Short wave signal direction finding method and device of irregular sparse array

Abstract

The invention provides a short-wave signal direction finding method and device of an irregular sparse array, belongs to the technical field of short-wave communication direction finding, and aims at solving the problem of direction finding fuzziness of the irregular sparse array, antenna array elements with different horizontal and vertical positions are adopted for arraying, and meanwhile angle fuzziness in orientation and pitching is eliminated; the dual-polarized antenna is adopted to receive incoming wave signals for direction finding, two polarized components of short wave sky wave signals are fully utilized, and the direction finding capability can be improved; a direction-finding azimuth angle range is obtained by using correlation peak searching of the current phase difference vector and different azimuth expected phase difference vectors, so that the DOA estimation calculation amount is reduced; and fusing the direction finding results by using azimuth angle consistency judgment and DOA spectrum peak size comparison methods to obtain a correct direction finding result. The method can effectively solve the direction finding fuzzy problem of the irregular sparse array, improves the direction finding capability of the incoming wave signal in the composite polarization mode, and has both accuracy and real-time performance.

Description

Technical Field

[0001] The invention relates to the technical field of shortwave communication direction finding, and in particular to a shortwave signal direction finding method and device of an irregular sparse array. Background Art

[0002] Traditional shortwave direction-finding stations basically adopt a uniform circular array, which has high requirements for the site environment. The spacing between array elements is generally less than half a wavelength. When the number of array elements is certain, the aperture size of the entire array is limited, thus affecting the direction-finding accuracy performance. Array elements generally use vertically polarized antennas, and their ability to receive horizontally polarized electromagnetic waves is weak. Irregular sparse arrays use conformal arrays, which do not have high requirements for the site. After the sparse array, the spacing between array elements is greater than half a wavelength, which reduces the mutual coupling between antenna elements, increases the array aperture, and has the ability to obtain higher direction-finding accuracy. Antenna array elements use both horizontal and vertical polarization forms, which can more effectively receive shortwave signals in a composite polarization mode after reflection from the ionosphere, thereby improving shortwave direction-finding performance.

[0003] After adopting the irregular sparse array mode, since the array element spacing is greater than half a wavelength, grating lobes and high side lobes will appear in the array. If these grating lobes and high side lobes are not suppressed, the direction finding will be ambiguous and errors will occur. The existing sidelobe suppression method uses a coprime or nested sparse array mode to use the different horizontal spacing of the array elements to resolve the direction finding ambiguity. This ambiguity resolution method has limited effect and can only resolve the ambiguity in azimuth, but cannot effectively resolve the ambiguity in elevation, and cannot be applied to occasions requiring two-dimensional direction finding. Due to the anisotropy of this irregular sparse array, multi-frequency array calibration is required from different azimuths to obtain a series of calibration vectors at different azimuths and different frequencies. In actual direction finding applications, on the one hand, these calibration vectors are used to estimate the direction of arrival of signal (DOA) one by one, which is computationally intensive and difficult to meet the real-time requirements of direction finding; on the other hand, how to fuse a series of direction finding results calculated by different calibration vectors to obtain correct direction finding results is also an urgent problem to be solved. Summary of the invention

[0004] The present invention provides a shortwave signal direction finding method and device of an irregular sparse array, which are used to solve the defects in the prior art and improve the direction finding capability of shortwave signals.

[0005] In a first aspect, the present invention provides a shortwave signal direction finding method of an irregular sparse array, comprising: using M antennas of an antenna array to synchronously collect target shortwave signals, obtaining data of M channels, selecting one of the channels as a reference channel, and calculating a current phase difference vector;

[0006] According to the center frequency of the target shortwave signal, N groups of calibration vectors in N directions are selected to determine N groups of expected phase difference vectors in N directions;

[0007] The current phase difference vector is correlated with N groups of expected phase difference vectors respectively, and the azimuth corresponding to the obtained maximum peak is used as the reference azimuth;

[0008] DOA estimation is performed on N1 groups of calibration vectors within a preset range near the reference azimuth, respectively, to determine a final direction finding result based on the direction finding results of multiple DOA estimates.

