Radar signal processing method based on polarization interference identification

Abstract

The invention provides a radar signal processing method based on polarization interference identification, and the method comprises the steps: decomposing a monochromatic wave in any polarization form into two orthogonal polarization components according to a polarization electromagnetic theory, employing a phase amplitude measurement method, and carrying out the polarization interference identification through a pair of polarization orthogonal antennas with equal phase centers, the radar wave polarization direction is indirectly measured by measuring the amplitude ratio and the phase difference of received signals of the two antennas, so that a set of complete polarization judgment technology implementation route is constructed. According to the method, the axial ratio, the ellipticity angle and the inclination angle of the ellipse are calculated according to the measured amplitude ratio and phase difference, and the polarization measurement error is calculated according to the calculation result, so that a set of complete polarization measurement technology implementation route is constructed. According to the invention, the polarization measurement function is realized through digital domain signal measurement and is carried out after intermediate frequency processing AD conversion, and the high-speed FPGA is adopted to process digital signals, so that a polarization judgment and polarization measurement process based on the high-speed FPGA is constructed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar polarization jamming, in particular to a radar signal processing method based on polarization jamming identification. BACKGROUND

[0002] Orthogonal variable polarization jamming is a new jamming method that uses the inconsistency between the main polarization of the radar antenna and the cross-polarization receiving vector to transmit electromagnetic waves with the same frequency as the radar operating frequency and orthogonal to the main polarization of the radar antenna to illuminate the radar, thereby achieving angle deception. This jamming method does not require multiple separate jamming sources in space and has great application potential in important target protection and missile penetration fields. It is widely considered to be an effective technical solution to deal with single-pulse angle measurement radars.

[0003] 1. Limitations of traditional jamming methods Traditional noise jamming (such as noise suppression and deception jamming) is easily identified and suppressed by modern radar anti-jamming techniques (such as pulse compression and Doppler filtering), limiting the effectiveness of the jamming. Polarization jamming, on the other hand, takes advantage of the polarization sensitivity of the radar receiving system to achieve more covert and efficient jamming effects.

[0004] 2. Availability of target polarization characteristics The scattering of electromagnetic waves by different targets (such as aircraft, ships, and ground vehicles) changes their polarization state, forming unique polarization fingerprints. Jamming machines can simulate or disrupt these polarization characteristics to effectively deceive radars.

[0005] 3. Information limitations of traditional radars Traditional radars only use the amplitude, phase, and Doppler information of the return to identify targets, making it difficult to distinguish between targets with similar electromagnetic characteristics (such as metal foil and real targets) and vulnerable to deception jamming.

[0006] 4. Unique value of polarization information The polarization scattering characteristics of a target are closely related to its shape, structure, and material. For example, there is a significant difference in the polarization response of metal and non-metal targets. By extracting and analyzing polarization information, the target recognition ability and anti-jamming performance of radars can be effectively improved.

[0007] To solve the above four problems, a complete radar signal processing solution based on polarization jamming identification is provided. Therefore, a radar signal processing method based on polarization jamming identification is proposed. SUMMARY

[0008] The application aims at the problems existing in the prior art. In order to achieve the above-mentioned application purposes, the application provides the following technical scheme: a radar signal processing method based on polarization interference recognition, step 1, receiving radar radio frequency signals through a pair of polarization orthogonal antennas with equal phase centers to obtain horizontal channel response signals Ex and vertical channel response signals Ey; Step 2, measuring the amplitude ratio χ and the phase difference δ of Ex and Ey by using a phase-amplitude measurement method; Step 3, calculating polarization parameters of radar waves according to the amplitude ratio χ and the phase difference δ, wherein the polarization parameters include an axial ratio, an inclination angle τ and an ellipticity angle ε; Step 4, determining the polarization mode of the radar waves based on the polarization parameters and calculating a polarization measurement error.

