RCS test echo calibration method based on directional filtering and related system

Abstract

The invention belongs to the field of communication, and discloses an RCS test echo calibration method based on directional filtering and a related system, which ensure that the relative position of a test environment and an antenna is accurately calibrated by placing a target and a positioning ball at specified positions and combining a scanning angle and the number of angles of a radar, thereby improving the accuracy of a measurement result. The target is scanned for multiple times according to the scanning angle and number, different angles and directions can be covered, and comprehensive acquisition of echo data is ensured. According to the method, the initial distance index is obtained through the echo data, key data can be effectively screened out, the complexity of subsequent data processing is reduced, and the processing efficiency is improved. By adopting the directional filtering method, noise interference can be effectively reduced, the target signal is enhanced, the phase calibration factor is more accurate, and the subsequent data calibration effect is further improved.

Description

Technical Field

[0001] The invention belongs to the field of communications, and in particular relates to an RCS test echo calibration method based on directional filtering and a related system. Background Art

[0002] In the test of RCS (Rich Communication Service) of converged communication, the traditional method is that the radar antenna is always aimed at the center of the target, and the relative trajectory between the antenna and the target must be based on the center of the target as the origin and the target center to the antenna position as the standard arc, and it must be uniform motion. Based on such a test environment, the measured RCS value can be accurate. Based on this test situation, in some special test environments, if the target must remain stationary during the test and the radar moves in a circle, it is basically impossible to require the trajectory of the radar movement to be a standard arc without any error. Therefore, during the movement, the actual position of the radar antenna deviates from the ideal position to a certain extent, and this deviation will cause a serious phase error between the actual echo of the target and the standard echo. This error will distort the RCS test results. Summary of the invention

[0003] The purpose of the present invention is to overcome the disadvantage that the actual echo of the target and the standard echo present a serious phase error due to the deviation between the actual position and the ideal position of the radar antenna, and to provide an RCS test echo calibration method based on directional filtering and a related system.

[0004] In order to achieve the above object, the present invention adopts the following technical solution: In a first aspect, the present invention provides an RCS test echo calibration method based on directional filtering, comprising the following steps: Calibrate the test environment; The target is placed in the test environment, and the positioning ball is placed at the desired position in the test environment according to the target size; According to the test requirements, preset the radar's scanning angle and number of scanning angles; Scan the target according to the scanning angle and the number of scanning angles, and receive the echo data after scanning; According to the echo data, the initial distance index is obtained; Directional filtering method is used to process echo data based on the initial distance index to obtain the phase calibration factor; Based on the phase calibration factor, the echo data is subjected to echo calibration and background cancellation to obtain the final echo signal.

[0005] A further improvement of the present invention is that the specific method for calibrating the test environment is as follows: Place the target at the location to be tested in the test environment and place a positioning ball next to the target; Shield the target and test the set-piece in different test environments; A positioning ball is used to replace the target, so that the center position of the positioning ball coincides with the center position of the target; Get the data of the current test environment as the calibration data of the test environment and take out the target.

[0006] A further improvement of the present invention is that the target is placed in the test environment, and the specific method of placing the positioning ball at a desired position in the test environment according to the target size is as follows:

[0007]

[0008] in, The X-axis coordinate of the positioning ball placed in the test environment, The Y-axis coordinate of the positioning ball placed in the test environment, is the distance between the positioning ball and the target center, is the current scan angle.

[0009] A further improvement of the present invention is that, according to the test requirements, the specific method of presetting the scanning angle and the number of scanning angles of the radar is as follows: Radar scanning angle The method to obtain is as follows:

[0010] in, is the starting angle of the radar, is the scanning step of the radar, , is the number of scanning angles of the radar, and the scanning step of the radar The method to obtain is as follows:

[0011] in, is the speed of light, is the highest frequency of the radar; Number of radar scanning angles The method to obtain is as follows:

[0012]

[0013] in, is the radar termination angle, is the scanning angle span threshold, scanning angle span threshold The method to obtain is as follows:

[0014] in, is the distance between the positioning ball and the target center, is the maximum receiving distance of the target, is the diameter of the target, The X-axis coordinate of the positioning ball placed in the test environment, The Y-axis coordinate of the positioning ball in the test environment.

