A four-channel radar monopulse angle measurement method and system in a complex electromagnetic environment

Abstract

This invention discloses a four-channel radar single-pulse angle measurement method and system for complex electromagnetic environments, comprising: constructing a four-channel radar system to obtain four-channel echo data; performing preprocessing such as down-conversion and sampling on the four-channel data; performing five adaptive processing steps on the obtained four-channel sampled data; performing pulse compression and coherent accumulation processing on the adaptively processed data; performing target detection processing on the sum channel data, and determining the target distance corresponding to the target point based on the time delay and sampling frequency; selecting points on the elevation (azimuth) sum channel and the elevation (azimuth) difference channel with the same distance unit number and frequency unit number as the target point as the angle measurement point, and obtaining the target angle measurement value through the difference ratio and single-pulse angle measurement method. This invention can achieve effective angle measurement in complex electromagnetic environments, solving the problems of low accuracy or incorrect measurement results of target angle measurement in complex electromagnetic environments.

Description

Technical Field

[0001] This invention belongs to the field of guidance and tracking radar signal processing technology, and particularly relates to a four-channel radar single-pulse angle measurement method and system under complex electromagnetic environments. Background Technology

[0002] Angle estimation is one of the main functions of a radar system. Radar systems often need to perform target localization and target tracking functions based on angle measurement results.

[0003] In radar system applications, active jamming signals released by enemy jammers are frequently encountered, interfering with the normal operation of the radar system. Because active jamming signals are often very strong, radar systems frequently fail to detect target signals or only detect false targets generated by the jamming signals. In such cases, if angle measurements are performed using the detected false targets, the obtained angle values ​​are often incorrect, affecting target localization and making stable target tracking impossible. The presence of active jamming signals significantly impacts angle estimation in radar systems. Therefore, it is essential to improve the anti-jamming capabilities and angle measurement accuracy of radar systems in complex electromagnetic environments.

[0004] The traditional single-pulse angle measurement method involves: the radar system acquiring target echo signals, performing coherent accumulation (i.e., Fourier transform) on multiple echo signals from the same range cell in the sum channel, converting the time-domain signal to a time-frequency domain signal, and using a sliding window of a certain length in the time-frequency domain to perform constant false alarm rate (CFAR) detection on adjacent cells within the window before and after each cell. After a target is detected, its position and amplitude in the time-frequency domain are recorded. The same coherent accumulation process is then performed on the difference channel to find the same position in the time-frequency domain as the target in the sum channel, and the target's amplitude in the difference channel is recorded. Finally, the sum of the target difference ratios is calculated and compared with a pre-measured S-curve to estimate the target's angle. However, due to active interference, the target signal in the time-frequency domain is relatively weak, often resulting in the detection of false targets or the failure to detect targets altogether. The former leads to the single-pulse angle measurement result being the angle location of the interference, while the latter results in an incorrect measurement. Therefore, the single-pulse angle measurement method must first improve its anti-interference capability in complex electromagnetic environments to ensure accurate target detection, and then improve the accuracy of angle measurement.

[0005] The above method has the drawbacks of low angle measurement accuracy or incorrect measurement results in complex interference environments, which leads to obvious defects such as incorrect target positioning and inability to track targets in the radar system. Summary of the Invention

[0006] The purpose of this invention is to provide a four-channel radar single-pulse angle measurement method and system for complex electromagnetic environments, solving the problem of low accuracy or incorrect measurement results of existing methods in complex electromagnetic environments.

[0007] The technical solution of this invention is:

[0008] Firstly, a four-channel radar single-pulse angle measurement method for complex electromagnetic environments is disclosed, including:

[0009] A four-channel radar system was constructed to obtain four-channel echo data;

[0010] The four-channel echo data are down-converted and pre-sampled to obtain the baseband digital signal within the detection range, which is used as the input for adaptive signal processing.

[0011] The four-channel preprocessed data is subjected to five adaptive processing steps to obtain five adaptive data channels: sum, pitch sum, pitch difference, azimuth sum, and azimuth difference.