[0009] As a preferred technical scheme of the application, the method for calculating the axial ratio in step 3 is that Ex and Ey are discretized into 360 points in the phase range of 0-2π, the instantaneous field strength amplitude ||E||=√(Ex²+Ey²) of each point is calculated, the maximum field strength amplitude ||E||max and the minimum field strength amplitude ||E||min are determined, and the axial ratio is the ratio of ||E||min to ||E||max.

[0010] As a preferred technical scheme of the application, the method for calculating the inclination angle τ in step 3 is that Ex(||E||max) and Ey(||E||max) corresponding to ||E||max are determined, and the inclination angle τ=arctan[Ey(||E||max) / Ex(||E||max)].

[0011] As a preferred technical scheme of the application, the method for calculating the ellipticity angle ε in step 3 is that the ellipticity angle ε=arctan(||E||min / ||E||max).

[0012] As a preferred technical scheme of the application, the rule for determining the polarization mode in step 4 is that: Step 41, if the value range of the axial ratio is 0-0.15, it is determined as linear polarization; Step 42, if the value range of the axial ratio is 0.85-1, it is determined as circular polarization; Step 43, if the value range of the axial ratio is 0.15-0.85, it is determined as elliptical polarization.

[0013] As a preferred technical scheme of the application, the linear polarization includes vertical polarization, horizontal polarization and 45° oblique polarization, which are distinguished by the value range of the inclination angle τ: (1) if τ∈(-112.5°, -67.5°] or τ∈(67.5°, 112.5°], it is determined as vertical polarization; (2) If τ∈(-22.5°, 22.5°], it is determined as horizontal polarization; (3) If τ∈(-67.5°, -22.5°] or τ∈(22.5°, 67.5°], it is determined as 45° oblique polarization.

[0014] As a preferred technical solution of the application, the circular polarization rotation direction is determined by phase difference δ: if δ∈(0, π], it is determined as right-hand circular polarization; if δ∈(-π, 0], it is determined as left-hand circular polarization.

[0015] As a preferred technical solution of the application, the method for calculating polarization measurement error in step 4 is: For vertical polarization, the polarization error is the difference between the calculated tilt angle τ and -90° or 90°; For horizontal polarization, the polarization error is the difference between the calculated tilt angle τ and 0°; For 45° oblique polarization, the polarization error is the difference between the calculated tilt angle τ and -45° or 45°; For circular polarization, the polarization error is the difference between the calculated ellipticity angle ε and 45°.

[0016] As a preferred technical solution of the application, the amplitude ratio χ and phase difference δ are measured by high-speed FPGA, and the specific process includes: (1) Receiving channel correction: amplitude and phase correction is performed on the received signals of the horizontal channel and the vertical channel; (2) Data acquisition: the corrected signals are digitized and collected using a high-speed ADC; (3) Signal measurement: the collected digital signals are preprocessed, and the preprocessing includes noise removal, filtering and signal enhancement; (4) Polarization measurement: the preprocessed signals are separated into horizontal and vertical components, and the amplitude ratio χ and the phase difference δ are measured.

[0017] A radar signal processing system, comprising: a polarization orthogonal antenna module, a signal acquisition module, an amplitude and phase measurement module, a polarization parameter calculation module, and a polarization determination and error calculation module; The polarization orthogonal antenna module is used to receive radar radio frequency signals and output horizontal channel response signals and vertical channel response signals; The signal acquisition module is used to digitize and collect the response signals; The amplitude and phase measurement module is used to measure the amplitude ratio and the phase difference of the collected signals; The polarization parameter calculation module is used to calculate the polarization parameters according to the amplitude ratio and the phase difference; The polarization determination and error calculation module is used for determining the polarization mode according to the polarization parameter and calculating the polarization measurement error.

