A DBF amplitude comparison direction finding method and device and storage medium

Abstract

This invention provides a DBF amplitude comparison direction finding method, device, and storage medium, belonging to the field of antenna feed direction finding technology. The method includes: importing multiple original incident angle amplitudes; constructing a beam pattern to be processed by performing a radiation pattern analysis on all original incident angle amplitudes; performing a fitting analysis on the beam pattern to be processed to obtain linear fitting coefficients; obtaining incident signals from multiple array elements of the array antenna; performing amplitude difference analysis on the incident signals to obtain the beam pattern to be corrected and multiple original beam amplitude differences; and performing a correction analysis on the beam pattern to be corrected based on all original beam amplitude differences to obtain the target beam pattern. This invention solves the problems of beam pointing velocity deformation at large angles and the decrease in direction finding accuracy as the beam pointing increases, thus improving the direction finding accuracy. It also solves the problem of increased direction finding error caused by phase spacing intersection point offset.

Description

Technical Field

[0001] This invention mainly relates to the field of antenna direction finding technology, specifically to a DBF amplitude comparison direction finding method, device, and storage medium. Background Technology

[0002] Direction finding is a passive direction finding technology that does not require the transmission of electromagnetic signals. It completes the azimuth measurement of radar signals through the direction finding system employed. Commonly used passive direction finding methods include amplitude comparison direction finding, interferometer direction finding, Doppler direction finding, amplitude and phase comparison direction finding, spatial spectrum direction finding, and compressed sensing direction finding.

[0003] Amplitude comparison direction finding has advantages such as simple equipment structure, low cost, and easy engineering implementation, but it suffers from relatively poor direction finding accuracy. Interferometer direction finding measures azimuth angle based on the phase difference of the received signal, offering advantages such as high direction finding accuracy and simple algorithm, but it faces a trade-off between accuracy and deambiguity probability, which limits its application to some extent. Doppler direction finding uses high-speed switching of antennas to generate a frequency offset from the incoming signal, achieving high accuracy, but it is susceptible to multiple signal interference in complex environments, limiting its application. Amplitude-phase comparison direction finding primarily uses the amplitude difference between the antennas with the largest and second-largest received signals to perform coarse direction finding, then uses the amplitude comparison result to guide phase comparison for deambiguity. When the amplitude comparison result has a large error, it can lead to deambiguity errors, resulting in larger direction finding errors, especially in complex environments where the deambiguity capability of this algorithm is unsatisfactory. Spatial spectrum direction finding falls under the category of array direction finding. It features the ability to simultaneously resolve multiple arriving signals and high direction finding accuracy. However, its high algorithm complexity and error-prone estimation of the number of signal sources limit its application to some extent. Compressed sensing direction finding applies compressed sensing theory to signal sampling, reducing back-end processing requirements. However, the complexity of compressed sensing theory and the unstable convergence of its algorithm limit its engineering applications.

[0004] Passive radar beamforming (DBF) direction finding technology is a key research area in electronic detection. Given DBF's high target resolution and long detection range, improving direction finding accuracy has always been a hot topic and a challenge. DBF direction finding technology has two drawbacks: the larger the beam scanning angle, the wider the beam width; and the more severe the waveform distortion, the larger the beam scanning angle. Some existing technologies improve direction finding accuracy by increasing the amplitude measurement accuracy, achieving an accuracy of 0.1 dB. However, considering that the amplitude fluctuation of microwave frequency conversion components in system equipment is generally greater than 0.5 dB, this limits its engineering application. Other existing technologies improve direction finding accuracy through linear fitting, but this does not consider the widening beam width and waveform distortion problems at large beam pointing angles. Still other existing technologies use an amplitude difference lookup table to calculate the angle of arrival, but this method does not consider the ambiguity of the amplitude difference when the beam points at large angles, leading to increased direction finding errors. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a DBF amplitude comparison and direction finding method, device and storage medium to address the shortcomings of the prior art.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A DBF amplitude comparison and direction finding method, comprising the following steps: Import multiple raw incident angle amplitudes, construct radiation patterns for all the raw incident angle amplitudes, and obtain the beam radiation pattern to be processed; The beam pattern to be processed is fitted and analyzed to obtain linear fitting coefficients; Incident signals are obtained from multiple elements of the array antenna, and amplitude difference analysis is performed on the incident signals to obtain the beam pattern to be corrected and multiple original beam amplitude differences. The beam pattern to be corrected is analyzed based on all the original beam amplitude differences to obtain the target beam pattern. An incident angle analysis was performed on the linear fitting coefficients and the target beam pattern, and the analysis results were used as the DBF amplitude ratio direction finding results.