[0012] The five data streams after adaptive processing are subjected to pulse compression and coherent accumulation processing, respectively.

[0013] The target detection process is performed on the combined channel data to obtain the target's missile-to-eye distance;

[0014] Points at the same position on the pitch and channel, and pitch difference channel are taken as angle measurement points. The target pitch angle measurement value is obtained by using the difference ratio and single pulse angle measurement methods. Points at the same position on the azimuth and channel, and azimuth difference channel are taken as angle measurement points. The target azimuth angle measurement value is obtained by using the difference ratio and single pulse angle measurement methods. The ranging and angle measurement results are output.

[0015] In one specific implementation, a four-channel radar system is constructed to obtain four-channel echo data, specifically including:

[0016] A four-channel radar system is constructed by uniformly dividing the radar array into four sub-regions A, B, C, and D. When receiving signals, the signal energy received by the four sub-regions is converted by a summator. The summator channel of the receiver obtains the vector superposition result of the in-phase echoes of the four sub-regions (A+B+C+D). The elevation difference channel obtains the echo data of (A+B)-(C+D). The azimuth difference channel obtains the echo data of (A+C)-(B+D). The diagonal difference channel obtains the echo data of (A+D)-(B+C).

[0017] In one specific implementation, the four-channel preprocessed data undergoes five adaptive processing iterations to obtain five adaptive data streams: sum of pitch, sum of elevation, pitch difference, sum of azimuth, and azimuth difference; specifically including:

[0018] The first adaptive processing uses all the sampled data from the four channels to obtain the adaptive sum channel data, which is used for subsequent target detection and ranging. The second to fifth adaptive processing uses the data from the four channels matched in pairs to obtain the adaptive pitch sum channel, pitch difference channel, azimuth sum channel, and azimuth difference channel data, which are used for subsequent target angle measurement.

[0019] In one specific implementation, the adaptive processing method is implemented using the following steps:

[0020] First, select L sampling points corresponding to distance units exceeding the amplitude threshold from the L and L channels. The amplitude threshold is determined by the interference-to-noise ratio. Calculate the mean of all sampling points as the noise floor, and take σ times the noise floor as the amplitude threshold. σ is adaptively adjusted according to the number of points exceeding the threshold until sampling points that meet the quantity requirements are selected. Then, take the points on the same distance unit from the sampling points of the pitch difference channel, azimuth difference channel, and diagonal difference channel as the sampling points of the L and L channels respectively.

[0021] In the first adaptive processing, the three difference channels are used as auxiliary channels to suppress interference signals in the difference channels;

[0022] The second to fifth adaptive processing steps respectively use the sampled data from the sum channel, azimuth difference channel, pitch difference channel, diagonal difference channel, sum channel, pitch difference channel, azimuth difference channel, and diagonal difference channel as input for adaptive processing. That is, firstly, the azimuth difference channel is used as an auxiliary channel to suppress azimuth interference in the sum channel, and the diagonal difference channel is used as an auxiliary channel to suppress azimuth interference in the pitch difference channel; then, the pitch difference channel is used as an auxiliary channel to suppress pitch interference in the sum channel, and finally, the diagonal difference channel is used as an auxiliary channel to suppress pitch interference in the azimuth difference channel.

[0023] In one specific implementation, points at the same location on the pitch and channel, and the pitch difference channel are taken as angle measurement points. The target pitch angle measurement value is obtained through the difference ratio and single-pulse angle measurement methods. Points at the same location on the azimuth and channel, and the azimuth difference channel are taken as angle measurement points. The target azimuth angle measurement value is obtained through the difference ratio and single-pulse angle measurement methods. The ranging and angle measurement results are output, specifically obtained as follows:

[0024]

[0025]

[0026] Where, θ P θ A These are the measurement of pitch angle deviation and the measurement of azimuth angle deviation, respectively, k P k A The slopes of the S-curves in the pitch and azimuth directions are respectively, APΔ A PΣ These represent the amplitudes of the pitch difference channel and the pitch sum channel measurement points, respectively. AΔ A AΣ These represent the amplitudes of the azimuth difference channel and the azimuth sum channel measurement points, respectively.

