Methods, apparatus, equipment, and dielectrics for full polarization compensation of antennas and waveforms

Abstract

This application relates to a method, apparatus, device, and medium for full polarization compensation of antennas and waveforms. First, the cross-polarization isolation and orthogonal waveform isolation of a simultaneous full polarization measurement radar system are measured and calculated. Then, the radar system is used to detect a target, and an estimate of the target's polarization scattering matrix is ​​obtained based on the echo results. Finally, a coefficient matrix is ​​constructed based on the isolation index, and this coefficient matrix is ​​used to compensate for the estimated polarization scattering matrix to obtain the true value of the target's polarization scattering matrix. By modeling and compensating for the radar system's polarization error, the accuracy of target PSM measurement is improved.

Description

Technical Field

[0001] This application relates to the field of radar detection technology, and in particular to a method, apparatus, device, and medium for full polarization compensation of antennas and waveforms. Background Technology

[0002] The term "polarization" originates from the English word "polarization," and is referred to as polarization in optics and polarization in radar. As an essential property of electromagnetic waves, polarization, along with fundamental parameters such as amplitude, phase, and frequency, constitutes a complete description of the vector characteristics of electromagnetic waves. When radar illuminates a target, the polarization state of the scattered wave changes relative to the incident wave, and a specific mapping transformation relationship exists between the two. This transformation is closely related to the target's attitude, size, structure, material, and other physical properties; therefore, the target can be considered a polarization transformer. The rich physical property information of the target implied by the target's variable polarization effect has great potential to improve radar's target detection, anti-jamming, classification, and identification capabilities, and is therefore widely used in space target surveillance and other important fields.

[0003] With the development and advancement of radar-related technologies, the acquisition of target polarization scattering information has evolved from incomplete polarization information to full polarization information. Correspondingly, from the perspective of the completeness of polarization information acquisition, polarization measurement systems have also evolved from single-polarization measurement to dual-polarization measurement to time-division full polarization measurement to simultaneous full polarization measurement.

[0004] With the development and deepening application of radar polarization technology, the measurement accuracy of target polarization scattering information has become one of the key factors restricting whether polarimetric radar can meet the ever-increasing demands of radar applications. For example, in meteorological observation, a relatively mature field of radar polarization application, in order to meet the accuracy of rainfall prediction under various weather conditions and to achieve accurate classification and identification of meteorological targets including hail, rain, and snow, high-precision measurement of target polarization scattering parameters is required. This necessitates that polarimetric radar possess high cross-polarization isolation and high measurement accuracy. In the anti-jamming application of polarimetric radar, in order to obtain high signal-to-noise ratio improvement using orthogonal polarization filtering technology, high phase measurement accuracy of PSM (polarization scattering matrix) elements is required.

[0005] Despite significant advancements in polarimetry measurement technology, the aforementioned measurement parameters remain a substantial technical challenge for the vast majority of current radar systems. Limited by device and manufacturing processes, early polarimetry radar systems generally had lower hardware platform performance, restricting the accuracy of radar polarimetry measurements. Since the 1980s, with the development of microwave devices and substantial improvements in manufacturing processes, the performance of polarimetry radar system hardware platforms has improved, generally meeting or even exceeding radar system design requirements. However, due to limitations in the theory and technology of polarimetry measurement signal / data processing, achieving high-precision PSM measurements of actual radar targets remains extremely difficult.

[0006] Traditional PSM measurements include: sequential measurement method, which involves transmitting and receiving signals with different polarizations multiple times to sequentially measure the target's scattering response under each polarization base, thereby determining the PSM; pulse Doppler method, which uses pulse compression and Doppler processing techniques to measure the response under different polarizations separately within one pulse period; and polarization synthesis method, which synthesizes waves with different polarizations to achieve a specific polarization and decomposes the target response to obtain the PSM.

[0007] However, the aforementioned traditional PSM measurement method suffers from the technical problem of low measurement accuracy. Summary of the Invention

[0008] Therefore, it is necessary to provide a method for full polarization compensation of antennas and waveforms, a device for full polarization compensation of antennas and waveforms, a computer device, and a computer-readable storage medium to address the above-mentioned technical problems.

[0009] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0010] On the one hand, a full polarization compensation method for antennas and waveforms is provided, including:

[0011] Measure and calculate the cross-polarization isolation and orthogonal waveform isolation of the radar system; the radar system is a simultaneous full polarization measurement system, and the cross-polarization isolation is an indicator of the orthogonal polarization isolation effect between antenna reception and transmission;

[0012] The radar system is used for detection, and the estimated value of the polarization scattering matrix of the target is obtained based on the detection echo results.

[0013] A coefficient matrix is ​​constructed based on the cross-polarization isolation and orthogonal waveform isolation. The estimated value of the polarization scattering matrix is ​​then compensated using the coefficient matrix to obtain the true value of the polarization scattering matrix.

