete band correlation function generation unit 13 generates the correlation function F2 based on the control signal from the band selection unit 18, and the discrete band correlation function generation unit 13 performs the first step as shown in FIG. Generates a correlation function F2 of the same discrete bands B1, B2, B3, B4, and B5 as the transmission signal, and outputs the correlation function F2 to the discrete band processing unit 14.

  As shown in FIG. 7, the discrete band processing unit 14 performs correlation processing between the correlation function F2 generated by the discrete band correlation function generating unit 13 and the received signal output by the temporary recording unit 10, and the correlation A processing signal P2 by the processing is output. Since the discrete band processing unit 14 performs correlation processing of the same signal using the received signal and the correlation function F2, a signal that is a false image of the target signal T2 is not generated as shown in FIG. Since the resolution of the signal T2 corresponds to the discrete band B1 + B2 + B3 + B4 + B5, it is worse than the processed signal P1.

  As shown in FIG. 8, the superimposition processing unit 15 includes a processing signal P1 output from the entire band processing unit 12 via the switching unit 17 and a processing signal P2 output from the discrete band processing unit 14. Superposition processing is performed, the partial signals P11 and P12 of the processing signal P1 included in the processing signal P2 are adopted as actual target signals, and these partial signals P11 and P12 are output to the convergence determination unit 16 as processing signals P3. . Further, as shown in FIG. 8, the overlay processing unit 15 outputs a processing signal P2 to the convergence determination unit 16 in parallel with the processing signal P3 for determination in the convergence determination unit 16.

  As shown in FIG. 9, the convergence determination unit 16 compares the processing signal P2 output from the superposition processing unit 15 with the processing signal P3, and if there is a difference in the number of peaks at the same time, it is still a false image. It is determined that it has not been completely removed, and the process proceeds to reprocessing. As shown in FIG. 9, for example, if the processing signal P2 has two peaks (target signals T11 and T12), the convergence determination unit 16 has two peaks of the processing signal P3. One of the target signals P11 or P12 is determined as a false image.

  When the convergence determination unit 16 shifts to reprocessing, the convergence determination unit 16 switches the signal line of the switching unit 17 and re-outputs the processing signal P3 to the overlay processing unit 15. Further, the convergence determination unit 16 controls the band selection unit 18 so as to select the band of the correlation function F2 'used for reprocessing. Further, the convergence determination unit 16 controls the temporary recording unit 10 to re-output the received signal for reprocessing.

In order to improve the resolution of the processing signal P2 based on the control from the convergence determination unit 16, the band selection unit 18 connects a part of the discrete bands of the correlation function F2 as shown in FIG. The band of the correlation function F2 ′ that increases the band is selected. The band selection unit 18 automatically controls the selection of the band of the correlation function F2 ′ in consideration of the balance with the generation of the false image so as to select the optimum band.
In the example shown in FIG. 10, the band selection unit 18 partially connects the discrete bands B3 and B4 of the correlation function F2 in order to improve the resolution of the processing signal P2 based on the control from the convergence determination unit 16. The band of the correlation function F2 ′ that increases the total band B3 ′ is selected.

  The discrete band correlation function generator 13 generates a correlation function F 2 ′ based on the control from the band selector 18, and outputs the correlation function F 2 ′ to the discrete band processor 14.

As shown in FIG. 11, the discrete band processing unit 14 calculates the stored reception signal re-output from the temporary recording unit 10 and the correlation function F2 ′ reproduced by the discrete band correlation function generation unit 13. Correlation processing is performed, and a processed signal P2 ′ by the correlation processing is output.
As shown in FIG. 11, the processed signal P2 ′ output from the discrete band processing unit 14 includes an actual target signal T and a target signal T indicated by bold lines as a result of correlation processing by the discrete band processing unit 14. Signals N3 and N4 that are false images are included.

As shown in FIG. 12, the superimposition processing unit 15 includes a processing signal P3 output from the convergence determination unit 16 via the switching unit 17 and a processing signal P2 output from the discrete band processing unit 14. And the partial signal T11 of the processing signal P3 included in the processing signal P2 ′ (particularly the target signal T) is adopted as the actual target signal T, and the convergence determination unit is used as the processing signal P3 ′. 16 is output. The overlay processing unit 15 also outputs a processing signal P2 ′ in parallel for determination by the convergence determination unit 16.
In the example shown in FIG. 12, since the partial signal T12 of the processing signal P3 is not included in the processing signal P2 ′, the superposition processing unit 15 targets the partial signal T12 of the processing signal P3 as a result of the superposition processing. The signal T is not adopted.

