A distributed aperture radar grating lobe effect compensation method and system

Abstract

The application provides a distributed aperture radar grating lobe compensation method and system, and relates to the technical field of radar signal processing, and comprises: adjusting a beam pointing angle to emit a plurality of pulses, and utilizing beam scanning to compensate for the gap between the grating lobes in the antenna pattern of the distributed aperture radar, and the specific steps are: obtaining the antenna pattern of the distributed aperture radar; obtaining the grating lobe and zero point position near the main lobe of the antenna pattern of the distributed aperture radar; obtaining the beam scanning angle of the compensation pulse according to the beam scanning compensation criterion; and obtaining the cumulative power of the observation range multi-pulse according to the beam scanning angle of the compensation pulse. The application can be applied to the case of high dynamic platform, long baseline, small number of apertures and large array element spacing, has low limitation on signal bandwidth, array element position and other parameters, has wide applicability, is less affected by errors, effectively improves the energy utilization rate and the efficiency of spatial search detection, and effectively covers the detection blind area in the visual range of a single radar.

Description

Technical Field

[0001] This invention belongs to the field of radar signal processing, specifically relating to a method and system for compensating for the grating lobe effect in distributed aperture radar. Background Technology

[0002] Distributed Aperture Radar (DAR) is a new type of radar system that can coherently process the signals of radar elements with large spacing between adjacent elements, thereby improving the signal-to-noise ratio of the target echo. Compared with traditional radar, it has advantages such as high detection power, high angular resolution, good scalability and high mobility. Taking the coherent cooperative detection of multi-aircraft phased array radar as an example, under far-field conditions, the target backscattering characteristics change little with the observation angle, while the baseline of the radar array, i.e., the spacing between adjacent elements, is much greater than half a wavelength. The radar array antenna pattern exhibits a severe grating lobe effect, which leads to problems such as a decrease in the main lobe power ratio, angular ambiguity, and detection blind spots in the visible area of ​​the unit radar.

[0003] Currently, the main methods for solving the grating lobe effect problem in large-spacing radar arrays include: optimized array configuration, frequency conversion suppression, and virtual element technology. Optimized array configuration suppresses grating lobes by designing aperiodic or sparse array configurations using optimization algorithms, but it is difficult to apply to high-dynamic platforms and situations with a small number of element apertures. Frequency conversion suppression suppresses grating lobes by multiplying antenna patterns of different frequency bands, but it has high limitations on parameters such as signal bandwidth and element position, narrow applicability, and is greatly affected by errors. Virtual element technology constructs virtual elements between distributed apertures through interpolation and other methods to make a sparse array become a full array to suppress grating lobes, but it is difficult to apply to situations with a small number of apertures and a large element spacing. In addition, in the case of long baselines, the number of grating lobes is large and the main lobe width is narrow. Existing methods only obtain a narrow main lobe by suppressing grating lobes, which greatly reduces energy utilization and the efficiency of space search and detection. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide a method and system for compensating for grating lobe effects in distributed aperture radar. This method involves acquiring the antenna pattern of a distributed aperture radar, obtaining the grating lobes and null positions near the main lobe of the pattern, obtaining the beam scanning angle of the compensation pulse based on the grating lobes and null positions near the main lobe and the beam scanning compensation criterion, and obtaining the cumulative power of multiple pulses within the observation range based on the beam scanning angle of the compensation pulse. This invention is applicable to high-dynamic platforms, long baselines, small aperture numbers, and large element spacing, effectively improving energy utilization and space search detection efficiency, and effectively covering the detection blind zone within the visible range of a single radar.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for compensating for grating lobe effects in distributed aperture radar. The method involves adjusting the beam pointing angle to transmit multiple pulses and using beam scanning to compensate for gaps between grating lobes in the antenna pattern of the distributed aperture radar. The specific steps are as follows:

[0007] Step 1: Obtain the radiation pattern of the distributed aperture radar antenna;

[0008] Step 2: Based on the distributed aperture radar antenna pattern, obtain the grating lobe and null positions near the main lobe of the distributed aperture radar antenna pattern;

[0009] Step 3: Obtain the beam scanning angle of the compensation pulse based on the grating lobe and null position near the main lobe of the distributed aperture radar antenna pattern and the beam scanning compensation criterion.