[0009] According to a shortwave signal direction finding method of an irregular sparse array provided by the present invention, N groups of calibration vectors of N azimuths are selected according to the center frequency of the target shortwave signal, and N groups of expected phase difference vectors of N azimuths are determined, including: reading pre-stored calibration vectors of different azimuths and frequencies, and selecting N groups of calibration vectors according to the center frequency of the target shortwave signal; calculating and obtaining the steering vectors of N azimuths of the antenna array at the center frequency according to the three-dimensional coordinates of M antennas; and multiplying the calibration vectors of N azimuths with the steering vectors of N azimuths correspondingly to obtain the expected phase difference vectors of N azimuths.

[0010] According to a shortwave signal direction finding method for an irregular sparse array provided by the present invention, DOA estimation is performed on N1 groups of calibration vectors within a preset range near a reference azimuth, so as to determine a final direction finding result according to the direction finding results of multiple DOA estimations, including: selecting N1 groups of calibration vectors within a preset range near a reference azimuth from the N groups of calibration vectors, and performing DOA estimation on them to obtain N1 groups of direction finding results; eliminating direction finding results that do not belong to the preset range from the N1 groups of direction finding results to obtain N2 groups of direction finding results; and selecting the azimuth and elevation angle with the largest spectrum peak from the N2 groups of direction finding results as the final direction finding result.

[0011] According to a shortwave signal direction finding method for an irregular sparse array provided by the present invention, the distance between the signal source and the center of the antenna array is greater than or equal to 5 times the aperture of the antenna array.

[0012] According to a shortwave signal direction finding method of an irregular sparse array provided by the present invention, M antennas have different horizontal and height positions.

[0013] According to a shortwave signal direction finding method of an irregular sparse array provided by the present invention, M antennas have two polarization modes: horizontal and vertical.

[0014] In a second aspect, the present invention further provides a shortwave signal direction finding device of an irregular sparse array, comprising:

[0015] The current phase difference vector calculation module is used to synchronously collect the target shortwave signal using the M antennas of the antenna array, obtain the data of M channels, select one of the channels as the reference channel, and calculate the current phase difference vector;

[0016] An expected phase difference vector calculation module is used to select N groups of calibration vectors in N directions according to the center frequency of the target shortwave signal, and determine N groups of expected phase difference vectors in N directions;

[0017] A reference azimuth determination module is used to perform correlation operations on the current phase difference vector and N groups of expected phase difference vectors, and use the obtained azimuth corresponding to the maximum peak as the reference azimuth;

[0018] The direction finding result determination unit is used to perform DOA estimation on N1 groups of calibration vectors within a preset range near the reference azimuth, so as to determine a final direction finding result according to the direction finding results of multiple DOA estimations.

[0019] In a third aspect, the present invention provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the shortwave signal direction finding method for an irregular sparse array as described in any one of the above are implemented.

[0020] In a fourth aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the shortwave signal direction finding method for an irregular sparse array as described in any one of the above.

[0021] The present invention provides a shortwave signal direction finding method and device for irregular sparse arrays. The present invention aims at the direction finding ambiguity problem of irregular sparse arrays. The current phase difference vector is correlated with the expected phase difference vectors in different azimuths to find the peak to obtain the direction finding azimuth range, thereby reducing the amount of DOA estimation calculations. The azimuth consistency judgment and DOA spectrum peak size comparison method are used to fuse the direction finding results to obtain the correct direction finding results. The method can effectively solve the direction finding ambiguity problem of irregular sparse arrays, improve the direction finding capability of composite polarization wave signals, and has both accuracy and real-time performance.

[0022] The present invention adopts antenna array elements with different horizontal and vertical positions, and eliminates angle ambiguity in azimuth and elevation at the same time; adopts dual-polarized antenna to receive incoming wave signals for direction finding, and makes full use of the two polarization components of shortwave skywave signals, which can improve the direction finding capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a flow chart of a shortwave signal direction finding method of an irregular sparse array provided by the present invention;

[0025] Figure 2 It is a design principle diagram of the shortwave direction finding method of the dual-polarization irregular sparse array provided by the present invention;

[0026] Figure 3 It is a schematic diagram of the implementation principle of the direction finding result fusion processing provided by the present invention;

[0027] Figure 4 is a diagram of actual measurement results of ground wave direction finding provided by an embodiment of the present invention;

[0028] Figure 5 is a diagram of actual measurement results of sky wave direction finding provided by an embodiment of the present invention;

[0029] Figure 6 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that, in the description of the embodiments of the present invention, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "include one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0032] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0033] Combine the following Figure 1-Figure 6 The shortwave signal direction finding method and device of an irregular sparse array provided by an embodiment of the present invention are described.