[0014] On the other hand, a full polarization compensation device for antennas and waveforms is also provided, comprising:

[0015] The measurement module is used to measure and calculate the cross-polarization isolation and orthogonal waveform isolation of the radar system. The radar system is a simultaneous full polarization measurement system, and the cross-polarization isolation is an important indicator of the orthogonal polarization isolation effect of the antenna reception and transmission.

[0016] The estimation module is used to detect targets using a radar system and obtain an estimate of the target's polarization scattering matrix based on the detected echo results.

[0017] The compensation module is used to construct a coefficient matrix based on the cross-polarization isolation and orthogonal waveform isolation, and to compensate the estimated value of the polarization scattering matrix using the coefficient matrix to obtain the true value of the polarization scattering matrix.

[0018] In another aspect, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described method for full polarization compensation of antennas and waveforms.

[0019] Furthermore, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the above-described method for full polarization compensation of antennas and waveforms.

[0020] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0021] The aforementioned full polarization compensation method, device, equipment, and medium for antennas and waveforms improve the accuracy of target PSM measurement by modeling and compensating for the polarization error of the radar system. Specifically, firstly, the cross-polarization isolation and orthogonal waveform isolation of the simultaneous full polarization measurement radar system are measured and calculated. Then, the radar system is used to detect the target, and the estimated value of the target polarization scattering matrix is ​​obtained based on the echo results. Finally, a coefficient matrix is ​​constructed based on the isolation index, and the estimated value of the polarization scattering matrix is ​​compensated using the coefficient matrix to obtain the true value of the target's polarization scattering matrix.

[0022] Compensation can eliminate polarization errors introduced by antennas and waveforms, improve the accuracy of matrix estimation, and make the true matrix value closer to the actual scattering characteristics of the target than the uncompensated estimate. This improves the accuracy of radar measurement and modeling of target polarization features. The true matrix value can more clearly reflect the polarization scattering mechanism of the target, which helps to improve radar imaging resolution and classification and recognition capabilities, and improves radar polarization imaging effects. It also enhances the full polarization processing capability of the radar system. The accurate matrix is ​​conducive to the analysis and utilization of full polarization information, and improves the system's anti-interference capability and target detection performance. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart illustrating a full polarization compensation method for an antenna and waveform in one embodiment.

[0025] Figure 2 This is a schematic diagram of a system block diagram of a simultaneous fully polarized measurement system in one embodiment;

[0026] Figure 3 This is a schematic diagram of the percentage error in PSM estimation when the target cross-polarization scattering element is much smaller than the main polarization component in one embodiment. In this diagram, (a) shows the percentage error in traditional PSM estimation, and (b) shows the percentage error in compensated PSM estimation.

[0027] Figure 4 This is a schematic diagram of the percentage error in PSM estimation when the target cross-polarization scattering element is much smaller than the main polarization component in another embodiment. In this diagram, (a) is the traditional PSM estimation error with a cross-polarization isolation of -20dB, (b) is the compensated PSM estimation error with a cross-polarization isolation of -20dB, (c) is the traditional PSM error with a cross-polarization isolation of -30dB, and (d) is the compensated PSM error with a cross-polarization isolation of -30dB.

[0028] Figure 5 This is a schematic diagram of the percentage error in PSM estimation after increasing the transmit waveform bandwidth when the target cross-polarization scattering element is much smaller than the main polarization component in one embodiment. In the diagram, (a) is the traditional PSM estimation error and (b) is the compensated PSM estimation error.

[0029] Figure 6 Figure (a) shows the percentage error of PSM when the target cross-polarization scattering element is equivalent to the main polarization component in one embodiment. Figure (b) shows the traditional PSM estimation error.

[0030] Figure 7 This is a schematic diagram of the module structure of a full polarization compensation device for antennas and waveforms in one embodiment. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0033] It should be noted that, in this document, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The presentation of this phrase in various locations throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments.

[0034] To improve the accuracy of PSM (Polarization Scattering Matrix) measurement of radar targets, this invention provides a full polarization compensation method for antennas and waveforms. By modeling and compensating for the polarization error of the radar system, the accuracy of target PSM measurement is improved. Specifically, firstly, the cross-polarization isolation and orthogonal waveform isolation of the simultaneous full polarization measurement radar system are measured and calculated. Then, the radar system is used to detect the target, and the estimated value of the target polarization scattering matrix is ​​obtained based on the echo results. Finally, a coefficient matrix is ​​constructed based on the isolation index, and the estimated value of the polarization scattering matrix is ​​compensated using the coefficient matrix to obtain the true value of the target's polarization scattering matrix.

