Support interference method based on situation awareness and random phase modulation

Abstract

The invention provides a support interference method based on situation awareness and random phase modulation, and relates to the technical field of radar interference, and the method comprises the steps: obtaining countermeasure scene space situation information, an interference target radar radial speed, and a shield target radial speed; wherein the confrontation scene space situation information comprises position information of an interference target and a shield target; the working frequency and the pulse repetition interval of the interference target radar are obtained through the investigation function; calculating hidden interference time delay according to the confrontation scene space situation information and the pulse repetition interval; performing interference signal modulation based on the hidden interference time delay; and performing support interference on an interference target by using the modulated interference signal. Aiming at the problems of intention exposure and interference energy waste of the existing support interference technology, the invention provides an energy controllable coverage method based on situation awareness and random phase modulation so as to realize'non-sensitive 'shielding interference of long-distance support interference.

Description

Technical Field

[0001] This invention relates to the field of radar jamming technology, and more specifically, to a support jamming method based on situational awareness and random phase modulation. Background Technology

[0002] Long-range support jamming is an effective electronic countermeasure. Its mission is to disrupt, delay, and reduce the radar's ability to intercept and detect the cover target. The necessity of support jamming technology and systems has been effectively verified.

[0003] Because traditional support jamming systems are limited to acquiring target information only in the frequency domain, time domain, and a limited spatial domain (azimuth), they typically need to spread jamming energy across the fast and slow time dimensions and distribute it across all range cells and Doppler channels to disrupt radar target detection. Therefore, they usually employ "noise jamming" or "dense decoy + noise" jamming patterns. Due to these characteristics of support jamming, the following problems arise: Traditional support jamming requires spreading jamming energy across all range cells and Doppler channels to raise the target's CFAR (Constant-False-Alarm Rate) detection threshold, resulting in a "screen-clearing" jamming effect. The situation on the radar P-display interface before and after jamming is significantly different, making the jamming easily detectable by the radar, which then takes anti-jamming measures or other evasion actions, leading to the failure of the jamming mission or the exposure of the intention.

[0004] The jamming targets are sparsely distributed in the radar range-velocity dimension, while the jamming energy is spread out in two dimensions. Due to the law of conservation of energy, the effective jamming energy is attenuated compared to coherent single-target jamming.

[0005] in, For radar waveform bandwidth, The number of Doppler channels represents the number of pulses processed by the MTD. To cover the number of targets, and with multiple targets distributed across different range cells and Doppler channels, it is evident that the larger the time-bandwidth product of the target signal and the more pulses, the more interference energy is "wasted."

[0006] Therefore, it is necessary to study an energy-controlled jamming coverage method based on situational awareness and random phase modulation, which can make full use of the spatial situational awareness capability of the multi-functional integrated equipment to achieve support jamming against designated targets and achieve the purpose of concealing and protecting the targets. Summary of the Invention

[0007] The present invention aims to solve at least one of the aforementioned technical problems existing in the prior art.

[0008] To this end, the present invention provides a support jamming method based on situational awareness and random phase modulation.

[0009] The proposed jamming support method based on situational awareness and random phase modulation includes: Acquire spatial situational information of the adversarial scenario, including the radial velocity of the jamming target's radar and the radial velocity of the cover target; wherein, the spatial situational information of the adversarial scenario includes the positional information of the jamming target and the cover target; The reconnaissance function is used to obtain the operating frequency and pulse repetition interval of the radar interfering with the target; The delay of covert interference is calculated based on the spatial situational information of the adversarial scenario and the pulse repetition interval. Modulate the interference signal based on the time delay of the concealed interference; The modulated jamming signal is used to provide support jamming against the target.

[0010] The situational awareness and random phase modulation-based jamming support method according to the above-described technical solution of the present invention may further have the following additional technical features: In the above technical solution, the spatial situational information of the adversarial scenario includes: The coordinates of the cover target and the jamming target in a spatial coordinate system established with the jamming support equipment as the origin.

[0011] In the above technical solution, the distance between the jamming target and the supporting jamming device, the distance between the cover target and the supporting jamming device, and the distance between the jamming target and the cover target are determined based on the spatial situation information of the confrontation scenario. The distance between the jamming target and the supporting jamming equipment, i.e., the jamming distance. for:

[0012] Distance between the cover target and the supporting jamming equipment for:

[0013] Distance between the jamming target and the cover target for:

[0014] The coordinates of the interfering target are: The coordinates of the cover target are .

