Method for ground radar to resist intermittent sampling forwarding interference based on subspace decomposition

Abstract

The invention relates to a subspace decomposition-based intermittent sampling forwarding interference resisting method for a ground radar. The method comprises the following steps of: performing pulse compression processing on a sum path orthogonal baseband signal received by the ground radar; carrying out self-correlation processing on the sum path orthogonal baseband signal after pulse compression; constructing a projection matrix for the autocorrelation matrix after autocorrelation processing, enabling an interference subspace to be orthogonal to a signal subspace, and carrying out pulse signal suppression; and projecting the sum path orthogonal baseband signal after interference suppression on a signal subspace to complete intermittent sampling forwarding interference confrontation. According to the characteristic that intermittent sampling forwarding interference and target signals are orthogonal after pulse compression, a projection matrix of a signal subspace is constructed through characteristic decomposition, echo signals are projected along a signal domain after being subjected to pulse compression, and intermittent sampling forwarding interference confrontation is achieved. After the intermittent sampling forwarding interference confrontation, the signal-to-noise ratio is not lost, and a better confrontation effect can be achieved under the condition that the interference pulse period and the duty ratio change range are larger.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of radar countermeasure technology, and in particular to a method, system and electronic device for ground radar to counter intermittent sampling and forwarding interference based on subspace decomposition. Background Art

[0002] With the continuous development of jamming theory and jammer technology, the electromagnetic environment faced by radar has become more complex, and radar anti-interference has become an important part of modern electronic warfare. On the one hand, digital frequency storage and forwarding jammers can generate interference waveforms with strong coherence with radar transmission waveforms, and on the other hand, they can quickly and accurately recognize the mode and frequency of radar transmission waveforms, and quickly cover the radar operating frequency. Digital frequency storage and forwarding jammers have been widely used in active jammers. Limited by the limitations of physical size and isolation of transceiver antennas, in some typical combat environments such as missile-borne jamming, in order to achieve intra-pulse interference of ground radars, intermittent sampling and forwarding jammers as a typical digital frequency storage and forwarding jammer are widely used in missile-borne active jammers. After pulse compression, intermittent sampling and forwarding jammers appear as multiple false target signals. Strong jamming signals can suppress real target signals, making it impossible for ground radars to stably track targets and achieve the purpose of RF stealth, which brings severe challenges to radar detection.

[0003] The recognition time of digital frequency storage and forwarding interference for radar waveforms has reached the microsecond level. Conventional methods of waveform agility or frequency agility can no longer counteract intermittent sampling interference. Zhang Jianzhong, Mu Heqiang, Wen Shuliang, et al. proposed a method based on intra-pulse LFM-Costas frequency stepping to resist intermittent sampling forwarding interference in their paper "Anti-intermittent sampling interference method based on intra-pulse LFM-Costas frequency stepping" (System Engineering and Electronic Technology, 2019, 41(10): 2170-2177). This method uses the idea of ​​orthogonality and mutual cover of sub-pulses, uses Costas sequence to replace LFM signal sequential steps, constructs a narrowband filter group, and uses the orthogonality between LFM-Costas frequency steps to suppress interference between adjacent pulses using narrowband filters. However, this method depends on the signal form, and the constructed narrowband filter group depends on the slice width of the intermittent sampling forwarding interference and the length of the Costas sequence. If the filter bandwidth is wider than the intermittent sampling interference, the interference signal will fall into the adjacent sub-pulse signal, the interference countermeasure effect will decrease, and the target detection effect will be affected; if the designed filter bandwidth is narrow, the anti-interference effect is good, but the number of filters and sections in the filter group is large, the system design is complex, the signal processing calculation is large, and the comprehensive synthesis loss of each pulse is large.

[0004] Existing methods to combat intermittent sampling and forwarding interference have problems such as dependence on radar transmission waveform and complex system design, making them difficult to apply and transplant in a systematic manner or to carry out engineering practice.