[0035] Compensation can eliminate polarization errors introduced by antennas and waveforms, improve the accuracy of matrix estimation, and make the true matrix value closer to the actual scattering characteristics of the target than the uncompensated estimate. This improves the accuracy of radar measurement and modeling of target polarization features. The true matrix value can more clearly reflect the polarization scattering mechanism of the target, which helps to improve radar imaging resolution and classification and recognition capabilities, and improves radar polarization imaging effects. It also enhances the full polarization processing capability of the radar system. The accurate matrix is ​​conducive to the analysis and utilization of full polarization information, and improves the system's anti-interference capability and target detection performance.

[0036] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0037] In one embodiment, such as Figure 1 As shown, this application provides a method for full polarization compensation of antennas and waveforms, including the following processing steps S12-16:

[0038] S12 measures and calculates the cross-polarization isolation and orthogonal waveform isolation of the radar system; the radar system is a simultaneous full polarization measurement system, and the cross-polarization isolation is an indicator of the orthogonal polarization isolation effect of the antenna reception and transmission.

[0039] It is understandable that the measurement and calculation of two indicators of a fully polarized radar system involves two aspects: cross-polarization isolation and orthogonal waveform isolation. Cross-polarization isolation refers to the antenna's isolation effect on signals from two orthogonally polarized states in both receive and transmit modes. Orthogonal waveform isolation refers to the isolation effect between two orthogonally polarized transmitted waveforms. The system block diagram for a fully polarized measurement system is shown below. Figure 2 As shown, by using an orthogonal transmission polarization channel to transmit a set of orthogonal waveforms, and simultaneously receiving the echoes at the receiving end through orthogonal polarization, the "simultaneous transmission and reception" of orthogonal polarized electromagnetic waves can be achieved. This enables the complete measurement of the target polarization scattering characteristics within one pulse repetition cycle and provides the capability for full intra-pulse polarization measurement.

[0040] Network analyzers and other equipment can be used to test the transmission coefficients of antenna ports under different polarization modes and calculate the separation degree. Alternatively, by connecting the radar transmit and receive paths and using calibration signals, the coupling relationship between two orthogonal polarization channels can be measured. Signal processing can be used to analyze the correlation of orthogonal waveforms and determine the waveform orthogonal isolation. After calculation and conversion, decibel values ​​can be obtained for cross-polarization isolation and waveform isolation. These two indicators reflect the polarization isolation effect of the radar system and are important parameters for polarization compensation.

[0041] S14 uses a radar system for detection and obtains an estimate of the target's polarization scattering matrix based on the detected echo results.

[0042] It is understandable that a fully polarimetric radar is used to transmit signals in different polarization modes: HH (horizontally polarized transmission and reception), VV (vertically polarized transmission and reception), HV (horizontally polarized transmission and reception), and VH (vertically polarized transmission and horizontally polarized reception) modes, to detect targets. The corresponding echo signals are received and processed to obtain the target's echo response under various polarizations. The echoes contain information about the target's scattering characteristics under that polarization. The echo signals from different polarizations are integrated to construct the target's polarization scattering matrix. Each element in the matrix represents the target's scattering coefficient for the corresponding combination of transmission and reception polarization modes. The scattering matrix obtained at this point is an estimate based on measured echo results and may contain errors. The next step is to compensate for these errors to obtain the true value of the matrix.

[0043] The estimated value of the polarization scattering matrix can be obtained using the peak detection method, or by the sequential measurement method or the polarization synthesis method.

[0044] S16. Construct a coefficient matrix based on the cross-polarization isolation and orthogonal waveform isolation, and use the coefficient matrix to compensate for the estimated value of the polarization scattering matrix to obtain the true value of the polarization scattering matrix.

[0045] It can be understood that the signal received by the antenna from the target can be represented as:

[0046] [r H (t),r V (t)] T =R T ST[s H (t),s V (t)] T ;

[0047] Where, r H (t) and r V (t) represents the received waveforms of channels H and V, respectively. H (t) and s V (t) represent the transmitted waveforms of channels H and V, respectively. and Let S represent the transmit and receive radiation patterns, respectively, and S be the target polarization scattering matrix. Expanding the above equation for the received signal, we get:

[0048]

[0049] After the received signal passes through the receiving filters of the H and V channels simultaneously, we can obtain:

[0050]

[0051] Among them, h H (t) and h V (t) represent the receiving filters for the H and V channels, respectively. This represents the convolution operation. If the two signals and the receiving filter have ideal correlation characteristics, after normalization, we have:

[0052]

[0053] However, in reality, the two signals cannot have ideal correlation characteristics, therefore:

[0054]

[0055] Where η represents waveform isolation, and for simplified analysis, the antenna pattern is as follows:

[0056]

[0057] Where γ represents the cross-polarization isolation of the antenna.

[0058] Therefore, the equation for estimating the target polarization scattering matrix can be expressed as:

[0059]

[0060] in These are the estimated values ​​of each element of the polarization scattering matrix obtained in step S14.