  As shown in FIG. 13, the convergence determination unit 16 compares the processing signal P3 ′ output from the overlay processing unit 15 and the processing signal P2 ′, and there is no difference in the number of peaks at the same time. It is determined that all the false images have been removed, and the processing signal P3 ′ is output as the target signal T.

Next, the effect by Embodiment 1 of this invention is demonstrated based on FIG.
As shown in FIG. 14A, when the radar can transmit and receive a continuous wideband signal S1 in the radar use band B, the target signal T1 with good resolution and no false image can be obtained. On the other hand, when only the discrete bands B1, B2, B3, B4, and B5 can be used in the radar band B as shown in the upper part of FIG. 14B, the discrete bands B1, B2, and B2 are used. When the target is detected using the signal S2 that uses B3, B4, and B5, the resolution is good, but as shown in FIG. 17, the target signal depends on how the bands B1, B2, B3, B4, and B5 are used. Many signals N1 and N2 which are false images of T1 are generated.

In the first embodiment of the present invention, as shown in FIG. 1, when a target is detected by discretely using the radar usage band B, the received signal is multiplied by the continuous correlation function F1 of the radar usage band B. A superposition process is performed on the processing signal P1 subjected to the matching process and the processing signal P2 subjected to the process of multiplying the reception signal by the correlation function F2 of the same discrete bands B1, B2, B3, B4, and B4 as the transmission signal. And removing the signals N1 and N2, which are false images of the target signal, by adopting the partial signal (T1) of the processed signal P1 included in the processed signal P2 as the actual target signal T. As shown in the lower part of FIG. 14B, even if the radar can only use the band discretely, the false image of the target can be removed, and the continuous broadband In which it is possible to obtain the effect of equivalent used.
(Embodiment 2)

  Next, a second embodiment of the present invention is a radar false image removal processing apparatus that employs a method in which a sufficient number of processing units and correlation function generation units are prepared in advance, and a false image is removed by a single overlay process. Will be described.

  The radar false image removal processing device according to the second embodiment of the present invention shown in FIG. 15 is compared with the radar false image removal processing device according to the first embodiment of the present invention shown in FIG. The radar false image removal processing device according to the first embodiment of the present invention in that it includes an all-band processing unit, a discrete band correlation function generation unit, a discrete band processing unit, and an overlay processing unit. And in common. The radar false image removal processing device according to the second embodiment of the present invention shown in FIG. 15 is replaced with a convergence determination unit, a switching unit, and a band selection unit for realizing a method of converging false image removal by feedback. A characteristic feature is that a sufficient number of necessary discrete band correlation function generation units and discrete band processing units are prepared in advance, and false images are removed by a single overlay process.

More specifically, as shown in FIG. 15, in addition to the discrete band processing unit 14 shown in FIG. 2, two or more discrete band processing units 14 _{1 to} 14 _n are arranged in parallel, as shown in FIG. in addition to discrete band correlation function generating unit 13 corresponding to the discrete band processing unit 14, two or more discrete band processing unit 14 _first correlation for two or more discrete bands corresponding to to 14 _n function generator 13 ₁ - the 13 _n arranged, a configuration of inputting the two or more processing by discrete band processing unit 14, 14 ₁ to 14 _n is correlated to the output signal _P2, P2 1 to P2 _n the parallel superimposition processing unit 15 Is building.

In the example shown in FIG. 15, the discrete band correlation function generator 13 corresponding to the discrete band processor 14 generates the same discrete band B correlation function F2 as the transmission signal as shown in FIG. The correlation function F2 is output to the discrete band processing unit 14.
The discrete band correlation function generators 13 _{1 to} 13 _n corresponding to the discrete band processing units 14 _{1 to} 14 _n other than the discrete band processing unit 14 have the same discrete band of the correlation function F2 as shown in FIG. Correlation functions F2 ₁ ′ to F2 _n ′ in which the total band increases by joining the parts are generated, and the correlation functions F2 ₁ ′ to F2 _n ′ are respectively assigned to the corresponding discrete band processing units 14 _{2 to} 14 _n . Output.
In this case, the discrete band correlation function generation units 13 and 13 _{1 to} 13 _n select the correlation bands F2 to be partially connected so that the discrete bands are different from each other, and connect the discrete bands of the correlation function F2 together. Correlation functions F2 ₁ ′ to F2 _n ′ that increase the total bandwidth are generated.

