Clutter-like based radar anti-reconnaissance signal design method

Abstract

The application discloses a radar anti-reconnaissance signal design method based on a clutter, and implementation steps are as follows: a radar signal is radiated by a radar of a home side; a baseband clutter of a Weibull distribution is generated by a protection node; the clutter is modulated to the received radar signal by the protection node, a main lobe of the protection signal is aimed at a reconnaissance receiver of a blue side, and a side lobe is aimed at a side lobe of the radar of the home side; the radar of the home side suppresses the clutter in the side lobe of the received signal through a moving target display technology; and the main lobe of the clutter protection signal interferes with a front-end detection performance of the reconnaissance receiver of the blue side. Through utilization of the clutter, the clutter is utilized to destroy the front-end detection performance of the reconnaissance system of the blue side, the radar of the home side adopts the moving target display technology to eliminate the influence of the clutter on the radar of the home side, so that the problem that active jamming causes interference to the radar of the home side is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of radar, and more particularly to the technical field of radar counter-reconnaissance, and discloses a radar counter-reconnaissance signal design method based on clutter. BACKGROUND

[0002] Radar counter-reconnaissance is mainly through the radar's own technology and tactical means to counter, and takes a series of measures to prevent the blue side from intercepting the red side electromagnetic radiation signal. The modern radar system is facing an increasingly complex environment, and the interference research for destroying the signal detection link of the reconnaissance system is relatively single, mainly the active noise interference to the reconnaissance system. The interception of the reconnaissance system to the radiation source signal is the first link of the system to obtain intelligence information, and its interception performance directly affects the subsequent signal parameter measurement, sorting, identification, positioning, threat judgment, etc. The traditional noise interference is an active interference mode, which aims to transmit interference signals to the blue reconnaissance receiver, so that it is difficult to distinguish the real target echo signal. Although this interference mode can significantly affect the signal interception performance of the reconnaissance system, it will also have a certain impact on the interception performance of the own radar.

[0003] Yang Junjia et al. in the paper "Influence Analysis of Active Noise on Signal Interception Performance of Reconnaissance System" (Electronic Information Countermeasure Technology, 2013, 28(03): 61-64.) discloses the influence of active noise on the signal interception performance of the reconnaissance system. The method is aimed at the influence of active noise interference on the signal pulse interception performance and the interception factor of the radiation source, and it is concluded that the active noise has a certain influence on the signal interception performance of the reconnaissance system, thereby destroying the signal detection link of the reconnaissance system. The deficiency of this method is that the active noise interference will interfere with the blue reconnaissance system, and at the same time, it will affect the front-end detection performance of the own radar, thereby interfering with the own radar.

[0004] Bi Daping et al. in the paper "Analysis of Active Noise Interference on Radar Counter-Reconnaissance System" (Electronic Information Countermeasure Technology, 2012, 27(05): 41-45.) discloses the possibility of radar counter-reconnaissance system being interfered by active noise at each stage and the performance indicators that may be interfered by active noise. Based on active noise interference, the paper analyzes the possibility of the radar counter-reconnaissance system being interfered by active noise and the performance indicators that may be interfered by active noise in the signal interception process, signal parameter measurement process and signal sorting process according to the working process of the system. The deficiency of this method is that the active interference will not only affect the detection probability and false alarm probability of the blue reconnaissance system, but also have a certain impact on the interception performance of the own radar, thereby interfering with the own radar. SUMMARY

[0005] The present application aims at the deficiency of the prior art, and provides a radar anti-reconnaissance signal design method based on clutter, which aims to solve the problem of single active jamming pattern in destroying the signal detection link of the blue reconnaissance receiver, and the problem that the active noise jamming not only destroys the signal detection link of the blue reconnaissance receiver, but also interferes with the radar of the self side.

