Method for direction finding of multi-beam single pulse signal by using amplitude comparison direction finder

Abstract

The application discloses a kind of to utilize the method for measuring direction of multi-beam single pulse signal of amplitude comparison direction-finding table, belong to electronic reconnaissance field.First, after antenna unit group array, utilize automatic test equipment control turntable to the antenna array all channel is measured antenna directional diagram;Second, since each microwave channel is relatively independent, utilize the amplitude correction that is completed to microwave front end and frequency conversion channel simultaneously by the self-checking source designed in microwave front end;Third, extract the Nth antenna directional diagram data, respectively at N-1 and N+1 antenna directional diagram data subtraction, obtain the amplitude comparison direction-finding table data of beam N, and load into digital signal processing;Finally, according to the result of multi-beam digital channelization detection, form the full pulse information of beam N pulse signal, simultaneously single pulse guide N-1 and N+1 beam carries out amplitude measurement, calculates out the amplitude difference of single pulse signal in beam N and beam N-1 or beam N+1, utilizes amplitude difference to look up corresponding amplitude comparison direction-finding table, obtains single pulse incident signal direction-finding result.

Description

Technical Field

[0001] This invention belongs to the field of electronic reconnaissance, and in particular, it is a method for direction finding of multi-beam single-pulse signals using an amplitude comparison direction finding table. Background Technology

[0002] With the continuous development of software-defined radio technology and the increasing complexity of the electromagnetic environment, electronic warfare plays an increasingly important role in modern warfare, especially placing higher demands on the performance of direction-finding systems. The accuracy of single-pulse passive direction finding is one of the most reliable key indicators in electronic reconnaissance technology, directly affecting the judgment of target azimuth information. Target azimuth information is a crucial parameter for functions such as signal sorting, guidance jamming, and radiation source localization. Currently commonly used single-pulse direction finding methods include amplitude comparison direction finding, interferometer direction finding, and amplitude / phase comparison direction finding.

[0003] Interferometer direction finding offers advantages such as high accuracy, low size, weight, and cost. However, single-baseline interferometers suffer from phase ambiguity, requiring multiple baselines to be combined for deambiguity resolution. It also demands high phase consistency between channels and requires shared spatial visibility among the arrayed antennas. Amplitude-phase comparison direction finding offers similar advantages, but like interferometer direction finding, it requires shared spatial visibility among the arrayed antennas, which highlights the trade-off between antenna gain and coverage area. Compared to interferometer and amplitude-phase comparison direction finding, amplitude-phase comparison direction finding, under the same coverage area conditions, features simpler structure, more stable performance, and stronger adaptability to complex environments. Furthermore, amplitude-phase comparison direction finding can significantly increase antenna gain, thereby increasing detection range and enabling beyond-line-of-sight reconnaissance capabilities. It also possesses strong anti-interference (multipath effect) capabilities and multi-beam simultaneous processing capabilities.

[0004] In his article "Comparison of Amplitude Comparison and Direction Finding Accuracy of Array Single Pulse and Interferometer," Fan Zhongliang focused on the conventional amplitude comparison direction finding method. This method requires correction for antenna processing distortion, mechanical installation errors, beam gain inconsistencies, beam normal deviation, and beamwidth variations. However, this method significantly increases the workload of system correction and is also detrimental to later maintenance and upgrades. Summary of the Invention

[0005] This invention proposes a direction finding method for multi-beam monopulse signals using an amplitude comparison direction finding table. Conventional amplitude comparison direction finding methods require corrections for antenna fabrication distortion, mechanical installation errors, beam gain inconsistencies, beam normal deviations, and beamwidth variations, significantly increasing the system calibration workload and hindering future maintenance and upgrades. After antenna elements are arrayed, antenna pattern measurements are performed individually for all channels of the antenna array, and amplitude corrections are performed individually for all microwave front-ends and frequency conversion channels. An amplitude comparison direction finding table is generated using the difference between the measured patterns of a channel and its adjacent channels and loaded into digital signal processing. Digital signal processing performs amplitude comparison direction finding lookups based on the amplitude differences between channels in the detection data, thereby solving the aforementioned problems.

