Ground guidance radar anti-interference method in main lobe and side lobe composite interference mode

Abstract

The embodiment of the invention relates to a ground guidance radar anti-interference method in a main lobe and side lobe composite interference mode. The method comprises the following steps: selecting a side lobe cancellation sample from side lobe cancellation data and side lobe cancellation delay section data; calculating a sidelobe cancellation weight based on the sidelobe cancellation sample; performing sidelobe cancellation processing on the sum path data by using the sidelobe cancellation weight to obtain the sum path data after sidelobe cancellation; performing time domain sliding window elimination processing on the sum path data after side lobe cancellation to obtain sum path data after intra-pulse preliminary elimination; performing multi-level threshold elimination processing on the sum path data after the intra-pulse preliminary elimination to obtain sum path data after the intra-pulse final elimination; and performing inter-pulse interference processing on the sum path data after the intra-pulse final elimination. According to the embodiment of the invention, by executing the sidelobe cancellation processing, the time domain sliding window elimination processing and the multi-level threshold elimination processing, the intra-pulse interference zero setting processing is carried out on the main lobe, and finally the inter-pulse interference processing is carried out on the main lobe, so that the anti-interference effect in the main-sidelobe composite interference mode is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of radar countermeasure technology, and in particular to an anti-interference method for ground-based guided radar in a main-sidelobe composite interference mode. Background Art

[0002] Air defense operations face a systematic air strike chain consisting of combat nodes such as long-range early warning reconnaissance and medium- and long-range interference suppression. Early warning reconnaissance in the air strike chain implements long-range support interference by discovering important targets and detecting ground electromagnetic signals at a long distance. It releases intermittent noise interference, which enters the receiver through the side lobes of the radar antenna, forming side lobe interference to the radar. It releases intermittent noise interference, which enters the receiver through the main lobe of the radar antenna, forming main lobe interference to the radar. The interference formed by each node in the air strike chain forms main-side lobe composite interference on the ground radar. The main-side lobe composite mode interference realizes all-round and full-spectrum interference suppression, causing the ground-guided radar to fail to work normally.

[0003] Most of the existing anti-interference methods deal with single long-range support or main lobe interference, and less deal with main-side lobe composite interference. Moreover, in the main-side lobe composite interference mode, the main-side lobe interference will overlap, resulting in the existing anti-interference methods not being ideal in anti-interference effect.

[0004] Therefore, it is necessary to provide a new technical solution to improve one or more problems existing in the above solutions.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] The purpose of the embodiments of the present disclosure is to provide a ground-guided radar anti-interference method in a main-sidelobe composite interference mode, so as to improve the anti-interference effect in the main-sidelobe composite interference mode.

[0007] According to an embodiment of the present disclosure, a ground-based guided radar anti-interference method in a main-sidelobe composite interference mode is provided, comprising:

[0008] Selecting sidelobe cancellation samples from the sidelobe cancellation data and the sidelobe cancellation delay node data;

[0009] Calculating a sidelobe cancellation weight based on the sidelobe cancellation samples;

[0010] Performing sidelobe cancellation processing on the summed data using the sidelobe cancellation weights to obtain the summed data after the sidelobe cancellation;

[0011] Performing time domain sliding window elimination processing on the sum path data after the side lobe cancellation to obtain the sum path data after preliminary elimination of the intra-pulse;

[0012] Performing multi-level threshold elimination processing on the sum-path data after preliminary elimination in the pulse to obtain the sum-path data after final elimination in the pulse;

[0013] The inter-pulse interference processing is performed on the sum-path data after the final elimination in the pulse.

[0014] In an exemplary embodiment of the present disclosure, the selecting of sidelobe cancellation samples from the sidelobe cancellation data and the sidelobe cancellation delay node data further includes the following steps:

[0015] Calculate first ratio data and second ratio data based on the sidelobe cancellation data and the sidelobe cancellation delay node data;

[0016] Performing a first threshold judgment on the sidelobe cancellation data and the first ratio data to obtain sum channel sample data and auxiliary branch channel sample data;

[0017] A second threshold judgment is performed on the sidelobe cancellation delay node data and the second ratio data to obtain sum path delay node sample data and auxiliary branch delay node sample data.

[0018] In an exemplary embodiment of the present disclosure,

[0019] The side lobe cancellation data includes sum-path side lobe cancellation sampling gate data and auxiliary branch side lobe cancellation sampling gate data, and the first ratio data is obtained by performing ratio processing on the auxiliary branch side lobe cancellation sampling gate data and the sum-path side lobe cancellation sampling gate data;

[0020] The side lobe cancellation delay node data includes the sum-path side lobe cancellation sampling gate delay node data and the auxiliary branch side lobe cancellation sampling gate delay node data. The second ratio data is obtained by ratio processing the auxiliary branch side lobe cancellation sampling gate delay node data with the sum-path side lobe cancellation sampling gate delay node data.