[0015] A further improvement of the present invention is that the echo data after scanning includes first echo data, second echo data and third echo data; The first echo data is the echo data of the positioning ball; The second echo data is the echo data of the background and positioning ball; The third echo data are the echo data of the background, positioning ball and target.

[0016] A further improvement of the present invention is that the calculation method of the initial distance index is as follows:

[0017] in, is the initial distance index, is the initial distance index variable, is the transform length of the inverse discrete Fourier transform.

[0018] A further improvement of the present invention is that the specific method for obtaining the phase calibration factor is as follows: Performing inverse discrete Fourier transform on the echo data to obtain the echo data after primary transformation; Get the actual peak index of the echo data after the primary transformation; Construct a rectangular window based on the actual peak index; Directional filtering is performed on the echo data after the primary transformation based on a rectangular window to obtain filtered echo data; Performing inverse discrete Fourier transform on the filtered echo data again to obtain echo data after secondary transformation; The phase calibration factor is obtained according to the echo data after the secondary transformation.

[0019] In a second aspect, the present invention provides an RCS test echo calibration system based on directional filtering, comprising: A calibration module, used to calibrate the test environment; A positioning module is used to place the target in the test environment and place the positioning ball at a desired position in the test environment according to the target size; The parameter setting module is used to preset the radar scanning angle and number of scanning angles according to the test requirements; A data receiving module is used to scan the target according to the scanning angle and the number of scanning angles, and receive the echo data after scanning; An index acquisition module is used to obtain an initial distance index based on the echo data; A phase calibration factor acquisition module is used to process the echo data based on the initial distance index using a directional filtering method to obtain a phase calibration factor; The echo signal calibration module is used to perform echo calibration and background cancellation on the echo data based on the phase calibration factor to obtain the final calibrated echo signal.

[0020] In a third aspect, the present invention provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor executes the steps of the RCS test echo calibration method based on directional filtering.

[0021] In a fourth aspect, the present invention provides a storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of an RCS test echo calibration method based on directional filtering.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The present invention places the target and the positioning ball at the specified position, and combines the scanning angle and the number of angles of the radar to ensure that the relative position of the test environment and the antenna is accurately calibrated, thereby improving the accuracy of the measurement result. The target is scanned multiple times according to the scanning angle and number, which can cover different angles and directions to ensure comprehensive acquisition of echo data. The present invention obtains the initial distance index through the echo data, can effectively screen out key data, reduce the complexity of subsequent data processing, and improve processing efficiency. The present invention adopts a directional filtering method to effectively reduce noise interference, enhance the target signal, make the phase calibration factor more accurate, and thus improve the effect of subsequent data calibration. The present invention calibrates the echo signal through the phase calibration factor and eliminates background interference, which can significantly improve the quality and accuracy of the final echo signal and ensure the reliability of the test result. The echo signal after comprehensive processing by the present invention is more accurate, and can provide high-precision data support for subsequent radar or antenna system performance evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a flow chart of the present invention; Figure 2 is a system diagram of the present invention; Figure 3 It is the relationship diagram between the positioning ball and the target coordinate system XOY; Figure 4It is the position map of the positioning ball and the background interference ball; Figure 5 is a comparison diagram of scanning angle errors of Example 10; Figure 6 This is a system diagram of Example 11. DETAILED DESCRIPTION

[0024] In order to further understand the content of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0025] Embodiment 1: See also Figure 1 , the RCS test echo calibration method based on directional filtering includes the following steps: S1, calibrate the test environment.

[0026] S2, placing the target in the test environment, and placing the positioning ball at the desired position in the test environment according to the target size.

[0027] S3: preset the radar scanning angle and number of scanning angles according to the test requirements.

[0028] S4, scanning the target according to the scanning angle and the number of scanning angles, and receiving the echo data after the scanning.