[0015] In the above technical solution, the step of calculating the concealed interference delay based on the spatial situational information of the adversarial scenario and the pulse repetition interval includes: The echo delay of the cover target is calculated based on the distance between the jamming target and the cover target; The concealed jamming delay is calculated based on the echo delay of the covered target, the jamming distance, the pulse repetition interval of the jamming target radar, and the delay of the jamming relay system.

[0016] In the above technical solution, the step of calculating the echo delay of the cover target based on the distance between the interference target and the cover target includes:

[0017] in, Indicates the echo delay of the protected target; Indicates the distance between the jamming target and the cover target; Represents the speed of light; The method for calculating the concealed interference delay includes:

[0018] in, Indicates the delay of covert interference; Indicates the pulse repetition interval of the jamming target radar; Indicates the interference distance; This indicates the delay in the interference forwarding system.

[0019] In the above technical solution, the modulation of the interference signal based on the concealed interference delay includes: Identify the baseband signals of the target radar collected by the supporting jamming equipment; Based on the radar baseband signal of the jamming target, an interference signal is generated according to the concealed interference time delay.

[0020] In the above technical solution, the baseband signal of the jamming target radar collected by the jamming equipment is:

[0021] in, This indicates interference with the target radar baseband signal; The signal represents the radar waveform envelope; t represents the time variable; T represents the pulse width of the signal; and K represents the frequency modulation slope of the linear modulation signal. The modulated interference signal is:

[0022] in, This represents the modulated interference signal; Indicates interference modulation; This indicates the Doppler frequency of the radar used to cover and jam the target; This represents the time in the slow time dimension.

[0023] In the above technical solution, the baseband signal of the jamming target radar collected by the jamming equipment is:

[0024] in, This indicates interference with the target radar baseband signal; The signal represents the radar waveform envelope; t represents the time variable; T represents the pulse width of the signal; and K represents the frequency modulation slope of the linear modulation signal. The modulated interference signal is:

[0025] in, This represents the modulated interference signal; Indicates interference modulation; This indicates the Doppler frequency of the radar used to cover and jam the target.

[0026] In the above technical solutions, interference modulation The expression is:

[0027] in, It is the noise modulation coefficient. It is Gaussian white noise.

[0028] In the above technical solutions, the Doppler frequency of the radars protecting the target and interfering with the target. The expression is:

[0029] in, Indicates the radial velocity of the shielding target; Indicates the pitch angle of the cover target relative to the supporting jamming equipment; Indicates the radial velocity of the jamming target radar; Indicates the pitch angle of the jamming target relative to the supporting jamming equipment; Indicates wavelength.

[0030] In summary, due to the adoption of the above-mentioned technical features, the beneficial effects of the present invention are: This invention addresses the problems of intentional exposure and wasted jamming energy in existing support jamming technologies by providing an energy-controllable coverage method based on situational awareness and random phase modulation, thereby achieving "unobtrusive" cover jamming for long-range support jamming.

[0031] Specifically, the interference effects of this invention and traditional jamming technologies are compared as follows: Interference-to-signal ratio at the target radar aperture The interference ratio (IRR) is a crucial parameter for effective jamming. Only when the IRR meets certain requirements (depending on the radar signal processing method and jamming modulation pattern) can the target be protected from radar detection. The radar simultaneously receives the target echo and the jamming signal, and processes the signals concurrently. Considering the radar as a linear time-invariant system, the matched filter is:

[0032] The output of the matched filter for the target echo signal is a point target. Assume the bandwidth of the frequency-modulated white noise interference signal is... Therefore, the effective interference area of ​​the method of this invention (the energy dispersion range after matching filter) after passing through the radar matched filter output is:

[0033] in, The ratio of the modulation noise bandwidth of the interfering signal to the bandwidth of the target signal. The distance corresponding to the radar signal pulse width shows that the width of the cover range can be adjusted by controlling the bandwidth of the jamming signal, thereby accurately suppressing and jamming the target. Under the condition of constant jamming energy, the signal-to-interference ratio of this cover range can be improved.

[0034] Compared to coherent single-dummy target interference, the effective interference energy attenuation of this invention is:

[0035] Compared to traditional noise suppression interference, the interference energy utilization rate of this invention will be improved:

[0036] In summary, this invention utilizes the detection capabilities of integrated equipment to detect and locate air cover targets and radar carrier platforms, creating a jamming countermeasure scenario. The jamming signal is precisely delayed and then modulated, concentrating the jamming energy after matched filtering into a specific range. Within the range. Due to the sparse spatiotemporal distribution of airborne aerodynamic targets, it enables covert support jamming of penetrating targets, thereby improving the efficiency of jamming energy utilization. times.

