A method for estimating multipath delay taps in a dense false target jamming environment

Abstract

The application discloses a method for estimating a multipath delay section under dense false target jamming, which comprises the following steps: obtaining a first data vector X' and a second data vector Y' based on target echo signals received by a main antenna and an auxiliary antenna; obtaining a first distance unit vector U based on the first data vector X'; obtaining a second distance unit vector V based on the second data vector Y'; and obtaining the number of delay distance units of multipath jamming relative to direct jamming to be estimated based on the first distance unit vector U and the second distance unit vector V. The application is simple in implementation, convenient in processing, capable of avoiding a large number of multiplication operations, reducing the calculation amount, accelerating the operation speed and saving storage resources.

Description

Technical Field

[0001] This invention belongs to the field of radar technology, specifically relating to a method for estimating multipath delay sections under dense false target interference. Background Technology

[0002] Dense decoy jamming is a common type of deceptive jamming signal. Because such jamming signals have strong coherence with radar echo signals, they produce a relatively high pulse compression gain after matched filtering, resulting in many false peaks. Typically, the power of the jamming signal is greater than the power of the radar echo signal. Therefore, multiple false peaks mix with the real target, leading to a decrease in radar detection performance. The radar antenna, upon receiving the target echo, is unable to distinguish between the real target and the decoy.

[0003] Sidelobe Blanking (SLB) is a common anti-jamming technique widely used due to its simplicity and good anti-jamming effect. It is an effective method to suppress deceptive interference such as false targets entering from the antenna sidelobes. It is implemented by using an auxiliary antenna to receive signals simultaneously with the main antenna. The signals received by both the main and auxiliary antennas undergo the same processing, such as pulse compression, detection, and constant false alarm rate (CFAR) detection. The results of the two processing steps are compared based on their corresponding range cells, and a blanking decision is made based on the comparison results. This decision determines whether the main antenna signal should pass through, thereby eliminating radar interference signals while preserving the target signal.

[0004] The performance of sidelobe concealment technology is related to the multipath effect of signals during propagation. During electromagnetic wave propagation, reflection or scattering from the ground or buildings results in multiple propagation paths. The electromagnetic waves from each path arrive at the radar receiver at different times, thus creating the multipath effect. Interference signals emitted from the interference source that are directly received by the radar antenna are called direct interference. Multipath interference, on the other hand, is direct interference that has been reflected or scattered before being received by the radar antenna. Due to differences in the propagation medium, the loss of the interference signal varies, leading to different signal amplitudes received by the radar antenna. Therefore, the multipath effect causes direct interference and multipath interference to differ in pulse range cell position and intensity; that is, multipath interference has a time delay relative to direct interference.

[0005] Sidelobe masking is an effective method to suppress deceptive interference such as false targets entering from the antenna sidelobes. However, in the presence of multipath effects, weak multipath interference signals may be received by the main lobe of the main antenna, preventing sidelobe masking from completely eliminating false target interference and thus hindering the radar's ability to detect the real target. Current multipath interference elimination techniques first estimate the number of delay sections relative to direct interference by calculating the cross-correlation function of the interference signals in the main and auxiliary channels. Then, delay sections are added in the auxiliary channel for joint sidelobe masking processing, thereby improving the suppression capability against multipath interference. However, estimating delay sections using the cross-correlation function method requires a large number of multiplication operations in practical systems, consuming significant storage space. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a method for estimating the multipath delay section under dense false target interference. In a multipath environment, when using sidelobe camouflage techniques to suppress dense false target interference, this method can directly estimate the time delay section between multipath interference and direct interference. The technical problem to be solved by this invention is achieved through the following technical solution:

[0007] A method for estimating multipath delay sections under dense false target interference background, the method comprising:

[0008] Based on the target echo signals received by the main antenna and the auxiliary antenna, the first data vector X′ corresponding to the main antenna and the second data vector Y′ corresponding to the auxiliary antenna are obtained.