[0010] Step 4: Obtain the cumulative power of the multi-pulse in the observation range based on the beam scanning angle of the compensation pulse.

[0011] Preferably, step 1, obtaining the distributed aperture radar antenna pattern, specifically includes:

[0012] Step 101: Read the system parameters of the distributed aperture radar. Assume the array is distributed along the y-direction with the x-direction as the normal direction, the subarrays are uniformly distributed, the array elements within the subarrays are uniformly distributed, and the operating frequency of the distributed aperture radar is f. c The wavelength is λ, and the azimuth beam pointing angle is θ. d The number of subarrays is M, and the inter-array spacing is d. s The number of array elements in the subarray is N, and the spacing between the array elements in the subarray is d. Therefore, the total number of array elements in all the subarrays is MN. The aperture length of the distributed aperture radar in the azimuth direction, i.e., the distribution range of the subarray, is calculated to be L. s =Md s The sub-aperture length of a single subarray, i.e., the distribution range of the array elements within the subarray, is L = Nd; the position of the i-th subarray is... The relative position of the j-th element within a single subarray is Then the absolute position of the array element in the z = (i-1)M+j, z = 1, ..., MN subarray of the distributed aperture radar is P. z =P Mi +P Nj z = 1, ..., MN;

[0013] Step 102: Calculate the antenna pattern of a single subarray and calculate the beam pointing angle θ. d The spatial frequency is The spatial frequency in the direction of the observation angle θ is The antenna pattern of a single subarray in the direction of the observation angle θ is then:

[0014]

[0015] Step 103: Calculate the antenna pattern of the subarray element. Treat each subarray as a single element and calculate the antenna pattern of the subarray element at the beam pointing angle θ. d The spatial frequency is The spatial frequency in the direction of the observation angle θ is The antenna pattern of the subarray element in the direction of the observation angle θ is then:

[0016]

[0017] Step 104: Calculate the distributed aperture radar antenna pattern according to the antenna pattern product principle. The distributed aperture radar antenna pattern is the product of the antenna pattern of the subarray and the antenna pattern of the subarray element.

[0018] F(θ)=F1(θ)F2(θ) (3)

[0019] Preferably, step 2, obtaining the grating lobe and null positions near the main lobe of the distributed aperture radar antenna pattern based on the distributed aperture radar antenna pattern, specifically includes:

[0020] Based on different amplitudes, the grating lobes near the main lobe are divided into main grating lobes and secondary grating lobes. First, the positions of the main grating lobes adjacent to one side of the main lobe are calculated.

[0021]

[0022] The angular range (θ) between the main lobe and the main grating lobes adjacent to each other on one side of the main lobe. d ,θ major There are M-1 zeros and M-2 secondary grating lobes in memory. Then, the positions of the zeros between the main lobe and the adjacent main grating lobes are calculated, and the position of the k-th zero is...

[0023]

[0024] Next, the positions of the secondary grating lobes between the main lobe and adjacent main grating lobes are calculated, and the position of the k-th secondary grating lobe is...

[0025]

[0026] Preferably, step 3, obtaining the beam scanning angle of the compensation pulse based on the grating lobe and null positions near the main lobe of the distributed aperture radar antenna pattern and the beam scanning compensation criterion, specifically includes:

[0027] The fine-tuning beam scanning angle of the compensation pulse is calculated according to the zero-point beam scanning compensation criterion or the half-power point beam scanning compensation criterion.