[0061] Since both waveform isolation η and antenna cross-polarization isolation γ are small quantities, their powers ( and their product Since these are all high-order minor quantities, the estimated equation for the target polarization scattering matrix can also be expressed as follows by ignoring the high-order minor quantities:

[0062]

[0063] Because the measurement error is caused by first-order small quantities η and γ, and second-order small quantity γ 2 It consists of γη and higher-order small quantities. Among them, the error influence of second-order and higher-order small quantities can be ignored. The reason is that the waveform isolation index η is usually lower than -30dB, and the cross-polarization isolation index γ is lower than -25dB (for mechanically scanned antennas, it can be better than -30dB). Therefore, the error of second-order and higher-order small quantities is lower than -50dB, which is much lower than that of first-order small quantities.

[0064] Based on the antenna cross-polarization isolation γ and orthogonal waveform isolation η measured in step S12, a coefficient matrix can be constructed. This coefficient matrix can be constructed either by equations that do not neglect higher-order insignificants, or by equations that neglect higher-order insignificants. Here, we take the equations that neglect higher-order insignificants as an example to construct the coefficient matrix. The estimated equation for the polarization scattering matrix can be expressed as:

[0065]

[0066] The left side of the equation represents the estimated values ​​of the polarization scattering matrix elements, while the right side represents the constructed coefficient matrix and the true values ​​of the elements of the polarization scattering matrix to be determined. Solving the above equations can reduce the impact of the non-idealities of the antenna cross-polarization isolation γ and orthogonal waveform isolation η on the estimation of the polarization scattering matrix, thereby recovering the true values ​​of the target polarization scattering matrix. Let... Let C be the estimated value of the polarization scattering matrix elements, and C be the coefficient matrix determined by the antenna cross-polarization isolation γ and the orthogonal waveform isolation η. Then, the true value of the elements of the compensated polarization scattering matrix is...

[0067] The aforementioned full polarization compensation method for antennas and waveforms can eliminate polarization errors introduced by the antenna and waveforms, improve the accuracy of matrix estimation, and make the true matrix value closer to the actual scattering characteristics of the target than the uncompensated estimate. This improves the accuracy of radar measurement and modeling of target polarization features. The true matrix value can more clearly reflect the polarization scattering mechanism of the target, which helps to improve radar imaging resolution and classification and recognition capabilities, and improves radar polarization imaging effects. It also enhances the full polarization processing capability of the radar system, and the accurate matrix is ​​conducive to the analysis and utilization of full polarization information, thereby improving the system's anti-interference capability and target detection performance.

[0068] In one embodiment, the above-described full polarization compensation method for antennas and waveforms, after constructing the coefficient matrix, further includes:

[0069] The equation for estimating the polarization scattering matrix is ​​expressed as:

[0070]

[0071] in, This represents the estimated values ​​of the scattering matrix elements under horizontally polarized emission and horizontally polarized reception conditions. This represents the estimated values ​​of the scattering matrix elements under vertically polarized emission and horizontally polarized reception conditions. This represents the estimated values ​​of the scattering matrix elements under horizontally polarized emission and vertically polarized reception conditions. This represents the estimated values ​​of the scattering matrix elements under vertically polarized emission and reception conditions, γ represents the cross-polarization isolation, η represents the orthogonal waveform isolation, and S... HH S represents the true value of the scattering matrix elements to be compensated under horizontally polarized emission and horizontally polarized reception conditions. VH S represents the true value of the scattering matrix elements to be compensated under vertically polarized emission and horizontally polarized reception conditions. HV S represents the true value of the scattering matrix elements to be compensated under horizontally polarized emission and vertically polarized reception conditions. VV This represents the true value of the scattering matrix element to be compensated under vertically polarized emission and vertically polarized reception conditions.

[0072] It is understandable that, based on the preliminary polarization scattering matrix estimation equation, after ignoring higher-order small quantities, the obtained polarization scattering matrix estimation equation is used to construct a coefficient matrix. The coefficient matrix includes cross-polarization isolation and orthogonal waveform isolation. Subsequently, the obtained polarization scattering matrix estimate, the measured cross-polarization isolation, and the orthogonal waveform isolation can be used to solve for the true value of the polarization scattering matrix.

[0073] The aforementioned full polarization compensation method for antennas and waveforms simplifies the mathematical model by ignoring higher-order minor quantities, thereby improving computational efficiency and stability. This simplification reduces complexity, especially when high powers and products are involved, making the problem easier to understand and solve. Although higher-order minor quantities have a relatively small impact on the solution, this simplification allows us to focus more on the main error sources, making numerical calculations more reliable and providing a more effective method for system design and performance optimization in practical applications.

[0074] In one embodiment, the above-described full polarization compensation method for antennas and waveforms uses peak detection to obtain an estimate of the polarization scattering matrix.