[0018] Compared with the prior art, the present application has the following advantages: The present application provides a polarization determination algorithm, according to the polarization electromagnetic theory, monochromatic wave of arbitrary polarization form can be decomposed into two orthogonal polarization components, using phase-amplitude measurement method, through a pair of polarization orthogonal antennas with equal phase center, the amplitude ratio and phase difference of the signals received by the two antennas are measured to indirectly measure the polarization direction of radar wave, thereby constructing a complete polarization determination technology implementation route.

[0019] The present application provides a polarization measurement algorithm, according to the measured amplitude ratio and phase difference, the axis ratio (short axis / long axis) of the ellipse, the ellipticity angle and the inclination angle are calculated, and the polarization measurement error is calculated according to the calculation result, thereby constructing a complete polarization measurement technology implementation route.

[0020] The present application provides a polarization determination and polarization measurement process based on high-speed FPGA, the polarization measurement function is realized by digital domain signal measurement, and the process is carried out after AD conversion, high-speed FPGA is used to realize the processing of digital signals, thereby constructing a polarization determination and polarization measurement process based on high-speed FPGA. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The structural schematic diagram provided by the present application is provided. Figure 2 The Matlab execution phase difference: 53.6, amplitude difference: 24.7 result schematic diagram provided by the present application is provided. Figure 3 The Matlab execution phase difference: -35.5, amplitude difference: -25.4 schematic diagram provided by the present application is provided. Figure 4 The Matlab execution phase difference: -5.34, amplitude difference: -0.15 schematic diagram provided by the present application is provided. Figure 5 The Matlab execution phase difference: 94.7, amplitude difference: 0.56 schematic diagram provided by the present application is provided. Figure 6 The polarization measurement process schematic diagram provided by the present application is provided. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments.

[0023] Therefore, the following detailed description of the embodiments of the application is not intended to limit the scope of the application as claimed, but merely represents some embodiments of an application. Based on the embodiments of the application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the application. It should be noted that the embodiments in the application and the features and technical solutions in the embodiments can be combined with each other without conflict, and similar reference numbers and letters represent similar items in the following drawings, so that once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0024] Embodiment 1: A radar signal processing method based on polarization interference recognition. For electromagnetic waves, polarization describes the shape and rotational direction of the spatial trajectory formed by the end point of the electric field vector as a function of time. The electric vector of a plane electromagnetic wave can be decomposed into horizontal and vertical components in a rectangular coordinate system, and the relative relationship between the two components constitutes the polarization mode of the plane electromagnetic wave.

[0025] Any plane electromagnetic wave can be represented as: After the radar signal enters the polarization diversity receiving system, the responses in the horizontal channel and the vertical channel are and , the amplitude ratio of the two is , and the phase difference is .

[0026] According to the polarization electromagnetic theory, a monochromatic wave of any polarization form can be decomposed into two orthogonal polarization components. Using the phase-amplitude measurement method, the polarization direction of the radar wave is indirectly measured by measuring the amplitude ratio and phase difference of the signals received by a pair of polarization orthogonal antennas with the same phase center.

[0027] Generally, the electric field vector E of a monochromatic electromagnetic wave propagating along the +z direction has both x and y components, which can be represented by a complex vector as: ; in the formula, and are the unit basis vectors in the +x and +y directions, respectively; x is the horizontal direction; and y is the vertical direction.

[0028] ; wherein, and the phase difference and the difference According to the FPGA, the ratio of and can be measured Also according to FPGA can measure.

[0029] According to the trajectory of the end point of the electric field vector of the plane electromagnetic wave in space, it can be generally divided into three polarization forms, namely linear polarization, circular polarization and elliptical polarization.

[0030] The elliptical equation can be obtained: ; The value is between 0 and , left-handed, and to 0, right-handed.

[0031] Linear polarization and circular polarization can be regarded as the degeneration of elliptical polarization under certain conditions.

[0032] According to the x horizontal component and the y vertical component, and the measured phase difference And the ratio .