[0009] Based on the first data vector X′, the first distance units corresponding to all over-detection threshold elements in the target echo signal received by the main antenna are obtained, and all the first distance units form the first distance unit vector U;

[0010] Based on the second data vector Y′, the second range units corresponding to all over-detection threshold elements in the target echo signal received by the auxiliary antenna are obtained, and all the second range units form the second range unit vector V;

[0011] Based on the first distance cell vector U and the second distance cell vector V, the number of delay distance cells of the multipath interference to be estimated relative to the direct interference is obtained.

[0012] In one embodiment of the present invention, based on the target echo signals received by the main antenna and the auxiliary antenna, obtaining a first data vector X′ corresponding to the main antenna and a second data vector Y′ corresponding to the auxiliary antenna includes:

[0013] Based on the target echo signals received by the main antenna and the auxiliary antenna, a first signal vector X corresponding to the main antenna and a second signal vector Y corresponding to the auxiliary antenna are obtained.

[0014] Based on the first signal vector X and the second signal vector Y, the first data vector X′ corresponding to the main antenna and the second data vector Y′ corresponding to the auxiliary antenna are obtained.

[0015] In one embodiment of the present invention, based on the target echo signals received by the main antenna and the auxiliary antenna, a first signal vector X corresponding to the main antenna and a second signal vector Y corresponding to the auxiliary antenna are obtained, including:

[0016] The target echo signal received by the main antenna is subjected to pulse compression processing to obtain the first signal vector X, and the target echo signal received by the auxiliary antenna is subjected to pulse compression processing to obtain the second signal vector Y.

[0017] In one embodiment of the present invention, obtaining a first data vector X′ corresponding to the main antenna and a second data vector Y′ corresponding to the auxiliary antenna based on the first signal vector X and the second signal vector Y includes:

[0018] The first signal vector X is subjected to square-law detection or linear detection to obtain the first data vector X′, and the second signal vector Y is subjected to square-law detection or linear detection to obtain the second data vector Y′.

[0019] In one embodiment of the present invention, first range units corresponding to all over-detection threshold elements in the target echo signal received by the main antenna are obtained based on the first data vector X′. All the first range units constitute a first range unit vector U, including:

[0020] The first data vector X′ is subjected to constant false alarm detection processing to obtain the first distance unit corresponding to all over-detection threshold elements in the first data vector X′. All the first distance units form the first distance unit vector U.

[0021] In one embodiment of the present invention, a second range cell corresponding to all over-detection threshold elements in the target echo signal received by the auxiliary antenna is obtained based on the second data vector Y′. All the second range cells constitute a second range cell vector V, including:

[0022] The second data vector Y′ is subjected to constant false alarm rate (CFAR) detection processing to obtain the second distance unit corresponding to all over-detection threshold elements in the second data vector Y′. All the second distance units form the second distance unit vector V.

[0023] In one embodiment of the present invention, the number of delay range cells of the multipath interference to be estimated relative to the direct interference is obtained based on the first range cell vector U and the second range cell vector V, including:

[0024] Step 4.1: Subtract the current number of delayed distance units k from each first distance unit in the first distance unit vector U to obtain the third distance unit vector D. k ;

[0025] Step 4.2: Based on the third distance unit vector D k The number of the same distance units between the vector V and the second distance unit is used to obtain r(k);

[0026] Step 4.3: Determine whether k = K is true, where K is the maximum number of delay distance units set. If yes, proceed to step 4.4; otherwise, set k = k + 1 and return to step 4.1 until k = K.

[0027] Step 4.4: Determine the maximum value in the final curve r(k), and obtain the number of delay distance units of the multipath interference to be estimated relative to the direct interference based on the k value corresponding to the maximum value.

[0028] In one embodiment of the present invention, the third distance unit vector D k The calculation formula is:

[0029] D k =Uk

[0030] =[u1-k,u2-k,...,u i -k,...,u I -k]

[0031] Among them, u i Let i represent the i-th first distance unit, where i = 1, 2, ..., I.

[0032] In one embodiment of the present invention, step 4.2 includes:

[0033] Statistics exist in the third distance unit vector D k The number of distance units existing in the second distance unit vector V is used to obtain the curve r(k).

[0034] In one embodiment of the present invention, the curve r(k) is represented as:

[0035] r(k) = crad(D) k ∩V)

[0036] Here, crad represents the number of elements in the finite set, and ∩ represents taking the intersection.