[0006] The specific idea for realizing the purpose of the present application is that the signal designed by the present application is a baseband clutter jamming signal with Weibull distribution generated by the protection side, which overcomes the problem of single active jamming pattern in destroying the signal detection link of the blue reconnaissance receiver, so that the application scenarios of the signal designed by the present application for the protection side are increased, and the protection side can not only select the active noise jamming, but also select the baseband clutter signal with Weibull distribution when selecting the active jamming pattern to interfere with the blue reconnaissance receiver, thereby solving the problem of single active jamming pattern. The signal designed by the present application utilizes the characteristic that the Doppler frequency of the clutter jamming signal is zero, and the baseband clutter jamming signal with Weibull distribution at the zero frequency is eliminated by using the moving target indication technology of the radar of the self side, thereby solving the problem of interference of the active noise jamming of the prior art with the radar of the self side.

[0007] To realize the above purpose, the steps of the method include the following:

[0008] Step 1, the radar of the self side radiates a radar signal;

[0009] Step 2, the protection node generates a baseband clutter with Weibull distribution;

[0010] Step 3, the protection node radiates the clutter modulated to the received radar signal, and the main lobe of the protection signal is aimed at the blue reconnaissance receiver, and the side lobe is aimed at the side lobe of the radar of the self side;

[0011] Step 4, the radar of the self side suppresses the clutter in the side lobe of the received signal by using the moving target indication technology;

[0012] Step 5, the main lobe of the clutter protection signal interferes with the front-end detection performance of the blue reconnaissance receiver.

[0013] Compared with the prior art, the present application has the following advantages:

[0014] Firstly, the present application transmits the baseband clutter signal with Weibull distribution by the protection side, overcomes the problem of single active jamming pattern in destroying the signal detection link of the blue reconnaissance receiver, so that the application scenarios of the signal designed by the present application for the protection side are increased, and the protection side can not only select the active noise jamming, but also select the baseband clutter signal with Weibull distribution when selecting the active jamming pattern to interfere with the blue reconnaissance receiver.

[0015] Secondly, the present invention eliminates the influence of clutter on its own radar by using moving target indication technology, thus overcoming the interference of active noise interference on its own radar in the prior art. This allows the present invention to remove the sidelobe interference caused by the sidelobe when the protector transmits clutter interference signals, by processing the echo signal with moving target indication technology. Attached Figure Description

[0016] Figure 1 This is a flowchart of an embodiment of the present invention;

[0017] Figure 2 This is a scene diagram of an embodiment of the present invention;

[0018] Figure 3 This is a block diagram of the generation of Weibull distribution-type clutter in this invention;

[0019] Figure 4 This is a schematic diagram of the clutter suppression principle of the present invention;

[0020] Figure 5 This is a result diagram of simulation experiment 1 of the present invention;

[0021] Figure 6 This is a result diagram of simulation experiment 2 of the present invention. Detailed Implementation

[0022] The present invention will now be further described with reference to the accompanying drawings and embodiments.

[0023] Reference Figure 1 The implementation steps of the embodiments of the present invention will be further described below.

[0024] Step 1, the working scenario of this embodiment of the invention.

[0025] Reference Figure 2 The working scenarios set in the embodiments of the present invention will be further described below.

[0026] In this embodiment of the invention, a protective node is deployed 15km directly east of the radar, a blue team reconnaissance receiver is deployed 20km northeast of the radar, and a moving target is deployed at 8km, 14km, and 25km north of the radar at 30 degrees east of north.

[0027] Our radar emits the following radar signals:

[0028]

[0029] Where s(t) represents the radar signal radiated at time t, t represents the time in the range [0,T], T represents the duration of the pulse in the radiated radar signal, A represents the amplitude of the radiated radar signal, rect(·) represents the rectangular envelope function, exp(·) represents the exponential operation with the natural constant e as the base, j represents the imaginary unit sign, π represents pi, and k represents the frequency modulation slope of the radiated radar signal. This indicates the initial phase of the radiated radar signal.