[0021] In an exemplary embodiment of the present disclosure,

[0022] The first threshold is determined as follows:

[0023] R Fp∑p (i:i+5)>gate1&&(A ∑pi >ceoff1*N ∑Re )&&(A Fpi >ceoff1*N FRe ) (1)

[0024] Among them, ceoff1 represents the first threshold coefficient, gate1 represents the threshold value, N ∑Re Indicates the noise level of the receiver, N FReRepresents the noise level of the auxiliary branch receiver, the value range of i is 1≤i≤M p -5, R Fp / ∑p Represents the first ratio data, A ∑pi A represents the i-th data in the roadside lobe cancellation sampling gate data, Fpi represents the i-th data in the auxiliary branch sidelobe cancellation sampling gate data, M p Indicates the number of sampling points of the sidelobe cancellation sampling gate;

[0025] The second threshold is determined as follows:

[0026] R DFp∑p (i:i+5)>gate1&&(A D∑pi >ceoff1*N ∑Re )&&(A DFpi >ceoff1*N FRe ) (2)

[0027] Among them, ceoff1 represents the first threshold coefficient, gate1 represents the threshold value, N ∑Re Indicates the noise level of the receiver, N FRe Represents the noise level of the auxiliary branch receiver, the value range of i is 1≤i≤M p -5, R DFp / ∑p Indicates the second ratio data, A D∑pi A represents the i-th data in the roadside lobe cancellation sampling gate delay section data, Fpi Represents the i-th data in the auxiliary branch sidelobe cancellation sampling gate delay section data.

[0028] In an exemplary embodiment of the present disclosure, the calculating of the sidelobe cancellation weight based on the sidelobe cancellation samples further includes the following steps:

[0029] Calculating the autocorrelation function of the auxiliary branch and the cross-correlation function of the sum branch and the auxiliary branch according to the sidelobe cancellation samples;

[0030] The sidelobe cancellation weight is calculated according to the autocorrelation function and the cross-correlation function.

[0031] In an exemplary embodiment of the present disclosure, the performing sidelobe cancellation processing on the sum path data by using the sidelobe cancellation weights further includes the following steps:

[0032] Obtaining the sum-branch orthogonal baseband signal and the auxiliary branch orthogonal baseband signal;

[0033] Constructing the auxiliary branch delay node data based on the auxiliary branch orthogonal baseband signal;

[0034] Based on the sidelobe cancellation weight, the auxiliary branch orthogonal baseband signal and the auxiliary branch delay node data, the summed orthogonal baseband signal is subjected to sidelobe cancellation processing to obtain the summed data after the sidelobe cancellation.

[0035] In an exemplary embodiment of the present disclosure, the performing time domain sliding window elimination processing on the sum path data after the sidelobe cancellation further includes the following steps:

[0036] Performing modulus processing on the sum-path data after the sidelobe cancellation to obtain a modulus value of the sum-path signal;

[0037] Performing multiple sliding window processing on each pulse signal in the sum-path data after the sidelobe cancellation, and performing mean processing on the modulus value of the sum-path signal in the window during each sliding window processing to obtain a mean value sequence of each pulse signal;

[0038] For each pulse signal, the minimum mean value in the corresponding mean value sequence is used as the threshold level;

[0039] A first threshold level judgment operation is performed on each of the pulse signals to obtain the sum path data after preliminary elimination of the pulses.

[0040] In an exemplary embodiment of the present disclosure, the multi-level threshold elimination processing is performed on the sum path data after the preliminary elimination of the pulse, and further includes the following steps:

[0041] Performing averaging processing on the non-zero values ​​in each pulse signal in the sum-path data after the preliminary elimination of the pulses, to obtain a first threshold;

[0042] Extracting an intermediate matrix from each pulse signal based on the first threshold, and performing averaging processing on the intermediate matrix to obtain a second threshold;

[0043] A second threshold level judgment operation is performed on each of the pulse signals to obtain the sum path data after the pulses are finally eliminated.

[0044] In an exemplary embodiment of the present disclosure, the inter-pulse interference processing of the sum path data after the final elimination in the pulse further includes the following steps:

[0045] Performing averaging processing on the non-zero values ​​in each pulse signal in the sum-path data after the final elimination of the intra-pulse, obtaining multiple mean values, and selecting the minimum value from the multiple mean values ​​as the inter-pulse threshold;

[0046] Perform inter-pulse threshold judgment on each pulse signal to obtain the summed data after inter-pulse interference processing.

[0047] In an exemplary embodiment of the present disclosure, after the inter-pulse interference processing is performed on the sum path data after the final elimination in the pulse, the following steps are also included:

[0048] Post-processing is performed on the sum-path signal data after the inter-pulse interference processing to obtain the final sum-path data after the interference processing.

[0049] The technical solution provided by the present disclosure may have the following beneficial effects:

[0050] In the embodiment of the present disclosure, firstly, sidelobe cancellation samples are selected from the sidelobe cancellation data and the sidelobe cancellation delay data, the sidelobe cancellation weights are calculated, and the sidelobe cancellation processing is completed for the sum data; then, the time domain characteristics of intermittent interference are used to process the sum data after the sidelobe cancellation in sequence in the pulse by using the time domain sliding window elimination and multi-level threshold elimination methods, and each pulse processing within a coherent accumulation cycle is completed. This processing method can maximize the guarantee that the sum signal level value is not affected by interference; finally, the sum data after the final elimination in the pulse is processed by using the inter-pulse interference processing method to perform the interference zeroing processing between pulses, so as to achieve the countermeasure against the intermittent noise interference. This embodiment performs the sidelobe cancellation processing first, and then performs the time domain sliding window elimination and multi-level threshold elimination processing on this basis to achieve the intra-pulse interference zeroing processing of the main lobe, and finally performs the inter-pulse interference processing on the main lobe, which significantly improves the anti-interference effect in the main-side lobe composite interference mode.