[0006] The technical solution for achieving the present invention is as follows: a method for direction finding of multi-beam monopulse signals using an amplitude comparison direction finding table, comprising the following steps:

[0007] Step 1: Measure the antenna patterns of all channels, and simultaneously perform amplitude correction on the microwave front-end and frequency conversion channels:

[0008] After the antenna elements are arrayed, the control turntable measures the antenna pattern of all channels of the antenna array; the antenna pattern data of K channels and L frequency points are stored as K×L data files in dat format, and the above dat format data files are named according to the channel + frequency point, and then proceed to step 2; at the same time, the amplitude of the microwave front end and the frequency conversion channel is corrected, and then proceed to step 4.

[0009] Step 2: Generate the left and right beam difference values ​​based on the antenna pattern data:

[0010] Use Matlab to extract the antenna pattern data files of all channels for each frequency point. Subtract the antenna pattern data of the beam channel from the antenna pattern data of its adjacent left and right channels to obtain the difference between all beam channels and the left and right beams, and then proceed to step 3.

[0011] Step 3: Generate a beam ratio direction finding table for all beams based on the difference between adjacent beams.

[0012] Use Matlab to find the linear region of the difference between adjacent beams and extract the effective data segment for generating the amplitude ratio direction finding table; fit the angle according to the amplitude resolution to generate the amplitude ratio direction finding table, and proceed to step 6.

[0013] Step 4: Use the self-test source designed in the microwave front end to simultaneously perform amplitude calibration on the microwave front end and the frequency conversion channel, generate a channel amplitude calibration table, and proceed to step 5.

[0014] Step 5: According to the channel amplitude calibration table, calibrate the beam amplitude and left and right beam amplitudes obtained from the digital channelization detection to obtain the difference between the left and right beam amplitudes:

[0015] Based on the multi-beam digital channelization detection results, the full pulse information of the beam N pulse signal is formed. At the same time, the amplitude of beams N-1 and N+1 is measured by single pulse. The beam amplitude and the amplitude of the left and right beams are calibrated by using the channel amplitude calibration table to obtain the amplitude difference between the left and right beams. Proceed to step 6.

[0016] Step 6: Use the amplitude difference between the left and right beams to look up the amplitude comparison direction finding table to obtain the direction finding result of the single-pulse incident signal:

[0017] The amplitude difference of the single-pulse signal between beam N and beam N-1 or beam N+1 is calculated. The corresponding amplitude ratio direction finding table is then looked up using the single-pulse frequency information and amplitude difference to obtain the direction finding result of the single-pulse incident signal.

[0018] Compared with the prior art, the significant advantages of this invention are:

[0019] 1) By measuring the beam pattern of each antenna array element after arraying, the amplitude of the microwave front-end and frequency conversion channel can be independently corrected, which reduces the workload of conventional amplitude comparison and direction finding methods and is conducive to equipment maintenance and upgrading.

[0020] 2) The amplitude ratio direction finding table of the current beam can be extracted by subtracting the radiation pattern data of the antennas of the current beam from those of the left and right adjacent beams.

[0021] 3) The amplitude of the left and right beams is guided by the full pulse information of the current beam and the amplitude difference between the current beam and the left and right beams is calculated. The direction finding result of the single pulse incident signal can be obtained by looking up the corresponding amplitude ratio direction finding table using the amplitude difference. Attached Figure Description

[0022] Figure 1 This is a flowchart of the direction finding method for multi-beam monopulse signals using an amplitude comparison direction finding table according to the present invention. Detailed Implementation

[0023] 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 a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] The technical solutions of the various embodiments of the present invention can be combined with each other, but only if they can be implemented by those skilled in the art. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0025] The following section will further introduce the specific implementation method, as well as the technical difficulties and inventive points of this invention, using this design example as an example.