[0007] Another technical solution of the present invention to solve the above-mentioned technical problems is as follows: A DBF amplitude comparison and direction finding device, comprising: The import module is used to import multiple raw incident angle amplitudes; The construction module is used to construct the radiation pattern of all the original incident angle amplitudes to obtain the beam radiation pattern to be processed; The fitting analysis module is used to perform fitting analysis on the beam pattern to be processed and obtain linear fitting coefficients. The amplitude difference analysis module is used to obtain the incident signal from multiple array elements of the array antenna, perform amplitude difference analysis on the incident signal, and obtain the beam pattern to be corrected and multiple original beam amplitude differences. The correction analysis module is used to perform correction analysis on the beam pattern to be corrected based on all the original beam amplitude differences to obtain the target beam pattern. The direction finding result acquisition module is used to perform incident angle analysis on the linear fitting coefficients and the target beam pattern, and use the analysis results as the DBF amplitude comparison direction finding results.

[0008] Based on the above-mentioned DBF amplitude comparison direction finding method, the present invention also provides a DBF amplitude comparison direction finding system.

[0009] Another technical solution of the present invention to solve the above-mentioned technical problems is as follows: A DBF amplitude comparison direction finding system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the DBF amplitude comparison direction finding method as described above.

[0010] Based on the aforementioned DBF amplitude comparison and direction finding method, the present invention also provides a computer-readable storage medium.

[0011] Another technical solution of the present invention to solve the above-mentioned technical problems is as follows: a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the DBF amplitude comparison and direction finding method as described above.

[0012] The beneficial effects of this invention are as follows: by constructing the beam pattern to be processed from the original incident angle amplitude pattern, the linear fitting coefficients are obtained from the fitting analysis of the beam pattern to be processed, the amplitude difference of the incident signal is analyzed to obtain the beam pattern to be corrected and the original beam amplitude difference, the target beam pattern is obtained from the correction analysis of the beam pattern to be corrected based on the original beam amplitude difference, the incident angle is analyzed on the linear fitting coefficients and the target beam pattern, and the analysis results are used as the DBF amplitude comparison direction finding results. This solves the problems of beam pointing velocity deformation at large angles and the problem of poor direction finding accuracy as the beam pointing direction increases, thus improving the direction finding accuracy and solving the problem of direction finding error deterioration caused by phase spacing intersection point offset. Attached Figure Description

[0013] Figure 1 This is a schematic flowchart of the DBF amplitude comparison and direction finding method provided in an embodiment of the present invention; Figure 2 A schematic diagram of a digital beam synthesizer for the DBF amplitude comparison and direction finding method provided in an embodiment of the present invention; Figure 3This is one of the beam patterns of different beam orientations in the DBF amplitude comparison and direction finding method provided in the embodiments of the present invention; Figure 4 The beam pattern of the large beam pointing of the DBF amplitude comparison direction finding method provided in the embodiments of the present invention; Figure 5 The amplitude difference diagram of the left and right waveforms of the DBF amplitude comparison direction finding method provided in the embodiment of the present invention; Figure 6 This is a diagram showing the 60° linear fitting effect of the DBF amplitude comparison direction finding method provided in this embodiment of the invention. Figure 7 This is a comparison image of the direction pattern before and after shaping in the DBF amplitude comparison and direction finding method provided in this embodiment of the invention; Figure 8 This is the second example of a beam pattern with different beam orientations for the DBF amplitude comparison and direction finding method provided in an embodiment of the present invention. Figure 9 The shaped beam pattern of the DBF amplitude comparison and direction finding method provided in this embodiment of the invention; Figure 10 This is a diagram showing the amplitude difference fitting effect of the DBF amplitude comparison direction finding method provided in an embodiment of the present invention. Figure 11 The direction finding accuracy diagrams for different direction finding algorithms of the DBF amplitude comparison direction finding method provided in the embodiments of the present invention are shown. Figure 12 This is a block diagram of the DBF amplitude comparison and direction finding device provided in an embodiment of the present invention. Detailed Implementation

[0014] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0015] Figure 1 This is a flowchart illustrating a DBF amplitude comparison and direction finding method provided in an embodiment of the present invention.