[0037] The beneficial effects of this invention are:

[0038] Based on the characteristic that dense false target interference signals form false peaks after pulse compression, this invention estimates the number of delay sections of multipath interference relative to direct interference. It uses all range cells where the auxiliary antenna's received signal passes the constant false alarm rate (CFAR) detection threshold as the position vector corresponding to direct interference, and all range cells where the main antenna's received signal passes the CFAR detection threshold as the position vector corresponding to multipath interference. This yields the positions of direct and multipath interference respectively. Building upon conventional sidelobe concealment techniques for eliminating multipath effects, this invention estimates the time delay sections based on the positional relationship between multipath and direct interference. Compared to the cross-correlation function method, this approach avoids numerous multiplication operations, reduces computational load, accelerates computation, saves storage resources, and is simpler to implement and more convenient to process. Attached Figure Description

[0039] Figure 1 This is a flowchart illustrating a method for estimating multipath delay sections under dense false target interference, as provided in an embodiment of the present invention.

[0040] Figure 2 This is a schematic diagram of a geometric model provided in an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of a model of direct interference and multipath interference provided in an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of multipath interference received by the main antenna and direct interference received by the auxiliary antenna, provided by an embodiment of the present invention.

[0043] Figure 5 This is a result diagram of constant false alarm rate (CFAR) detection performed on the data received by the main antenna, as provided in an embodiment of the present invention.

[0044] Figure 6 This is a result diagram of constant false alarm rate (CFAR) detection performed on the data received by the auxiliary antenna, as provided in an embodiment of the present invention.

[0045] Figure 7 This is a result image of a conventional sidelobe concealment method provided in an embodiment of the present invention;

[0046] Figure 8 This is a correlation curve obtained by a cross-correlation function method provided in an embodiment of the present invention;

[0047] Figure 9 This is a diagram showing the number of delay nodes obtained using the method of the present invention, provided by an embodiment of the present invention.

[0048] Figure 10 This is a combined sidelobe anechoic image provided by an embodiment of the present invention. Detailed Implementation

[0049] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0050] Example 1

[0051] Since auxiliary antennas are typically low-gain omnidirectional antennas and multipath interference is much weaker than direct interference, most of the interference received by auxiliary antennas is direct interference. However, the main lobe gain of the radar's main antenna is much greater than that of the auxiliary antenna. Therefore, even very weak multipath interference entering from the main lobe direction of the main antenna can become very strong and cannot be ignored compared to direct interference. It should be noted that multipath interference is not always present during radar scanning; it only exists in certain specific directions. Furthermore, because the main lobe beamwidth of the main antenna is very narrow, the received multipath interference is usually only one or two paths.

[0052] To address the technical problem that conventional sidelobe masking techniques cannot effectively eliminate multipath interference entering from the main lobe of the main antenna, existing methods first estimate the number of time delay sections of multipath interference relative to direct interference using interference data from the main channel and the masking channel. Then, corresponding delay sections are added to the received signal of the auxiliary channel to obtain the received signal of the virtual auxiliary channel. Finally, the received signals of the main antenna and auxiliary antenna, as well as the received signals of the main antenna and the virtual auxiliary antenna at the same distance cell, are compared separately. The two comparison results are combined for masking detection to determine whether the signal at that distance cell of the main channel can pass. Ultimately, interference signals (including direct interference and multipath interference) are not allowed to pass, while the target signal is allowed to pass, achieving the effect of preserving the target signal and suppressing interference signals.

[0053] When eliminating the impact of multipath effects on conventional sidelobe masking techniques, estimating the number of time delay segments between multipath interference and direct interference is crucial. A conventional method uses the cross-correlation function method, which involves shifting the main path received interference signal relative to the auxiliary path received interference signal. The correlation is calculated for each shift (each distance cell), and the number of distance cells corresponding to the maximum correlation value is the estimated number of time delay segments between the multipath interference and the direct interference. While the cross-correlation function method provides a direct representation of the time delay segment number, it requires extensive multiplication operations, consuming significant storage resources in practical applications.