[0005] Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

[0006] It should be noted that this section is intended to provide background or context for the technical solutions of the present disclosure stated in the claims. The description herein is not admitted to be prior art by virtue of being included in this section. Summary of the invention

[0007] The purpose of the embodiments of the present disclosure is to provide a method, system and electronic device for a ground radar to counter intermittent sampling and forwarding interference based on subspace decomposition, thereby overcoming one or more problems caused by the limitations and defects of related technologies at least to a certain extent.

[0008] The embodiment of the present disclosure first provides a method for ground radar to counteract intermittent sampling and forwarding interference based on subspace decomposition, including:

[0009] S101, performing pulse compression processing on the orthogonal baseband signal received by the ground radar;

[0010] S102, performing autocorrelation processing on the sum-path orthogonal baseband signals after the pulse compression processing;

[0011] S103, constructing a projection matrix for the autocorrelation matrix after the autocorrelation processing, so that the interference subspace is orthogonal to the signal subspace, so as to suppress the interference signal received by the ground radar;

[0012] S104, projecting the interference suppressed orthogonal baseband signals onto the signal subspace to complete intermittent sampling and forwarding interference countermeasures.

[0013] In one embodiment of the present disclosure, S101 includes:

[0014] Assume that a coherent processing cycle of ground radar is T CPI , the number of pulses in a coherent processing cycle is N, and the pulse repetition period is T r , the gate width is T bm , the sampling frequency is F s , then the length of the orthogonal baseband signal is M = F s T bm , the sum of the orthogonal baseband signals within a coherent processing cycle is expressed as follows:

[0015]

[0016] In formula (1), A ijrepresents 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];

[0017] The received and quadrature baseband signals are pulse compressed, and the results are shown as follows:

[0018]

[0019] In formula (2), P c is the matrix representation of the orthogonal baseband signal after pulse compression processing.

[0020] In one embodiment of the present disclosure, P c The autocorrelation matrix is ​​as follows:

[0021]

[0022] In formula (3), R xx Indicates P c The autocorrelation matrix of .

[0023] In one embodiment of the present disclosure, the autocorrelation matrix R xx Perform eigenvalue decomposition:

[0024]

[0025] In formula (4), V = [v1, v2, …, v N ],D=diag[d1,d2,…,d N ],d n represents the nth eigenvalue and is arranged in descending order, v n Denotes the eigenvalue d n The corresponding feature vector.

[0026] In one embodiment of the present disclosure, the interference subspace is expressed as:

[0027]

[0028] The signal subspace is expressed as:

[0029]

[0030] Where I represents the identity matrix.

[0031] In one embodiment of the present disclosure, the matrix P after pulse suppression is c Projecting on the signal subspace, we have

[0032] P1 c =P S P c (7)

[0033] In formula (7), P1 c is the projection of the pulse pressure matrix on the signal subspace, for P1 c Subsequent clutter cancellation, coherent accumulation, constant false alarm detection, and sum-difference normalization processing can complete the intermittent sampling and forwarding interference countermeasure.

[0034] The embodiment of the present disclosure also provides a system for ground radar to counteract intermittent sampling and forwarding interference based on subspace decomposition, the system comprising:

[0035] A pulse compression processing module is used to perform pulse compression processing on the orthogonal baseband signal received by the ground radar;

[0036] An autocorrelation processing module is used to perform autocorrelation processing on the sum-path orthogonal baseband signal after pulse compression processing;

[0037] An interference suppression module is used to construct a projection matrix for the autocorrelation matrix after autocorrelation processing, so that the interference subspace is orthogonal to the signal subspace, so as to suppress the interference signal received by the ground radar;

[0038] The projection module is used to project the orthogonal baseband signals after interference suppression onto the signal subspace to achieve intermittent sampling and forwarding interference countermeasures.

[0039] The present disclosure also provides an electronic device, including:

[0040] Processor; and

[0041] A memory, configured to store executable instructions of the processor;

[0042] The processor is configured to execute the steps of any one of the above-mentioned methods for ground radar counteracting intermittent sampling forwarding interference based on subspace decomposition by executing the executable instructions.