[0030] In this embodiment of the invention, the amplitude A of the radiated radar signal is 5, the pulse duration T of the radiated radar signal is 20 μs, and the frequency modulation slope k of the radiated radar signal is 10. 11 Hz / s, the initial phase of the radiating radar signal

[0031] Step 2: The protection node generates baseband clutter with a Weibull distribution.

[0032] Reference Figure 3 The following is a further description of the baseband clutter generated by the protection node in the embodiments of the present invention.

[0033] Step 1: Randomly generate two independent and uncorrelated Gaussian distribution sequences {n} 1,i} and {n 2,i}, i = 1, 2, ..., N, where N represents the total number of Gaussian distributed data points, 10 3 ≤N≤10 6 ;

[0034] Step 2, for {n 1,i} and {n 2,i Linear spectral modulation is performed to obtain a correlated Gaussian distributed random sequence {w}. 1,k} and {w 2,k};

[0035] Step 3, {w 1,k} and {w 2,k Substitute x into the formula k =(w 1,k 2 +w 2,k 2 ) 1 / p In this process, a relevant Weibull distribution-like clutter random sequence {x} is generated. k}, k = 1, 2, ..., N1, p represents the shape parameter of the Weibull distribution skewness, and N1 represents the clutter-like {x k The total number of elements, N1 = N.

[0036] In this embodiment of the invention, the total number of Gaussian distributed data is N = N1 = 10 3 .

[0037] Step 3: Modulate the protected node's radiated clutter onto the received radar signal, align the main lobe of the protected signal with the blue team's reconnaissance receiver, and align the side lobe with the side lobe of the friendly radar.

[0038] The clutter-like signal is modulated onto the received radar signal according to the following formula:

[0039]

[0040] Where s1(t) represents the modulated radar signal, τ0 represents the delay time from the friendly radar signal to the receiving end of the protection node, τ0=2R0 / c, R0 represents the radial distance between the friendly radar and the protection node, and c represents the speed of light. N represents the initial phase of the received radar signal. r C(t) represents the noise interference signal, and C(t) represents the clutter interference signal.

[0041] In this embodiment of the invention, the delay time τ0 from the radar signal to the receiving end of the protection node is 100 μs, the radial distance R0 between the radar and the protection node is 15 km, and the speed of light c is 3 × 10⁻⁶. 8 The initial phase of the received radar signal Noise interference signal N r (t) uses 1 dB Gaussian noise, and the clutter C(t) uses 8 dB signals with both scale and shape parameters of 2.

[0042] Step 4: Our radar suppresses clutter-like noise in the sidelobes of the received signal.

[0043] The aforementioned moving target display technology refers to the use of delay line cancellers to suppress clutter-like noise. The delay line canceller includes a single delay line canceller and a dual delay line filter.

[0044] The single-delay-line canceller suppresses clutter by simply differentially dividing the received data from the preceding and following periods in the time domain. Its impulse response is as follows:

[0045] h1(t)=δ(t)-δ(tT) r )

[0046] Where h1(t) represents the impulse response of the single-delay line canceller, δ(·) represents the impulse function, and T r This indicates the delay time of the delay line canceller.

[0047] The aforementioned dual-delay-line canceller achieves cancellation by performing two subtraction operations on the received data of the preceding and following periods in the time domain. Its impulse response is as follows:

[0048] h2(t)=δ(t)-2δ(tT) r )+δ(t-2T r )

[0049] Where h2(t) represents the impulse response of the dual delay line canceller.

[0050] The steps for suppressing clutter-like noise in the sidelobes of the received signal are as follows:

[0051] Step 1: Perform pulse compression processing on the signal received by your own radar according to the following formula:

[0052]

[0053] Where y(t) represents the output signal after pulse compression, x(t) represents the signal received by our radar, and h(t) represents the matched filter used for pulse compression, h(t) = s * (-t), s * (-t) represents the inverse of the conjugate of the radar's transmitted signal, Sa(·) represents the sampling function, B represents the bandwidth of the radar's transmitted signal, T1 represents the pulse width of the radar's transmitted signal, N(t) represents the noise interference signal received by the radar, and J(t) represents the interference signal in the signal received by the radar.