[0016] like Figure 1 As shown, a DBF amplitude comparison and direction finding method includes the following steps: S1: Import multiple raw incident angle amplitudes, construct radiation patterns for all the raw incident angle amplitudes, and obtain the beam radiation pattern to be processed; S2: Perform a fitting analysis on the beam pattern to be processed to obtain linear fitting coefficients; S3: Obtain the incident signal from multiple array elements of the array antenna, perform amplitude difference analysis on the incident signal, and obtain the beam pattern to be corrected and multiple original beam amplitude differences; S4: Perform correction analysis on the beam pattern to be corrected based on all the original beam amplitude differences to obtain the target beam pattern; S5: Perform incident angle analysis on the linear fitting coefficients and the target beam pattern, and use the analysis results as the DBF amplitude comparison direction finding results.

[0017] It should be understood that, under microwave anechoic chamber conditions, the turntable is set with a starting angle of −180° and an ending angle of +180°, with a step angle of 1°.

[0018] In the above embodiments, the beam pattern to be processed is obtained by constructing the original incident angle amplitude pattern, the linear fitting coefficient is obtained by fitting analysis of the beam pattern to be processed, the amplitude difference of the incident signal is analyzed to obtain the beam pattern to be corrected and the original beam amplitude difference, the target beam pattern is obtained by the correction analysis of the original beam amplitude difference to be corrected beam pattern, the incident angle is analyzed on the linear fitting coefficient and the target beam pattern, and the analysis results are used as the DBF amplitude comparison direction finding results. This solves the problems of beam pointing velocity deformation at large angles and the problem of poor direction finding accuracy as the beam pointing increases, thus improving the direction finding accuracy and solving the problem of direction finding error deterioration caused by phase spacing intersection point offset.

[0019] Optionally, as an embodiment of the present invention, the process of constructing a radiation pattern for all the original incident angle amplitudes to obtain the beam radiation pattern to be processed includes: The original beam pattern is constructed using all the original incident angle amplitudes; The original radiation pattern is normalized to obtain the beam pattern to be processed.

[0020] It should be understood that the amplitude response corresponding to different incident angles is tested to obtain the beam pattern (i.e., the original beam pattern), and the pattern (i.e., the original beam pattern) is normalized.

[0021] In the above embodiments, a radiation pattern is constructed for all original incident angle amplitudes to obtain the radiation pattern of the beam to be processed, which solves the problems of beam pointing speed deformation at large angles and the problem that the larger the beam pointing, the worse the direction finding accuracy, thus improving the direction finding accuracy.

[0022] Optionally, as an embodiment of the present invention, the process of performing fitting analysis on the beam pattern to be processed to obtain linear fitting coefficients includes: Extract the label vector and feature matrix to be processed from the beam pattern to be processed; The label vector to be processed, the feature matrix to be processed, and the beam pattern to be processed are subjected to shaping analysis to obtain a shaped beam pattern, which includes the shaped feature matrix. The linear fitting coefficients are obtained by calculating the label vector to be processed and the shaped feature matrix using the first equation, which is: , in, These are the linear fitting coefficients. The feature matrix after reshaping. For transpose, This is the tag vector to be processed.

[0023] Specifically, for the shaped beam pattern (i.e., the shaped beam pattern), according to the formula... Obtain the linear fitting coefficients between the incident angle and the amplitude difference. .

[0024] In the above embodiments, the beam pattern to be processed is fitted and analyzed to obtain linear fitting coefficients, which solves the problems of beam pointing speed deformation at large angles and the problem of poorer direction finding accuracy as the beam pointing direction increases, thereby improving the direction finding accuracy.

[0025] Optionally, as an embodiment of the present invention, the process of performing shaping analysis on the label vector to be processed, the feature matrix to be processed, and the beam pattern to be processed to obtain the shaped beam pattern includes: The first integer coefficient is obtained by calculating the label vector to be processed and the feature matrix to be processed using the second equation. The second equation is: , in, The first integer coefficient, The feature matrix to be processed. For transpose, The vector of labels to be processed; The first integer formula is constructed using the third equation, which is: , in, For beam pointing And the angle of incidence is The first beam amplitude, For beam pointing And the angle of incidence is The first beam amplitude, For the first The preset pointing angle of each beam. To preset the beam center offset angle, The first integer coefficient; The beam pattern to be processed is shaped using the first shaping formula to obtain the shaped beam pattern.