[0027] Secondly, this invention discloses a four-channel radar monopulse angle measurement system for complex electromagnetic environments, comprising:

[0028] The building unit is used to construct a four-channel radar system and obtain four-channel echo data.

[0029] The preprocessing unit is used to perform down-conversion and sampling preprocessing on the four-channel echo data to obtain the baseband digital signal within the detection range, which serves as the input for adaptive signal processing.

[0030] The adaptive unit is used to perform five adaptive processes on the four-channel preprocessed data to obtain five adaptive data channels: sum, pitch sum, pitch difference, azimuth sum, and azimuth difference.

[0031] The processing unit is used to perform pulse compression and coherent accumulation processing on the five channels of data after adaptive processing.

[0032] The detection unit is used to acquire channel data for target detection processing to obtain the target's missile-to-target distance;

[0033] The angle measurement unit is used to take points at the same position on the pitch and channel and the pitch difference channel as angle measurement points, and obtain the target pitch angle measurement value through the difference ratio and single pulse angle measurement methods; it takes points at the same position on the azimuth and channel and the azimuth difference channel as angle measurement points, and obtains the target azimuth angle measurement value through the difference ratio and single pulse angle measurement methods, and outputs the distance and angle measurement results.

[0034] In one specific implementation: a four-channel radar system is constructed, and the radar array is evenly divided into four sub-regions A, B, C, and D. When receiving signals, the signal energy received by the four sub-regions is converted by a summator. The summator channel of the receiver obtains the vector superposition result of the in-phase echoes of the four sub-regions (A+B+C+D). The elevation difference channel obtains the echo data of (A+B)-(C+D). The azimuth difference channel obtains the echo data of (A+C)-(B+D). The diagonal difference channel obtains the echo data of (A+D)-(B+C).

[0035] In one specific implementation: the first adaptive processing uses all the sampled data of the four channels to obtain the adaptive sum channel data, which is used for subsequent target detection and ranging; the second to fifth adaptive processing uses the data of the four channels matched in pairs to obtain the adaptive pitch sum channel, pitch difference channel, azimuth sum channel, and azimuth difference channel data, which are used for subsequent target angle measurement.

[0036] Thirdly, a computing device is provided, comprising at least one processor and at least one memory, wherein the memory stores a computer program, and the processor is configured to read the computer program from the memory and execute any step of the method described in the first aspect.

[0037] Fourthly, a computer-readable storage medium is provided, the computer-readable storage medium storing computer-executable instructions for causing a computer to perform any step of the method described in the first aspect.

[0038] The beneficial technical effects of this invention are:

[0039] The measurement results of this invention are closer to the target; that is, compared with direct angle measurement methods, the angle measurement method disclosed in this invention has significantly improved measurement accuracy and does not produce obvious angle measurement errors. Therefore, the angle measurement method proposed in this invention can effectively solve the problem of low accuracy or erroneous measurement results of existing methods in complex electromagnetic environments. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the four-channel radar system constructed in the specification of this invention;

[0041] Figure 2 This is a flowchart of the single-pulse angle measurement method for the four-channel radar system of the present invention;

[0042] Figure 3 This is a diagram of the four-channel planar array antenna used in the simulation example of this invention;

[0043] Figure 4 These are the time-frequency domain diagrams of the original and channel coherently accumulated echoes from the simulation case of this invention;

[0044] Figure 5 This is a time-frequency domain diagram of the adaptively processed echo and the channel coherently accumulated echo in the simulation case of this invention;

[0045] Figure 6 This is a time-frequency domain diagram of the pitch and channel coherent accumulated echo after adaptive processing in the simulation case of this invention;

[0046] Figure 7 This is the time-frequency domain diagram of the coherent accumulated echo of the pitch difference channel after adaptive processing in the simulation case of this invention;

[0047] Figure 8 This is a time-frequency domain diagram of the azimuth and channel coherent accumulated echo after adaptive processing in the simulation case of this invention;

[0048] Figure 9 This is the time-frequency domain diagram of the coherent accumulated echo of the azimuth difference channel after adaptive processing in the simulation case of this invention;

[0049] Figure 10 This is a comparison chart of the angle measurement results in the simulation case of this invention;

[0050] Figure 11 This is a flowchart illustrating a four-channel radar single-pulse angle measurement method for complex electromagnetic environments. Detailed Implementation

[0051] The detailed technical solution of the present invention will now be described in conjunction with the accompanying drawings.