[0037] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a flowchart of a support jamming method based on situational awareness and random phase modulation according to an embodiment of the present invention; Figure 2 This is a schematic diagram of an adversarial scenario in a support jamming method based on situational awareness and random phase modulation according to an embodiment of the present invention. Figure 3 This is a schematic diagram illustrating the principle of covert jamming delay calculation in a support jamming method based on situational awareness and random phase modulation according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the target echo signal and interference signal waveforms in scenario 1 as set by the present invention; Figure 5 This is a schematic diagram of the pulse compression output waveform of the echo superimposed interference signal under scenario 1 set by the present invention; Figure 6 This is a schematic diagram of the MTD processing output result of the echo superimposed interference signal under scenario 1 set by the present invention; Figure 7 This is a schematic diagram of the CFAR output result of the echo superimposed interference signal under scenario 1 set by the present invention; Figure 8 This is a schematic diagram of the target echo signal and interference signal waveforms in scenario 2 as set by the present invention; Figure 9 This is a schematic diagram of the pulse compression output waveform of the echo superimposed interference signal under scenario 2 set by the present invention; Figure 10 This is a schematic diagram of the MTD processing output result of the echo superimposed interference signal under scenario 2 set by the present invention; Figure 11 This is a schematic diagram of the CFAR output result of the echo superimposed interference signal under scenario 2 set by the present invention. Detailed Implementation

[0039] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0041] The following reference Figures 1 to 11 This describes a situational awareness and random phase modulation-based jamming support method provided according to some embodiments of the present invention.

[0042] Some embodiments of this application provide a support jamming method based on situational awareness and random phase modulation.

[0043] like Figure 1As shown, the first embodiment of the present invention proposes a support jamming method based on situational awareness and random phase modulation, including the following steps S1 to S5.

[0044] S1. Acquire spatial situational information of the adversarial scenario, including the radial velocity of the jamming target's radar and the radial velocity of the cover target; wherein, the spatial situational information of the adversarial scenario includes the positional information of the jamming target and the cover target.

[0045] In some embodiments, the adversarial scenario spatial situation information includes: the coordinates of the cover target and the jamming target in a spatial coordinate system established with the supporting jamming device as the origin. Adversarial scenarios include... Figure 2 As shown, it is understood that the spatial coordinate system established above is only a schematic representation. Other reference points can also be used to establish spatial coordinate systems, as long as the spatial situation information of the adversarial scenario, including the relative position information of the jamming target, the cover target, and the supporting jamming equipment, can be obtained.

[0046] It should be noted that spatial situational information in adversarial scenarios can be obtained using the detection capabilities of existing radar-communication multi-functional integrated systems.

[0047] exist Figure 2 In the illustrated embodiment, the distance between the jamming target and the supporting jamming device, the distance between the cover target and the supporting jamming device, and the distance between the jamming target and the cover target are determined based on the spatial situation information of the adversarial scenario. The distance between the jamming target and the supporting jamming equipment, i.e., the jamming distance. for:

[0048] Distance between the cover target and the supporting jamming equipment for:

[0049] Distance between the jamming target and the cover target for:

[0050] The coordinates of the interfering target are: The coordinates of the cover target are .

[0051] S2. Utilize reconnaissance capabilities to obtain the operating frequency of the target radar being jammed. and pulse repetition interval Similarly, the aforementioned electromagnetic parameters can be obtained using the reconnaissance capabilities of existing radar-communication multi-functional integrated systems.

[0052] S3. Calculate the concealed interference delay based on the spatial situation information of the adversarial scenario and the pulse repetition interval.

[0053] In some embodiments, such as Figure 3 As shown, step S3 includes: S31. Calculate the echo delay of the cover target based on the distance between the jamming target and the cover target; the specific calculation method is as follows:

[0054] in, Indicates the echo delay of the protected target; To represent the speed of light, take 3 × 10⁻⁶. 8 m / s; S32. Calculate the concealed jamming delay based on the echo delay of the protected target, the jamming distance, the pulse repetition interval of the jamming target radar, and the delay of the jamming relay system; the calculation method is as follows:

[0055] in, This indicates the delay of covert interference, also known as interference delay; Indicates the pulse repetition interval of the jamming target radar; Indicates the interference distance; This indicates the delay in the interference forwarding system.

[0056] S4. Modulate the interference signal based on the concealed interference delay.

[0057] In some embodiments, step S4 includes: S41. Determine the baseband signal of the jamming target radar collected by the supporting jamming equipment; Typically, radar detection waveforms are linear frequency modulated (LFM) signals, while the target radar baseband signals acquired by jamming equipment are:

[0058] in, This indicates interference with the target radar baseband signal; The signal represents the radar waveform envelope; t represents the time variable; T represents the pulse width of the signal; and K represents the frequency modulation slope of the linear modulation signal. B is the signal bandwidth.