[0075] It is understandable that obtaining an estimate of the polarization scattering matrix using peak detection involves inferring the target's polarization characteristics by detecting peaks in the radar echo signal. This can include the following steps: transmitting a waveform (the radar system sends a specific waveform); receiving the echo (receiving the signal reflected back from the target, caused by the target scattering the transmitted waveform, and potentially affected by noise and other interference); signal processing (preprocessing the received signal, typically including filtering and noise reduction steps to improve the signal-to-noise ratio); peak detection (using a peak detection algorithm to find peaks in the echo signal, which correspond to the target's scattered signal, and whose amplitude and phase information contain the target's polarization information); and estimating the polarization scattering matrix (using the amplitude and phase information of the peaks, combined with the system's waveform characteristics, to estimate the target's polarization scattering matrix, which describes the target's scattering characteristics under different polarization states).

[0076] In the aforementioned full polarization compensation method for antennas and waveforms, the peak detection method is used to obtain the estimated value of the polarization scattering matrix. The peak detection method is a simple and efficient technique that directly extracts the polarization information of the target by finding the peaks in the echo signal, avoiding complex processing steps. This method generally has low computational complexity and is suitable for real-time systems, especially important in radar systems that require rapid response and processing of target changes. The peak detection method directly measures the peaks in the target echo, and these peaks directly correspond to the reflection characteristics of the target under different polarization states. This method does not depend on the specific transmitted waveform, so it has wide applicability to different types of waveforms. Since the peak detection method does not place too much emphasis on the shape and size of the target, it can be used for various types of targets to estimate their polarization scattering matrix.

[0077] In one embodiment, the above-described full polarization compensation method for antennas and waveforms uses a calibration signal to measure the cross-polarization isolation of the antenna.

[0078] Understandably, in full-polarization compensation methods, measuring the cross-polarization isolation of an antenna using calibration signals aims to understand the antenna's response characteristics in different polarization directions. The calibration signal is a signal with a known polarization direction; by analyzing the antenna's response to these signals, information about the cross-polarization isolation can be obtained. This information is crucial for compensating for polarization errors introduced by the antenna, thereby improving the system's full-polarization measurement accuracy.

[0079] Specifically, the measurement can be performed using the following steps: Calibration signal generation: Design a calibration signal with a known polarization direction. This signal can be a linear or circular polarization signal with a specific polarization direction, ensuring its polarization characteristics are known. Calibration signal transmission: Transmit the designed calibration signal to the antenna system, ensuring that its specific polarization state is maintained during signal transmission. Response reception and recording: Use a receiving system to capture the antenna's response to the calibration signal and record the response data, including signal amplitude, phase, and other information. Data analysis: Analyze the recorded data to understand the antenna's response characteristics in different polarization directions. This may include extracting polarization components using signal processing techniques and comparing signal characteristics in different directions. Cross-polarization isolation calculation: Using the analyzed data and appropriate calculation methods, calculate the antenna's response in different polarization directions and obtain the cross-polarization isolation value.

[0080] In the aforementioned full polarization compensation method for antennas and waveforms, a calibration signal is used to measure the antenna's cross-polarization isolation. Since the calibration signal has a known polarization direction, its polarization characteristics can be designed and controlled to accurately measure the antenna's cross-polarization isolation. This provides a more controllable and reliable measurement benchmark, reducing errors caused by uncertainties. The polarization direction of the calibration signal can be flexibly designed according to specific needs, making this method highly applicable to different polarization states and antenna types. Compared to other methods, it is not limited by specific signals or scenarios and is more versatile. Because the polarization direction of the calibration signal is known, the antenna response can be analyzed more accurately, thereby reducing measurement errors. This is particularly beneficial in complex environments where interference may exist, improving measurement stability and accuracy compared to other methods. Furthermore, the cross-polarization isolation information obtained using the calibration signal is easier to interpret. The known polarization direction of the input signal makes the data interpretation more intuitive, helping engineers and researchers understand the antenna's performance under different polarization states.

[0081] In some embodiments, to more intuitively and comprehensively illustrate the above-described full polarization compensation method for antennas and waveforms, the following are application examples of this method. It should be noted that the embodiments given in this specification are merely illustrative and not the only specific embodiments of the present invention. Those skilled in the art can use the above-described full polarization compensation method for antennas and waveforms, based on the illustrative embodiments provided by the present invention, to improve the measurement accuracy of PSM.

[0082] Numerical simulation experiments were conducted for two different scenarios to demonstrate the effectiveness of the proposed compensation method as follows:

[0083] (i) The target cross-polarization scattering element is much smaller than the principal polarization component.