[0026] Specifically, according to Beam pattern shaping coefficients (i.e., the first integer coefficient), and according to The radiation pattern (i.e., the beam pattern to be processed) is shaped.

[0027] In the above embodiments, the label vector to be processed, the feature matrix to be processed, and the beam pattern to be processed are shaped to obtain the shaped beam pattern, which solves the problems of large-angle beam pointing velocity deformation and the problem of poor direction finding accuracy as the beam pointing becomes larger, thus improving the direction finding accuracy.

[0028] Optionally, as an embodiment of the present invention, the incident signal includes the incident signal wavelength and the original incident angle, and the process of performing amplitude difference analysis on the incident signal to obtain the beam pattern to be corrected and multiple original beam amplitude differences includes: The incident signal wavelength and the original incident angle are calculated using the fourth equation to obtain multiple second beam amplitudes. The beam pattern to be corrected is then constructed using all the second beam amplitudes. The fourth equation is: , in, , in, For beam pointing And the angle of incidence is The second beam amplitude, The original angle of incidence. For the first The preset pointing angle of each beam. The total number of array elements. The imaginary unit, The wavelength of the incident signal, For the first Phase compensation values ​​corresponding to each beam; The fifth equation is used to calculate the amplitude of each of the second beams, resulting in multiple original beam amplitude differences. , in, For the first The original beam amplitude difference corresponding to each beam For beam pointing And the angle of incidence is The second beam amplitude, For beam pointing And the angle of incidence is The second beam amplitude, It is an absolute value function.

[0029] It should be understood that after a uniform linear array receives a signal (i.e., the incident signal), it is processed by the formula... N different equally spaced beam directions are formed.

[0030] Specifically, through the formula Calculate the signal amplitude corresponding to different waveforms of the signal, and obtain the amplitude difference between the maximum amplitude and the second largest amplitude (i.e., the original beam amplitude difference).

[0031] In the above embodiments, amplitude difference analysis is performed on the incident signal to obtain the beam pattern to be corrected and multiple original beam amplitude differences. This solves the problems of large-angle beam pointing velocity deformation and the fact that the larger the beam pointing, the worse the direction finding accuracy, thus improving the direction finding accuracy.

[0032] Optionally, as an embodiment of the present invention, the process of performing correction analysis on the beam pattern to be corrected based on all the original beam amplitude differences to obtain the target beam pattern includes: Extract the label vector to be corrected from the beam pattern to be corrected; Construct the target feature matrix using all the original beam amplitude differences; The second integer coefficient is obtained by calculating the label vector to be corrected and the target feature matrix using the sixth equation. The sixth equation is: , in, This is the second integer coefficient. For the target feature matrix, For transpose, The label vector to be corrected; The second integer formula is constructed using the seventh formula, which is: , in, For beam pointing And the angle of incidence is The second beam amplitude, For beam pointing And the angle of incidence is The second beam amplitude, For the first The preset pointing angle of each beam. To preset the beam center offset angle, This is the second integer coefficient; The beam pattern to be corrected is shaped according to the second shaping formula and the second shaping coefficient to obtain the processed beam pattern, which includes multiple third beam amplitudes. The incident signal wavelength and the amplitude of each of the third beams are calculated using the eighth equation to obtain multiple fourth beam amplitudes. A target beam pattern is then constructed using all the fourth beam amplitudes. The eighth equation is: , in, For beam pointing And the angle of incidence is The amplitude of the fourth beam, The original angle of incidence. For the first The preset pointing angle of each beam. For beam pointing And the angle of incidence is The amplitude of the third beam, To preset the beamwidth, For beam pointing And the angle of incidence is The amplitude of the third beam.

[0033] Specifically, based on the shaping coefficient (i.e., the second shaping coefficient) shapes the radiation pattern (i.e., the beam pattern to be corrected), according to the formula... The beam (i.e., the amplitude of the third beam) is processed to be constant beam.

[0034] In the above embodiments, the beam pattern to be corrected is analyzed based on the amplitude differences of all original beams to obtain the target beam pattern. This solves the problems of beam pointing speed deformation at large angles and the fact that the larger the beam pointing direction, the worse the direction finding accuracy, thus improving the direction finding accuracy.