[0033] ; it is derived that:

[0034] When When the change is between 2Π, divide 2Π into 360 points for calculation, and the obtained points can be drawn into an ellipse: the instantaneous field strength amplitude of each point , and the maximum field strength amplitude And the minimum field strength amplitude , and the maximum field strength amplitude Corresponding And .

[0035] ; the axial ratio (elliptical polarization parameter) ranges from 0 to 1, the value is closer to 0, which is closer to linear polarization, and closer to 1, which is closer to circular polarization.

[0036] ;

[0037] According to the measured amplitude ratio and phase difference, the axial ratio (short axis / long axis) of the ellipse, the ellipticity angle and the inclination angle are calculated, and the polarization mode and the polarization measurement error are calculated according to the calculation results.

[0038] Set the axial ratio (elliptical polarization parameter) range between 0-0.15, determine as linear polarization, and determine vertical polarization, horizontal polarization and 45° oblique polarization through the inclination angle when linear polarization.

[0039] Set the axial ratio (elliptical polarization parameter) range between 0.85-1, determine as circular polarization, and the error of circular polarization is the ellipticity angle the difference from 45°. But in polarization measurement, the propagation direction of the signal and the receiving direction of the signal are just opposite, so the measured value is between 0 and π / 4 is right-handed, and between π / 4 and 0 is left-handed.

[0040] The algorithm is as follows: %% Measure the amplitude-phase difference of the two channels, and calculate the axial ratio and polarization angle % The response of the radar signal entering the polarization diversity receiving system in the horizontal channel and the vertical channel is Ex and Ey %% Input: phase difference amplitude ratio deltPh = -5.34; %% phase difference ratioPa = -0.15; %% amplitude component ratio (dB) ratioPa = power(10,ratioPa / 20); %% Calculate deltPh = deltPh / 180 pi; tick = 1; % angle accuracy 1 degree.

[0041] t = (0:tick:359) / 360; phx = 0; E0x = 1; %% initial value E0y = E0x ratioPa; phy = phx + deltPh; Ex = E0x. cos(2. pi. t+phx); Ey = E0y. cos(2. pi. t+phy); checkPa = sqrt(Ex.^2 + Ey.^2); %% To calculate the polarization angle maxPa = max(checkPa); maxloc = find(checkPa == maxPa); maxloc =maxloc(1); minPa = min(checkPa); minloc = find(checkPa == minPa); back_Ratio = minPa / maxPa; %% 0~1 if Ex(maxloc) == 0 arcTan = 10000; else arcTan = Ey(maxloc).Ex(maxloc); end % deltPh : -180~180 if deltPh < 0 str = 'left-handed'; else str = 'right-rotation'; end If back_Ratio < 0.15, enable linear polarization. Po_Angle = atan(arcTan) / pi 180; Po_Ratio = back_Ratio; if -112.5 < Po_Angle & Po_Angle <= -67.5 str1 = strcat('', 'Vertical polarization'); str2 = strcat('Polarization Error', num2str(Po_Angle + 90)); elseif -67.5 < Po_Angle & Po_Angle <= -22.5 str1 = strcat('', '-45° oblique polarization'); str2 = strcat('Polarization Error', num2str(Po_Angle + 45)); elseif -22.5 < Po_Angle & Po_Angle <= 22.5 str1 = strcat('', 'Horizontal polarization'); str2 = strcat('Polarization Error', num2str(Po_Angle - 0)); elseif 22.5 < Po_Angle && Po_Angle <= 67.5 str1 = strcat('', '45° oblique polarization'); str2 = strcat('Polarization Error', num2str(Po_Angle - 45)); elseif 67.5 < Po_Angle & Po_Angle <= 112.5 str1 = strcat('', 'Vertical polarization'); str2 = strcat('Polarization Error', num2str(Po_Angle - 90)); end elseif back_Ratio > 0.85 %% Circular polarization Po_Angle = atan(back_Ratio) / pi 180; Po_Ratio = back_Ratio; str1 = strcat(str, 'circular polarization'); str2 = strcat('Polarization Error', num2str(45 - Po_Angle)); else %% Elliptic polarization Po_Angle = atan(arcTan) / pi 180; Po_Ratio = back_Ratio; str1 = strcat(str, 'Elliptic Polarization'); str2 = strcat('Polarization Error', num2str(Po_Angle - 90)); end %% Vector Graphics figure(1); subplot(221);stem(t 360,Ex); title(['ratioPa:' num2str(ratioPa) ' deltPh:' num2str(deltPh 180 / pi)]); subplot(222);stem(t 360,Ey); subplot(223); plot(Ex, Ey, 'o'); axis equal; grid on; title(['Axial ratio' num2str(Po_Ratio)'Polarization angle' num2str(Po_Angle)]) subplot(224); axis([0 1 0 1]); text(0.3, 0.5, str1); text(0.3, 0.3, str2); axis off; The dual-polarized receiving antenna of the polarization interference subsystem receives the radar radio frequency signal, and the parameter of the received signal of the two orthogonal polarizations is measured and the phase-amplitude measurement method is used to measure the amplitude ratio and phase difference of the signals received by the two antennas, so as to indirectly measure the polarization direction of the radar wave. At the same time, by controlling the amplitude and phase of the two receiving channels, variable polarization reconnaissance can be carried out.