Superimposition processing unit 15, two or more full-band processing unit 12, in parallel processing signals _P1, P2, P2 1 ~P2 _n by the correlation processing discrete-band processing unit 14, 14 ₁ to 14 _n outputs As shown in FIG. 16, two or more processed signals P1, P2, and P2 _{1 to} P2 _n are superposed to obtain a target signal T.

Next, the case where the radar false image removal processing method is executed using the radar false image removal processing apparatus having the configuration shown in FIG. 15 will be described in detail. This embodiment, three full-band processing unit 12, the discrete and band processing unit 14, 14 _1, these correlation functions for all bands corresponding to the generating unit 11, a discrete band correlation function generating unit 13, 13 ₁ However, the present invention is not limited to this combination example, and the same applies when the number of the discrete band processing units and the discrete band correlation function generating units is increased. In the example shown in FIG. 15, the discrete band correlation function generators 13 and 13 _{1 to} 13 _n are illustrated as one discrete band correlation function generator, and the discrete band correlation function generator is generated. ₁ are illustrated as a configuration in which different correlation functions F2, F2 ₁ ′ to F2 _n ′ are output to the corresponding discrete band processing units 14 and 14 _{1 to} 14 _n , respectively, for convenience of explanation, Description will be made based on an example in which the correlation function generation units 13 and 13 _{1 to} 13 _n are independently constructed.

In FIG. 15, the all-band correlation function generator 11 generates a continuous band correlation function F1 based on the necessary resolution instruction D from the outside, as shown on the left side of FIG. The function F1 is output to the all-band all-band processing unit 12.
As shown on the left side of FIG. 16A, the all-band processing unit 12 correlates the correlation function F1 output from the all-band correlation function generation unit 11 with the received signal output from the temporary recording unit 10. Processing is performed, and a processing signal P1 resulting from the correlation processing is output to the overlay processing unit 15. Since the all-band processing unit 12 performs correlation processing between the correlation function F1 of the continuous band B and the received signal of the discrete band B, as shown on the right side of FIG. A good target signal T1 is obtained, but at the same time, a large number of signals N1 and N2 that are false images of the target signal T1 are generated.

In FIG. 15, the discrete band correlation function generation unit 13 generates a correlation function F2 of the same discrete bands B1, B2, B3, B4, and B5 as the transmission signal, as shown on the left side of FIG. The correlation function F2 is output to the discrete band processing unit 14.
As shown on the left side of FIG. 16B, the discrete band processing unit 14 performs a correlation process between the correlation function F2 generated by the discrete band correlation function generating unit 13 and the received signal output by the temporary recording unit 10. And output a processed signal P2 by the correlation processing. Since the discrete band processing unit 14 performs correlation processing of the same signal with the received signal and the correlation function F2, as shown on the right side of FIG. 16B, a signal that is a false image of the target signal T2 is Although it does not occur, the resolution of the target signal T2 corresponds to the discrete band B1 + B2 + B3 + B4 + B5, and thus becomes worse than the processing signal P1.

Discrete bands for correlation function generating unit 13 ₁ as shown on the right side of FIG. 16 (C), the in order to improve the resolution of the processed signal P2, increasing the bandwidth of the total by connecting some discrete bands of the correlation function F2 'generates, the correlation function F2' correlation function F2 so as to output a discrete band processing unit 14 _1.
The discrete band processing unit 14 ₁ as shown in the right side of FIG. 16 (C9, the temporary storage section 10 the correlation function the discrete bands for correlation function generating unit 13 ₁ and the reception signal output generated from F2 ' performs correlation processing with the processing signal P2 1 by the correlation process _'outputs a. as shown in the right side of FIG. 16 (C), the processed signal P2 to the discrete band processing unit 14 ₁ outputs', the result of the correlation process by the discrete band processing unit 14 _1, contains a signal N3, N4 is the actual artifacts of the target signal T1 and the target signal T1 shown by bold lines.

Superimposition processing unit 15 as shown in FIG. 17, three full-band processing unit 12, in parallel processing signals P1, P2, P2 ₁ by the correlation processing discrete band processing unit 14, 14 ₁ outputs The two or more processed signals P1, P2, and P21 ₁ are superposed to obtain a target signal T.

  According to the example shown in FIG. 15, it is difficult to completely remove a signal that is a false image of the target signal, but there is an advantage that the configuration can be simplified and the processing speed can be improved. is doing.

  The present invention can be applied to a radar using a low frequency band in the field of remote sensing. In particular, it can be used for a synthetic aperture radar that requires a wide band for high resolution.