[0034] Figure 1 FIG. 1 is a flow chart of a shortwave signal direction finding method for an irregular sparse array provided by the present invention, such as Figure 1 As shown, including but not limited to the following steps:

[0035] Step 101: Use M antennas of an antenna array to synchronously collect target shortwave signals, obtain data of M channels, select one of the channels as a reference channel, and calculate a current phase difference vector.

[0036] Optionally, the antenna array in the present invention is an irregular sparse array layout with two polarization modes, horizontal and vertical, and includes M antennas.

[0037] A channel is selected from the data of the M channels as a reference channel, and the phase difference of each antenna relative to the reference channel is calculated to form a current phase difference vector.

[0038] Optionally, the M antennas have different horizontal and height positions.

[0039] Optionally, the distance between the signal source and the center of the antenna array is greater than or equal to 5 times the aperture of the antenna array.

[0040] Step 102: According to the center frequency of the target shortwave signal, N groups of calibration vectors in N directions are selected to determine N groups of expected phase difference vectors in N directions.

[0041] Optionally, step 102 is implemented as follows:

[0042] (1) Read the pre-stored calibration vectors of different azimuths and frequencies, and select N groups of calibration vectors according to the center frequency of the target shortwave signal.

[0043] The present invention can pre-establish a database containing calibration vector data of different orientations and frequencies, which are usually obtained by precise measurement in a laboratory environment or simulated by simulation software.

[0044] According to the center frequency of the target shortwave signal, a series of calibration vectors closest to the frequency are found in the database.

[0045] (2) Based on the three-dimensional coordinates of the M antennas, the steering vectors of the antenna array in N directions at the center frequency are calculated.

[0046] Based on the precise three-dimensional coordinates of the M antennas in the antenna array, for a given center frequency, the steering vectors in different directions are calculated according to the geometric layout of the antenna array and the electromagnetic wave propagation characteristics. The steering vector represents the response characteristics of the antenna array to the incident signal in a specific direction.

[0047] (3) Multiply the calibration vectors of the N azimuths by the steering vectors of the N azimuths to obtain the expected phase difference vectors of the N azimuths.

[0048] For each selected azimuth, the corresponding calibration vector is multiplied element by element with the steering vector. The purpose of this is to obtain the relationship between the actual phase difference and the ideal phase difference at the azimuth. Through the above multiplication operation, the desired phase difference vectors at N azimuths can be obtained.

[0049] Step 103: perform correlation operations on the current phase difference vector and the N groups of expected phase difference vectors respectively, and use the obtained azimuth corresponding to the maximum peak as the reference azimuth.

[0050] Optionally, the reference orientation is denoted as A in the present invention.

[0051] Step 104: performing DOA estimation on N1 groups of calibration vectors within a preset range near the reference azimuth respectively, so as to determine a final direction finding result according to the direction finding results of multiple DOA estimates.

[0052] Optionally, step 104 is implemented as follows:

[0053] (1) Select N1 groups of calibration vectors within a preset range A1 near the reference azimuth A from the N groups of calibration vectors, and perform DOA estimation on each of them to obtain N1 groups of direction finding results.

[0054] On the basis of the previously determined reference orientation, a preset range A1 is defined as [A-α, A+α], where α is a preset angle, and N1 groups of calibration vectors are selected within this range.

[0055] The present invention uses the N1 sets of calibration vectors to perform DOA estimation and obtain N1 sets of direction finding results; wherein, DOA estimation can adopt a variety of methods, such as minimum variance distortionless response (MVDR), multiple signal classification (MUSIC), estimated signal parameter rotation invariant technique (ESPRIT), etc.

[0056] (2) The direction finding results that are not within the preset range are eliminated from the N1 group of direction finding results to obtain the N2 group of direction finding results.