[0054] Please see Figure 1 and Figure 2 , Figure 1This is a flowchart illustrating a method for estimating multipath delay sections under dense false target interference conditions, as provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of a geometric model provided by an embodiment of the present invention. The present invention provides a method for estimating multipath delay sections under dense false target interference background, the method comprising:

[0055] Step 1: Based on the target echo signals received by the main antenna and the auxiliary antenna, obtain the first data vector X′ corresponding to the main antenna and the second data vector Y′ corresponding to the auxiliary antenna.

[0056] Here, as Figure 3 As shown, Figure 3 A schematic diagram of a model for direct interference and multipath interference is provided, that is, interference includes direct interference and multipath interference.

[0057] Step 1.1: Based on the target echo signals received by the main antenna and the auxiliary antenna, obtain the first signal vector X corresponding to the main antenna and the second signal vector Y corresponding to the auxiliary antenna.

[0058] Specifically, the target echo signal received by the main antenna is pulse-compressed to obtain a first signal vector X, and the target echo signal received by the auxiliary antenna is pulse-compressed to obtain a second signal vector Y.

[0059] Here, the first signal vector obtained after pulse compression of the target echo signal received by the main antenna is denoted as X = [x1, x2, ..., x]. M The second signal vector obtained by pulse compression of the target echo signal received by the auxiliary antenna is denoted as Y = [y1, y2, ..., y]. M ], where the first signal vector X and the second signal vector Y are both 1×M matrices, and M represents the total number of distance units.

[0060] Step 1.2: Based on the first signal vector X and the second signal vector Y, obtain the first data vector X′ corresponding to the main antenna and the second data vector Y′ corresponding to the auxiliary antenna.

[0061] Specifically, the first signal vector X is subjected to square-law detection or linear detection to obtain the first data vector X′, and the second signal vector Y is subjected to square-law detection or linear detection to obtain the second data vector Y′.

[0062] Here, the first data vector X′ is X′=[x1′,x2′,...,x M The second signal vector Y is Y′=[y1′,y2′,...,y′]. M ′], where x M ′ is for x M The signal after detection processing, yM ′ for y M The signal after detection processing.

[0063] Step 2: Based on the first data vector X′, obtain the first range cells corresponding to all over-detection threshold elements in the target echo signal received by the main antenna, and all the first range cells form the first range cell vector U.

[0064] Specifically, constant false alarm rate (CFAR) detection is performed on the first data vector X′ to obtain the first range units corresponding to all over-detection threshold elements in the target echo signal received by the main antenna. All the first range units form the first range unit vector U.

[0065] Here, constant false alarm rate (CFAR) detection is performed on the first data vector X′ to obtain the first distance unit corresponding to all over-detection threshold elements in the first data vector, and the first distance unit corresponding to the i-th over-detection threshold element in the first data vector X′ is denoted as u. i Where i = 1, 2, ..., I represents the index of the threshold element of the first data vector X′, I represents the total number of threshold elements of the first data vector X′, and I ≤ M, where I is a non-negative integer. All the first distance units form the first distance unit vector U, U = [u1, u2, ..., u...]. I ].

[0066] Step 3: Based on the second data vector Y′, obtain the second range cells corresponding to all over-detection threshold elements in the target echo signal received by the auxiliary antenna. All the second range cells form the second range cell vector V.

[0067] Specifically, constant false alarm rate (CFAR) detection is performed on the second data vector Y′ to obtain the second distance units corresponding to all over-detection threshold elements in the second data vector Y′. All the second distance units form the second distance unit vector V.

[0068] Here, constant false alarm rate (CFAR) detection is performed on the second data vector Y′ to obtain the second distance unit corresponding to all over-detection threshold elements in the second data vector Y′, and the second distance unit corresponding to the j-th over-detection threshold element in the second data vector Y′ is denoted as v. j , where j = 1, 2, ..., J, represents the index of the threshold element of the second data vector Y′, J represents the total number of threshold elements of the second data vector J, and J ≤ M, where J is a non-negative integer.

[0069] Step 4: Based on the first distance unit vector U and the second distance unit vector V, obtain the number of delay distance units of the multipath interference to be estimated relative to the direct interference, which is the number of delay nodes.

[0070] Step 4.1: Subtract the current number of delayed distance units k from each first distance unit in the first distance unit vector U to obtain the third distance unit vector D. k .