[0043] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0044] In the disclosed embodiment, a method for ground radar to counter intermittent sampling and forwarding interference based on subspace decomposition is used. The method is based on the characteristics of intermittent sampling and forwarding interference, which has strong adaptability and is independent of signal waveform. According to the characteristics that intermittent sampling and forwarding interference is orthogonal to the target signal after pulse compression, feature decomposition is used to construct a projection matrix of the signal subspace, and the echo signal is projected into the signal domain after pulse compression to achieve intermittent sampling and forwarding interference countermeasure. After intermittent sampling and forwarding interference countermeasure, the signal-to-noise ratio is not lost, and a good countermeasure effect can be achieved when the interference pulse period and duty cycle have a relatively large range of variation. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] 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.

[0046] Figure 1 A schematic flow chart showing a method for counteracting intermittent sampling and forwarding interference of a ground radar based on subspace decomposition in an exemplary embodiment of the present disclosure;

[0047] Figure 2 A graph showing the real part of an echo signal within a range period when intermittent interference exists in an exemplary embodiment of the present disclosure;

[0048] Figure 3 A pulse compression process diagram of a single pulse without interference and with interference in an exemplary embodiment of the present disclosure is shown;

[0049] Figure 4 A diagram showing the results before and after the "subspace decomposition" process (interference is effectively suppressed) in an exemplary embodiment of the present disclosure;

[0050] Figure 5 A diagram showing the comparison between the result after "subspace decomposition" processing and the result without interference (no loss of signal-to-noise ratio after processing) in an exemplary embodiment of the present disclosure is shown;

[0051] Figure 6 A schematic structural diagram of an electronic device in an exemplary embodiment of the present disclosure is shown;

[0052] Figure 7 A schematic diagram showing the structure of a program product for implementing a method for ground radar to combat intermittent sampling forwarding interference based on subspace decomposition in an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0053] 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.

[0054] In addition, the accompanying drawings are only schematic illustrations of the embodiments 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 descriptions 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.

[0055] First of all, it should be noted that, in view of the problems existing in the existing intermittent sampling forwarding interference countermeasure technology, the purpose of the present invention is to provide a generally applicable method for counteracting intermittent sampling forwarding interference. For the convenience of description, the method for counteracting intermittent sampling forwarding interference of the present invention is named as a "subspace decomposition" processing method.

[0056] In this example implementation, a method for ground radar to counteract intermittent sampling and forwarding interference based on subspace decomposition is first provided. Please refer to Figure 1 , may include: Step S101-Step S104. Specifically as follows:

[0057] S101, performing pulse compression processing on the orthogonal baseband signal received by the ground radar;

[0058] S102, performing autocorrelation processing on the sum-path orthogonal baseband signals after the pulse compression processing;

[0059] S103, constructing a projection matrix for the autocorrelation matrix after the autocorrelation processing, so that the interference subspace is orthogonal to the signal subspace, so as to suppress the interference signal received by the ground radar;

[0060] S104, projecting the interference suppressed orthogonal baseband signals onto the signal subspace to complete intermittent sampling and forwarding interference countermeasures.

[0061] In this embodiment, in view of the characteristics of intermittent sampling forwarding interference, which has strong adaptability and is independent of signal waveform, according to the characteristics that intermittent sampling forwarding interference and target signal are orthogonal after pulse compression, feature decomposition is used to construct a projection matrix of the signal subspace, and the echo signal is projected into the signal domain after pulse compression to achieve intermittent sampling forwarding interference confrontation. After intermittent sampling forwarding interference confrontation, the signal-to-noise ratio is not lost, and a good confrontation effect can be achieved when the interference pulse period and duty cycle have a relatively large range of variation.

[0062] The above steps are described in more detail below.