[0051] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0053] Figure 1 A flow chart showing a method for anti-interference of a ground-guided radar in a main-sidelobe composite interference mode in an exemplary embodiment of the present disclosure;

[0054] Figure 2 The sum signal modulus value and the auxiliary branch signal modulus value in the sidelobe cancellation sampling gate in the exemplary embodiment of the present disclosure are shown;

[0055] Figure 3 The diagram shows a sampling gate delay section signal of a side lobe cancellation of a path and a sampling gate delay section signal of a side lobe cancellation of an auxiliary branch in an exemplary embodiment of the present disclosure;

[0056] Figure 4 The signal modulus values ​​of the 8th pulse and the roadside lobe cancellation processing before and after the cancellation processing in an exemplary embodiment of the present disclosure are shown;

[0057] Figure 5 The figure shows the signal modulus values ​​of the sum of the eighth pulses in a coherent processing cycle before and after the interference processing in the pulse in the exemplary embodiment of the present disclosure;

[0058] Figure 6 The signal modulus values ​​of the 9th pulse and the roadside lobe cancellation processing before and after the cancellation processing in an exemplary embodiment of the present disclosure are shown;

[0059] Figure 7 The signal modulus values ​​of the 9th pulse and the path pulse before and after the interference processing in an exemplary embodiment of the present disclosure are shown;

[0060] Figure 8 The coherent accumulation processing result after the inter-path interference processing in the exemplary embodiment of the present disclosure is shown;

[0061] Fig. 9 A schematic diagram of target distance dimension envelope before and after interference processing in an exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0062] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0063] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and their repeated description will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor devices and / or microcontroller devices.

[0064] In this example implementation, a ground-based guided radar anti-interference method in a main-sidelobe composite interference mode is first provided. Figure 1 As shown in , the method may include the following steps:

[0065] Step S101: selecting sidelobe cancellation samples from sidelobe cancellation data and sidelobe cancellation delay node data;

[0066] Step S102: calculating the sidelobe cancellation weight based on the sidelobe cancellation samples;

[0067] Step S103: performing sidelobe cancellation processing on the summed data using the sidelobe cancellation weights to obtain the summed data after the sidelobe cancellation;

[0068] Step S104: performing time domain sliding window elimination processing on the sum path data after the side lobe cancellation, and obtaining the sum path data after the preliminary elimination of the intra-pulse;

[0069] Step S105: performing multi-level threshold elimination processing on the sum-path data after preliminary elimination in the pulse, and obtaining the sum-path data after final elimination in the pulse;

[0070] Step S106: performing inter-pulse interference processing on the sum-path data after the pulse is finally eliminated.

[0071] In the embodiment of the present disclosure, firstly, sidelobe cancellation samples are selected from the sidelobe cancellation data and the sidelobe cancellation delay data, the sidelobe cancellation weights are calculated, and the sidelobe cancellation processing is completed for the sum data; then, the time domain characteristics of intermittent interference are used to process the sum data after the sidelobe cancellation in sequence in the pulse by using the time domain sliding window elimination and multi-level threshold elimination methods, and each pulse processing within a coherent accumulation cycle is completed. This processing method can maximize the guarantee that the sum signal level value is not affected by interference; finally, the sum data after the final elimination in the pulse is processed by using the inter-pulse interference processing method to perform the interference zeroing processing between pulses, so as to achieve the countermeasure against the intermittent noise interference. This embodiment performs the sidelobe cancellation processing first, and then performs the time domain sliding window elimination and multi-level threshold elimination processing on this basis to achieve the intra-pulse interference zeroing processing of the main lobe, and finally performs the inter-pulse interference processing on the main lobe, which significantly improves the anti-interference effect in the main-side lobe composite interference mode.

[0072] Below, each step of the above method in this example implementation will be described in more detail.

[0073] In one embodiment, the coherent processing period of the pulse radar is set to 18.2 ms, and the width of the sidelobe cancellation sampling gate is T pbdx =800μs, data sampling rate F s1 =1MHz, then the baseband signal length in the sidelobe cancellation sampling gate is M pbdx =F s1 T pbdx , and obtain the sampling gate data of the side lobe cancellation of the road and the sampling gate data of the auxiliary branch side lobe cancellation, as well as the sampling gate delay section data of the side lobe cancellation of the road and the sampling gate delay section data of the auxiliary branch side lobe cancellation.

[0074] The step of selecting the sidelobe cancellation samples from the sidelobe cancellation data and the sidelobe cancellation delay node data in step S101 further includes the following steps:

[0075] Step S1011: calculating first ratio data and second ratio data based on the sidelobe cancellation data and the sidelobe cancellation delay node data;

[0076] Step S1012: performing a first threshold judgment on the sidelobe cancellation data and the first ratio data to obtain sum channel sample data and auxiliary branch channel sample data;

[0077] Step S1013: Perform a second threshold judgment on the sidelobe cancellation delay node data and the second ratio data to obtain the sum path delay node sample data and the auxiliary branch delay node sample data.