[0042] The polarization measurement function is realized by digital domain signal measurement, and is carried out after AD conversion into an intermediate frequency. The high-speed FPGA is used to realize the processing of the digital signal.

[0043] The main processing process of the polarization measurement includes the following stages, (1) receiving channel correction: in order to accurately measure the amplitude and phase of the two received signals, a high-precision amplitude and phase correction scheme needs to be designed; (2) data acquisition: using a high-speed ADC to digitize and collect the echo of the signal target; (3) signal measurement: pre-processing the collected signal, including removing noise, filtering, enhancing signal, etc; (4) polarization measurement: separating the pre-processed signal into horizontal and vertical components for polarization analysis; (5) polarization analysis: performing polarization analysis on the separated horizontal and vertical components to calculate the polarization parameters of the signal, such as polarization degree, polarization angle, etc; (6) statistical processing: statistically processing the calculated polarization parameters to obtain analyzable and comparable information.

[0044] Embodiment 2: a radar signal processing method based on polarization interference recognition, step 1, receiving radar radio frequency signals through a pair of polarization orthogonal antennas with equal phase centers to obtain horizontal channel response signal Ex and vertical channel response signal Ey; Step 2, using the phase-amplitude measurement method to measure the amplitude ratio χ and the phase difference δ of Ex and Ey; Step 3, calculating the polarization parameters of the radar wave according to the amplitude ratio χ and the phase difference δ, the polarization parameters including the axial ratio, the inclination angle τ and the ellipticity angle ε; Step 4, determine the polarization mode of the radar wave based on the polarization parameter, and calculate the polarization measurement error.

[0045] The method for calculating the axial ratio in step 3 is: discretize Ex and Ey in the phase range of 0-2π into 360 points, calculate the instantaneous field strength amplitude ||E||=√(Ex²+Ey²) of each point, determine the maximum field strength amplitude ||E||max and the minimum field strength amplitude ||E||min, and the axial ratio is the ratio of ||E||min to ||E||max.

[0046] The method for calculating the tilt angle τ in step 3 is: determine Ex(||E||max) and Ey(||E||max) corresponding to ||E||max, and the tilt angle τ=arctan[Ey(||E||max) / Ex(||E||max)].

[0047] The method for calculating the ellipticity angle ε in step 3 is: ellipticity angle ε=arctan(||E||min / ||E||max).

[0048] The rule for determining the polarization mode in step 4 is: Step 41, if the value range of the axial ratio is 0-0.15, it is determined as linear polarization; Step 42, if the value range of the axial ratio is 0.85-1, it is determined as circular polarization; Step 43, if the value range of the axial ratio is 0.15-0.85, it is determined as elliptical polarization.