[0035] Optionally, as an embodiment of the present invention, the process of performing incident angle analysis on the linear fitting coefficients and the target beam pattern, and using the analysis results as the DBF amplitude comparison and direction finding results, includes: The linear fitting slope and linear fitting intercept are extracted from the linear fitting coefficients, and multiple target beam amplitude differences are extracted from the target beam pattern. The ninth equation is used to calculate the linear fitting slope, the linear fitting intercept, and the amplitude difference of each target beam to obtain multiple target incidence angles. All target incidence angles are then used as DBF amplitude comparison direction finding results. The ninth equation is as follows: , in, For the first The target incident angle of each beam The slope of the linear fit. For the first The target beam amplitude difference of each beam The intercept is the linear fit.

[0036] It should be understood that, based on the linear fit coefficients Japanese style Find the angle of incidence of the signal (i.e. the angle of incidence of the target).

[0037] In the above embodiments, the incident angle analysis is performed on the linear fitting coefficients and the target beam pattern, and the analysis results are used as the DBF amplitude comparison direction finding results. This solves the problems of large-angle beam pointing velocity deformation and the poorer direction finding accuracy as the beam pointing becomes larger, thus improving the direction finding accuracy. It also solves the problem of the direction finding error deteriorating due to the offset of the phase spacing intersection point.

[0038] Alternatively, as another embodiment of the present invention, the beam synthesized by the digital beamforming of the present invention has the following two characteristics: (a) Different beam directions result in different beam widths; the greater the beam direction, the wider the beam width. (ii) The greater the beam direction, the more obvious the asymmetry between the left and right halves of the beam, that is, the more severe the beam deformation.

[0039] Due to the two main characteristics of beamforming mentioned above, existing linear fitting and table lookup methods for amplitude-based direction finding have the following drawbacks: (i) When the algorithm does not consider the large-angle beam pointing, beam deformation leads to poor direction finding accuracy; (ii) The larger the beam direction, the greater the direction finding error, which limits the range of reconnaissance angles.

[0040] This invention mainly addresses the characteristics of radiation pattern synthesis by proposing a radiation pattern shaping technique. It performs constant beam processing on the radiation pattern, solving the problem of beam pointing and wave velocity deformation at large angles. Furthermore, it uses the least squares method to fit and obtain the azimuth angle, thus solving the problem that the larger the beam pointing, the worse the direction finding accuracy, thereby improving the direction finding accuracy.

[0041] Alternatively, as another embodiment of the present invention, such as Figure 2 As shown, the spacing between the pairs of elements in this invention is... A uniform linear array, with a frequency of (wavelength is) The signal is in the incident direction angle. The projectile is incident on the battle surface in the direction of the incident point.

[0042] The interval between the pairs is A uniform linear array, with a frequency of (wavelength is) The signal is in the incident direction angle. The signal s(t) is incident on the array surface in the direction of , and its complex envelope (or baseband signal) is assumed to be narrowband. Taking the first array element on the left as a reference, let the signal received by the first array element at time t be... for: , The signal received by the second array element is delayed relative to that received by the first array element. The received signal is: , In narrowband mode, if latency Much smaller than aperture transit time Then the time delay of the slowly varying envelope can be approximated as: , Adding the outputs of all array elements together, the array output in the normal direction is: , make Furthermore, by performing modulo normalization on the following expression, we obtain the following result: , Assuming we want to form multiple beams, each with a different direction, to achieve the beam direction of the Kth beam as follows: Therefore, the digital beamforming processor needs to provide the corresponding array phase compensation value. ,in, , In the following formula, let Then, by adding the outputs of all array elements, we get the result. The array output in the direction is: , After further processing, the following results can be obtained: , As can be seen from the above formula, when At that time, the beam output has a maximum value. If By varying the beam pattern within a certain range, different beam patterns can be obtained, allowing multiple beams to be output simultaneously.

[0043] Assuming the DBF forms N beams, and the amplitude difference between two adjacent beams is: , When the angle of incidence If this is confirmed, then there will exist two adjacent beams that measure the maximum and second-largest amplitudes, and the incident angle and the amplitude difference between the two adjacent beams will have an approximately linear relationship. Therefore: , In the formula denoted as , where is the slope of the angle as a function of the amplitude difference, and b is the reference angle.

[0044] In the above formula, k and b can be obtained by linear fitting of measured beam data, assuming the amplitude difference between the measured data of two adjacent beams is: , Assuming the amplitude difference between measured data of two adjacent beams is n, After vectorization, we have , in: , , , The least squares method yields the following equation: .