[0059] S42. Based on the radar baseband signal of the jamming target, generate an interference signal according to the concealed interference delay.

[0060] In some embodiments, the interference signal modulated on the acquired sample is:

[0061] in, This represents the modulated interference signal; Indicates interference modulation; This indicates the Doppler frequency of the radar used to cover and jam the target; The time representing the slow time dimension is usually taken as the pulse repetition interval. Integer multiples of.

[0062] In one specific embodiment, interference modulation The expression is:

[0063] in, It is the noise modulation coefficient. This represents Gaussian white noise with variance . The mean is 0. This indicates the operation of differentiating Gaussian white noise.

[0064] Doppler frequencies for shielding and jamming target radars The expression is:

[0065] in, Indicates the radial velocity of the shielding target; Indicates the pitch angle of the cover target relative to the supporting jamming equipment; Indicates the radial velocity of the jamming target radar; Indicates the pitch angle of the jamming target relative to the supporting jamming equipment; Indicates wavelength.

[0066] The modulated interference signal can then be written as:

[0067] Analysis of the above formula shows that the interference signal is mainly divided into three parts, the first term To support the interception of target radar waveform sample signal envelope delay by jamming equipment, it can be seen that the jamming modulation signal of this disclosure has good coherence, and its main function is to align the jamming signal with the target echo; Second item For the frequency modulation noise term of the interference signal, the white noise bandwidth is... In order to make full use of interference energy, Generally acceptable ; Third item For the Doppler frequency targeting term, energy focusing is performed in the slow time dimension.

[0068] In other embodiments, considering that the supporting jamming device and the radar are asynchronous systems, the fast time dimension is white noise jamming. Generally, the supporting jamming device does not carry out strict slow time dimension coherent modulation. Therefore, the slow time dimension Doppler jamming is difficult to focus on a specific fixed channel, which manifests as all Doppler channels being filled with energy.

[0069] Based on this, the modulated interference signal can be degraded to:

[0070] Right now:

[0071] The Doppler frequency aiming term was removed from the aforementioned interference signals.

[0072] S5. Use the modulated jamming signal to provide support jamming for the jamming target.

[0073] In one specific embodiment, in order to verify the effectiveness of this disclosure, an example of supporting jamming and countermeasures against airborne early warning aircraft radar is designed as follows.

[0074] The distance between the jamming equipment and the early warning aircraft radar (i.e., the jamming target). The range is 350km; the distance between the jamming equipment and the cover target. The range is 130km; the distance between the early warning aircraft radar and the protected target. The distance is 220km; another target is located 225km from the AWACS radar.

[0075] Radar waveform linear modulation signal parameters: bandwidth Take 5MHz, pulse width The pulse repetition interval (PRI) is set to 3.1 ms, and the accumulated pulse count is 64 pulses; the interference signal noise modulation bandwidth is [not specified]. The frequencies are 0.05MHz (covert interference) and 5MHz (traditional noise interference); based on the radar waveform parameters, the radar matched filter gain is 34.7dB, and the pulse accumulation gain is 15dB.

[0076] Based on the above configuration, support interference tests were conducted under both the traditional noise suppression interference pattern and the covert interference pattern proposed in this invention.

[0077] Scenario 1 is a traditional noise suppression interference pattern with a signal-to-interference ratio (JSR) of 33 dB.

[0078] Traditional noise suppression interference methods are used, such as Figure 4 As shown, the echo signal in the time domain covers the original echo pulse train. The waveforms after pulse compression of each pulse are displayed as follows. Figure 5 As shown, the target signal is submerged in interference. The distance and Doppler two-dimensional distribution after pulse accumulation are as follows: Figure 6 As shown. The distance dimension CFAR processing output is as follows. Figure 7 As shown, the target is detected normally because the pulse pressure gain is 34.7dB + pulse accumulation gain is 15dB - interference-to-signal ratio is 33dB = 16.7dB.

[0079] Scenario 2 is the covert interference pattern proposed in this invention, with a signal-to-interference ratio (JSR) of 13dB.

[0080] Employing covert interference techniques, such as Figure 8 As shown, the echo signal in the time domain covers the original echo pulse train. The waveforms after pulse compression of each pulse are displayed as follows. Figure 9 As shown, the interference energy after pulse compression is concentrated near the target. The distance and Doppler two-dimensional distribution after pulse accumulation are as follows: Figure 10 As shown, nearby targets are displayed normally, while targets under cover are obscured by noise. The range-dimensional CFAR processing output is as follows: Figure 11 As shown, the cover target cannot be detected, while nearby targets are detected normally, and the interference-to-signal ratio is reduced by nearly 20dB, which is consistent with the theoretical analysis.