[0057] For the N1 azimuth results obtained by multiple DOA estimations, determine whether the azimuth is within the range of [A-α, A+α] one by one. If it is not within the range, the result is discarded; if it is within the range, the result is retained. After N1 judgments, N2 direction finding results are screened.

[0058] (3) In the N2 group of direction finding results, the azimuth and elevation angle with the largest spectrum peak are selected as the final direction finding results.

[0059] For the N2 group of direction finding results, analyze its spectrum peak (i.e., the value with the largest intensity), and select the azimuth and elevation angle with the largest spectrum peak as the final direction finding result. This is because the position with the largest spectrum peak often represents the direction with the strongest signal, that is, the direction where the most likely target is located.

[0060] The present invention aims at the direction finding ambiguity problem of irregular sparse arrays, uses the correlation peak search between the current phase difference vector and the expected phase difference vectors in different azimuths to obtain the direction finding azimuth range, thereby reducing the amount of DOA estimation calculations; uses the azimuth consistency judgment and DOA spectrum peak size comparison method to fuse the direction finding results to obtain the correct direction finding results. This method can effectively solve the direction finding ambiguity problem of irregular sparse arrays, improve the direction finding capability of composite polarization wave signals, and has both accuracy and real-time performance.

[0061] The present invention adopts antenna array elements with different horizontal and vertical positions, and eliminates angle ambiguity in azimuth and elevation at the same time; adopts dual-polarized antenna to receive incoming wave signals for direction finding, and makes full use of the two polarization components of shortwave skywave signals, which can improve the direction finding capability.

[0062] Figure 2 : is a design principle diagram of the shortwave direction finding method of the dual-polarization irregular sparse array provided by the present invention, such as Figure 2 As shown, the main application scenario of the method of the present invention is shortwave communication signal direction finding. After completing the multi-channel synchronous acquisition of dual-polarized antenna array signals, the current phase difference vector is calculated. The expected phase difference vector is calculated and constructed according to the known target signal center frequency, and the direction finding azimuth range is determined by the correlation between the two. Multiple DOA estimates are performed in this azimuth, and multiple results are fused to output the final direction finding result.

[0063] The method comprises:

[0064] Use M antennas to receive the target shortwave signal, the signal center frequency is f, synchronously collect M channel data, select one channel as the reference channel, and calculate the current phase difference vector;

[0065] Read the calibration vectors of N different frequencies in different directions, and select the closest N groups of calibration vectors according to the target signal frequency;

[0066] According to the three-dimensional coordinates of the M antennas, the steering vectors of the array in N azimuths at the frequency f are calculated;

[0067] Multiply the calibration vectors of N azimuths by the steering vectors of N azimuths to obtain the expected phase difference vectors of N azimuths;

[0068] The current phase difference vector is correlated with N groups of expected phase difference vectors, and the obtained azimuth corresponding to the maximum peak is taken as the reference azimuth A;

[0069] Select N1 groups of calibration vectors in a certain range A1 near the reference azimuth A from the N groups of calibration vectors to perform DOA estimation, and obtain N1 groups of direction finding results;

[0070] Eliminate the direction finding results that do not belong to the range A1 from the N1 group of direction finding results to obtain the N2 group of direction finding results;

[0071] The azimuth and elevation angles with the largest spectrum peaks in the N2 group of direction finding results are selected as the final direction finding results.

[0072] The method of the present invention is now further described by way of embodiments:

[0073] The dual-polarization irregular sparse array has a total of M array elements (antennas), and the three-dimensional coordinates of each array element are (x i ,y i , z i ), the three-dimensional coordinates of the reference array element are (0,0,0), the signal incident azimuth (relative to the north direction) is φ, the elevation angle (relative to the ground plane) is θ, the incident signal frequency is f, and the speed of light is c, then the delay of each array element is:

[0074]

[0075] Among them, i=1, 2, 3,…,M.