[0052] Example 1

[0053] A method for four-channel radar monopulse angle measurement in complex electromagnetic environments includes the following steps:

[0054] Step 1: According to the attached... Figure 1 The diagram illustrates the construction of a four-channel radar system. The radar array is uniformly divided into four sub-regions A, B, C, and D. When receiving signals, the signal energy received by the four sub-regions is converted by a summator. The summator channel of the receiver yields the vector superposition result of the in-phase echoes of the four sub-regions (A+B+C+D). The elevation difference channel yields the echo data of (A+B)-(C+D). The azimuth difference channel yields the echo data of (A+C)-(B+D). The diagonal difference channel yields the echo data of (A+D)-(B+C).

[0055] Step 2: Perform preprocessing such as downconversion and sampling on the obtained four-channel data to obtain the baseband digital signal within the detection range, which serves as the input for adaptive signal processing.

[0056] Step 3: According to the appendix Figure 2 The system architecture diagram shown illustrates that after obtaining four-channel sampled data, five adaptive processing steps are performed. The first adaptive processing uses all sampled data from the four channels to obtain the adaptive sum channel data, which is used for subsequent target detection and ranging. The second to fifth adaptive processing steps use the pairwise matched data from the four channels to obtain the adaptive pitch sum channel, pitch difference channel, azimuth sum channel, and azimuth difference channel data, which are used for subsequent target angle measurement.

[0057] The specific implementation steps of the adaptive processing method in the above process are as follows.

[0058] First, select L (L is generally greater than 200) sampling points corresponding to distance units exceeding the amplitude threshold from the sum and difference channels. The amplitude threshold is determined by the interference-to-noise ratio (INR). Generally, the mean of all sampling points is calculated as the noise floor, and σ times the noise floor is taken as the amplitude threshold. σ is adaptively adjusted according to the number of points exceeding the threshold until sampling points meeting the quantity requirements are selected. Then, select points at the same distance unit from the pitch difference channel, azimuth difference channel, and diagonal difference channel, as well as the sampling points from the sum and difference channels, as the sampling points for their respective channels.

[0059] In the first adaptive processing, the three difference channels are used as auxiliary channels to suppress interference signals in the main channels. The sampled data from the three difference channels are used to form a 3×L sampling matrix M. Δ As shown below

[0060]

[0061] Among them, M PΔ M AΔ M ΔΔ These are 1×L vectors composed of sampled data from the pitch difference channel, azimuth difference channel, and diagonal difference channel, respectively.

[0062] The covariance matrix of the three difference channel sampled data is calculated using the following formula.

[0063]

[0064] Next, calculate the covariance matrix between the sum channel sampled data and the difference channel sampled data, using the following formula:

[0065]

[0066] Where M ∑ It is a 1×L sum channel sampling vector.

[0067] Finally, the adaptive weighting coefficients for the difference channel are calculated using the following formula:

[0068]

[0069] Where w is a 3×1 vector, corresponding to the weighting coefficients of the three difference channels.

[0070] The output adaptive and channel data are

[0071] y Σ (t)=x Σ (t)-w(1)x PΔ (t)-w(2)x AΔ (t)-w(3)x ΔΔ (t)

[0072] Where, x Σ(t) represents the sum channel data, x PΔ (t) represents the pitch difference channel data, x AΔ (t) represents the azimuth difference channel data, x ΔΔ (t) represents the diagonal difference channel data.