[0084] Assuming the radar transmit signal bandwidth is B = 100MHz, the pulse width is T = 50us, and a positive / negative slope linear frequency modulation (LFM) signal system is used, then based on the above parameters, the waveform isolation is η = -37.44dB. If the antenna cross-polarization isolation is γ = -25dB, the signal-to-noise ratio (SNR) is SNR = 15dB, and the target's polarization scattering matrix is:

[0085]

[0086] After conducting 100 Monte Carlo simulation experiments, the percentage estimation error of each element was statistically analyzed, such as... Figure 3 As shown, the percentage error in estimating the PSM is when the target cross-polarization scattering element is much smaller than the principal polarization component. Figure (a) shows the percentage error in estimating the PSM using the traditional method, and Figure (b) shows the percentage error in estimating the PSM using the compensation method. The percentage error is defined as (ΔS) pq / S pq )*100,p,q=H,V,where ΔS pq Represents element S pq The estimation error. From Figure 3 It can be seen that after compensation using the known antenna cross-polarization isolation and waveform isolation, the PSM estimation error is significantly reduced. The polarization measurement error of the cross-polarization channel element is reduced from 300% to 10%-20%, which is more than 10 times lower, significantly improving the estimation accuracy of PSM.

[0087] Further changing the antenna's cross-polarization isolation to γ ​​= -20dB and -30dB, while keeping other parameters unchanged, the percentage estimation error of each element is statistically analyzed. For example... Figure 4As shown, the percentage error in PSM estimation is represented when the target cross-polarization scattering element is much smaller than the main polarization component. Figure (a) shows the percentage error in PSM estimation using the traditional method when the antenna cross-polarization isolation is -20dB; Figure (b) shows the percentage error using the compensation method; Figure (c) shows the percentage error using the traditional method when the antenna cross-polarization isolation is -30dB; and Figure (d) shows the percentage error using the compensation method. Changes in antenna cross-polarization isolation have a significant impact on the PSM estimation error of the traditional method, but a smaller impact on the compensation method. This is because the estimation error of the compensation method is determined by the smaller of the cross-polarization isolation and waveform isolation (a larger factor is easier to compensate, while a smaller factor is more sensitive to compensation). In this case, the waveform isolation η = -37.44dB << γ = -20dB, -30dB.

[0088] By changing the radar transmit waveform parameters to B = 1000MHz and pulse width to T = 50µs, and using a positive and negative slope linear frequency modulation signal system, the waveform isolation is η = -47.44dB. With other parameters unchanged, the percentage estimation error of each element is calculated as follows: Figure 5 As shown, the percentage error in estimating the PSM after increasing the transmit waveform bandwidth is illustrated when the target cross-polarization scattering element is much smaller than the main polarization component. Figure (a) shows the percentage error in estimating the PSM using the traditional method, and Figure (b) shows the percentage error in estimating the PSM using the compensation method. Figure 5 It can be seen that changes in waveform isolation have a relatively small impact on the PSM estimation error of the traditional method, but a significant impact on the compensation method. Under the above parameters, the polarization measurement error of the cross-polarization channel element is reduced from 300% to 4%-6%, a reduction of more than 50 times. The reason is the same as above; at this point, the estimation error of the compensation method is determined by the smaller of the two factors: cross-polarization isolation and waveform isolation.

[0089] (ii) The target cross-polarization scattering element is comparable to the principal polarization component.

[0090] Assuming the radar transmit signal bandwidth is B = 100MHz, the pulse width is T = 50us, and a positive / negative slope linear frequency modulation (LFM) signal system is used, then based on the above parameters, the waveform isolation is η = -37.44dB. If the cross-polarization isolation is γ = -25dB, the signal-to-noise ratio (SNR) is SNR = 15dB, and the target's polarization scattering matrix is...

[0091]

[0092] After conducting 100 Monte Carlo simulation experiments, the estimated percentage error of each element was statistically analyzed as follows: Figure 6As shown, the percentage error of the PSM is represented when the target cross-polarized scattering element is comparable to the principal polarization component. Figure (a) shows the percentage error of the PSM estimated using the traditional method, and Figure (b) shows the percentage error of the PSM estimated using the compensation method. It can be seen that when the target cross-polarized scattering element is comparable to the principal polarization component, the compensation method proposed in this report still outperforms the traditional method. Under these simulation parameters, the estimation error for all elements does not exceed 3%.

[0093] The compensation method proposed in this invention significantly improves the estimation error of the PSM (Polarization Scattering Matrix) under existing antenna hardware cross-polarization isolation levels, i.e., γ is approximately -25dB to -30dB. When the waveform isolation is better than -30dB, the compensation method can significantly improve the PSM estimation error. Under existing antenna hardware cross-polarization isolation levels, the smaller the waveform isolation, the higher the accuracy of the proposed estimation method. When the antenna cross-polarization isolation is γ = -25dB and the waveform isolation reaches η ≤ -45dB, the estimation error for cross elements of the polarization scattering matrix with a relative size of -30dB can be less than 10%, and the estimation error for cross elements of the polarization scattering matrix with a relative size of -10dB can be less than 3%. In summary, by introducing this invention, more accurate polarization scattering matrix values ​​can be obtained, improving the measurement accuracy of radar for target polarization characteristics.