[0054] The signal x(t) received by our own radar is obtained by the following formula:

[0055] x(t)=s0(t)+s τ (t)+N1(t)+C1(t)

[0056] Where s0(t) represents the signal transmitted by the protection node after a time delay and reaching the receiver of the friendly radar, s τ (t) represents the target echo signal of our own radar, N1(t) represents the noise interference signal in the signal received by our own radar, and C1(t) represents the sum of the clutter-like signal and the clutter interference signal in the signal received by our own radar.

[0057] The signal s0(t) is obtained by the following formula:

[0058]

[0059] Where τ1 represents the time delay from the radiated signal of the protected node to the radar receiver of the user. This indicates the phase of the transmitted signal from the protected node after a time delay before reaching the receiver of the radar.

[0060] The signal s τ (t) is obtained from the following formula:

[0061]

[0062] Where τ represents the target delay of the signal transmitted by our own radar.

[0063] Step 2: Perform moving target display processing on the pulse-compressed signal y(t):

[0064] Y1(t) = y(t) - y(tT) r )

[0065] Y2(t)=y(t)-2y(tT) r )+y(t-2T r )

[0066] Where Y1(t) represents the output of y(t) after passing through a single delay line canceller, and Y2(t) represents the output of y(t) after passing through a double delay line canceller.

[0067] The delay time T of the delay line canceller in this embodiment of the invention r =30μs, the bandwidth of the signal transmitted by the radar is B=10MHz, the pulse width of the signal transmitted by the radar is T1=20μs, the noise interference signal N(t) received by the radar is a 3dB Gaussian noise signal, and the interference signal J(t) in the signal received by the radar is a 7dB active interference signal.

[0068] Reference Figure 4 The principle of the delay line canceller in the moving target display technology of the present invention will be further described.

[0069] Figure 4 The horizontal axis represents the Doppler frequency, and the vertical axis represents the signal amplitude. Figure 4 (a) The clutter is mainly distributed at the zero Doppler frequency. Since the Doppler frequency of the target is related to its speed, it is distributed at the non-zero Doppler frequency. Figure 4 (b) The cancellation filter has a deep notch at the zero Doppler frequency. If the target and clutter are processed together through the cancellation filter, the clutter-like signal at the zero Doppler frequency will be canceled out, leaving only the moving target signal effect. Figure 4 As shown in (c).

[0070] Step 5: The main lobe of the clutter protection signal interferes with the front-end detection performance of the Blue Team's reconnaissance receiver.

[0071] The steps for interfering with the front-end detection performance of the Blue Team's reconnaissance receiver are as follows:

[0072] The first step is to calculate the probability of the Blue Force's reconnaissance receiver intercepting the radar signal front-end detection in the absence of clutter interference:

[0073]

[0074] Among them, P fa V represents the probability that the Blue Team's reconnaissance receiver intercepts a radar signal envelope exceeding the 4-volt threshold level. T This indicates the 4-volt threshold level of the Blue Team's reconnaissance receiver, r o r represents the amplitude of the radar signal envelope intercepted by the Blue Team's reconnaissance receiver. o ≥0, σ 2 This represents the variance of the radar signals intercepted by the Blue Team's reconnaissance receiver.

[0075] The second step is to calculate the front-end detection probability of the blue team's reconnaissance receiver intercepting radar signals and clutter signals under clutter-like interference conditions:

[0076]

[0077] Among them, P dj I represents the probability that the Blue Team's reconnaissance receiver intercepts radar signals and clutter-like interference signal envelopes exceeding a 4-volt threshold level. o (·) denotes the zero-order modified Bessel function, r1 represents the amplitude of the detector envelope after clutter-like interference; σ nj 2 σ represents the sum of variances of clutter interference. nj 2 =σ 2 +σ j 2 , σ j 2 This represents the variance of clutter-like interference signals.