[0028] If the zero-point beam scanning compensation criterion is adopted, the beam scanning angle of the compensation pulse is the position θ of each zero point between the main lobe and the adjacent main grating lobe on one side. nullk k = 1, 2, ..., M-1;

[0029] If the half-power point beam scanning compensation criterion is used, the zero-point beamwidth Θ of the main lobe is calculated. BW0

[0030]

[0031] Calculate the angular spacing ΔΘ between the main lobe and the adjacent main grating lobes on one side of the main lobe. msl

[0032] ΔΘ msl = (M-2)·Θ BW0 (8)

[0033] Calculate the half-power point beamwidth Θ BW3dB

[0034]

[0035] The angle θ at which the power drops by 3dB on the right side of the main lobe r3dB

[0036]

[0037] Estimate the number of pulses N required to transmit compensation pulses at the half-power point of the main lobe of the beam. 3dB

[0038]

[0039] In the formula, [·] represents rounding, and is used to calculate the beam pointing angle θ of the half-power point beam scanning compensation pulse. 3dB

[0040] θ 3dBk =k·θ r3dB k = 1, 2, ... N 3dB (12)

[0041] Preferably, step 4, obtaining the cumulative power of multiple pulses within the observation range based on the beam scanning angle of the compensation pulse, specifically includes:

[0042] The compensation pulse is transmitted according to the beam scanning angle of the compensation pulse, while keeping other distributed aperture radar parameters unchanged. If the zero-point beam scanning compensation criterion is adopted, the beam scanning angle θ of the compensation pulse is changed sequentially. nullk The compensation pulse is transmitted by k = 1, 2, ..., M-1;

[0043] If the half-power point beam scanning compensation criterion is adopted, then the beam scanning angle θ of the compensation pulse is changed sequentially. 3dBk k = 1, 2, ..., N 3dB The compensation pulse is transmitted to complete the grating lobe effect compensation of the distributed aperture radar.

[0044] A distributed aperture radar grating lobe effect compensation system, applied to the distributed aperture radar grating lobe effect compensation method, includes:

[0045] The radiation pattern acquisition module is used to acquire the radiation pattern of the distributed aperture radar antenna;

[0046] The position acquisition module is used to acquire the positions of the grating lobes and nulls near the main lobe of the distributed aperture radar antenna pattern based on the distributed aperture radar antenna pattern.

[0047] An angle acquisition module is used to acquire the beam scanning angle of the compensation pulse based on the grating lobe and null position near the main lobe of the distributed aperture radar antenna pattern and the beam scanning compensation criterion.

[0048] The power acquisition module is used to acquire the cumulative power of multiple pulses within the observation range based on the beam scanning angle of the compensation pulse.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0050] This invention provides a method and system for compensating for grating lobe effects in distributed aperture radar (DAR). It involves adjusting the beam pointing angle to transmit multiple pulses and using beam scanning to compensate for gaps between grating lobes in the DARPR antenna pattern. The specific steps are as follows: Step 1, acquiring the DARPR antenna pattern; Step 2, acquiring the grating lobe and null positions near the main lobe of the DARPR antenna pattern based on the pattern; Step 3, acquiring the beam scanning angle of the compensation pulse based on the grating lobe and null positions near the main lobe and the beam scanning compensation criteria; Step 4, acquiring the cumulative power of multiple pulses within the observation range based on the beam scanning angle of the compensation pulse. This invention is applicable to high-dynamic platforms, long baselines, small aperture numbers, and large element spacing. It has low limitations on parameters such as signal bandwidth and element position, wide applicability, and is less affected by errors. It effectively improves energy utilization and spatial search and detection efficiency, and effectively covers the detection blind zone within the visible range of a single radar. Attached Figure Description

[0051] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0052] Figure 1 A flowchart of a distributed aperture radar grating lobe effect compensation method based on multi-pulse accumulation provided in an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram of a distributed aperture radar array configuration provided in an embodiment of the present invention;

[0054] Figure 3 (a) is a sub-aperture antenna pattern provided in an embodiment of the present invention;

[0055] Figure 3 (b) is an equivalent orientation diagram of the aperture center position provided in an embodiment of the present invention;

[0056] Figure 3 (c) is a distributed aperture antenna pattern provided in an embodiment of the present invention;

[0057] Figure 4 (a) is a schematic diagram of the zero-point beam scanning compensation criterion provided in an embodiment of the present invention;

[0058] Figure 4 (b) is a schematic diagram of the half-power point beam scanning compensation criterion provided in an embodiment of the present invention;