[0049] Linear polarization includes vertical polarization, horizontal polarization and 45° oblique polarization, which are distinguished by the value range of the tilt angle τ: (1) If τ∈(-112.5°,-67.5°] or τ∈(67.5°,112.5°], it is determined as vertical polarization; (2) If τ∈(-22.5°,22.5°], it is determined as horizontal polarization; (3) If τ∈(-67.5°,-22.5°] or τ∈(22.5°,67.5°], it is determined as 45° oblique polarization.

[0050] The handedness of circular polarization is determined by the phase difference δ: if δ∈(0,π], it is determined as right-handed circular polarization; if δ∈(-π,0], it is determined as left-handed circular polarization.

[0051] The method for calculating the polarization measurement error in step 4 is: For vertical polarization, the polarization error is the difference between the calculated tilt angle τ and -90° or 90°; For horizontal polarization, the polarization error is the difference between the calculated tilt angle τ and 0°; For 45° slant polarization, the polarization error is the difference between the calculated tilt angle τ and -45° or 45°; For circular polarization, the polarization error is the difference between the calculated ellipticity angle ε and 45°.

[0052] The amplitude ratio χ and the phase difference δ are measured by a high-speed FPGA, and the specific process includes: (1) Receive channel correction: amplitude and phase correction is performed on the received signals of the horizontal channel and the vertical channel; (2) Data acquisition: the corrected signals are digitized and collected using a high-speed ADC; (3) Signal measurement: the collected digital signals are preprocessed, which includes noise removal, filtering and signal enhancement; (4) Polarization measurement: the preprocessed signals are separated into horizontal and vertical components, and the amplitude ratio χ and the phase difference δ are measured.

[0053] A radar signal processing system, comprising: a polarization orthogonal antenna module, a signal acquisition module, an amplitude and phase measurement module, a polarization parameter calculation module, and a polarization determination and error calculation module; The polarization orthogonal antenna module is used to receive radar radio frequency signals and output horizontal channel response signals and vertical channel response signals; The signal acquisition module is used to digitize and collect the response signals; The amplitude and phase measurement module is used to measure the amplitude ratio and the phase difference of the collected signals; The polarization parameter calculation module is used to calculate the polarization parameters according to the amplitude ratio and the phase difference; The polarization determination and error calculation module is used to determine the polarization mode according to the polarization parameters and calculate the polarization measurement error.

[0054] The above embodiments are only used to illustrate the present application and not to limit the technical solutions described in the present application. Although the present application has been described in detail with reference to the above embodiments, the present application is not limited to the above specific embodiments. Therefore, any modification or equivalent replacement of the present application; and all technical solutions and improvements without departing from the spirit and scope of the application are encompassed in the scope of the claims of the present application.

Claims

1. A radar signal processing method based on polarization interference identification, characterized in that, Includes the following steps: Step 1: Receive radar radio frequency signals through a pair of polarized orthogonal antennas with equal phase centers to obtain the horizontal channel response signal Ex and the vertical channel response signal Ey; Step 2: Use the phase-amplitude measurement method to measure the amplitude ratio χ and phase difference δ of Ex and Ey; Step 3: Calculate the polarization parameters of the radar wave based on the amplitude ratio χ and phase difference δ. The polarization parameters include the axial ratio, tilt angle τ, and ellipticity angle ε. Step 4: Based on the polarization parameters, determine the polarization mode of the radar wave and calculate the polarization measurement error.

2. The radar signal processing method based on polarization interference identification according to claim 1, characterized in that, The method for calculating the axial ratio in step 3 is as follows: Discretize Ex and Ey into 360 points within the phase range of 0 to 2π, calculate the instantaneous field strength amplitude at each point ||E||=√(Ex²+Ey²), determine the maximum field strength amplitude ||E||max and the minimum field strength amplitude ||E||min, and the axial ratio is the ratio of ||E||min to ||E||max.