[0045] Alternatively, as another embodiment of the present invention, such as Figure 3 and 4 As shown, the main research object of this invention is the array pattern of a uniform linear array. (The rest of the text appears to be a fragment and doesn't translate directly.) It can be seen that when When it is very small, then: , but It can be approximated as: , This shows that the radiation pattern of a linear uniform linear array is approximately a Sinc function.

[0046] When the beam points The larger, The larger the value, the larger the approximation error. (Assuming...) The simulation results are as follows Figure 3 As shown in the figure, the greater the beam direction, the larger the beam width and the more severe the beam distortion.

[0047] For large-angle beam pointing, there is also the phenomenon of phase-spaced antenna intersection point offset, which leads to a larger direction-finding error, such as... Figure 4 As shown, the greater the beam pointing, the greater the change in waveform shape, leading to a larger direction-finding error. When the beam pointing is within ±45°, the beam shape change is small. Therefore, the instantaneous detection range of a typical uniform array is only 90° of the spatial domain, which limits the use of the algorithm to some extent. An algorithm is urgently needed to solve this problem.

[0048] Alternatively, as another embodiment of the present invention, such as Figures 4 to 7 As shown, by Figure 4It can be seen that when the beam velocity direction of the present invention is larger, the waveforms on the left and right sides of the beam are asymmetrical. The larger the direction, the more obvious the asymmetry. Let the difference between the waveforms on the left and right sides of the beam be denoted as... Then we have: , From the above equation, it can be seen that since the sine function is in the interval [0, 2, 3], the sine function is in the interval [0, 2, 3]. When the slope changes, the slower the rate of increase, the more... The larger, when hour, Furthermore, it is even larger, thus leading to a larger pointing error with a large beam. Assuming... The beam is pointed at 70°, and the amplitude difference between the waveforms on the left and right sides of the beam is... ,like Figure 5 As shown, from Figure 5 It can be seen that, within the beamwidth range, the amplitude difference between the waveforms pointing to the left and right of the beam is a curve, which can be linearly represented by a quadratic function. Therefore: , The formula Substitution After sorting, we get: , in .

[0049] From the above formula, it can be seen that the amplitude difference between the waveform pointing to the left and the waveform pointing to the right within the beamwidth range... It can be linearly represented by a quadratic function of the amplitude difference between the largest and second-largest beams.

[0050] The above equation can be expressed in vector form as follows: , Assuming the amplitude difference between measured data of two adjacent beams is n, After vectorization, we have , in, , , , We can obtain the following using the least squares method: , The reshaped orientation pattern is as follows: , Assumption The beam is pointed at 60°, and the fitting effect diagram is as follows. Figure 6 As shown, the comparison diagrams before and after pattern fitting are as follows: Figure 7 As shown.

[0051] Let the directional pattern after pattern shaping be When the beam points to 0, the radiation pattern is... The beamwidth is B. Constant beam processing is performed on different beam directions to avoid the phenomenon of crossover point offset of phase-spaced antennas.

[0052] = .

[0053] Alternatively, as another embodiment of the present invention, such as Figures 8 to 11 As shown, the simulation conditions of this invention are: uniform linear array, array spacing... The beam scanning step is 8°, and a random jitter of 0.5dB is added to the radiation pattern. The array radiation pattern is as follows: Figure 8 As shown, after shaping the radiation pattern using this invention, the simulation results are as follows. Figure 9 As shown in the simulation diagram, the beam pattern has been improved after reshaping, and the beam widths of different beams are basically consistent. This solves the problem of worsening direction finding error caused by phase-interval crossover point offset. A linear fit was performed on the amplitude difference between adjacent beams after reshaping, and the fitting result is shown in the figure below. Figure 10 As shown in Table 1, the slope of the fitted line is basically consistent after the shaping process. Table 1 shows the parameters of the fitted line for the amplitude difference.

[0054] Table 1 like Figure 11 The figure shows a comparison between the present invention and existing algorithms. As can be seen from the figure, the present invention has less fluctuation throughout the entire direction finding range and higher accuracy at large angles of incidence.