[0078] In this embodiment of the invention, the amplitude r of the radar signal envelope intercepted by the blue team's reconnaissance receiver is... o =5, the variance σ of the radar signal intercepted by the Blue Team's reconnaissance receiver 2 =1, the amplitude value of the detector envelope after clutter interference r1 = 5, the variance of the clutter interference signal σ j 2 =1, the sum of variances of clutter interference σ nj 2 =2.

[0079] The effects of the present invention will be further illustrated below through simulation experiments.

[0080] 1. Simulation experimental conditions:

[0081] The simulation experiments of this invention were run on a Windows 10 operating system and MATLAB R2023a environment on an Intel Core i5-1135G7 CPU computer.

[0082] 2. Simulation Experiment Content and Result Analysis:

[0083] The present invention includes two simulation experiments: Simulation Experiment 1 simulates radar signal processing, and Simulation Experiment 2 simulates clutter interference on the blue team's reconnaissance receiver.

[0084] In simulation experiment 1, the radar pulse width was set to 20 μs, the radar wavelength to 0.05 m, the sampling frequency to 30 MHz, the pulse repetition period to 200 μs, and the number of pulses to 32. The clutter-like interference signal adopted a Weibull distribution model with the following parameters: scale parameter p = 2, shape parameter q = 2, and variance 1.0. The simulation also included three moving targets with radial velocities relative to the radar of 30 m / s, 150 m / s, and 200 m / s, respectively, and distances of 8 km, 15 km, and 25 km, respectively. The signal-to-noise ratio was set to 10 dB.

[0085] Simulation Experiment 1 of this invention uses the method of this invention and a prior art, employing pulse compression technology and moving target display technology to process the echo signal, respectively, to obtain the spectrum diagrams before and after pulse compression, before MTI cancellation, after single / dual delay line cancellation, and after MTD and CFAR detection, as shown below. Figure 5 As shown.

[0086] In simulation experiment 1, one existing technology used is:

[0087] Prior art 1 refers to the method for pulse compression and moving target detection of echo signals proposed by Xi'an University of Electronic Science and Technology in its patent application document "An Optimization Processing Method for Pulse Compression Radar Echo Signal" (application number: 201710895204, application publication number: CN201710895204.X).

[0088] Simulation Experiment 2 is a simulation of clutter interference on the Blue Team's reconnaissance receiver.

[0089] The clutter interference power N set in simulation experiment 2 of this invention j For σ j 2 At the same time, the threshold level is determined to be V. T Internal noise power N ro The value is σ ro 2 The amplitude A of the radar signal was set to 5, the carrier frequency f to 1 GHz, and the bandwidth Δf to 5 MHz. For the reconnaissance system, a typical intercept receiver was selected in the experiment, whose instantaneous bandwidth is typically in the range of 5–20 MHz. The bandwidth Δf for clutter interference was further set. jIt is 3Δf, which is 15MHz, and its center frequency is ensured to be consistent with the frequency of the protected radar, which is 1GHz.

[0090] Simulation Experiment 2 of this invention uses the method of this invention and a prior art, employing a front-end intercept probability model of a reconnaissance receiver to obtain the relationship between the threshold level and the false intercept probability under clutter-like interference, as well as the relationship between the threshold level and the intercept probability under clutter-like interference conditions. Figure 6 As shown.

[0091] In simulation experiment 2, an existing technology was used.

[0092] The prior art 1 refers to the front-end interception model of the reconnaissance system proposed by Yin Xiaofeng et al. in their published paper "Analysis of the interception probability of the radar reconnaissance system front end" (Ship Electronic Engineering, 2004, 24(3):107-109,113.), which includes the window functions of the reconnaissance system in the time domain, spatial domain and frequency domain and their influence on the interception probability.