[0063] In S101, it is assumed that a coherent processing cycle of the ground radar is T CPI , the number of pulses in a coherent processing cycle is N, and the pulse repetition period is T r , the gate width is T bm , the sampling frequency is F s , then the length of the orthogonal baseband signal is M = F s T bm , the sum of the orthogonal baseband signals within a coherent processing cycle is expressed as follows:

[0064]

[0065] In formula (1), 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];

[0066] The received and quadrature baseband signals are pulse compressed, and the results are shown as follows:

[0067]

[0068] In formula (2), P c is the matrix representation of the orthogonal baseband signal after pulse compression processing.

[0069] In S102, P c The autocorrelation matrix is ​​as follows:

[0070]

[0071] In formula (3), R xx Indicates P c The autocorrelation matrix of .

[0072] For the autocorrelation matrix R xx Perform eigenvalue decomposition:

[0073]

[0074] In formula (4), V = [v1, v2, …, v N ],D=diag[d1,d2,…,d N ],d n represents the nth eigenvalue and is arranged in descending order, v n Denotes the eigenvalue d n The corresponding feature vector.

[0075] In S103, due to the characteristics of the jammer delay, the target and the interference after pulse compression are orthogonal in the distance dimension of pulse compression. Therefore, the interference subspace can be orthogonal to the signal subspace after eigendecomposition using eigendecomposition and subspace theory. In order to achieve radar signal suppression, the interference energy is large. The interference subspace can be composed of the eigenvector corresponding to the previous eigenvalue in the eigenvalue set. The value can be determined by the number of interference sources sent by the front-end interference reconnaissance of the radar system. The interference subspace is expressed as:

[0076]

[0077] The signal subspace is expressed as:

[0078]

[0079] Where I represents the identity matrix.

[0080] In S104, the matrix P after pulse suppression is c Projecting on the signal subspace, we have

[0081] P1 c =P S P c (7)

[0082] In formula (7), P1 c is the projection of the pulse pressure matrix on the signal subspace, for P1 c Subsequent clutter cancellation, coherent accumulation, constant false alarm detection, and sum-difference normalization processing can complete the intermittent sampling and forwarding interference countermeasure.

[0083] The method of the present application is described below with reference to specific examples.

[0084] Assume that the coherent processing period of a pulse radar is 1ms and the pulse repetition period is T r The number of transmitted pulses in a coherent processing cycle is 10, the pulse width is 32 μs, and the sampling frequency F s =40MHz. The length of the baseband signal sampling points in one pulse repetition period is 3520 points.

[0085] (1) Calculation of autocorrelation matrix

[0086] Perform pulse compression processing on the received baseband signal to obtain the pulse compression matrix P c , find the pulse pressure matrix P c Perform correlation processing to obtain the autocorrelation matrix R xx .

[0087] (2) Signal projection matrix construction

[0088] R xx Perform eigenvalue decomposition and construct the signal projection matrix P according to the number of interferences transmitted by the system front end S .

[0089] (3) Interference suppression

[0090] The pulse compression matrix P is constructed by using the signal projection matrix c Projection is performed in the signal domain to complete interference countermeasure, and then corresponding processing operations are performed. The subsequent processing operations include: clutter cancellation, coherent accumulation, constant false alarm detection, and sum-difference normalization processing.

[0091] Figure 2 is the real part of the sum of the orthogonal baseband signals of a target tracking position under intermittent sampling and forwarding interference conditions; the pulse compression results of a single pulse with and without interference are shown in Figure 3After pulse compression, subspace decomposition, and moving target detection processing, the time domain distance dimension profile of the target is as follows: Figure 4 As shown in the figure, it can be seen that when subspace decomposition is not performed, the target signal is submerged in the intermittent sampling forwarding interference and cannot be detected. After the intermittent sampling forwarding interference countermeasure method based on subspace decomposition of the present invention is used for processing, the intermittent sampling forwarding interference is effectively suppressed and the target signal can be detected normally. Figure 5 It can be seen that after being processed by the method of the present invention, there is no loss in the signal-to-noise ratio of the target and the anti-interference effect is better.