[0081] In this specification, the illustrative expressions of the terms used do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0082] Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention shall be included within the scope of protection of this invention.

Claims

1. A support jamming method based on situational awareness and random phase modulation, characterized in that, include: Acquire spatial situational information of the adversarial scenario, including the radar radial velocity of the jamming target and the radial velocity of the cover target; wherein, the spatial situational information of the adversarial scenario includes the positional information of the jamming target and the cover target; The reconnaissance function is used to obtain the operating frequency and pulse repetition interval of the radar interfering with the target; The delay of covert interference is calculated based on the spatial situational information of the adversarial scenario and the pulse repetition interval. Modulate the interference signal based on the time delay of the concealed interference; The modulated jamming signal is used to provide support jamming against the target.

2. The support jamming method based on situational awareness and random phase modulation according to claim 1, characterized in that, The spatial situational information of the adversarial scenario includes: The coordinates of the cover target and the jamming target in a spatial coordinate system established with the jamming support equipment as the origin.

3. The support jamming method based on situational awareness and random phase modulation according to claim 2, characterized in that, Based on the spatial situational information of the adversarial scenario, determine the distance between the jamming target and the supporting jamming equipment, the distance between the cover target and the supporting jamming equipment, and the distance between the jamming target and the cover target; The distance between the jamming target and the supporting jamming equipment, i.e., the jamming distance. for: Distance between the cover target and the supporting jamming equipment for: Distance between the jamming target and the cover target for: The coordinates of the interfering target are: The coordinates of the cover target are .

4. The support jamming method based on situational awareness and random phase modulation according to claim 1, characterized in that, The calculation of the concealed interference delay based on the spatial situational information of the adversarial scenario and the pulse repetition interval includes: The echo delay of the cover target is calculated based on the distance between the jamming target and the cover target; The concealed jamming delay is calculated based on the echo delay of the covered target, the jamming distance, the pulse repetition interval of the jamming target radar, and the delay of the jamming relay system.

5. The support jamming method based on situational awareness and random phase modulation according to claim 4, characterized in that, The calculation of the echo delay of the cover target based on the distance between the jamming target and the cover target includes: in, Indicates the echo delay of the protected target; Indicates the distance between the jamming target and the cover target; Represents the speed of light; The method for calculating the concealed interference delay includes: in, Indicates the delay of covert interference; Indicates the pulse repetition interval of the jamming target radar; Indicates the interference distance; This indicates the delay in the interference forwarding system.

6. The support jamming method based on situational awareness and random phase modulation according to claim 1, characterized in that, The modulation of the interference signal based on the concealed interference delay includes: Determine the baseband signal of the target radar collected by the supporting jamming equipment; Based on the radar baseband signal of the jamming target, an interference signal is generated according to the concealed interference time delay.

7. The support jamming method based on situational awareness and random phase modulation according to claim 6, characterized in that, The baseband signal of the target radar collected by the jamming equipment is as follows: in, This indicates interference with the target radar baseband signal; The signal represents the radar waveform envelope; t represents the time variable; T represents the pulse width of the signal; and K represents the frequency modulation slope of the linear modulation signal. The modulated interference signal is: in, This represents the modulated interference signal; Indicates interference modulation; This indicates the Doppler frequency of the radar used to cover and jam the target; This represents the time in the slow time dimension.

8. The support jamming method based on situational awareness and random phase modulation according to claim 6, characterized in that, The baseband signal of the target radar collected by the jamming equipment is as follows: in, This indicates interference with the target radar baseband signal; The signal represents the radar waveform envelope; t represents the time variable; T represents the pulse width of the signal; and K represents the frequency modulation slope of the linear modulation signal. The modulated interference signal is: in, This represents the modulated interference signal; Indicates interference modulation; This indicates the Doppler frequency of the radar used to cover and jam the target.

9. The support jamming method based on situational awareness and random phase modulation according to claim 7 or 8, characterized in that, Interference modulation The expression is: in, It is the noise modulation coefficient. It is Gaussian white noise.

10. The support jamming method based on situational awareness and random phase modulation according to claim 7, characterized in that, Doppler frequencies for shielding and jamming target radars The expression is: in, Indicates the radial velocity of the shielding target; Indicates the pitch angle of the cover target relative to the supporting jamming equipment; Indicates the radial velocity of the jamming target radar; Indicates the pitch angle of the jamming target relative to the supporting jamming equipment; Indicates wavelength.

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