[0094] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0095] In one embodiment, such as Figure 7 As shown, a full polarization compensation device 200 for antennas and waveforms is provided, comprising:

[0096] Measurement module 22 is used to measure and calculate the cross-polarization isolation and orthogonal waveform isolation of the radar system. The radar system is a simultaneous full polarization measurement system radar system. Cross-polarization isolation is an important indicator of the orthogonal polarization isolation effect of antenna reception and transmission.

[0097] The estimation module 24 is used to detect targets using a radar system and obtain an estimate of the target's polarization scattering matrix based on the detected echo results.

[0098] The compensation module 26 is used to construct a coefficient matrix based on the cross-polarization isolation and the orthogonal waveform isolation, and to compensate the estimated value of the polarization scattering matrix using the coefficient matrix to obtain the true value of the polarization scattering matrix.

[0099] The aforementioned full polarization compensation device 200 for antennas and waveforms can eliminate polarization errors introduced by the antenna and waveforms through compensation, improve the accuracy of matrix estimation, and make the true matrix value closer to the actual scattering characteristics of the target than the uncompensated estimate. This improves the accuracy of radar measurement and modeling of target polarization characteristics. The true matrix value can more clearly reflect the polarization scattering mechanism of the target, which helps to improve radar imaging resolution and classification and recognition capabilities, and improves radar polarization imaging effects. It also enhances the full polarization processing capability of the radar system, and the accurate matrix is ​​conducive to the analysis and utilization of full polarization information, thereby improving the system's anti-interference capability and target detection performance.

[0100] In one embodiment, the compensation module 26 of the above-described full polarization compensation device 200 for antennas and waveforms includes:

[0101] The computational submodule is used to obtain the estimation equation for the polarization scattering matrix, expressed as:

[0102]

[0103] in, This represents the estimated values ​​of the scattering matrix elements under horizontally polarized emission and horizontally polarized reception conditions. This represents the estimated values ​​of the scattering matrix elements under vertically polarized emission and horizontally polarized reception conditions. This represents the estimated values ​​of the scattering matrix elements under horizontally polarized emission and vertically polarized reception conditions. This represents the estimated values ​​of the scattering matrix elements under vertically polarized emission and reception conditions, γ represents the cross-polarization isolation, η represents the orthogonal waveform isolation, and S... HH S represents the true value of the scattering matrix elements to be compensated under horizontally polarized emission and horizontally polarized reception conditions. VH S represents the true value of the scattering matrix elements to be compensated under vertically polarized emission and horizontally polarized reception conditions. HV S represents the true value of the scattering matrix elements to be compensated under horizontally polarized emission and vertically polarized reception conditions. VV This represents the true value of the scattering matrix element to be compensated under vertically polarized emission and vertically polarized reception conditions.

[0104] In one embodiment, the estimation module 24 of the above-described full polarization compensation device 200 for antennas and waveforms uses peak detection to obtain an estimate of the polarization scattering matrix.

[0105] In one embodiment, the measurement module 22 of the above-described full polarization compensation device 200 for antennas and waveforms measures the cross-polarization isolation of the antenna using a calibration signal.

[0106] Specific limitations regarding the full polarization compensation device 200 for antennas and waveforms can be found in the limitations of the full polarization compensation method for antennas and waveforms described above, and will not be repeated here. Each module in the aforementioned full polarization compensation device 200 for antennas and waveforms can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the operations corresponding to each module.

[0107] In one embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to perform the following steps: measuring and calculating the cross-polarization isolation and orthogonal waveform isolation of a radar system; the radar system is a simultaneous full polarization measurement radar system, and the cross-polarization isolation is an indicator representing the orthogonal polarization isolation effect of antenna reception and transmission; using the radar system to perform detection, and obtaining an estimate of the polarization scattering matrix of the target based on the detected echo results; constructing a coefficient matrix based on the cross-polarization isolation and orthogonal waveform isolation, and using the coefficient matrix to compensate for the estimate of the polarization scattering matrix to obtain the true value of the polarization scattering matrix.

[0108] It is understood that, in addition to the memory and processor mentioned above, the computer equipment described above also includes other hardware and software components not listed in this specification. The specific components can be determined according to the model of the computer equipment in different application scenarios, and will not be listed and described in detail in this specification.

[0109] In one embodiment, when the processor executes the computer program, it can also implement the steps or sub-steps added in the various embodiments of the full polarization compensation method for antennas and waveforms described above.

[0110] In one embodiment, a computer-readable storage medium is also provided, on which a computer program is stored. When the computer program is executed by a processor, it performs the following steps: measuring and calculating the cross-polarization isolation and orthogonal waveform isolation of a radar system; the radar system is a simultaneous full-polarization measurement radar system, and the cross-polarization isolation is an indicator representing the orthogonal polarization isolation effect of antenna reception and transmission; using the radar system to perform detection, and obtaining an estimate of the polarization scattering matrix of the target based on the detected echo results; constructing a coefficient matrix based on the cross-polarization isolation and orthogonal waveform isolation, and using the coefficient matrix to compensate for the estimate of the polarization scattering matrix to obtain the true value of the polarization scattering matrix.