[0092] The present invention also provides a system for ground radar to counteract intermittent sampling and forwarding interference based on subspace decomposition, the system comprising:

[0093] A pulse compression processing module is used to perform pulse compression processing on the orthogonal baseband signal received by the ground radar;

[0094] An autocorrelation processing module is used to perform autocorrelation processing on the sum-path orthogonal baseband signal after pulse compression processing;

[0095] An interference suppression module is used to construct a projection matrix for the autocorrelation matrix after autocorrelation processing, so that the interference subspace is orthogonal to the signal subspace, so as to suppress the interference signal received by the ground radar;

[0096] The projection module is used to project the orthogonal baseband signals after interference suppression onto the signal subspace to achieve intermittent sampling and forwarding interference countermeasures.

[0097] The method of using the system in this embodiment is essentially the same as that in the above method embodiment, and will not be repeated here.

[0098] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0099] It should be noted that although several modules of the system for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to an embodiment of the present invention, the features and functions of two or more modules described above can be concretized in one module. Conversely, the features and functions of a module described above can be further divided into multiple modules for concretization. The components displayed as modules may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of the present invention. Those of ordinary skill in the art can understand and implement it without paying creative work.

[0100] See also Figure 6 The embodiment of the present invention further provides an electronic device 300, which includes at least one memory 310, at least one processor 320, and a bus 330 for connecting different platform systems.

[0101] The memory 310 may include a readable medium in the form of a volatile memory, such as a random access memory (RAM) 311 and / or a cache memory 312 , and may further include a read-only memory (ROM) 313 .

[0102] Among them, the memory 310 also stores a computer program, which can be executed by the processor 320, so that the processor 320 executes the steps of the method for ground radar based on subspace decomposition to combat intermittent sampling and forwarding interference in any embodiment of the present invention. The specific implementation method is consistent with the implementation method and the technical effect recorded in the above-mentioned embodiment of the method for ground radar based on subspace decomposition to combat intermittent sampling and forwarding interference, and some contents will not be repeated here.

[0103] The memory 310 may also include a utility 314 having at least one program module 315, such program module 315 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0104] Accordingly, the processor 320 may execute the above-mentioned computer program and may execute the utility 314 .

[0105] Bus 330 may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor or a local bus using any of a variety of bus architectures.

[0106] The electronic device 300 may also communicate with one or more external devices 340 such as keyboards, pointing devices, Bluetooth devices, etc., and may also communicate with one or more devices that can interact with the electronic device 300, and / or communicate with any device (such as a router, a modem, etc.) that enables the electronic device 300 to communicate with one or more other computing devices. Such communication may be performed through an input / output interface 350. In addition, the electronic device 300 may also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 360. The network adapter 360 may communicate with other modules of the electronic device 300 through a bus 330. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 300, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms.

[0107] An embodiment of the present invention also provides a computer-readable storage medium, which is used to store a computer program. When the computer program is executed, it implements the steps of the method for ground radar based on subspace decomposition to combat intermittent sampling and forwarding interference in the embodiment of the present invention. The specific implementation method is consistent with the implementation method and the technical effect recorded in the embodiment of the method for ground radar based on subspace decomposition to combat intermittent sampling and forwarding interference, and some contents will not be repeated here.

[0108] Figure 7 The program product 400 provided in this embodiment for implementing the above-mentioned method of ground radar counteracting intermittent sampling forwarding interference based on subspace decomposition is shown, which can adopt a portable compact disk read-only memory (CD-ROM) and include program code, and can be run on a terminal device, such as a personal computer. However, the program product 400 of the present invention is not limited to this. In the present invention, the readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it. The program product 400 can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared or semiconductor system, device or device, or any combination of the above. More specific examples of readable storage media (non-exhaustive list) include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0109] Computer-readable storage media may include data signals propagated in baseband or as part of a carrier wave, wherein readable program codes are carried. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable storage medium may also be any readable medium, which may send, propagate, or transmit a program for use by an instruction execution system, an apparatus, or a device or for use in combination with it. The program code contained on the readable storage medium may be transmitted by any suitable medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above. The program code for performing the operation of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and also conventional procedural programming languages ​​such as C language or similar programming languages. The program code may be executed entirely on a user computing device, partially on a user device, as an independent software package, partially on a user computing device, partially on a remote computing device, or entirely on a remote computing device or server. Where a remote computing device is involved, the remote computing device may be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., through the Internet using an Internet service provider).