[0059] Figure 5(a) is a schematic diagram of the zero-point beam scanning compensation method provided in an embodiment of the present invention;

[0060] Figure 5 (b) is an enlarged schematic diagram of the zero-point beam scanning compensation method provided in an embodiment of the present invention;

[0061] Figure 5 (c) is a schematic diagram of the half-power point beam scanning compensation method provided in an embodiment of the present invention;

[0062] Figure 5 (d) is an enlarged schematic diagram of the half-power point beam scanning compensation method provided in an embodiment of the present invention;

[0063] Figure 6 The diagram shows the structure of a distributed aperture radar grating lobe effect compensation system provided in an embodiment of the present invention. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0065] The present invention will now be described in further detail with reference to the accompanying drawings:

[0066] like Figure 1 As shown, this invention discloses a method for compensating for the grating lobe effect in distributed aperture radar. It involves finely adjusting the beam pointing angle to transmit multiple pulses and using beam scanning to compensate for gaps between grating lobes in the radiation pattern of the distributed aperture radar antenna. The specific steps are as follows:

[0067] Step 1: Obtain the radiation pattern of the distributed aperture radar antenna;

[0068] Step 2: Based on the distributed aperture radar antenna pattern, obtain the grating lobe and null positions near the main lobe of the distributed aperture radar antenna pattern;

[0069] Step 3: Obtain the beam scanning angle of the compensation pulse based on the grating lobe and null position near the main lobe of the distributed aperture radar antenna pattern and the beam scanning compensation criterion.

[0070] Step 4: Obtain the cumulative power of the multi-pulse in the observation range based on the beam scanning angle of the compensation pulse.

[0071] Further, step 1, obtaining the distributed aperture radar antenna pattern, specifically includes:

[0072] Establish the configuration of the distributed aperture radar system, read the parameters of the distributed aperture radar system, first calculate the radiation pattern of the antenna of a single subarray, then calculate the radiation pattern of the antenna of the subarray element, and finally calculate the radiation pattern of the distributed aperture radar antenna according to the product theorem of antenna radiation patterns.

[0073] Step 101, read the distributed aperture radar system parameters, such as... Figure 2 As shown, a one-dimensional distributed aperture radar antenna configuration is considered for simplicity. It is assumed that the array is distributed along the y-direction with the x-direction as the normal direction, and the array elements within the subarray are uniformly distributed. The distributed aperture radar system parameters are read; in this embodiment, these specifically include the operating frequency f. c =1GHz, speed of light C =3×10 8 wavelength λ = 0.3m, azimuth beam pointing angle θ d =0.0°, number of sub-aperture elements N=8, sub-aperture element spacing d=0.5λ=0.15m, number of sub-arrays M=4, sub-aperture element spacing d s =100m, so the total number of array elements is MN=32. Calculate the aperture length of the distributed aperture radar in the azimuth direction, i.e., the distribution range of the subarrays, as L. s =(M-1)d s =300m; the sub-aperture length of a single subarray, i.e., the distribution range of the subarray elements, is L = (N-1)d = 4.65m; the position of the i-th subarray is The relative position of the j-th element within a single subarray is Then the absolute position of the z = 4(i-1) + j, z = 1, ..., 32nd element in the distributed aperture radar is P. z =P Mi +P Nj ,z=1,…,32.

[0074] Step 102, as follows Figure 3 As shown in (a), to calculate the radiation pattern of a single subarray antenna, the beam pointing angle θ is first calculated. d The spatial frequency is The spatial frequency in the direction of the observation angle θ is The antenna pattern of a single subarray in the direction of the observation angle θ is then:

[0075]

[0076] Step 103, as follows Figure 3 As shown in (b), the antenna pattern of the subarray element is calculated by treating a single subarray as an array element and calculating the subarray element at the beam pointing angle θ. d The spatial frequency is The spatial frequency in the direction of the observation angle θ is The antenna pattern of the subarray element in the direction of the observation angle θ is as follows:

[0077]

[0078] Step 104, as follows Figure 3 As shown in (c), based on the principle of antenna pattern product, the distributed aperture radar antenna pattern is calculated as the product of the subarray antenna pattern and the single antenna pattern of the subarray.