[0078] Specifically, the sidelobe cancellation data in step S1011 includes the sum-path sidelobe cancellation sampling gate data and the auxiliary branch sidelobe cancellation sampling gate data, which can be respectively expressed as:

[0079]

[0080] Among them, A ∑p A represents the matrix composed of the sampling gate data of the roadside lobe cancellation, Fp A matrix representing the auxiliary branch sidelobe cancellation sampling gate data;

[0081] The first ratio data is obtained by performing ratio processing on the auxiliary branch side lobe cancellation sampling gate data and the sum branch side lobe cancellation sampling gate data. The first ratio data is as follows:

[0082]

[0083] Among them, R Fp∑p Represents the first ratio data.

[0084] Specifically, the side lobe cancellation delay node data in step S1011 includes the sum side lobe cancellation sampling gate delay node data and the auxiliary branch side lobe cancellation sampling gate delay node data, which can be respectively expressed as:

[0085]

[0086] Among them, A D∑p A represents the matrix composed of the sampling gate delay data of the roadside lobe cancellation, DFp A matrix representing the auxiliary branch sidelobe cancellation sampling gate delay data;

[0087] The second ratio data is obtained by performing ratio processing on the auxiliary branch side lobe cancellation sampling gate delay section data and the sum road side lobe cancellation sampling gate delay section data. The second ratio data is as follows:

[0088]

[0089] Among them, R DFp / ∑p Represents the second ratio data.

[0090] Specifically, in step S1012, a first threshold determination operation is performed on the sidelobe cancellation data and the first ratio data, and the first threshold determination is:

[0091] R Fp∑p (i:i+5)>gate1&&(A ∑pi >ceoff1*N ∑Re )&&(A Fpi >ceoff1*N FRe ) (1)

[0092] Among them, ceoff1 represents the first threshold coefficient, gate1 represents the threshold value, N ∑Re Indicates the noise level of the receiver, N FRe Represents the noise level of the auxiliary branch receiver, the value range of i is 1≤i≤M p -5, R Fp / ∑p Represents the first ratio data, A ∑pi A represents the i-th data in the roadside lobe cancellation sampling gate data, Fpi represents the i-th data in the auxiliary branch sidelobe cancellation sampling gate data, M p Indicates the number of sampling points of the sidelobe cancellation sampling gate;

[0093] If the judgment condition in the above formula (1) is met, the data of the sum path and the data of the auxiliary branch are recorded as samples until the data traversal is completed, and the sum path sample data A is obtained. S∑p And auxiliary branch sample data A SFp .

[0094] Specifically, in step S1013, a second threshold determination operation is performed on the sidelobe cancellation delay node data and the second ratio data, and the second threshold determination is:

[0095] R DFp / ∑p (i:i+5)>gate1&&(A D∑pi >ceoff1*N ∑Re )&&(A DFpi >ceoff1*N FRe ) (2)

[0096] Among them, ceoff1 represents the first threshold coefficient, gate1 represents the threshold value, N ∑Re Indicates the noise level of the receiver, N FRe Represents the noise level of the auxiliary branch receiver, the value range of i is 1≤i≤M p -5, R DFp / ∑p represents the second ratio matrix, A D∑pi A represents the i-th data in the roadside lobe cancellation sampling gate delay section data,Fpi represents the i-th data in the auxiliary branch sidelobe cancellation sampling gate delay section data, M p Indicates the number of sampling points of the sidelobe cancellation sampling gate;

[0097] If the judgment condition in the above formula (2) is met, the delay node data of the sum path and the delay node data of the auxiliary branch are recorded as samples until the data traversal is completed, and the delay node sample data A of the sum path is obtained. DS∑p And auxiliary branch delay section sample data A DSFp .

[0098] The step of calculating the sidelobe cancellation weight based on the sidelobe cancellation samples in step S102 further includes the following steps:

[0099] Step S1021: Calculate the autocorrelation function of the auxiliary branch and the cross-correlation function between the sum branch and the auxiliary branch according to the sidelobe cancellation samples;

[0100] Step S1022: Calculate the sidelobe cancellation weights according to the autocorrelation function and the cross-correlation function.

[0101] Specifically, in step S1021, the autocorrelation function of the auxiliary branch is calculated according to the sidelobe cancellation samples, and the autocorrelation function is:

[0102]

[0103] Among them, R xx represents the autocorrelation function, A′ SFp Indicates A SFp The conjugate transpose of DSFp Indicates A DSFp The conjugate transpose of ;

[0104] The cross-correlation function between the sum path and the auxiliary branch is calculated based on the sidelobe cancellation samples. The cross-correlation function is:

[0105]

[0106] Among them, R xd represents the cross-correlation function, A′ S∑p Indicates A S∑p The conjugate transpose of .

[0107] Specifically, in step S1022, the sidelobe cancellation weight is calculated according to the autocorrelation function and the cross-correlation function, and the sidelobe cancellation weight is:

[0108] ω opt =inv(R xx )*R xd (9)

[0109] Among them, ω opt represents the sidelobe cancellation weight, Rxx represents the autocorrelation function, R xd represents the cross-correlation function.

[0110] In one embodiment, a coherent processing cycle T of the ground pulse radar is set CPI The number of transmitted pulses in is N = 12, and the pulse repetition period is T r , pulse width tau = 172μs, gate width is T bm =184μs, sampling frequency F s =20MHz, then the length of the baseband signal sampling points within one pulse repetition period is M=3680.