[0055] Optionally, as another embodiment of the present invention, passive radar direction finding is a key research area in the field of electronic detection. Compared with interferometer direction finding systems, amplitude comparison direction finding systems have poorer direction finding accuracy. How to improve the accuracy of amplitude comparison direction finding is a challenge in developing this direction finding system. For amplitude comparison direction finding algorithms under the DBF system, this invention proposes a pattern shaping technique based on the characteristics of pattern synthesis. This technique performs constant beam processing on the pattern, solving the problem of beam velocity deformation under large-angle beam pointing. The azimuth angle is obtained through least squares fitting. Finally, the correctness of the algorithm is verified through extensive simulation data and comparative experiments.

[0056] Figure 12 This is a block diagram of a DBF amplitude comparison and direction finding device provided in an embodiment of the present invention.

[0057] Alternatively, as another embodiment of the present invention, such as Figure 12 As shown, a DBF amplitude comparison and direction finding device includes: The import module is used to import multiple raw incident angle amplitudes; The construction module is used to construct the radiation pattern of all the original incident angle amplitudes to obtain the beam radiation pattern to be processed; The fitting analysis module is used to perform fitting analysis on the beam pattern to be processed and obtain linear fitting coefficients. The amplitude difference analysis module is used to obtain the incident signal from multiple array elements of the array antenna, perform amplitude difference analysis on the incident signal, and obtain the beam pattern to be corrected and multiple original beam amplitude differences. The correction analysis module is used to perform correction analysis on the beam pattern to be corrected based on all the original beam amplitude differences to obtain the target beam pattern. The direction finding result acquisition module is used to perform incident angle analysis on the linear fitting coefficients and the target beam pattern, and use the analysis results as the DBF amplitude comparison direction finding results.

[0058] Optionally, another embodiment of the present invention provides a DBF amplitude comparison direction finding system, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the DBF amplitude comparison direction finding method as described above. This system can be a computer or similar system.

[0059] Optionally, another embodiment of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the DBF amplitude comparison and direction finding method as described above.

[0060] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0061] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described apparatus and unit can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0062] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0063] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0064] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0065] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A DBF amplitude comparison and direction finding method, characterized in that, Includes the following steps: Import multiple raw incident angle amplitudes, construct radiation patterns for all the raw incident angle amplitudes, and obtain the beam radiation pattern to be processed; The beam pattern to be processed is fitted and analyzed to obtain linear fitting coefficients; Incident signals are obtained from multiple elements of the array antenna, and amplitude difference analysis is performed on the incident signals to obtain the beam pattern to be corrected and multiple original beam amplitude differences. The beam pattern to be corrected is analyzed based on all the original beam amplitude differences to obtain the target beam pattern. An incident angle analysis was performed on the linear fitting coefficients and the target beam pattern, and the analysis results were used as the DBF amplitude ratio direction finding results.

2. The DBF amplitude comparison and direction finding method according to claim 1, characterized in that, The process of constructing a radiation pattern for all the original incident angle amplitudes to obtain the beam radiation pattern to be processed includes: The original beam pattern is constructed using all the original incident angle amplitudes; The original radiation pattern is normalized to obtain the beam pattern to be processed.

3. The DBF amplitude comparison and direction finding method according to claim 1, characterized in that, The process of fitting and analyzing the beam pattern to be processed to obtain linear fitting coefficients includes: Extract the label vector and feature matrix to be processed from the beam pattern to be processed; The label vector to be processed, the feature matrix to be processed, and the beam pattern to be processed are subjected to shaping analysis to obtain a shaped beam pattern, which includes the shaped feature matrix. The linear fitting coefficients are obtained by calculating the label vector to be processed and the shaped feature matrix using the first equation, which is: ， in, These are the linear fitting coefficients. The feature matrix after reshaping. For transpose, This is the tag vector to be processed.

4. The DBF amplitude comparison and direction finding method according to claim 3, characterized in that, The process of performing shaping analysis on the label vector to be processed, the feature matrix to be processed, and the beam pattern to be processed to obtain the shaped beam pattern includes: The first integer coefficient is obtained by calculating the label vector to be processed and the feature matrix to be processed using the second equation. The second equation is: ， in, The first integer coefficient, The feature matrix to be processed. For transpose, The vector of labels to be processed; The first integer formula is constructed using the third equation, which is: ， in, For beam pointing And the angle of incidence is The first beam amplitude, For beam pointing And the angle of incidence is The first beam amplitude, For the first The preset pointing angle of each beam. To preset the beam center offset angle, The first integer coefficient; The beam pattern to be processed is shaped using the first shaping formula to obtain the shaped beam pattern.