[0079] F(θ)=F1(θ)F2(θ) (3)

[0080] Further, step 2: obtaining the grating lobe and null positions near the main lobe of the distributed aperture radar antenna pattern based on the distributed aperture radar antenna pattern, specifically includes:

[0081] Based on their amplitude, the grating lobes near the main lobe can be divided into main grating lobes and secondary grating lobes. First, the positions of the adjacent main grating lobes on one side of the main lobe are calculated.

[0082]

[0083] The angular range (θ) between the main lobe and the adjacent main lobe on one side of the main lobe. d ,θ major There are M-1 zeros and M-2 secondary grating lobes in the memory. Then, the positions of the zeros between the main lobe and adjacent main grating lobes are calculated, and the position of the k-th zero is...

[0084]

[0085] Next, the positions of the secondary grating lobes between the main lobe and adjacent main grating lobes are calculated. The position of the k-th secondary grating lobe is...

[0086]

[0087] Further, step 3: obtaining the beam scanning angle of the compensation pulse based on the grating lobe and null positions near the main lobe of the distributed aperture radar antenna pattern and the beam scanning compensation criterion, specifically includes:

[0088] like Figure 4 As shown, the fine-tuning beam scanning angle of the compensation pulse can be calculated based on the zero-point beam scanning criterion or the half-power point beam scanning criterion. Zero-point beam scanning requires fewer compensation pulses and shorter accumulation time, but has lower accuracy; half-power point beam scanning requires more compensation pulses and longer accumulation time, but has higher accuracy.

[0089] If the zero-point beam scanning criterion is adopted, the beam scanning angle of the compensation pulse is the position θ of each zero point between the main lobe and the adjacent main grating lobe on one side. null = [0.043, 0.086, 0.129]°.

[0090] If the half-power point beam scanning criterion is adopted, the main lobe zero-point beamwidth Θ should be calculated first. BW0 =0.086°

[0091]

[0092] Then, the angular spacing ΔΘ between the main lobe and the adjacent main grating lobes on one side of the main lobe is calculated. msl =0.172°

[0093] ΔΘ msl = (M-2)·Θ BW0 (8)

[0094] Next, calculate the half-power point beamwidth Θ. BW3dB =0.038°

[0095]

[0096] The angle θ at which the power drops by 3dB on one side (right side) of the main lobe can be obtained. r3dB =0.019°

[0097]

[0098] Further estimate the number of pulses N required to transmit compensation pulses at the half-power point of the main lobe of the beam. 3dB =9

[0099]

[0100] In the formula, [·] represents rounding. The final calculated beam pointing angle of the half-power point beam scanning compensation pulse is:

[0101] θ 3dB =[0.019,0.038,0.057,0.076,0.095,0.114,0.133,0.152]°

[0102] θ 3dBk =k·θ r3dB k = 1, 2, ... N 3dB (12)

[0103] Further, step 4: obtaining the cumulative power of multiple pulses within the observation range based on the beam scanning angle of the compensation pulse, specifically includes:

[0104] Keeping other distributed aperture radar parameters constant, the beam scanning angle θ of the compensation pulse is changed sequentially. nullk k = 1, 2, ..., M-1 or θ 3dBk k = 1, 2, ..., N 3dB Transmit pulses to complete the compensation of grating lobe effect in distributed aperture radar.

[0105] like Figure 5 As shown, the cumulative power of multiple pulses within the observation range is calculated based on the beam scanning angle of the compensation pulse. The beam scanning angle of the compensation pulse is changed sequentially, and the corresponding distributed aperture radar antenna pattern F is calculated. k (θ), k=1,2,…, sum the radiation patterns corresponding to all beam scanning angles to obtain the compensated distributed aperture radar antenna radiation pattern. By using beam scanning compensation, an antenna pattern with a wide main lobe beam was obtained. If the null-point beam scanning compensation method is used, the required accumulation time is shorter due to the smaller number of compensation pulses, but the compensation accuracy is lower. If the half-power point beam scanning compensation method is used, the required accumulation time is longer due to the larger number of compensation pulses, but the compensation accuracy is higher.