[0093] The following is combined Figure 5 , Figure 6 The simulation diagrams further illustrate the effects of the present invention.

[0094] This invention performs echo processing on LFM signals. Echo signals are obtained by simulating the reflection and propagation process of the signal; these signals contain the position and velocity information of the target object. Subsequently, these echo signals undergo pulse compression processing. The image before pulse compression processing is shown below. Figure 5 As shown in (a). Figure 5 In (a), the horizontal axis represents frequency in Hz, and the vertical axis represents amplitude. Figure 5 The signal in (a) contains noise, clutter, and target echo. The pulse compression diagram is shown below. Figure 5 As shown in (b) Figure 5 (b) The horizontal axis represents time in microseconds, and the vertical axis represents amplitude. Figure 5 (b) is a graph of the signal after pulse compression. Figure 5 (b) It can be seen that the signal-to-noise ratio has been improved, and the information of the target object is clearer and more distinguishable.

[0095] After pulse compression, the signal undergoes further MTI processing. In this step, the result before MTI processing is first plotted to visually observe the distribution of clutter and target objects in the signal. Figure 5 In (c), the horizontal axis represents distance in kilometers, and the vertical axis represents amplitude. Figure 5 (c) There are three moving targets located at (X=8, Y=1321.74), (X=14, Y=1249.5), and (X=25, Y=1321.17). FromFigure 5 As can be seen in (c), clutter permeates the entire region from 0 to 30 kilometers, severely interfering with target detection.

[0096] This invention employs an MTI filter to cancel the signal. Through single, double, and triple cancellation operations, noise components in the signal are successfully removed. Figure 5 (d) Figure 5 (e) and Figure 5 In (f), the horizontal axis represents distance in kilometers, and the vertical axis represents amplitude. From Figure 5 (d) Figure 5 (e) and Figure 5 As can be seen in (f), the MTI filter perfectly cancels out clutter, making the information of the target object more prominent and clear. The three moving targets are respectively in Figure 5 (d) Figure 5 (e) and Figure 5 (f) shows X=8, X=14 and X=25, and the clutter has been canceled out, highlighting only the remaining moving target.

[0097] This invention applies Moving Target Detection (MTD) processing and Constant False Alarm Rate (CFAR) processing to the signal. MTD processing further extracts information about moving targets, while CFAR processing improves the target detection probability while maintaining a constant false alarm rate. These two processing steps result in more accurate and reliable target detection results. Figure 6 As shown in (g). Figure 6 In the 3D diagram of (g), the x-axis is the distance axis in kilometers, the y-axis is the velocity axis in m / s, and the z-axis is the amplitude axis. The MTD can display the velocities of the moving target as follows: Y = 29.85 m / s, Y = 149.283 m / s, and Y = 194.068 m / s. Figure 6 The x-axis of (h) represents the distance unit, and the y-axis represents the amplitude, in dB. Figure 6 (h) highlights three moving targets and the CFAR threshold, and increases the threshold value at the moving target.

[0098] Figure 6 In (a), the horizontal axis represents the threshold level in volts, and the vertical axis represents the false alarm probability. ​A clear trend is evident in (a): as the threshold value increases, the false alarm probability (FAP) decreases significantly. However, when the threshold value remains constant, the FAP increases continuously with the gradual increase in clutter power, potentially leading to the inability to meet the low FAP standard for specific detection sensitivity requirements. To meet the stringent requirements of reconnaissance systems regarding false alarm rates, the threshold level must be increased to effectively reduce the FAP and ensure the stability and accuracy of the reconnaissance system.