5. The DBF amplitude comparison and direction finding method according to claim 1, characterized in that, The incident signal includes the incident signal wavelength and the original incident angle. The process of performing amplitude difference analysis on the incident signal to obtain the beam pattern to be corrected and multiple original beam amplitude differences includes: The incident signal wavelength and the original incident angle are calculated using the fourth equation to obtain multiple second beam amplitudes. The beam pattern to be corrected is then constructed using all the second beam amplitudes. The fourth equation is: ， in, , in, For beam pointing And the angle of incidence is The second beam amplitude, The original angle of incidence. For the first The preset pointing angle of each beam. The total number of array elements. The imaginary unit, The wavelength of the incident signal, For the first Phase compensation values ​​corresponding to each beam; The fifth equation is used to calculate the amplitude of each of the second beams, resulting in multiple original beam amplitude differences. ， in, For the first The original beam amplitude difference corresponding to each beam For beam pointing And the angle of incidence is The second beam amplitude, For beam pointing And the angle of incidence is The second beam amplitude, It is an absolute value function.

6. The DBF amplitude comparison and direction finding method according to claim 1, characterized in that, The process of performing correction analysis on the beam pattern to be corrected based on all the original beam amplitude differences to obtain the target beam pattern includes: Extract the label vector to be corrected from the beam pattern to be corrected; Construct the target feature matrix using all the original beam amplitude differences; The second integer coefficient is obtained by calculating the label vector to be corrected and the target feature matrix using the sixth equation. The sixth equation is: ， in, This is the second integer coefficient. For the target feature matrix, For transpose, The label vector to be corrected; The second integer formula is constructed using the seventh formula, which is: ， in, For beam pointing And the angle of incidence is The second beam amplitude, For beam pointing And the angle of incidence is The second beam amplitude, For the first The preset pointing angle of each beam. To preset the beam center offset angle, This is the second integer coefficient; The beam pattern to be corrected is shaped according to the second shaping formula and the second shaping coefficient to obtain the processed beam pattern, which includes multiple third beam amplitudes. The incident signal wavelength and the amplitude of each of the third beams are calculated using the eighth equation to obtain multiple fourth beam amplitudes. A target beam pattern is then constructed using all the fourth beam amplitudes. The eighth equation is: ， in, For beam pointing And the angle of incidence is The amplitude of the fourth beam, The original angle of incidence. For the first The preset pointing angle of each beam. For beam pointing And the angle of incidence is The amplitude of the third beam, To preset the beamwidth, For beam pointing And the angle of incidence is The amplitude of the third beam.

7. The DBF amplitude comparison and direction finding method according to claim 1, characterized in that, The process of performing incident angle analysis on the linear fitting coefficients and the target beam pattern, and using the analysis results as DBF amplitude comparison and direction finding results, includes: The linear fitting slope and linear fitting intercept are extracted from the linear fitting coefficients, and multiple target beam amplitude differences are extracted from the target beam pattern. The ninth equation is used to calculate the linear fitting slope, the linear fitting intercept, and the amplitude difference of each target beam to obtain multiple target incidence angles. All target incidence angles are then used as DBF amplitude comparison direction finding results. The ninth equation is as follows: ， in, For the first The target incident angle of each beam The slope of the linear fit. For the first The target beam amplitude difference of each beam The intercept is the linear fit.

8. A DBF amplitude comparison and direction finding device, characterized in that, include: The import module is used to import multiple raw incident angle amplitudes; The construction module is used to construct the radiation pattern of all the original incident angle amplitudes to obtain the beam radiation pattern to be processed; The fitting analysis module is used to perform fitting analysis on the beam pattern to be processed and obtain linear fitting coefficients. The amplitude difference analysis module is used to obtain the incident signal from multiple array elements of the array antenna, perform amplitude difference analysis on the incident signal, and obtain the beam pattern to be corrected and multiple original beam amplitude differences. The correction analysis module is used to perform correction analysis on the beam pattern to be corrected based on all the original beam amplitude differences to obtain the target beam pattern. The direction finding result acquisition module is used to perform incident angle analysis on the linear fitting coefficients and the target beam pattern, and use the analysis results as the DBF amplitude comparison direction finding results.

9. A DBF amplitude comparison and direction finding device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the DBF amplitude comparison and direction finding method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the DBF amplitude comparison and direction finding method as described in any one of claims 1 to 7.

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