[0106] like Figure 6 As shown, a distributed aperture radar grating lobe effect compensation system 12, applied to the distributed aperture radar grating lobe effect compensation method based on multi-pulse accumulation, includes:

[0107] The radiation pattern acquisition module 1201 is used to acquire the radiation pattern of the distributed aperture radar antenna.

[0108] The position acquisition module 1202 is used to acquire the grating lobe and null position near the main lobe of the distributed aperture radar antenna pattern based on the distributed aperture radar antenna pattern.

[0109] Angle acquisition module 1203 is used to acquire the beam scanning angle of the compensation pulse based on the grating lobe and null position near the main lobe of the distributed aperture radar antenna pattern and the beam scanning compensation criterion.

[0110] The power acquisition module 1204 is used to acquire the cumulative power of multiple pulses within the observation range based on the beam scanning angle of the compensation pulse.

[0111] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a method and system for compensating for the grating lobe effect of distributed aperture radar. Multiple pulses are emitted by adjusting the beam pointing angle, and beam scanning is used to compensate for the gaps between grating lobes in the antenna pattern of the distributed aperture radar. The specific steps are: Step 1, obtaining the antenna pattern of the distributed aperture radar; Step 2, obtaining the grating lobe and null positions near the main lobe of the distributed aperture radar antenna pattern based on the antenna pattern; Step 3, obtaining the beam scanning angle of the compensation pulse based on the grating lobe and null positions near the main lobe of the distributed aperture radar antenna pattern and the beam scanning compensation criterion; Step 4, obtaining the cumulative power of multiple pulses within the observation range based on the beam scanning angle of the compensation pulse. The present invention is applicable to high dynamic platforms, long baselines, small number of apertures, and large element spacing. It has low limitations on parameters such as signal bandwidth and element position, wide applicability, and is less affected by errors. It effectively improves energy utilization and space search and detection efficiency, and effectively covers the detection blind zone within the visible range of a single radar.