[0073] According to the appendix Figure 2 The second to fifth adaptive processing uses the sampled data of the sum channel, azimuth difference channel, pitch difference channel, diagonal difference channel, sum channel, pitch difference channel, azimuth difference channel, and diagonal difference channel as input for the adaptive processing. That is, the azimuth (pitch) difference channel is first used as an auxiliary channel to suppress the azimuth (pitch) interference in the sum channel, and then the diagonal difference channel is used as an auxiliary channel to suppress the azimuth (pitch) interference in the pitch (azimuth) difference channel.

[0074] First, the azimuth difference channel is used as an auxiliary channel to suppress azimuth interference in the same channel. Then, the diagonal difference channel is used as an auxiliary channel to suppress azimuth interference in the pitch difference channel. Next, the pitch difference channel is used as an auxiliary channel to suppress pitch interference in the same channel. Finally, the diagonal difference channel is used as an auxiliary channel to suppress pitch interference in the azimuth difference channel.

[0075] The formula for calculating the adaptive weighting coefficient is as follows:

[0076]

[0077]

[0078]

[0079]

[0080] Among them, M ∑ M PΔ M AΔ M ΔΔ Consistent with the above representation, w represents a 1×L sampling vector composed of sampled data from the sum channel, pitch difference channel, azimuth difference channel, and diagonal difference channel, respectively. P∑ w PΔ w A∑ w AΔ These are the adaptive weighting coefficients for pitch sum, pitch difference, azimuth sum, and azimuth difference, respectively.

[0081] To ensure that the angle measurement remains unchanged after adaptive processing, the pitch (azimuth) weighting coefficient is generally taken as the average of the adaptive weighting coefficients of pitch (azimuth) sum and pitch (azimuth) difference during calculation, i.e.

[0082]

[0083]

[0084] Final calculation

[0085] y PΣ (t)=x Σ (t)-w P x PΔ (t)

[0086] y PΔ (t)=x AΔ (t)-w P x ΔΔ (t)

[0087] y AΣ (t)=x Σ (t)-w A x AΔ (t)

[0088] y AΔ (t)=x PΔ (t)-w A x ΔΔ (t)

[0089] Output y PΣ (t), y PΔ (t), y AΣ (t), y AΔ (t) represent the adaptively processed pitch and channel data, the adaptively processed pitch difference channel data, the adaptively processed azimuth and channel data, and the adaptively processed azimuth difference channel data, respectively.

[0090] Step 4: Perform pulse compression and coherent accumulation processing on the adaptively processed pitch and azimuth channel data, pitch difference channel data, azimuth and azimuth difference channel data, respectively.

[0091] Step 5: Take the channel data and perform target detection processing. Generally, select the detection point that has been detected and has the largest amplitude as the target point for tracking. Then, determine the bullet-target distance corresponding to the target point based on the time delay and sampling frequency.

[0092] Step Six: Select the point on the pitch (azimuth) channel and pitch (azimuth) difference channel that is at the same distance from the target point as the unit number and frequency unit number as the angle measurement point. The angle is calculated as follows:

[0093]

[0094]

[0095] Where, θ P θ AThese are the measurement of pitch angle deviation and the measurement of azimuth angle deviation, respectively, k P k A The slopes of the S-curves in the pitch and azimuth directions are respectively, A PΔ A PΣ These represent the amplitudes of the pitch difference channel and the pitch sum channel measurement points, respectively. AΔ A AΣ These represent the amplitudes of the azimuth difference channel and the azimuth sum channel measurement points, respectively.

[0096] Step 7: Output the distance and angle measurement results.

[0097] Simulation Case Description:

[0098] The method proposed in this invention is verified by simulation below. The simulation uses the attached... Figure 3 The planar array shown has an element spacing of half a wavelength. The subarray is divided into four channels along the x and y axes, with each channel symmetrical about the array center. The array is oriented at (0°, 0°). A main lobe jammer with an interference ratio (IRR) of 40dB is placed at (3°, 2°), and a sidelobe jammer with an IRR of 50dB is placed at (5°, -10°). Both jammers are noise suppression jammers. The target is placed at (1°, 1°), with an IRR of 0dB. It is assumed that the target's echo signal is a linear frequency modulated signal with a bandwidth of 40MHz and a pulse width of 1µs, and a pulse compression gain of approximately 16dB.