[0071] Specifically, firstly, let the maximum number of delay range cells to be estimated be K, and the current number of delay range cells be k, and initialize k = 0. Then, based on the first range cell vector U obtained from the main antenna received signal, for each first range cell u... i Subtract the current number of delayed distance cells k to form the updated distance cell vector, denoted as the third distance cell vector D. k ,Right now:

[0072] D k =Uk

[0073] =[u1-k,u2-k,...,u I -k]

[0074] Among them, u i Let i represent the i-th first distance unit, where i = 1, 2, ..., I.

[0075] Step 4.2: Based on the third distance unit vector D k The number of identical distance units between the second distance unit vector V and the second distance unit vector V is used to obtain r(k).

[0076] Specifically, statistics exist in the third distance unit vector D. k Furthermore, the number of distance units existing in the second distance unit vector V is used to obtain r(k), which is equivalent to obtaining D. k The intersection with V, and the number of elements in the intersection, denoted as r(k), is specifically expressed as:

[0077] r(k) = crad(D) k ∩V)

[0078] Here, crad represents the number of elements in the finite set, and ∩ represents taking the intersection.

[0079] Step 4.3: Determine if k = K is true. If yes, proceed to step 4.4. If no, set k = k + 1 and return to step 4.1 until k = K.

[0080] Step 4.4: Determine the maximum value (i.e. the peak value in the curve) in the final curve r(k), and obtain the number of delay distance cells of the multipath interference to be estimated relative to the direct interference based on the k value corresponding to the maximum value.

[0081] Specifically, for the curve r(k), where k = 0 to K represents the number of delay units, the specific value of r(k) indicates how many signals among the multipath interference signals received by the main antenna have found their corresponding direct interference signals. The k value corresponding to the maximum value of r(k) is determined as the number of delay units τ between the multipath interference and the direct interference, that is:

[0082] r(τ) = maxr(k)

[0083] Where max represents the maximum value.

[0084] Please see Figure 4 This diagram, based on measured data, shows a subset of range elements and illustrates the multipath interference received by the main antenna and the direct interference received by the auxiliary antenna (the data received by the auxiliary antenna is divided by 5 for easier display). The horizontal axis represents the range element, and the vertical axis represents the amplitude. Please refer to [link to relevant documentation]. Figure 5 , Figure 5 This is the result graph after performing constant false alarm rate (CFAR) detection on the data received by the main antenna. The horizontal axis represents the range unit, and the vertical axis represents the signal amplitude, in dB. Figure 5 It can be seen that there are 12 elements whose received signals from the main antenna exceed the detection threshold, and their corresponding range cells are 337, 2708, 3537, 4366, 5195, 6853, 8184, 10765, 11594, 13252, 14081, and 14794. Due to the presence of multipath interference, many false peaks appear, and the interference of real targets and false targets is mixed together. At this time, it is impossible to correctly identify the range cell where the real target is located. Figure 6 This is the result graph after performing constant false alarm rate (CFAR) detection on the data received by the auxiliary antenna. The horizontal axis represents the range element, and the vertical axis represents the signal amplitude, in dB. Figure 6 It can be seen that there are 58 elements whose received signals from the auxiliary antenna exceed the detection threshold. These are mainly direct false target interference received by the auxiliary antenna.

[0085] The cloning result obtained using the conventional sidelobe cloning method is as follows: Figure 7 As shown, the horizontal axis represents the distance unit, and the vertical axis represents the signal amplitude, in dB. At this point, there are 12 elements that have passed the stealth threshold, with corresponding distance units of 337, 2708, 3537, 4366, 5195, 6853, 8184, 10765, 11594, 13252, 14081, and 14794. Figure 5 The results were consistent. This demonstrates that conventional methods cannot suppress multipath interference; the real target remains mixed with the false target, and the radar cannot detect the real target.

[0086] The correlation curve obtained using the cross-correlation function method is as follows: Figure 8As shown in the figure, the horizontal axis represents the number of delay sections, and the vertical axis represents the correlation. It can be seen from the figure that the maximum value of the correlation curve corresponds to a delay section number of 10. Therefore, the estimated number of delay sections between multipath interference and direct interference is 10.