[0112] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for compensating for the grating lobe effect in distributed aperture radar, characterized in that, Adjust the beam pointing angle to transmit multiple pulses. The specific steps for compensating for gaps between grating lobes in the antenna pattern of the distributed aperture radar using beam scanning are as follows: Step 1: Obtain the radiation pattern of the distributed aperture radar antenna; Step 2: Based on the distributed aperture radar antenna pattern, obtain the area near the main lobe of the distributed aperture radar antenna pattern. Grid lobe and zero point position; Step 3: Obtain the beam scanning angle of the compensation pulse based on the grating lobe and null position near the main lobe of the distributed aperture radar antenna pattern and the beam scanning compensation criterion. Step 4: Obtain the cumulative power of the multi-pulse in the observation range based on the beam scanning angle of the compensation pulse; Step 3, obtaining the beam scanning angle of the compensation pulse based on the grating lobe and null positions near the main lobe of the distributed aperture radar antenna pattern and the beam scanning compensation criterion, specifically includes: The beam scanning angle of the compensation pulse is calculated according to the zero-point beam scanning compensation criterion or the half-power point beam scanning compensation criterion. If the zero-point beam scanning compensation criterion is adopted, the beam scanning angle of the compensation pulse is the position of each zero point between the main lobe and the adjacent main grating lobe on one side. ; If the half-power point beam scanning compensation criterion is used, the main lobe zero-point beamwidth is calculated. : （7） Then, the angular spacing between the main lobe and the adjacent main grating lobes on one side of the main lobe is calculated. : （8） Calculate the half-power point beamwidth : （9） The power on the main lobe side decreased. Angle position : （10） Estimate the number of pulses required to transmit compensation pulses at the half-power point of the main lobe of the beam. : （11） In the formula Indicates rounding down. For wavelength, The azimuth beam pointing angle. The number of subarrays. The inter-array spacing of the subarrays; calculate the beam pointing angle of the half-power point beam scanning compensation pulse. : （12）。 2. The distributed aperture radar grating lobe effect compensation method as described in claim 1, characterized in that, Step 1, obtaining the distributed aperture radar antenna radiation pattern, specifically includes: Step 101: Read the parameters of the distributed aperture radar system, assuming the array is... The direction is the normal direction, along Directional distribution, uniform subarray distribution, uniform distribution of array elements within the subarray, and the operating frequency of the distributed aperture radar is [missing information]. , wavelength is The azimuth beam pointing angle is The number of subarrays is The inter-array spacing of the subarrays is The number of array elements in the subarray is The spacing between the array elements within the subarray is The total number of all array elements is obtained as follows: ; Calculate the aperture length of the distributed aperture radar in the azimuth direction, i.e., the distribution range of the subarray. The sub-aperture length of a single subarray, i.e., the distribution range of the array elements within the subarray, is... ;No. The positions of the sub-arrays are: ; within a single subarray The relative positions of the array elements are Then the distributed aperture radar within the first... The absolute position of each array element is ; Step 102: Calculate the radiation pattern of a single subarray antenna and calculate the beam pointing angle. The spatial frequency is Observation angle The spatial frequency of the direction is Then a single subarray will be observed from the following angle. The antenna pattern in the direction is as follows: （1） Step 103: Calculate the antenna pattern of the subarray element. Treat each subarray as an array element and calculate the antenna pattern of the subarray element at the beam pointing angle. The spatial frequency is The observation angle The spatial frequency of the direction is Then the subarray element at the observation angle The antenna pattern in the direction is as follows: （2） Step 104: Calculate the distributed aperture radar antenna pattern according to the antenna pattern product principle. The distributed aperture radar antenna pattern is the product of the subarray antenna pattern and the single antenna pattern of the subarray. （3）。 3. The distributed aperture radar grating lobe effect compensation method as described in claim 2, characterized in that, Step 2, which involves obtaining the grating lobe and null positions near the main lobe of the distributed aperture radar antenna pattern based on the pattern, specifically includes: Based on different amplitudes, the grating lobes near the main lobe are divided into main grating lobes and secondary grating lobes. First, the adjacent grating lobes on one side of the main lobe are calculated. The position of the main grating lobe is: （4） The angular range between the main lobe and the adjacent main grating lobes on one side of the main lobe. Memory exists One zero point, The first sub-lobes are calculated; then the positions of the zeros between the main lobe and adjacent main grating lobes are calculated, and the second sub-lobes are... The positions of the zero points are: （5） Next, the positions of the secondary grating lobes between the main lobe and adjacent main grating lobes are calculated. The positions of the sub-lobes are: （6）。 4. The distributed aperture radar grating lobe effect compensation method as described in claim 1, characterized in that, Step 4, obtaining the cumulative power of multiple pulses within the observation range based on the beam scanning angle of the compensation pulse, specifically includes: The compensation pulse is transmitted according to the beam scanning angle of the compensation pulse, while keeping other distributed aperture radar parameters unchanged. If the zero-point beam scanning compensation criterion is adopted, the beam scanning angle of the compensation pulse is changed sequentially. Transmit compensation pulse; If the half-power point beam scanning compensation criterion is adopted, then the beam scanning angle of the compensation pulse is changed sequentially. The compensation pulse is emitted to complete the compensation for the distributed aperture radar grating lobe effect.

5. A distributed aperture radar grating lobe effect compensation system, applied to the distributed aperture radar grating lobe effect compensation method according to any one of claims 1 to 4, characterized in that, include: The radiation pattern acquisition module is used to acquire the radiation pattern of the distributed aperture radar antenna; The position acquisition module is used to acquire the positions of the grating lobes and nulls near the main lobe of the distributed aperture radar antenna pattern based on the distributed aperture radar antenna pattern. An angle acquisition module is used to acquire the beam scanning angle of the compensation pulse based on the grating lobe and null position near the main lobe of the distributed aperture radar antenna pattern and the beam scanning compensation criterion. The power acquisition module is used to acquire the cumulative power of multiple pulses within the observation range based on the beam scanning angle of the compensation pulse.

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