[0099] Appendix Figure 4 The data presented are time-frequency domain data of the original and channel echoes after pulse compression and coherent accumulation. Coherent accumulation was performed using 128 echoes, with a sample size of 3000. The target location is shown at coordinates (1601, 1) in the figure. As can be seen, due to interference, it is difficult to distinguish the target from the interference, and angle measurement is also affected. (See attached image.) Figure 5 The first adaptive processing and channel time-frequency domain data proposed in this invention show that the target can be easily detected after interference suppression. (Appendix) Figure 6-9 The figures show the pitch and difference channels, azimuth and difference channels after the second to fifth adaptive processing proposed in this invention. The interference suppression effect shown in the figure is not as good as that of the first adaptive processing. This is because the sum and difference channels need to be retained simultaneously when measuring angles, while only one auxiliary channel can be used during adaptive processing. This is less than the three auxiliary channels used for ranging, so the interference suppression effect is slightly worse, but it can still ensure that the angle measurement results do not change significantly.

[0100] Appendix Figure 10The figure shows the angle measurement results after 30 Monte Carlo simulations. The stars in the figure indicate the target location, and the crosshairs represent the angle measurement results from traditional methods. It is evident that under interference conditions, previous methods have significant errors in angle measurement, and sometimes, due to incorrect target detection, the measured angle is not the target angle. The circles in the figure represent the angle measurement results of the method proposed in this invention. It can be seen from the figure that the measurement results of the proposed method are closer to the target; that is, compared to the direct angle measurement method, the angle measurement accuracy of the proposed method is greatly improved, and there are no obvious angle measurement errors. Therefore, the angle measurement method proposed in this invention can effectively solve the problem of low accuracy or erroneous measurement results of existing methods in complex electromagnetic environments.

[0101] This invention discloses a four-channel radar single-pulse angle measurement method under complex electromagnetic environments; the method includes: according to the appendix Figure 1 A four-channel radar system is constructed to obtain four-channel echo data. The four-channel data undergoes down-conversion and sampling preprocessing to obtain four-channel digital signals, which serve as input for adaptive signal processing. After obtaining the four-channel sampled data, five adaptive processing steps are performed. The first adaptive processing uses all sampled data from the four channels to obtain the adaptive sum channel data. The second to fifth adaptive processing steps use pairwise matched data from the four channels to obtain the adaptive elevation sum channel, elevation difference channel, azimuth sum channel, and azimuth difference channel data, respectively. Pulse compression and coherent accumulation processing are performed on the adaptive sum channel data, elevation sum channel data, elevation difference channel data, azimuth sum channel data, and azimuth difference channel data, respectively. The sum channel data is used for target detection processing, and the target distance is determined based on the time delay and sampling frequency. Points with the same distance and frequency unit numbers on the elevation (azimuth) sum channel and elevation (azimuth) difference channel are selected as angle measurement points. The target angle measurement value is obtained using the difference ratio and single-pulse angle measurement methods. The present invention adopts the above technical solution, which can effectively measure angles in complex electromagnetic environments and solve the problem of low accuracy or incorrect measurement results of target angles in complex electromagnetic environments by existing methods.

[0102] Based on the same technical concept, this application also provides a four-channel radar monopulse angle measurement system for complex electromagnetic environments. Since the principle of the above system in solving the problem is similar to that of a four-channel radar monopulse angle measurement method for complex electromagnetic environments, the implementation of the above device can refer to the implementation of the method, and the repeated parts will not be described again.

[0103] A four-channel radar monopulse angle measurement system for complex electromagnetic environments includes:

[0104] The building unit is used to construct a four-channel radar system and obtain four-channel echo data.

[0105] The preprocessing unit is used to perform down-conversion and sampling preprocessing on the four-channel echo data to obtain the baseband digital signal within the detection range, which serves as the input for adaptive signal processing.

[0106] The adaptive unit is used to perform five adaptive processes on the four-channel preprocessed data to obtain five adaptive data channels: sum, pitch sum, pitch difference, azimuth sum, and azimuth difference.