[0026] The method for direction finding of multi-beam monopulse signals using an amplitude comparison direction finding table as described in this invention first involves assembling the antenna elements and then using an automated testing device to control a turntable to measure the antenna pattern of all channels in the antenna array. Since each microwave channel is relatively independent, a self-test source designed in the microwave front-end is used to simultaneously perform amplitude correction on both the microwave front-end and the frequency conversion channel. Then, the Nth antenna pattern data is extracted and subtracted from the N-1 and N+1 antenna pattern data to obtain the amplitude comparison direction finding table data for beam N, which is then loaded into digital signal processing. Finally, based on the multi-beam digital channelization detection results, the full pulse information of the beam N pulse signal is formed. Simultaneously, the monopulse guides the amplitude measurements of beams N-1 and N+1, calculating the amplitude difference between beam N and beams N-1 or N+1. This amplitude difference is then used to look up the corresponding amplitude comparison direction finding table to obtain the direction finding result of the monopulse incident signal.

[0027] This invention independently corrects the amplitude of the microwave front-end and frequency conversion channel by measuring the beam pattern of each antenna array element after arraying. This reduces the workload of conventional amplitude comparison direction finding methods and facilitates equipment maintenance and upgrades. By subtracting the antenna pattern data of the current beam from those of the left and right adjacent beams, the amplitude comparison direction finding table of the current beam is extracted. The full pulse information of the current beam guides the amplitude measurement of the left and right beams and calculates the amplitude difference between the current beam and the left and right beams. By using the amplitude difference to look up the corresponding amplitude comparison direction finding table, the direction finding result of the single pulse incident signal can be obtained.

[0028] Combination Figure 1 A method for direction finding of multi-beam monopulse signals using an amplitude comparison direction finding table includes the following steps:

[0029] Step 1: After the antenna elements are assembled, control the turntable to measure the antenna pattern of all channels of the antenna array. Store the antenna pattern data of K channels and L frequencies into K×L .dat format data files, and name these .dat format data files according to the channel + frequency. Proceed to Step 2. Simultaneously, perform amplitude correction on the microwave front-end and frequency conversion channels, then proceed to Step 4.

[0030] Step 2: Read the antenna pattern data, generate the left and right beam differences, and use Matlab software to extract the antenna pattern data files of all channels at the current frequency point one by one. Subtract the antenna pattern data of all beam channels from the adjacent left and right channel antenna pattern data to obtain the left and right beam differences of all beam channels.

[0031] Step 21: Select a frequency point and use Matlab to read the antenna pattern data file of all channels at the current frequency point.

[0032] Step 22: Extract antenna pattern data for the left near sidelobe, m direction-finding beams, and right near sidelobe.

[0033] Step 23: Subtract the antenna pattern data of each of the m direction-finding beams from the antenna pattern data of the left and right beams respectively to obtain the difference between the m direction-finding beams and the left and right beams.

[0034] Step 3: Generate an amplitude ratio direction finding table for all beams based on the differences between adjacent beams. Use Matlab to find the linear region of the differences between adjacent beams and extract the effective data segments for generating the amplitude ratio direction finding table. Fit the angles according to the amplitude resolution to generate the amplitude ratio direction finding table.

[0035] Step 31: Draw the direction difference patterns of the m direction-finding beams and the left and right beams at the current frequency.

[0036] Step 32: Find the linear regions in the m left and right difference direction patterns respectively, and manually extract the direction coordinates of the three points: the intersection point a of the left and right difference curves, the minimum point b of the left difference curve, and the minimum point c of the right difference curve in the linear region.

[0037] Step 33: Calculate the difference between the coordinates of point a in the left-right difference direction diagram and the coordinates of point b in the right-right difference direction diagram. Calculate the difference between the coordinates of point c in the left-right difference direction diagram and the coordinates of point a in the right-right difference direction diagram. For each direction-finding beam, select the segment with the smaller coordinate difference as the angle range for the left-right beam amplitude comparison.

[0038] Step 34: Extract the effective data segment of the left and right beam difference based on the angle range of the left and right beam amplitude ratio of each direction-finding beam.

[0039] Step 35: Based on the amplitude resolution, perform linear interpolation fitting on the effective data segments of the left and right beam differences for each direction-finding beam.