[0110] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for ground radar to counteract intermittent sampling and forwarding interference based on subspace decomposition, characterized in that: include: S101, performing pulse compression processing on the orthogonal baseband signal received by the ground radar; S102, performing autocorrelation processing on the sum-path orthogonal baseband signals after the pulse compression processing; S103, constructing a projection matrix for the autocorrelation matrix after the autocorrelation processing, so that the interference subspace is orthogonal to the signal subspace, so as to suppress the interference signal received by the ground radar; S104, projecting the interference suppressed orthogonal baseband signals onto the signal subspace to complete intermittent sampling and forwarding interference countermeasures.

2. The method for ground radar to counteract intermittent sampling and forwarding interference based on subspace decomposition according to claim 1 is characterized in that: S101 includes: Assume that a coherent processing cycle of ground radar is T CPI , the number of pulses in a coherent processing cycle is N, and the pulse repetition period is T r , the gate width is T bm , the sampling frequency is F s , then the length of the orthogonal baseband signal is M = F s T bm , the sum of the orthogonal baseband signals within a coherent processing cycle is expressed as follows: In formula (1), 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]; The received and quadrature baseband signals are pulse compressed, and the results are shown as follows: In formula (2), P c is the matrix representation of the orthogonal baseband signal after pulse compression processing.

3. The method for ground radar to counteract intermittent sampling and forwarding interference based on subspace decomposition according to claim 2 is characterized in that: In S102, P c The autocorrelation matrix is ​​as follows: In formula (3), R xx Indicates P c The autocorrelation matrix of .

4. The method for ground radar to counteract intermittent sampling and forwarding interference based on subspace decomposition according to claim 3 is characterized in that: For the autocorrelation matrix R xx Perform eigenvalue decomposition: In formula (4), V = [v1, v2, …, v N ],D=diag[d1,d2,…,d N ],d n represents the nth eigenvalue and is arranged in descending order, v n Denotes the eigenvalue d n The corresponding feature vector.

5. The method for ground radar to counteract intermittent sampling and forwarding interference based on subspace decomposition according to claim 4 is characterized in that: In S103, the interference subspace is expressed as: The signal subspace is expressed as: Where I represents the identity matrix.

6. The method for ground radar to counteract intermittent sampling and forwarding interference based on subspace decomposition according to claim 5 is characterized in that: In S104, the matrix P after pulse suppression is c Projecting on the signal subspace, we have P1 c =P S P c (7) In formula (7), P1 c is the projection of the pulse pressure matrix on the signal subspace, for P1 c Subsequent clutter cancellation, coherent accumulation, constant false alarm detection, and sum-difference normalization processing can complete the intermittent sampling and forwarding interference countermeasure.

7. A system for ground radar to counter intermittent sampling and forwarding interference based on subspace decomposition, characterized in that: The system comprises: A pulse compression processing module is used to perform pulse compression processing on the orthogonal baseband signal received by the ground radar; An autocorrelation processing module is used to perform autocorrelation processing on the sum-path orthogonal baseband signal after pulse compression processing; An interference suppression module is used to construct a projection matrix for the autocorrelation matrix after autocorrelation processing, so that the interference subspace is orthogonal to the signal subspace, so as to suppress the interference signal received by the ground radar; The projection module is used to project the orthogonal baseband signals after interference suppression onto the signal subspace to achieve intermittent sampling and forwarding interference countermeasures.

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