[0107] The processing unit is used to perform pulse compression and coherent accumulation processing on the five channels of data after adaptive processing.

[0108] The detection unit is used to acquire channel data for target detection processing to obtain the target's missile-to-target distance;

[0109] The angle measurement unit is used to take points at the same position on the pitch and channel and the pitch difference channel as angle measurement points, and obtain the target pitch angle measurement value through the difference ratio and single pulse angle measurement methods; it takes points at the same position on the azimuth and channel and the azimuth difference channel as angle measurement points, and obtains the target azimuth angle measurement value through the difference ratio and single pulse angle measurement methods, and outputs the distance and angle measurement results.

[0110] For ease of description, the above sections are divided into modules (or units) according to their functional modules and described separately. Of course, in implementing this invention, the functions of each module (or unit) can be implemented in one or more software or hardware components.

[0111] Based on the same technical concept, the present invention provides a computing device, including at least one processor and at least one memory, wherein the memory stores a computer program, and the processor is used to read the computer program in the memory and execute a four-channel radar monopulse angle measurement method under complex electromagnetic environment.

[0112] Based on the same technical concept, the present invention provides a computer-readable storage medium storing computer-executable instructions for causing a computer to execute a four-channel radar monopulse angle measurement method under complex electromagnetic environment.

[0113] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A four-channel radar single-pulse angle measurement method for complex electromagnetic environments, characterized in that, include: A four-channel radar system was constructed to obtain four-channel echo data; The four-channel echo data are down-converted and pre-sampled to obtain the baseband digital signal within the detection range, which is used as the input for adaptive signal processing. The four-channel preprocessed data is subjected to five adaptive processing steps to obtain five adaptive data channels: sum, pitch sum, pitch difference, azimuth sum, and azimuth difference. The five data streams after adaptive processing are subjected to pulse compression and coherent accumulation processing, respectively. The target detection process is performed on the combined channel data to obtain the target's missile-to-eye distance; Points at the same position on the pitch and channel, and pitch difference channel are taken as angle measurement points. The target pitch angle measurement value is obtained by using the difference ratio and single pulse angle measurement methods. Points at the same position on the azimuth and channel, and azimuth difference channel are taken as angle measurement points. The target azimuth angle measurement value is obtained by using the difference ratio and single pulse angle measurement methods. The ranging and angle measurement results are output.

2. The method according to claim 1, characterized in that, A four-channel radar system was constructed to obtain four-channel echo data, specifically including: A four-channel radar system is constructed by uniformly dividing the radar array into four sub-regions A, B, C, and D. When receiving signals, the signal energy received by the four sub-regions is converted by a summator. The summator channel of the receiver obtains the vector superposition result of the in-phase echoes of the four sub-regions (A+B+C+D). The elevation difference channel obtains the echo data of (A+B)-(C+D). The azimuth difference channel obtains the echo data of (A+C)-(B+D). The diagonal difference channel obtains the echo data of (A+D)-(B+C).

3. The method according to claim 2, characterized in that, The four-channel preprocessed data is subjected to five adaptive processing steps to obtain five adaptive data channels: sum, pitch sum, pitch difference, azimuth sum, and azimuth difference. Specifically, it includes: The first adaptive processing uses all the sampled data from the four channels to obtain the adaptive sum channel data, which is used for subsequent target detection and ranging. The second to fifth adaptive processing uses the data from the four channels matched in pairs to obtain the adaptive pitch sum channel, pitch difference channel, azimuth sum channel, and azimuth difference channel data, which are used for subsequent target angle measurement.