[0040] Step 36: Extract the angle values ​​corresponding to the portion of the fitted amplitude difference data that are greater than 0 as valid data for the amplitude comparison direction finding table, and use the maximum and minimum values ​​of the corresponding angles to fill the left and right direction finding tables of the beam respectively, to ensure that the amplitude comparison direction finding table is continuous within the traversal range of the amplitude difference.

[0041] Step 37: Generate the amplitude ratio direction finding table for all direction finding beams at the current frequency in order from left to right.

[0042] Step 38: Select the next frequency point and repeat steps 31 to 37 until the amplitude comparison direction finding table for all frequencies is completed.

[0043] Step 39: Convert all amplitude and direction finding table data into two's complement code to generate a COE format file.

[0044] Step 4: Use the self-test source designed in the microwave front end to simultaneously perform amplitude calibration on the microwave front end and the frequency conversion channel, and generate a channel amplitude calibration table.

[0045] Step 41: Select P frequency points within the measurement bandwidth according to the fixed frequency step, and use the self-test source designed in the microwave front end to measure the amplitude of all channels of the P frequency points within the bandwidth.

[0046] Step 42: Using the amplitude of direction-finding beam 1 as a reference, obtain the amplitude difference between other beams and direction-finding beam 1, and generate an amplitude calibration table for P frequency points within the bandwidth of all beams.

[0047] Step 5: According to the channel amplitude calibration table, calibrate the beam amplitude and the left and right beam amplitudes obtained from the digital channelization detection to obtain the difference between the left and right beam amplitudes.

[0048] Step 51: Based on the multi-beam digital channelization detection results, form the full pulse information of the beam N pulse signal.

[0049] Step 52: The beam N-pulse signal guides the left and right beams and sidelobe beams to perform amplitude measurement, and the beam amplitude and the amplitude of the left and right beams are calibrated using a channel amplitude calibration table.

[0050] Step 53: Based on the amplitude relationship between the beam N-pulse signal, the left and right beams, and the sidelobe beams, eliminate false information in the beam N-pulse signal.

[0051] Step 54: Calculate the amplitude difference of the single pulse signal between beam N and beam N-1 or beam N+1 to obtain the amplitude difference value between the left and right beams.

[0052] Step 6: Use the single pulse frequency information and the amplitude difference between the left and right beams to look up the amplitude ratio direction finding table and obtain the direction finding result of the single pulse incident signal.

[0053] Step 61: Locate the amplitude comparison direction finding table for the corresponding frequency band based on the single pulse signal frequency information.

[0054] Step 62: Based on the amplitude difference between the left and right beams of the single-pulse signal, find the amplitude ratio direction finding table for the corresponding frequency band to obtain the direction finding result of the single-pulse incident signal.

[0055] The above method enables the extraction of amplitude comparison direction finding tables and the acquisition of single-pulse direction finding results in multi-beam amplitude comparison direction finding systems. This reduces the workload of conventional amplitude comparison direction finding methods, facilitates equipment maintenance and upgrades, and helps improve the equipment's beyond-line-of-sight detection capabilities.

[0056] Example:

[0057] Suppose an amplitude comparison direction finding system has three direction finding beams, one left near-side lobe, and one right near-side lobe, with a detection frequency range of 300MHz to 2000MHz. The signal is incident from beam 1. This amplitude comparison direction finding system follows the direction finding method for multi-beam single-pulse signals using an amplitude comparison direction finding table disclosed in this patent. The specific steps are as follows:

[0058] Step 1: After the antenna elements are assembled, select 171 frequency points within the measurement bandwidth in 10MHz frequency steps, and control the turntable to measure the antenna pattern of all channels of the antenna array. Store the antenna pattern data of all 5 channels and 171 frequency points as 5×171 .dat format data files, and name the .dat format data files according to the channel + frequency point format, then proceed to Step 2. At the same time, perform amplitude calibration on the microwave front end and frequency conversion channel, then proceed to Step 4.