[0099] ​ (b) The horizontal axis represents the threshold level in volts, and the vertical axis represents the front-end interception probability. From ​ The information presented in (b) reveals the relationship between the threshold and the probability of front-end interception. As the threshold gradually increases, the probability of front-end interception shows a significant downward trend. More complexly, even if the threshold remains constant, an increase in jamming power still leads to a significant decrease in the probability of front-end interception. At the same time, the system faces the serious challenge of a continuously rising probability of false interception, which undoubtedly poses a significant test to the performance of the reconnaissance system. ​ (b) Clearly demonstrates that enhanced clutter-like interference has a dual negative impact on reconnaissance systems: it not only reduces the probability of front-end interception but also increases the probability of false interception. This necessitates more precise adjustments and optimizations of various parameters for reconnaissance systems when dealing with complex electromagnetic environments to ensure stable and reliable performance.

[0100] In summary, the data processing and analysis from the simulation experiments of this invention demonstrate that clutter-like interference does not have a substantial impact on friendly radar. The effective application of the MTI filter enables the elimination of clutter components in the signal, thereby achieving accurate detection of target objects. Clutter-like interference can impair the front-end detection performance of reconnaissance receivers. As the power of clutter-like interference gradually increases, the probability of interception at the front-end of the reconnaissance receiver gradually decreases, while the probability of false interception increases. This indicates that increased clutter-like interference leads to varying degrees of performance degradation in the reconnaissance system.

Claims

1. A radar counter-reconnaissance signal design method based on clutter-like signals, characterized in that, A protective node is deployed 15km directly east of the friendly radar, and a blue force reconnaissance receiver is deployed 20km northeast of the friendly radar. Clutter-like signals are used to disrupt the front-end detection performance of the blue force's reconnaissance system. The friendly radar uses moving target indication (MTI) technology to eliminate the impact of clutter-like signals on the received signals. The steps of this method are as follows: Step 1: Our own radar radiates radar signals; The expression for the radar signal is as follows: Where s(t) represents the radar signal radiated at time t, t represents the time in the range [0,T], T represents the duration of the pulse in the radiated radar signal, A represents the amplitude of the radiated radar signal, rect(·) represents the rectangular envelope function, exp(·) represents the exponential operation with the natural constant e as the base, j represents the imaginary unit sign, π represents pi, and k represents the frequency modulation slope of the radiated radar signal. Indicates the initial phase of the radiated radar signal; Step 2: The protection node generates baseband clutter with a Weibull distribution. The steps are as follows: The first step is to randomly generate two independent and uncorrelated Gaussian distribution sequences {n}. 1,i } and {n 2,i }, i = 1, 2, ..., N, where N represents the total number of Gaussian distributed data points, 10 3 ≤N≤10 6 ; The second step is to process {n} 1,i } and {n 2,i Linear spectral modulation is performed to obtain a correlated Gaussian distributed random sequence {w}. 1,k } and {w 2,k }; The third step is to... 1,k } and {w 2,k Substitute x into the formula k =(w 1,k 2 +w 2,k 2 ) 1 / p In this process, a relevant Weibull distribution-like clutter random sequence {x} is generated. k }, k = 1, 2, ..., N1, p represents the shape parameter of the Weibull distribution skewness, and N1 represents the clutter-like {x k The total number of elements, N1 = N; Step 3: Modulate the protected node's radiated clutter onto the received radar signal, align the main lobe of the protected signal with the blue team's reconnaissance receiver, and align the side lobe with the side lobe of the friendly radar. The clutter radiated by the protection node is modulated onto the received radar signal as follows: Where s1(t) represents the modulated radar signal, τ0 represents the delay time from the friendly radar signal to the receiving end of the protection node, τ0=2R0 / c, R0 represents the radial distance between the friendly radar and the protection node, and c represents the speed of light. N represents the initial phase of the received radar signal. r C(t) represents the noise interference signal, and C(t) represents the clutter interference signal. Step 4: Our radar suppresses clutter-like noise in the sidelobes of the received signal using moving target indication