4. The method according to claim 3, characterized in that, The specific implementation steps of the adaptive processing method are as follows: First, select L sampling points corresponding to distance units exceeding the amplitude threshold from the sum channel. The amplitude threshold is determined by the interference-to-noise ratio. Calculate the mean of all sampling points as the noise floor, and take σ times the noise floor as the amplitude threshold. σ is adaptively adjusted according to the number of points exceeding the threshold until sampling points that meet the quantity requirements are selected. Then, select the points in the pitch difference channel, azimuth difference channel, and diagonal difference channel that are at the same distance unit as the sampling points in the sum channel as the sampling points of their respective channels. In the first adaptive processing, the three difference channels are used as channels to suppress interference signals in the channels; The second to fifth adaptive processing steps respectively target the sum channel and the azimuth difference channel; Pitch difference channel, diagonal difference channel; And channel, pitch difference channel; The sampling data of the azimuth difference channel and the diagonal difference channel are used as input for adaptive processing. That is, the azimuth difference channel is first used as an auxiliary channel to suppress the azimuth interference in the channel, and the diagonal difference channel is used as an auxiliary channel to suppress the azimuth interference in the pitch difference channel. Then, the pitch difference channel is used as an auxiliary channel to suppress pitch interference in the channel, and the diagonal difference channel is used as an auxiliary channel to suppress pitch interference in the azimuth difference channel.

5. The method according to claim 4, characterized in that, Points at the same location on the pitch and channel, and pitch difference channel are selected as angle measurement points. The target pitch angle is measured using the difference ratio and single-pulse angle measurement methods. Points at the same location on the azimuth and channel, and azimuth difference channel are selected as angle measurement points. The target azimuth angle is measured using the difference ratio and single-pulse angle measurement methods. The ranging and angle measurement results are output as follows: Where, θ P θ A These are the measurement of pitch angle deviation and the measurement of azimuth angle deviation, respectively, k P k A The slopes of the S-curves in the pitch and azimuth directions are respectively, A PΔ A PΣ These represent the amplitudes of the pitch difference channel and the pitch sum channel measurement points, respectively. AΔ A AΣ These represent the amplitudes of the azimuth difference channel and the azimuth sum channel measurement points, respectively.

6. A four-channel radar monopulse angle measurement system for complex electromagnetic environments, characterized in that, include: The building unit is used to construct a four-channel radar system and obtain four-channel echo data. The preprocessing unit is used to perform down-conversion and sampling preprocessing on the four-channel echo data to obtain the baseband digital signal within the detection range, which serves as the input for adaptive signal processing. The adaptive unit is used to perform five adaptive processes on the four-channel preprocessed data to obtain five adaptive data channels: sum, pitch sum, pitch difference, azimuth sum, and azimuth difference. The processing unit is used to perform pulse compression and coherent accumulation processing on the five channels of data after adaptive processing. The detection unit is used to acquire channel data for target detection processing to obtain the target's missile-to-target distance; The angle measurement unit is used to take points at the same position on the pitch and channel and the pitch difference channel as angle measurement points, and obtain the target pitch angle measurement value through the difference ratio and single pulse angle measurement methods; it takes points at the same position on the azimuth and channel and the azimuth difference channel as angle measurement points, and obtains the target azimuth angle measurement value through the difference ratio and single pulse angle measurement methods, and outputs the distance and angle measurement results.

7. The system according to claim 6, characterized in that, The building unit is specifically used for: A four-channel radar system is constructed by uniformly dividing the radar array into four sub-regions A, B, C, and D. When receiving signals, the signal energy received by the four sub-regions is converted by a summator. The summator channel of the receiver obtains the vector superposition result of the in-phase echoes of the four sub-regions (A+B+C+D). The elevation difference channel obtains the echo data of (A+B)-(C+D). The azimuth difference channel obtains the echo data of (A+C)-(B+D). The diagonal difference channel obtains the echo data of (A+D)-(B+C).

8. The system according to claim 7, characterized in that, The preprocessing unit is specifically used for: The first adaptive processing uses all the sampled data from the four channels to obtain the adaptive sum channel data, which is used for subsequent target detection and ranging. The second to fifth adaptive processing uses the data from the four channels matched in pairs to obtain the adaptive pitch sum channel, pitch difference channel, azimuth sum channel, and azimuth difference channel data, which are used for subsequent target angle measurement.

9. A computing device, characterized in that, The method includes at least one processor and at least one memory, wherein the memory stores a computer program, and the processor is configured to read the computer program from the memory and execute the method according to any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to perform the method described in any one of claims 1 to 5.

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