[0076] The steering vector of each array element is:

[0077]

[0078] The calibration vector of each array element at the closest frequency f is:

[0079]

[0080] Then the corresponding elements of the two are multiplied to obtain the expected phase difference vector:

[0081]

[0082] N groups of expected phase difference vectors can be obtained from N different azimuth angles:

[0083] E=[e1e2 e3…e N ];

[0084] Perform FFT transformation on the synchronously collected M channel data, find the maximum peak point after taking the modulus, and take the frequency domain normalized complex vector of the peak point as the current phase difference vector of the received signal. Compare the current phase difference vector with the N groups of expected phase difference vectors [e1e2 e3…e N ]Sum and modulus the relevant values ​​one by one, compare the sizes of these N modulus values, and the azimuth represented by the maximum modulus value is the direction finding reference azimuth A.

[0085] Based on the reference azimuth A, a certain range A1∈[A-α,A+α] is selected as the possible distribution range of the azimuth angle. Within this range, there are N1 azimuth calibration vectors. The currently synchronously collected M channel IQ data is conjugate multiplied with the N1 groups of calibration vectors to obtain the calibrated IQ data, and the DOA estimation is performed to obtain N1 direction finding results.

[0086] Figure 3 This is a schematic diagram of the implementation principle of the direction finding result fusion processing provided by the present invention. Figure 3 Provide explanation.

[0087] For the N1 azimuth results obtained by multiple DOA estimations, determine whether the azimuth is within the range of [A-α, A+α] one by one. If it is not within the range, the result is discarded; if it is within the range, the result is retained. After N1 judgments, N2 direction finding results are screened.

[0088] In the N2 direction finding results, the corresponding DOA estimation spectrum peaks are taken out respectively and the peak values ​​are compared. According to the direction finding principle, the peak value represents the correlation between the calibrated received signal and the steering vector of the corresponding azimuth. The higher the peak value, the higher the correlation. Therefore, the azimuth and elevation angle corresponding to the highest peak value in the N2 direction finding spectra are selected as the final direction finding result.

[0089] The effect of using the above method on the direction finding of the actual shortwave ground wave and sky wave signals is as follows: Figure 4 and Figure 5 As shown, Figure 4 is a diagram of the actual measurement results of ground wave direction finding provided by an embodiment of the present invention, Figure 5This is a diagram of the actual measurement results of the sky wave direction finding provided by the embodiment of the present invention. In the test sample, 68 antennas are used for synchronous acquisition, of which 34 are horizontally polarized and 34 are vertically polarized antennas. The entire antenna array is arranged irregularly and sparsely, and the aperture is greater than 1 km.

[0090] See also Figure 4 , is the direction finding result of the array for the 7762.5kHz ground wave signal. The true value of the azimuth is 152.5°, and the actual measured azimuth is 152.7°, with an error of only 0.2°. Figure 5 , is the direction finding result of the array for the 11630kHz skywave signal. The true value of the azimuth is 102.9°, and the actual measured azimuth is 102.4°, with an error of only 0.5°. It can be seen that through the method of the present invention, the dual-polarization irregular sparse array can achieve higher accuracy in both ground wave and sky wave direction finding.

[0091] On the other hand, the present invention also provides a shortwave signal direction finding device of irregular sparse array, comprising:

[0092] The current phase difference vector calculation module is used to synchronously collect the target shortwave signal using the M antennas of the antenna array, obtain the data of M channels, select one of the channels as the reference channel, and calculate the current phase difference vector;

[0093] An expected phase difference vector calculation module is used to select N groups of calibration vectors in N directions according to the center frequency of the target shortwave signal, and determine N groups of expected phase difference vectors in N directions;

[0094] A reference azimuth determination module is used to perform correlation operations on the current phase difference vector and N groups of expected phase difference vectors, and use the obtained azimuth corresponding to the maximum peak as the reference azimuth;

[0095] The direction finding result determination unit is used to perform DOA estimation on N1 groups of calibration vectors within a preset range near the reference azimuth, so as to determine a final direction finding result according to the direction finding results of multiple DOA estimations.

[0096] It should be noted that the shortwave signal direction finding device for irregular sparse array provided in the embodiment of the present invention can execute the shortwave signal direction finding method for irregular sparse array described in any of the above embodiments during specific operation, which will not be described in detail in this embodiment.