3. The radar signal processing method based on polarization interference identification according to claim 2, characterized in that, The method for calculating the tilt angle τ in step 3 is as follows: determine Ex(||E||max) and Ey(||E||max) corresponding to ||E||max, and the tilt angle τ = arctan[Ey(||E||max) / Ex(||E||max)].

4. The radar signal processing method based on polarization interference identification according to claim 2, characterized in that, The method for calculating the ellipticity angle ε in step 3 is as follows: ellipticity angle ε = arctan(||E||min / ||E||max).

5. The radar signal processing method based on polarization interference identification according to claim 1, characterized in that, The rule for determining the polarization mode in step 4 is as follows: Step 41: If the axial ratio ranges from 0 to 0.15, it is determined to be linear polarization; Step 42: If the axial ratio ranges from 0.85 to 1, it is determined to be circular polarization; Step 43: If the axial ratio ranges from 0.15 to 0.85, it is determined to be elliptic polarization.

6. The radar signal processing method based on polarization interference identification according to claim 5, characterized in that, The linear polarization includes vertical polarization, horizontal polarization, and 45° oblique polarization, distinguished by the range of values ​​for the tilt angle τ: (1) If τ∈(-112.5°,-67.5°] or τ∈(67.5°,112.5°], then it is determined to be vertical polarization; (2) If τ∈(-22.5°,22.5°], then it is determined to be horizontal polarization; (3) If τ∈(-67.5°,-22.5°] or τ∈(22.5°,67.5°], then it is determined to be 45° oblique polarization.

7. The radar signal processing method based on polarization interference identification according to claim 5, characterized in that, The direction of circular polarization is determined by the phase difference δ: if δ∈(0,π], it is determined to be right-hand circular polarization; if δ∈(-π,0], it is determined to be left-hand circular polarization.

8. The radar signal processing method based on polarization interference identification according to claim 1, characterized in that, The method for calculating the polarization measurement error in step 4 is as follows: For vertical polarization, the polarization error is the difference between the calculated tilt angle τ and -90° or 90°; For horizontal polarization, the polarization error is the difference between the calculated tilt angle τ and 0°; For 45° oblique polarization, the polarization error is the difference between the calculated tilt angle τ and -45° or 45°; For circular polarization, the polarization error is the difference between the calculated ellipticity angle ε and 45°.

9. The radar signal processing method based on polarization interference identification according to claim 1, characterized in that, The amplitude ratio χ and phase difference δ are measured using a high-speed FPGA. The specific process includes: (1) Receiver channel correction: Amplitude and phase correction is performed on the received signals of the horizontal and vertical channels; (2) Data acquisition: The corrected signal is digitally acquired using a high-speed ADC; (3) Signal measurement: The acquired digital signal is preprocessed, including noise removal, filtering and signal enhancement; (4) Polarization measurement: The preprocessed signal is separated into horizontal and vertical components, and the amplitude ratio χ and phase difference δ are measured.

10. A radar signal processing system for implementing the radar signal processing method based on polarization interference identification as described in any one of claims 1-9, characterized in that, include: The system includes a polarization orthogonal antenna module, a signal acquisition module, an amplitude and phase measurement module, a polarization parameter calculation module, and a polarization determination and error calculation module. The polarized orthogonal antenna module is used to receive radar radio frequency signals and output horizontal channel response signals and vertical channel response signals. The signal acquisition module is used to digitally acquire the response signal; The amplitude and phase measurement module is used to measure the amplitude ratio and phase difference of the acquired signal; The polarization parameter calculation module is used to calculate polarization parameters based on the amplitude ratio and phase difference; The polarization determination and error calculation module is used to determine the polarization mode based on the polarization parameters and to calculate the polarization measurement error.

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