[0059] Step 2: Read the antenna pattern data, generate the left and right beam differences, and use Matlab software to extract the antenna pattern data files of all channels at the current frequency point one by one. Subtract the antenna pattern data of all beam channels from the adjacent left and right channel antenna pattern data to obtain the left and right beam differences of all beam channels.

[0060] Step 21: Select a frequency point and use Matlab software to read the antenna pattern data file of all channels at the current frequency point.

[0061] Step 22: Extract antenna pattern data for the left near sidelobe, the three direction-finding beams, and the right near sidelobe.

[0062] Step 23: Subtract the antenna pattern data of the left and right beams from the three direction-finding beams respectively to obtain the difference data between the three direction-finding beams and the left and right beams.

[0063] Step 3: Generate an amplitude ratio direction finding table for all beams based on the differences between adjacent beams. Use Matlab to find the linear region of the differences between adjacent beams and extract the effective data segments for generating the amplitude ratio direction finding table. Fit the angles according to the amplitude resolution to generate the amplitude ratio direction finding table.

[0064] Step 31: Draw the direction difference patterns of the three direction-finding beams and the left and right beams at the current frequency.

[0065] Step 32: Locate the linear regions in the three left and right difference direction maps respectively, and manually extract the direction coordinates of the three points: the intersection point a of the left and right difference curves, the minimum point b of the left difference curve, and the minimum point c of the right difference curve in the linear region.

[0066] Step 33: Calculate the difference between the coordinates of point a in the left-right difference direction diagram and the coordinates of point b in the right-right difference direction diagram. Calculate the difference between the coordinates of point c in the left-right difference direction diagram and the coordinates of point a in the right-right difference direction diagram. For each direction-finding beam, select the segment with the smaller coordinate difference as the angle range for the left-right beam amplitude comparison.

[0067] Step 34: Extract the effective data segment of the left and right beam difference based on the angle range of the left and right beam amplitude ratio of each direction-finding beam.

[0068] Step 35: Based on the amplitude resolution, perform linear interpolation fitting on the effective data segments of the left and right beam differences for each direction-finding beam.

[0069] Step 36: Extract the angle values ​​corresponding to the portion of the fitted amplitude difference data that are greater than 0 as valid data for the amplitude comparison direction finding table, and use the maximum and minimum values ​​of the corresponding angles to fill the left and right direction finding tables of the beam respectively, to ensure that the amplitude comparison direction finding table is continuous within the traversal range of the amplitude difference.

[0070] Step 37: Generate the amplitude ratio direction finding table for all direction finding beams at the current frequency in order from left to right.

[0071] Step 38: Select the next frequency point and repeat steps 31 to 37 until the amplitude comparison direction finding table for all frequencies is completed.

[0072] Step 39: Convert all amplitude and direction finding table data into two's complement, generate a COE format file, and download this file to the signal processing FPGA software.

[0073] Step 4: Use the self-test source designed in the microwave front end to simultaneously perform amplitude calibration on the microwave front end and the frequency conversion channel, and generate a channel amplitude calibration table.

[0074] Step 41: Select 171 frequency points within the measurement bandwidth in 10MHz frequency steps, and use the self-test source designed in the microwave front end to measure the amplitude of all channels of the 171 frequency points within the bandwidth.

[0075] Step 42: Using the amplitude of direction-finding beam 1 as a reference, obtain the amplitude difference between other beams and direction-finding beam 1, and generate an amplitude calibration table for 171 frequency points within the bandwidth of all beams.

[0076] Step 43: Download the amplitude calibration table to the beam digital channelization detection FPGA program.

[0077] Step 5: According to the channel amplitude calibration table, calibrate the beam amplitude and the left and right beam amplitudes obtained from the digital channelization detection to obtain the difference between the left and right beam amplitudes.

[0078] Step 51: Based on the multi-beam digital channelization detection results, form the full pulse information of the beam 1 pulse signal.

[0079] Step 52: The beam 1 pulse signal guides the left and right beams and sidelobe beams to perform amplitude measurement, and the beam amplitude and the amplitude of the left and right beams are calibrated using the channel amplitude calibration table.