[0111] The step of performing sidelobe cancellation processing on the sum path data by using the sidelobe cancellation weights in step S103 further includes the following steps:

[0112] Step S1031: Acquire the sum branch orthogonal baseband signal and the auxiliary branch orthogonal baseband signal;

[0113] Step S1032: constructing auxiliary branch delay node data based on the auxiliary branch orthogonal baseband signal;

[0114] Step S1033: Based on the sidelobe cancellation weights, the auxiliary branch orthogonal baseband signals and the auxiliary branch delay node data, sidelobe cancellation processing is performed on the summed orthogonal baseband signals to obtain summed data after sidelobe cancellation.

[0115] Specifically, the sum branch orthogonal baseband signal and the auxiliary branch orthogonal baseband signal in step S1031 can be expressed as:

[0116]

[0117] Among them, A ∑ represents the sum of the orthogonal baseband signals within a coherent processing cycle, A ∑ij represents the amplitude of the sum-path orthogonal baseband signal of the j-th distance unit in the i-th pulse repetition period within the coherent processing period, the value range of i is [1, N], and the value range of j is [1, M];

[0118]

[0119] Among them, A F represents the auxiliary branch orthogonal baseband signal within a coherent processing cycle, A Fij It represents the amplitude of the auxiliary branch orthogonal baseband signal of the jth range unit in the i-th pulse repetition period within the coherent processing period. The value range of i is [1, N] and the value range of j is [1, M].

[0120] Specifically, the auxiliary branch delay node data in step S1032 can be expressed as:

[0121]

[0122] Among them, A DF Indicates auxiliary branch delay data.

[0123] Specifically, in step S1033, based on the sidelobe cancellation weight, the auxiliary branch orthogonal baseband signal and the auxiliary branch delay node data, the sidelobe cancellation processing is performed on the auxiliary branch orthogonal baseband signal through the following formula (13):

[0124]

[0125] Among them, A ∑ represents the sum of the orthogonal baseband signals within a coherent processing cycle, w′ opt represents the conjugate transpose of the sidelobe cancellation weights, A F represents the auxiliary branch orthogonal baseband signal within a coherent processing cycle, A DF Indicates the auxiliary branch delay data, A ∑slc Represents the summed data after sidelobe cancellation.

[0126] The step of performing time domain sliding window elimination processing on the summed path data after the sidelobe cancellation in step S104 further includes the following steps:

[0127] Step S1041: performing modulus processing on the sum-path data after sidelobe cancellation to obtain a modulus value of the sum-path signal;

[0128] Step S1042: performing sliding window processing multiple times on each pulse signal in the sum-path data after sidelobe cancellation, and performing mean processing on the modulus of the sum-path signal in the window during each sliding window processing to obtain a mean value sequence of each pulse signal;

[0129] Step S1043: for each pulse signal, taking the minimum mean value in the corresponding mean value sequence as the threshold level;

[0130] Step S1044: perform the first threshold level judgment operation on each pulse signal to obtain the sum path data after preliminary elimination of the pulse.

[0131] Specifically, in step S1041, the sum-path data after the sidelobe cancellation is subjected to modulus processing to obtain the sum-path signal modulus value, and the sum-path signal modulus value is:

[0132]

[0133] Among them, A1 ∑slc Represents the matrix composed of the modulus values ​​of the AND-path signals. The value range of i is [1,N], and the value range of j is [1,M].

[0134] In one embodiment, A1 ∑slc The operations of step S1042 to step S1044 are described by taking the i-th pulse signal in as an example:

[0135] In step S1042, the summed data A1 after sidelobe cancellation is ∑slc The i-th pulse signal A in i Perform multiple sliding window processing, where the window length of the sliding window processing can be set to win_len, the step can be set to step_len points, and the number of sliding windows can be set to P times; in each sliding window processing, the modulus value of the sum signal in the window is averaged to obtain the average sequence avg of each pulse signal i =[avg i1 ,avg i2 ,…,avg iP ], the mean sequence avg i Contains P means.

[0136] Among them, in step S1043, the pulse signal A i The corresponding mean sequence avg i The minimum mean value in is used as the threshold level gate i1 ;

[0137] In step S1044, the pulse signal A i Execute the first threshold level judgment operation, that is, A ∑slci The amplitude of each sampling point in |A ∑slcij |Compare with the interference nulling threshold as follows:

[0138]

[0139] Among them, K represents the second threshold coefficient, gate i1 Represents the first threshold level, represents the summed data after the sidelobe cancellation in step S103 is subjected to the first threshold level judgment operation by the above formula (15), A ij Represents the sampling point data of the jth distance unit in the i-th pulse repetition period;

[0140] By executing the judgment condition in the above formula (15), i1 The sampling points are set to zero, and the sampling points not greater than the threshold level K×gate i1 The sampling points are retained to obtain data The threshold value of interference zeroing in step S1044 is K×gate i1 .

[0141] It should be noted that for A1∑slc After all the i pulse signals in the image are executed through steps S1042 to S1044, the summed data after preliminary elimination of the pulses can be obtained.