10 temporary storage section 11 correlation function generator 12 full-band processing unit 13, 13 ₁ to 13 _n discrete bands for correlation function generating unit 14, 14 ₁ to 14 _n discrete band processing unit 15 superimposition processing unit 16 for the entire band Convergence determination unit 17 Switching unit 18 Band selection unit

Claims (6)

In a radar false image removal processing device that removes a false image of a target signal included in a received signal that has received a reflected wave at a detection target or the like,
Generate a continuous band correlation function based on the required resolution instruction from the outside, and output the correlation function for all bands, a correlation function generator for all bands,
A correlation function output from the correlation function generator for all bands and a processing section for all bands that performs a correlation process with the received signal and outputs a first processing signal;
A discrete band correlation function generating unit that generates a correlation function of the same discrete band as the transmission signal and outputs the correlation function;
A discrete band processing unit that performs correlation processing between the correlation function generated by the discrete band correlation function generation unit and the received signal and outputs a second processed signal;
The partial signal of the first processing signal included in the second processing signal is adopted as an actual target signal by superimposing the first processing signal and the second processing signal. And a superimposing processing unit that removes a signal that is a false image of the target signal. Furthermore, it has a convergence determination unit and a band selection unit,
The overlay processing unit has a function of outputting the processing signal adopted as the actual target signal and the processing signal subjected to correlation processing by the discrete band processing unit to the convergence determination unit,
The convergence determination unit determines whether the processing signal output from the overlay processing unit includes a target false image, and if the target false image is not included, outputs the processing signal as it is as a target signal. If the false image of the target is included, the processing signal output by the superposition processing unit for reprocessing is output to the superposition processing unit,
The band selection unit, based on the control signal from the convergence determination unit, uses the discrete band as a band control signal to generate band information that is used to generate a correlation function in the discrete band correlation function generation unit. Output to the correlation function generator for
The discrete band correlation function generation unit has a function of generating a partially continuous correlation function based on a control signal from the band selection unit and outputting the correlation function to the discrete band processing unit. And
The discrete band processing unit performs a correlation process between the correlation function newly output by the discrete band correlation function generation unit and the reception signal output by the temporary recording unit, and superimposes the processing signals by the correlation processing on the superposition It has a function to output to the processing unit,
The superposition processing unit has a function of inputting the processing signal output from the convergence determination unit and the processing signal newly subjected to correlation processing by the discrete band processing unit, and superimposing these processing signals. The radar false image removal processing device according to claim 1. In addition to the discrete band processing units, two or more discrete band processing units are arranged in parallel,
Two or more discrete band correlation function generation units corresponding to the discrete band processing unit,
The superposition processing unit inputs the processing signal correlated by the all-band processing unit and the processing signal correlated by the discrete band processing unit, and superimposes the processing signals. The radar false image removal processing device according to claim 1, which has a function of acquiring a target signal. In a radar false image removal processing method for removing a false image of a target signal included in a received signal that has received a reflected wave at a detection target or the like,
A first processed signal obtained by multiplying the received signal by a continuous correlation function of a radar use band and a process obtained by multiplying the received signal by a correlation function of the same discrete band as the transmission signal. 2 is overlaid with the processed signal
A radar false image characterized in that a signal that is a false image of a target signal is removed by employing a partial signal of the first processed signal included in the second processed signal as an actual target signal. Removal processing method. The superimposed third processing signal and the second processing signal are compared, and if there is a difference in the number of peaks at the same time, it is determined that the false image has not been completely removed, and Move on to processing,
When shifting to the reprocessing, a correlation function is generated so as to increase a total band by connecting a part of the discrete bands of the correlation function, and a correlation process between the correlation function and the received signal is performed, and the correlation process is performed. Output a fourth processed signal by
Both the third processing signal and the fourth processing signal are overlapped, the fifth processing signal output by the overlapping processing is compared with the fourth processing signal, and both at the same time The radar false image removal processing method according to claim 4, wherein it is determined that the false image has been removed when there is no difference in the number of peaks. Performing a process of multiplying the received signal by a continuous correlation function of a radar use band to generate a first processed signal;
A process of multiplying the reception signal by a correlation function of the same discrete band as the transmission signal to generate two or more second processed signals;
By performing a superimposition process of the first processing signal and the two or more second processing signals, a partial signal of the first processing signal included in the second processing signal is converted into an actual target signal. 5. The radar false image removal processing method according to claim 4, wherein a signal that is a false image of the target signal is removed by adopting as the above.

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