[0080] Step 53: Based on the amplitude relationship between the beam 1 pulse signal, the left and right beams and the side lobe beams, eliminate false information in the beam 1 pulse signal.

[0081] Step 54: The beam full pulse information after amplitude comparison and false detection is transmitted to the signal processing FPGA software in real time via a high-speed serial port.

[0082] Step 55: Calculate the amplitude difference of the single pulse signal between beam 1 and the left near sidelobe or beam 2 to obtain the amplitude difference value between the left and right beams.

[0083] Step 6: Use the single pulse frequency information and the amplitude difference between the left and right beams to look up the amplitude ratio direction finding table and obtain the direction finding result of the single pulse incident signal.

[0084] Step 61: Locate the amplitude comparison direction finding table for the corresponding frequency band based on the single pulse signal frequency information.

[0085] Step 62: Based on the amplitude difference between the left and right beams of the single-pulse signal, find the amplitude ratio direction finding table for the corresponding frequency band to obtain the direction finding result of the single-pulse incident signal.

Claims

1. A method for direction finding of multi-beam monopulse signals using an amplitude comparison direction finding table, characterized in that, Includes the following steps: Step 1: Measure the antenna patterns of all channels, and simultaneously perform amplitude correction on the microwave front-end and frequency conversion channels: After the antenna elements are arrayed, the control turntable measures the antenna pattern of all channels of the antenna array; the antenna pattern data of K channels and L frequency points are stored as K×L data files in dat format, and the above dat format data files are named according to the channel + frequency point, and then proceed to step 2; at the same time, the amplitude of the microwave front end and the frequency conversion channel is calibrated, and then proceed to step 4. Step 2: Generate the left and right beam difference values ​​based on the antenna pattern data: Use Matlab to extract the antenna pattern data files of all channels for each frequency point, subtract the antenna pattern data of the beam channel from the antenna pattern data of its adjacent left and right channels to obtain the difference between all beam channels and the left and right beams, and then proceed to step 3. Step 3: Generate a beam ratio direction finding table for all beams based on the difference between adjacent beams. Using Matlab, the linear region of the difference between adjacent beams is found, and the effective data segment for generating the amplitude ratio direction finding table is extracted. Angles are fitted based on the amplitude resolution to generate the amplitude ratio direction finding table, as detailed below: Step 31: Draw the direction difference patterns of the m direction-finding beams and the left and right beams at the current frequency. Step 32: Find the linear regions in the m left and right difference direction patterns respectively, and manually extract the direction coordinates of the three points: the intersection point a of the left and right difference curves, the minimum point b of the left difference curve, and the minimum point c of the right difference curve in the linear region. Step 33: Calculate the difference between the coordinates of point a in the left and right difference direction diagrams and the coordinates of point b in the right and left difference direction diagrams, and calculate the difference between the coordinates of point c in the left and right difference direction diagrams and the coordinates of point a in the left and right difference direction diagrams. For each direction finding beam, select the segment with the smaller coordinate difference as the angle range for the amplitude comparison of the left and right beams. Step 34: Extract the effective data segment of the left and right beam difference based on the angle range of the left and right beam amplitude ratio of each direction-finding beam; Step 35: Based on the amplitude resolution, perform linear interpolation fitting on the effective data segments of the left and right beam differences for each direction-finding beam. Step 36: Extract the angle values ​​corresponding to the portion of the fitted amplitude difference data that are greater than 0 as valid data for the amplitude comparison direction finding table, and fill the left and right direction finding tables of the beam with the maximum and minimum values ​​of the corresponding angles, respectively, to ensure that the amplitude comparison direction finding table is continuous within the traversal range of the amplitude difference. Step 37: Generate an amplitude comparison direction finding table for all direction finding beams at the current frequency in order from left to right; Step 38: Select the next frequency point and repeat steps 31 to 37 until the amplitude comparison direction finding table for all frequencies is completed; Step 39: Convert all amplitude and direction finding table data into two's complement code to generate a COE format file; Proceed to step 6; Step 4: Use the self-test source designed in the microwave front end to simultaneously perform amplitude calibration on the microwave front end and the frequency conversion channel, generate a channel amplitude calibration table, and proceed to step 5. Step 5: According to the channel amplitude calibration table, calibrate the beam amplitude and left and right beam amplitudes obtained from the digital channelization detection to obtain the difference between the left and right beam amplitudes: Based on the multi-beam digital channelization detection results, the full pulse information of the beam N pulse signal is formed. At the same time, the single pulse guides the N-1 and N+1 beams to perform amplitude measurement. The beam amplitude and the amplitude of the left and right beams are calibrated using the channel amplitude calibration table to obtain the amplitude difference between the left and right beams. Proceed to step 6. Step 6: Use the amplitude difference between the left and right beams to look up the amplitude comparison direction finding table to obtain the direction finding result of the single-pulse incident signal: The amplitude difference of the single-pulse signal between beam N and beam N-1 or beam N+1 is calculated. The corresponding amplitude ratio direction finding table is then looked up using the single-pulse frequency information and amplitude difference to obtain the direction finding result of the single-pulse incident signal.