[0142] The step of performing multi-level threshold elimination processing on the sum path data after the preliminary elimination of the pulse in step S105 also includes the following steps:

[0143] Step S1051: average the non-zero values ​​in each pulse signal in the sum-path data after the initial elimination of the pulses to obtain a first threshold;

[0144] Step S1052: extracting an intermediate matrix from each pulse signal based on the first threshold, and performing mean processing on the intermediate matrix to obtain a second threshold;

[0145] Step S1053: Perform a second threshold level judgment operation on each pulse signal to obtain the sum path data after the pulse is finally eliminated.

[0146] In one embodiment, the operation of step S1051 to step S1053 is described by taking the i-th pulse signal in the sum path data after preliminary elimination of the pulse as an example:

[0147] In step S1051, the i-th pulse signal in the sum path data after the initial elimination of the pulse is The non-zero values ​​in are averaged to obtain the first threshold corresponding to the i-th pulse signal:

[0148]

[0149] Among them, avg1 i represents the first threshold, K represents the second threshold coefficient, Represents the data in the i-th pulse signal, and the value range of j is [1,M];

[0150] Among them, in step S1052, first based on the first threshold avg1 i Extract the intermediate matrix from the i-th pulse signal. Specifically, the intermediate matrix is ​​obtained by: taking the first threshold avg1 i As the threshold, The middle modulus value is less than the first threshold avg1 i The elements of are assigned to the intermediate matrix to obtain the intermediate matrix A3 i =[A3 i1 ,…,A3 i2 ,…,A3 is ];

[0151] Then the intermediate matrix A3 i =[A3 i1 ,…,A3i2 ,…,A3 is ] to perform averaging processing to obtain the second threshold corresponding to the i-th pulse signal:

[0152]

[0153] Among them, avg2 i Indicates the second threshold, A3 is represents the elements in the intermediate matrix, and S represents the number of non-zero elements in the intermediate matrix;

[0154] In step S1053, a second threshold level determination operation is performed on the i-th pulse signal, that is, A ∑slci The amplitude of each sampling point in |A ∑slcij |Compare with the interference nulling threshold as follows:

[0155]

[0156] Among them, K2 represents the third threshold coefficient, avg2 i represents the second threshold, represents the summed data after the sidelobe cancellation in step S103 is eliminated by the above equations (15) and (18), Represents the sampling point data of the jth distance unit in the i-th pulse repetition period;

[0157] By executing the judgment condition in the above formula (18), for the value greater than the threshold level K2×avg2 i The sampling points are set to zero, and the sampling points not greater than the threshold level K2×avg2 i The sampling points are retained to obtain data The threshold value of interference zeroing in the above step S1053 is K2×avg2 i .

[0158] It should be noted that by executing steps S1051 to S1053 on all i pulse signals in the sum path data after preliminary elimination of the pulse, the sum path data after final elimination of the pulse can be obtained.

[0159] It should also be noted that completing the processing of the i-th pulse signal according to step 104 and step 105 is equivalent to completing the pulse processing within one coherent accumulation cycle. The processing of the intra-pulse interference of the sum path can be considered to be completed only after executing step 104 and step 105 for all N pulse signals in the sum path data after the sidelobe cancellation obtained in step S103, which is equivalent to completing the pulse processing within N coherent accumulation cycles, and only then can step S106 be executed.

[0160] It should also be noted that when actually executing step S104 and step S105 calculations, for the sum path data including N pulse signals, step S104 and step S105 can be executed on the previous pulse signal in the order from the 1st pulse signal to the Nth pulse signal; and then step S104 and step S105 are executed on the next pulse signal; until step S104 and step S105 are executed on all pulse signals, then step S601 is executed.

[0161] The step of performing inter-pulse interference processing on the sum-path data finally removed from the pulse in step S106 further includes the following steps:

[0162] Step S1061: average the non-zero values ​​in each pulse signal in the sum-path data after the final elimination of the intra-pulse, obtain multiple averages, and select the minimum value from the multiple averages as the inter-pulse threshold;

[0163] Step S1062: Perform inter-pulse threshold judgment on each pulse signal to obtain summed data after inter-pulse interference processing.

[0164] Specifically, in step S1061, the non-zero values ​​in each pulse signal in the sum-path data after the pulse is finally eliminated are averaged to obtain multiple average values ​​PRT_Am, and the minimum value PRT_Am is selected from the multiple average values ​​PRT_Am. min As the inter-pulse threshold.

[0165] Specifically, in step S1062, the pulse threshold judgment PRT_Am(j)>K3PRT_Am is performed on each pulse signal. min ; Where K3 represents the fourth threshold coefficient. For a value greater than the threshold level K3PRT_Am min The pulse data is reset to zero, and the pulse data not greater than the threshold level K3PRT_Am min The pulse data is retained to obtain the summed data after inter-pulse interference processing.

[0166] In one embodiment, after the inter-pulse interference processing is performed on the sum path data after the final elimination in the pulse, the following steps are also included:

[0167] Perform post-processing on the sum signal data after the pulse-to-pulse interference processing to obtain the final sum signal data after the interference processing.

[0168] Optionally, post-processing of the sum signal data after the inter-pulse interference processing may include: MTD processing, constant false alarm processing, target recognition processing, and normalization processing. MTD processing, constant false alarm processing, target recognition processing, and normalization processing belong to the existing technical means for radar signal processing, which will not be described in detail here.