[0097] Figure 6 is a schematic diagram of the structure of the electronic device provided by the present invention, such as Figure 6As shown, the electronic device may include: a processor 610, a communication interface 620, a memory 630 and a communication bus 640, wherein the processor 610, the communication interface 620 and the memory 630 communicate with each other through the communication bus 640. The processor 610 may call the logic instructions in the memory 630 to execute the shortwave signal direction finding method of the irregular sparse array.

[0098] In addition, the logic instructions in the above-mentioned memory 630 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0099] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the shortwave signal direction finding method for an irregular sparse array provided in the above-mentioned embodiments.

[0100] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to execute the shortwave signal direction finding method for an irregular sparse array provided in the above embodiments.

[0101] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0102] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A shortwave signal direction finding method for an irregular sparse array, characterized in that: include: The target shortwave signal is synchronously collected using the M antennas of the antenna array to obtain data from M channels, one of the channels is selected as the reference channel, and the current phase difference vector is calculated; According to the center frequency of the target shortwave signal, N groups of calibration vectors in N directions are selected to determine N groups of expected phase difference vectors in N directions; The current phase difference vector is correlated with N groups of expected phase difference vectors respectively, and the azimuth corresponding to the obtained maximum peak is used as the reference azimuth; DOA estimation is performed on N1 groups of calibration vectors within a preset range near the reference azimuth, respectively, to determine a final direction finding result based on the direction finding results of multiple DOA estimates.

2. The shortwave signal direction finding method of irregular sparse array according to claim 1, characterized in that: According to the center frequency of the target shortwave signal, N groups of calibration vectors in N directions are selected to determine N groups of expected phase difference vectors in N directions, including: Read the pre-stored calibration vectors of different azimuths and frequencies, and select N groups of calibration vectors according to the center frequency of the target shortwave signal; According to the three-dimensional coordinates of the M antennas, the steering vectors of the antenna array in N directions at the center frequency are calculated; The calibration vectors of the N azimuths are correspondingly multiplied with the steering vectors of the N azimuths to obtain the expected phase difference vectors of the N azimuths.

3. The shortwave signal direction finding method of irregular sparse array according to claim 1, characterized in that: Within a preset range near the reference azimuth, DOA estimation is performed on each of the N1 groups of calibration vectors to determine the final direction finding result based on the direction finding results of multiple DOA estimations, including: Selecting N1 groups of calibration vectors within a preset range near the reference azimuth from the N groups of calibration vectors, and performing DOA estimation on each of them to obtain N1 groups of direction finding results; Eliminate the direction finding results that are not within the preset range from the N1 group of direction finding results to obtain the N2 group of direction finding results; The azimuth and elevation angles with the largest spectrum peaks in the N2 group of direction finding results are selected as the final direction finding results.

4. The shortwave signal direction finding method of irregular sparse array according to claim 1, characterized in that: The distance between the signal source and the center of the antenna array is greater than or equal to 5 times the aperture of the antenna array.

5. The shortwave signal direction finding method of irregular sparse array according to claim 1, characterized in that: The M antennas have different horizontal and height positions.

6. The shortwave signal direction finding method of irregular sparse array according to claim 1, characterized in that: The M antennas have two polarization modes: horizontal and vertical.

7. A shortwave signal direction finding device with irregular sparse array, characterized in that: include: The current phase difference vector calculation module is used to synchronously collect the target shortwave signal using the M antennas of the antenna array, obtain the data of M channels, select one of the channels as the reference channel, and calculate the current phase difference vector; An expected phase difference vector calculation module is used to select N groups of calibration vectors in N directions according to the center frequency of the target shortwave signal, and determine N groups of expected phase difference vectors in N directions; A reference azimuth determination module is used to perform correlation operations on the current phase difference vector and N groups of expected phase difference vectors, and use the obtained azimuth corresponding to the maximum peak as the reference azimuth; The direction finding result determination unit is used to perform DOA estimation on N1 groups of calibration vectors within a preset range near the reference azimuth, so as to determine a final direction finding result according to the direction finding results of multiple DOA estimations.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the shortwave signal direction finding method for an irregular sparse array as claimed in any one of claims 1 to 6 are implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the shortwave signal direction finding method for an irregular sparse array as claimed in any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the shortwave signal direction finding method for an irregular sparse array as claimed in any one of claims 1 to 6 are implemented.

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