[0111] In one embodiment, when the computer program is executed by the processor, it can also implement the steps or sub-steps added to the various embodiments of the full polarization compensation method for antennas and waveforms described above.

[0112] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0113] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0114] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for full polarization compensation of antennas and waveforms, characterized in that, Including the following steps: Measure and calculate the cross-polarization isolation and orthogonal waveform isolation of the radar system; the radar system is a simultaneous full polarization measurement radar system, and the cross-polarization isolation is an indicator of the orthogonal polarization isolation effect between antenna reception and transmission; The radar system is used for detection, and the estimated value of the polarization scattering matrix of the target is obtained based on the detection echo results. A coefficient matrix is ​​constructed based on the cross-polarization isolation and the orthogonal waveform isolation. The estimated value of the polarization scattering matrix is ​​compensated using the coefficient matrix to obtain the true value of the polarization scattering matrix. After constructing the coefficient matrix, the following is also included: The estimation equation for the polarization scattering matrix is ​​obtained as follows: in, This represents the estimated values ​​of the scattering matrix elements under horizontally polarized emission and horizontally polarized reception conditions. This represents an estimate of the elements of the scattering matrix under the conditions of vertically polarized emission and horizontally polarized reception. This represents an estimate of the elements of the scattering matrix under the conditions of horizontally polarized emission and vertically polarized reception. This represents an estimate of the elements of the scattering matrix under the conditions of vertical polarization emission and vertical polarization reception. This indicates the cross-polarization isolation. This represents the isolation degree of the orthogonal waveform. This represents the true value of the scattering matrix element to be compensated under the horizontally polarized emission and reception conditions. This represents the true value of the scattering matrix element to be compensated under the conditions of vertical polarization emission and horizontal polarization reception. This represents the true value of the scattering matrix element to be compensated under the conditions of horizontally polarized emission and vertically polarized reception. This represents the true value of the scattering matrix element to be compensated under the conditions of vertical polarization emission and vertical polarization reception.

2. The full polarization compensation method for antennas and waveforms according to claim 1, characterized in that, The estimated value of the polarization scattering matrix is ​​obtained using the peak detection method.

3. The full polarization compensation method for antennas and waveforms according to claim 1, characterized in that, The cross-polarization isolation of the antenna is measured using a calibration signal.

4. A fully polarization compensation device for antennas and waveforms, characterized in that, include: The measurement module is used to measure and calculate the cross-polarization isolation and orthogonal waveform isolation of the radar system; The radar system is a simultaneous full polarization measurement radar system, and the cross polarization isolation is an important indicator of the orthogonal polarization isolation effect of antenna reception and transmission. An estimation module is used to perform detection using the radar system and obtain an estimate of the target's polarization scattering matrix based on the detected echo results. The compensation module is used to construct a coefficient matrix based on the cross-polarization isolation and the orthogonal waveform isolation, and to use the coefficient matrix to compensate for the estimated value of the polarization scattering matrix to obtain the true value of the polarization scattering matrix. The compensation module includes: The computational submodule is used to obtain the estimation equation for the polarization scattering matrix, expressed as: in, This represents the estimated values ​​of the scattering matrix elements under horizontally polarized emission and horizontally polarized reception conditions. This represents an estimate of the elements of the scattering matrix under the conditions of vertically polarized emission and horizontally polarized reception. This represents an estimate of the elements of the scattering matrix under the conditions of horizontally polarized emission and vertically polarized reception. This represents an estimate of the elements of the scattering matrix under the conditions of vertical polarization emission and vertical polarization reception. This indicates the cross-polarization isolation. This represents the isolation degree of the orthogonal waveform. This represents the true value of the scattering matrix element to be compensated under the horizontally polarized emission and reception conditions. This represents the true value of the scattering matrix element to be compensated under the conditions of vertical polarization emission and horizontal polarization reception. This represents the true value of the scattering matrix element to be compensated under the conditions of horizontally polarized emission and vertically polarized reception. This represents the true value of the scattering matrix element to be compensated under the conditions of vertical polarization emission and vertical polarization reception.

5. The full polarization compensation device for antennas and waveforms according to claim 4, characterized in that, The estimation module uses peak detection to obtain an estimate of the polarization scattering matrix.

6. The full polarization compensation device for antennas and waveforms according to claim 4, characterized in that, The measurement module uses a calibration signal to measure the cross-polarization isolation of the antenna.

7. A computer device, comprising a memory and a processor, characterized in that, The memory stores a computer program, and when the processor executes the computer program, it implements the steps of the full polarization compensation method for antennas and waveforms as described in any one of claims 1 to 3.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the full polarization compensation method for antennas and waveforms as described in any one of claims 1 to 3.

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