[0087] After obtaining the distance cells where multipath interference and direct interference are located through constant false alarm rate (CFAR) detection, the number of delay nodes obtained using this invention is as follows: Figure 9 As shown in the figure, the horizontal axis represents the number of delay nodes, and the vertical axis represents the number of elements counted. It can be seen from the figure that when the number of delay nodes is 10, the number of elements counted that exist in both the direct interference range cell vector and the updated multipath interference range cell vector reaches its maximum value. Therefore, the estimated number of delay nodes for multipath interference relative to direct interference is 10, which aligns with the cross-correlation method... Figure 8 The results are consistent, which verifies the effectiveness of the method of the present invention.

[0088] Ten delay sections are added to the auxiliary channel to construct a virtual auxiliary channel for receiving signals. These signals are then combined with the original auxiliary channel signal and the main channel signal for joint sidelobe masking. The resulting masking effect is as follows: Figure 10 As shown, the horizontal axis represents the distance unit, and the vertical axis represents the signal amplitude, in dB. At this point, only one element has passed the stealth threshold, and its corresponding distance unit is 8184. Figure 7 In contrast, all other elements exceeding the detection threshold are suppressed, meaning multipath interference is eliminated. This demonstrates that by adding a virtual auxiliary antenna, multipath interference entering from the main antenna can be suppressed, while the real target is preserved, allowing the radar to detect the range cell containing the real target.

[0089] Due to the multipath effect, compared to direct interference, multipath interference not only experiences amplitude attenuation but also time delay, specifically a delay of several range units. Dense decoy interference contains multiple decoys, which, after pulse compression, form multiple decoy peaks. Each decoy will generate multipath interference due to the multipath effect. Since direct interference is delayed to generate multipath interference, the multipath interference component also forms a peak after pulse compression. In other words, the peak value of direct interference from decoys and its multipath interference peak appear correspondingly, and the specific number of range units between them is the estimated number of delay sections. The method of this invention first performs pulse compression processing, detection processing, and constant false alarm rate (CFAR) detection processing on the received signals of the main and auxiliary antennas, respectively. Then, based on the positional relationship between the range units corresponding to the detection threshold elements of the main antenna received signal and the range units corresponding to the detection threshold elements of the auxiliary antenna received signal, the number of time delay sections between multipath interference and direct interference is obtained. This method is a direct estimation method of delay sections, and its key lies in clearly identifying the positions of multipath interference and direct interference. When multipath interference enters from the main lobe of the main antenna, the interference signal received by the main antenna is mainly multipath interference. Therefore, if constant false alarm rate (CFAR) detection is performed on the signal received by the main antenna, the interference signal that exceeds the detection threshold is likely to be a multipath interference signal. Meanwhile, the interference signal received by the auxiliary antenna is mainly a direct interference signal, and the interference signal that exceeds the detection threshold is likely to be a direct interference signal. In this way, the positions of direct interference and multipath interference can be obtained respectively.

[0090] In engineering implementation, computational speed and storage resources need to be considered. This invention aims to address the shortcomings of the cross-correlation function method by reducing computational load and saving resources. Considering the characteristic that dense false target interference signals form multiple spurious peaks after pulse compression, this invention proposes a method to directly estimate the delay section of multipath interference relative to direct interference. This addresses the technical problem of sidelobe masking techniques consuming more storage resources due to calculating the delay section using cross-correlation. The method of this invention is an improvement based on the characteristics of dense false target interference. Unlike the cross-correlation method, this method calculates how many multipath interferences can be matched with their corresponding direct interferences based on the distance cell positions of the multipath and direct interferences. This avoids numerous multiplication operations, shortens computation time, and saves storage resources.

[0091] After estimating the delay section of multipath interference relative to direct interference using the method of this invention, a delay section is first added to the auxiliary channel to construct a virtual auxiliary channel. Then, the original auxiliary channel and the virtual auxiliary channel are combined and processed together with the main channel for sidelobe masking. This can eliminate the influence of multipath interference and improve the performance of conventional sidelobe masking.