2. The method for direction finding of multi-beam monopulse signals using an amplitude comparison direction finding table according to claim 1, characterized in that, In step 2, the left and right beam differences are generated based on the antenna pattern data, specifically as follows: Step 21: Select a frequency point and use Matlab to read the antenna pattern data file of all channels at the current frequency point; Step 22: Extract antenna pattern data for the left near sidelobe, m direction-finding beams, and right near sidelobe; Step 23: Subtract the antenna pattern data of each of the m direction-finding beams from the antenna pattern data of the left and right beams respectively to obtain the difference between the m direction-finding beams and the left and right beams.

3. The method for direction finding of multi-beam monopulse signals using an amplitude comparison direction finding table according to claim 1, characterized in that, In step 4, the self-test source designed in the microwave front-end is used to simultaneously perform amplitude calibration on both the microwave front-end and the frequency conversion channel, generating a channel amplitude calibration table, specifically as follows: Step 41: Select P frequency points within the measurement bandwidth according to the fixed frequency step, and use the self-test source designed in the microwave front end to measure the amplitude of all channels of the P frequency points within the bandwidth; Step 42: Using the amplitude of direction-finding beam 1 as a reference, obtain the amplitude difference between other beams and direction-finding beam 1, and generate an amplitude calibration table for P frequency points within the bandwidth of all beams.

4. The method for direction finding of multi-beam monopulse signals using an amplitude comparison direction finding table according to claim 1, characterized in that, In step 5, the beam amplitude and the left and right beam amplitudes obtained from the digital channelization detection are calibrated according to the channel amplitude calibration table to obtain the difference between the left and right beam amplitudes, specifically: Step 51: Based on the multi-beam digital channelization detection results, form the full pulse information of the beam N-pulse signal; Step 52: The beam N-pulse signal guides the left and right beams and sidelobe beams to perform amplitude measurement, and the beam amplitude and the amplitude of the left and right beams are calibrated using the channel amplitude calibration table; Step 53: Based on the amplitude relationship between the beam N-pulse signal, the left and right beams, and the sidelobe beams, eliminate false information in the beam N-pulse signal; Step 54: Calculate the amplitude difference of the single pulse signal between beam N and beam N-1 or beam N+1 to obtain the amplitude difference value between the left and right beams.

5. The method for direction finding of multi-beam monopulse signals using an amplitude comparison direction finding table according to claim 1, characterized in that, Step 6 uses the single-pulse frequency information and the amplitude difference between the left and right beams to look up the amplitude comparison direction finding table and obtain the direction finding result of the single-pulse incident signal, specifically: Step 61: Locate the amplitude comparison and direction finding table for the corresponding frequency band based on the single pulse signal frequency information; Step 62: Based on the amplitude difference between the left and right beams of the single-pulse signal, find the amplitude ratio direction finding table for the corresponding frequency band to obtain the direction finding result of the single-pulse incident signal.

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