technology. The steps are as follows: The first step is to perform pulse compression processing on the signal received by our own radar according to the following formula: Where y(t) represents the output signal after pulse compression, x(t) represents the signal received by our radar, and h(t) represents the matched filter used for pulse compression, h(t) = s * (-t), s * (-t) represents the inverse of the conjugate of the radar's transmitted signal, Sa(·) represents the sampling function, B represents the bandwidth of the radar's transmitted signal, T1 represents the pulse width of the radar's transmitted signal, N(t) represents the noise interference signal received by the radar, and J(t) represents the interference signal in the signal received by the radar. The signal x(t) received by our own radar is obtained by the following formula: x(t)=s0(t)+s τ (t)+N1(t)+C1(t); Where s0(t) represents the signal transmitted by the protection node after a time delay and reaching the receiver of the friendly radar, s τ (t) represents the target echo signal of our own radar, N1(t) represents the noise interference signal in the signal received by our own radar, and C1(t) represents the sum of the clutter-like signal and the clutter interference signal in the signal received by our own radar. The signal s0(t) is obtained by the following formula: Where τ1 represents the time delay from the radiated signal of the protected node to the radar receiver of the user. This indicates the phase of the transmitted signal from the protected node that reaches the receiver of the radar after a time delay; The signal s τ (t) is obtained from the following formula: Where τ represents the target delay of the signal transmitted by our own radar; The second step is to perform moving target display processing on the pulse-compressed signal y(t): Y1(t)=y(t)-y(t-T r ); Y2(t)=y(t)-2y(t-T r )+y(t-2T r ); Where Y1(t) represents the output of y(t) after passing through a single-delay-line canceller, Y2(t) represents the output of y(t) after passing through a double-delay-line canceller, and T r Indicates the delay time of the delay line canceller; Step 5: The main lobe of the clutter protection signal interferes with the front-end detection performance of the Blue Team's reconnaissance receiver. The steps are as follows: The first step is to calculate the probability of the Blue Force's reconnaissance receiver intercepting the radar signal front-end detection in the absence of clutter interference: Among them, P fa V represents the probability that the Blue Team's reconnaissance receiver intercepts a radar signal envelope exceeding the 4-volt threshold level. T This indicates the 4-volt threshold level of the Blue Team's reconnaissance receiver, r o r represents the amplitude of the radar signal envelope intercepted by the Blue Team's reconnaissance receiver. o ≥0, σ 2 This represents the variance of the radar signals intercepted by the Blue Team's reconnaissance receiver; The second step is to calculate the front-end detection probability of the blue team's reconnaissance receiver intercepting radar signals and clutter signals under clutter-like interference conditions: Among them, P dj I represents the probability that the Blue Team's reconnaissance receiver intercepts radar signals and clutter-like interference signal envelopes exceeding a 4-volt threshold level. o (·) denotes the zero-order modified Bessel function, r1 represents the amplitude of the detector envelope after clutter-like interference; σ nj 2 σ represents the sum of variances of clutter interference. nj 2 =σ 2 +σ j 2 , σ j 2 This represents the variance of clutter-like interference signals.

2. The radar counter-reconnaissance signal design method based on clutter-like features according to claim 1, characterized in that, The moving target display technology mentioned in step 4 refers to the use of delay line cancellers to suppress clutter-like noise. The delay line cancellers include single delay line cancellers and dual delay line cancellers.

3. The radar counter-reconnaissance signal design method based on clutter as described in claim 2, characterized in that, The single-delay-line canceller suppresses clutter by simply differentially dividing the received data from the preceding and following periods in the time domain. Its impulse response is as follows: h1(t)=δ(t)-δ(tT r ); Where h1(t) represents the impulse response of the single-delay line canceller, δ(·) represents the impulse function, and T r This indicates the delay time of the delay line canceller.

4. The radar counter-reconnaissance signal design method based on clutter as described in claim 3, characterized in that, The aforementioned dual-delay-line canceller achieves cancellation by performing two subtraction operations on the received data of the preceding and following periods in the time domain. Its impulse response is as follows: h2(t)=δ(t)-2δ(t-T r )+δ(t-2T r ); Where h2(t) represents the impulse response of the dual delay line canceller.

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