[0092] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0093] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0094] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for estimating multipath delay sections under dense false target interference background, characterized in that, The method includes: Based on the target echo signals received by the main antenna and the auxiliary antenna, the first data vector corresponding to the main antenna is obtained. The second data vector corresponding to the auxiliary antenna ; Based on the first data vector The first range cells corresponding to all over-detection threshold elements in the target echo signal received by the main antenna are obtained, and all the first range cells form a first range cell vector. ; Based on the second data vector The second range cells corresponding to all over-detection threshold elements in the target echo signal received by the auxiliary antenna are obtained, and all the second range cells form a second range cell vector. ; Based on the first distance unit vector and the second distance unit vector The method obtains the number of delay range cells of the multipath interference to be estimated relative to the direct interference; including the steps of: 1) converting the first range cell vector The number of current delay distance units is subtracted from each first distance unit. The third distance unit vector is obtained. ;2) Based on the third distance unit vector and the second distance unit vector The number of identical distance units between them is obtained. ;3) Judgment Whether it is valid, This is the maximum delay distance unit number set. If so, proceed to step 4; otherwise, let... Return to step 1) until ;4) The final curve is obtained Determine the The maximum value in, according to the maximum value corresponding to It is worth noting the number of distance cells in the delay distance of the multipath interference relative to the direct interference.

2. The method for estimating multipath delay sections under dense false target interference background as described in claim 1, characterized in that, Based on the target echo signals received by the main antenna and the auxiliary antenna, the first data vector corresponding to the main antenna is obtained. The second data vector corresponding to the auxiliary antenna ,include: Based on the target echo signals received by the main antenna and the auxiliary antenna, the first signal vector corresponding to the main antenna is obtained. The second signal vector corresponding to the auxiliary antenna ; Based on the first signal vector and the second signal vector The first data vector corresponding to the main antenna is obtained. The second data vector corresponding to the auxiliary antenna .

3. The method for estimating multipath delay sections under dense false target interference background as described in claim 2, characterized in that, Based on the target echo signals received by the main antenna and the auxiliary antenna, the first signal vector corresponding to the main antenna is obtained. The second signal vector corresponding to the auxiliary antenna ,include: The target echo signal received by the main antenna is subjected to pulse compression processing to obtain the first signal vector. The target echo signal received by the auxiliary antenna is subjected to pulse compression processing to obtain the second signal vector. .

4. The method for estimating multipath delay sections under dense false target interference background as described in claim 2, characterized in that, Based on the first signal vector and the second signal vector The first data vector corresponding to the main antenna is obtained. The second data vector corresponding to the auxiliary antenna ,include: For the first signal vector The first data vector is obtained by performing square-law detection or linear detection. For the second signal vector The second data vector is obtained by performing square-law detection or linear detection. .

5. The method for estimating multipath delay sections under dense false target interference background as described in claim 2, characterized in that, Based on the first data vector The first range cells corresponding to all over-detection threshold elements in the target echo signal received by the main antenna are obtained, and all the first range cells form a first range cell vector. ,include: For the first data vector Perform constant false alarm rate (CFAR) detection processing to obtain the first data vector. The first distance unit is formed by the first distance unit corresponding to all elements that have passed the detection threshold. All the first distance units form the first distance unit vector. .

6. The method for estimating multipath delay sections under dense false target interference background as described in claim 2, characterized in that, Based on the second data vector The second range cells corresponding to all over-detection threshold elements in the target echo signal received by the auxiliary antenna are obtained, and all the second range cells form a second range cell vector. ,include: For the second data vector Perform constant false alarm rate (CFAR) detection processing to obtain the second data vector. The second distance unit is formed by the second distance unit corresponding to all elements that have passed the detection threshold. All the second distance units constitute the second distance unit vector. .

7. The method for estimating multipath delay sections under dense false target interference background as described in claim 1, characterized in that, The third distance unit vector The calculation formula is: in, Indicates the first i The first distance unit, .

8. The method for estimating multipath delay sections under dense false target interference background as described in claim 1, characterized in that, Step 2) includes: Statistics exist in the third distance unit vector It also exists in the second distance unit vector. The number of distance cells in the curve is used to obtain the curve. .

9. The method for estimating multipath delay sections under dense false target interference background as described in claim 1, characterized in that, The curve Represented as: in, This represents the number of elements in a finite set. This indicates finding the intersection.

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