[0169] In the embodiment of the present application, in order to further verify the effect of the ground-guided radar anti-interference method in the main-sidelobe composite interference mode proposed in the present application, a simulation experiment was carried out. The simulation data and simulation results in the simulation experiment process are referenced to Figures 2 to 9 As shown:

[0170] refer to Figure 2 As shown in Figure 2 The sum signal modulus value and the auxiliary branch signal modulus value in the sidelobe cancellation sampling gate in this embodiment are shown, wherein the sum signal modulus value is the data obtained by calculating the modulus value of the sum sidelobe cancellation sampling gate data, and the auxiliary branch signal modulus value is the data obtained by calculating the modulus value of the auxiliary branch sidelobe cancellation sampling gate data.

[0171] refer to Figure 3 As shown in Figure 3 1 shows the sampling gate delay section signal of the neutral path side lobe cancellation and the sampling gate delay section signal of the auxiliary branch side lobe cancellation in this embodiment. Figure 2 and Figure 3 By processing the data in step S102, the sidelobe cancellation weight value in step S102 can be obtained.

[0172] refer to Figure 4 and Figure 6 As shown in Figure 4 and Figure 6 Figure 2 shows the data modulus values ​​of two pulses before and after the sidelobe cancellation process in a coherent processing cycle, where: Figure 4 Graphs show the signal modulus values ​​of the 8th pulse in a coherent processing cycle in this embodiment before and after the side lobe cancellation processing. Figure 6 Graph 1 shows the signal modulus values ​​of the 9th pulse in a coherent processing cycle in this embodiment before and after the side lobe cancellation processing. Figure 4 and Figure 6 It can be seen that the sidelobe interference signal can be eliminated through sidelobe cancellation processing.

[0173] refer to Figure 5 and Figure 7 As shown in Figure 5 and Figure 7 The sum of the data after the final elimination of the pulse is shown, that is, the comparison results before and after the zeroing of the pulse interference, where: Figure 5 1 shows the signal modulus values ​​of the sum of the eighth pulses in a coherent processing cycle in this embodiment before and after the interference processing. Figure 7 Figure 2 shows the signal modulus values ​​of the 9th pulse and path pulse in a coherent processing cycle before and after interference processing in this embodiment. Figure 5 and Figure 7 It can be seen that intra-pulse interference processing can be achieved through the processing of steps S104 and S105.

[0174] refer to Figure 8 As shown in Figure 8 Figure 2 shows the coherent accumulation processing result after the inter-path interference processing in this embodiment. Figure 8 It can be seen that inter-pulse interference processing can be achieved through step S106.

[0175] refer to Fig. 9 As shown in Fig. 9 FIG. 2 shows a schematic diagram of target distance dimension envelope before and after interference processing in this embodiment. Fig. 9 It can be seen that before interference processing, the target envelope is submerged in the main sidelobe interference and the target cannot be detected; after interference processing, the interference can be effectively suppressed and the target signal can be detected normally.

[0176] By adopting the anti-interference method of the ground-guided radar in the main-sidelobe composite interference mode proposed by the present invention, the interference can be effectively suppressed and the target signal can be detected normally.

[0177] It should be noted that, although the steps of the method in the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step for execution, and / or one step may be decomposed into multiple steps for execution, etc. In addition, it is also easy to understand that these steps may be, for example, executed synchronously or asynchronously in multiple modules / processes / threads.

[0178] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A ground-guided radar anti-interference method in a main-sidelobe composite interference mode, characterized in that: include: Selecting sidelobe cancellation samples from the sidelobe cancellation data and the sidelobe cancellation delay node data; Calculating a sidelobe cancellation weight based on the sidelobe cancellation samples; Performing sidelobe cancellation processing on the summed data using the sidelobe cancellation weights to obtain the summed data after the sidelobe cancellation; Performing time domain sliding window elimination processing on the sum path data after the side lobe cancellation to obtain the sum path data after preliminary elimination of the intra-pulse; Performing multi-level threshold elimination processing on the sum-path data after preliminary elimination in the pulse to obtain the sum-path data after final elimination in the pulse; The inter-pulse interference processing is performed on the sum-path data after the final elimination in the pulse.

2. The ground-guided radar anti-interference method in the main-sidelobe composite interference mode according to claim 1 is characterized in that: The step of selecting the sidelobe cancellation samples from the sidelobe cancellation data and the sidelobe cancellation delay node data further comprises the following steps: Calculate first ratio data and second ratio data based on the sidelobe cancellation data and the sidelobe cancellation delay node data; Performing a first threshold judgment on the sidelobe cancellation data and the first ratio data to obtain sum channel sample data and auxiliary branch channel sample data; A second threshold judgment is performed on the sidelobe cancellation delay node data and the second ratio data to obtain sum path delay node sample data and auxiliary branch delay node sample data.

3. The ground-guided radar anti-interference method in the main-sidelobe composite interference mode according to claim 2 is characterized in that: The side lobe cancellation data includes sum-path side lobe cancellation sampling gate data and auxiliary branch side lobe cancellation sampling gate data, and the first ratio data is obtained by performing ratio processing on the auxiliary branch side lobe cancellation sampling gate data and the sum-path side lobe cancellation sampling gate data; The side lobe cancellation delay node data includes the sum-path side lobe cancellation sampling gate delay node data and the auxiliary branch side lobe cancellation sampling gate delay node data. The second ratio data is obtained by ratio processing the auxiliary branch side lobe cancellation sampling gate delay node data with the sum-path side lobe cancellation sampling gate delay node data.

4. The ground-guided radar anti-interference method in the main-sidelobe composite interference mode according to claim 3 is characterized in that: The first threshold is determined as follows: R Fp / ∑p (i:i+5)>gate1&&(A ∑pi >ceoff1*N ∑Re )&&(A Fpi >ceoff1*N FRe ) (1) Among them, ceoff1 represents the first threshold coefficient, gate1 represents the threshold value, N ∑Re Indicates the noise level of the receiver, N FRe Represents the noise level of the auxiliary branch receiver, the value range of i is 1≤i≤M p -5, R Fp∑p Represents the first ratio data, A ∑pi A represents the i-th data in the roadside lobe cancellation sampling gate data, Fpi represents the i-th data in the auxiliary branch sidelobe cancellation sampling gate data, M p Indicates the number of sampling points of the sidelobe cancellation sampling gate; The second threshold is determined as follows: R DFp / ∑p (i:i+5)>gate1&&(A D∑pi >ceoff1*N ∑Re )&&(A DFpi >ceoff1*N FRe ) (2) Among them, ceoff1 represents the first threshold coefficient, gate1 represents the threshold value, N ∑Re Indicates the noise level of the receiver, N FRe Represents the noise level of the auxiliary branch receiver, the value range of i is 1≤i≤M p -5, R DFp / ∑p Indicates the second ratio data, A D∑pi A represents the i-th data in the roadside lobe cancellation sampling gate delay section data, Fpi represents the i-th data in the auxiliary branch sidelobe cancellation sampling gate delay section data, M p Indicates the number of sampling points of the sidelobe cancellation sampling gate.

5. The anti-interference method of ground-guided radar in the main-sidelobe composite interference mode according to claim 1 is characterized in that: The calculating of the sidelobe cancellation weight based on the sidelobe cancellation samples further comprises the following steps: Calculating the autocorrelation function of the auxiliary branch and the cross-correlation function of the sum branch and the auxiliary branch according to the sidelobe cancellation samples; The sidelobe cancellation weight is calculated according to the autocorrelation function and the cross-correlation function.

6. The ground-guided radar anti-interference method in the main-sidelobe composite interference mode according to claim 1 is characterized in that: The method of using the sidelobe cancellation weights to perform sidelobe cancellation processing on the sum path data further comprises the following steps: Obtaining the sum-branch orthogonal baseband signal and the auxiliary branch orthogonal baseband signal; Constructing the auxiliary branch delay node data based on the auxiliary branch orthogonal baseband signal; Based on the sidelobe cancellation weight, the auxiliary branch orthogonal baseband signal and the auxiliary branch delay node data, the summed orthogonal baseband signal is subjected to sidelobe cancellation processing to obtain the summed data after the sidelobe cancellation.

7. The ground-guided radar anti-interference method in the main-sidelobe composite interference mode according to claim 1 is characterized in that: The performing time domain sliding window elimination processing on the sum path data after the sidelobe cancellation also includes the following steps: Performing modulus processing on the sum-path data after the sidelobe cancellation to obtain a modulus value of the sum-path signal; Performing multiple sliding window processing on each pulse signal in the sum-path data after the sidelobe cancellation, and performing mean processing on the modulus value of the sum-path signal in the window during each sliding window processing to obtain a mean value sequence of each pulse signal; For each pulse signal, the minimum mean value in the corresponding mean value sequence is used as the threshold level; A first threshold level judgment operation is performed on each of the pulse signals to obtain the sum path data after preliminary elimination of the pulses.

8. The ground-guided radar anti-interference method in the main-sidelobe composite interference mode according to claim 1 is characterized in that: The multi-level threshold elimination process is performed on the sum path data after the preliminary elimination in the pulse, and further comprises the following steps: Performing averaging processing on the non-zero values ​​in each pulse signal in the sum-path data after the preliminary elimination of the pulses, to obtain a first threshold; Extracting an intermediate matrix from each pulse signal based on the first threshold, and performing averaging processing on the intermediate matrix to obtain a second threshold; A second threshold level judgment operation is performed on each of the pulse signals to obtain the sum path data after the pulses are finally eliminated.

9. The ground-guided radar anti-interference method in the main-sidelobe composite interference mode according to claim 8, characterized in that: The inter-pulse interference processing of the sum path data finally removed from the pulse further includes the following steps: Performing averaging processing on the non-zero values ​​in each pulse signal in the sum-path data after the final elimination of the intra-pulse, obtaining multiple mean values, and selecting the minimum value from the multiple mean values ​​as the inter-pulse threshold; Perform inter-pulse threshold judgment on each pulse signal to obtain the summed data after inter-pulse interference processing.

10. The ground-guided radar anti-interference method in the main-sidelobe composite interference mode according to claim 9, characterized in that: After the inter-pulse interference processing is performed on the sum path data finally removed from the pulse, the following steps are also included: Post-processing is performed on the sum-path signal data after the inter-pulse interference processing to obtain the final sum-path data after the interference processing.

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