[0029] S5, obtaining an initial distance index according to the echo data.

[0030] S6, using the directional filtering method based on the initial distance index, the echo data is processed to obtain the phase calibration factor.

[0031] S7, based on the phase calibration factor, echo calibration and background cancellation are performed on the echo data to obtain the final calibrated echo signal.

[0032] Embodiment 2: See also Figure 2 , RCS test echo calibration system based on directional filtering, including: A calibration module, used to calibrate the test environment; A positioning module is used to place the target in the test environment and place the positioning ball at a desired position in the test environment according to the target size; The parameter setting module is used to preset the radar scanning angle and number of scanning angles according to the test requirements; A data receiving module is used to scan the target according to the scanning angle and the number of scanning angles, and receive the echo data after scanning; An index acquisition module is used to obtain an initial distance index based on the echo data; A phase calibration factor acquisition module is used to process the echo data based on the initial distance index using a directional filtering method to obtain a phase calibration factor; The echo signal calibration module is used to perform echo calibration and background cancellation on the echo data based on the phase calibration factor to obtain the final calibrated echo signal.

[0033] Embodiment 3: This embodiment limits the specific implementation of S1 in Embodiment 1.

[0034] The specific method for calibrating the test environment is as follows: Step 1: Place the target at the position to be tested in the test environment and place a positioning ball next to the target.

[0035] Step 2: Shield the target and test the positioning ball under different test environments.

[0036] Step three, use a positioning ball to replace the target, so that the center position of the positioning ball coincides with the center position of the target.

[0037] Step 4: Get the data of the current test environment as the calibration data of the test environment and take out the target.

[0038] Assume that the target coordinate system is XOY coordinate system and the target size diameter is , with the target rotation center as the origin O(0,0).

[0039] Given the distance from the positioning ball to the origin O is , and satisfies and , is the maximum unambiguous distance.

[0040] Embodiment 4: This embodiment limits the specific implementation of S2 in Embodiment 1.

[0041] See also Figure 3 , place the target in the test environment. According to the target size, the specific method of placing the positioning ball at the required position in the test environment is as follows: Let the circle formed by the target with the center at the origin O be circle 1, and the ray The angle between the origin O and the positive half axis of the X-axis is rays, rays For rays The ray rotates 90° clockwise around the origin O and intersects circle 1 at point A. With point A as the rotation center, Rotate 90 degrees clockwise to get a ray, so that the straight line Parallel to this ray, the straight line The equation represents same.

[0042]

[0043] According to the distance from the positioning ball to the origin O is , determine the center of the circle is at the origin O and the radius is The equation of circle 2 is:

[0044] in, The X-axis coordinate of the positioning ball placed in the test environment, The Y-axis coordinate of the positioning ball placed in the test environment, is the distance between the positioning ball and the target center, is the current scan angle.

[0045] Combined straight line The equation of and the equation of circle 2 can be used to obtain the desired position of the positioning ball in the test environment. .

[0046] Embodiment 5: This embodiment limits the specific implementation of S3 in Embodiment 1.

[0047] According to the test requirements, the specific method of presetting the radar's scanning angle and number of scanning angles is as follows: Radar scanning angle The method to obtain is as follows:

[0048] in, is the starting angle of the radar, is the scanning step of the radar, , is the number of scanning angles of the radar, and the scanning step of the radar The method to obtain is as follows:

[0049] in, , is the highest frequency of the radar; Number of radar scanning angles The method to obtain is as follows:

[0050]

[0051] in, is the radar termination angle, is the scanning angle span threshold, scanning angle span threshold The method to obtain is as follows:

[0052] in, is the maximum receiving distance of the target, is the diameter of the target.

[0053] Embodiment 6: This embodiment limits the specific implementation of S4 in Embodiment 1.

[0054] Scan the target according to the scanning angle and the number of scanning angles, and receive the echo data after scanning. The echo data after scanning includes the echo data of the positioning ball. , background and positioning ball echo data , as well as echo data of background, positioning ball and target , is the radar scanning frequency, which is calculated as follows:

[0055]

[0056] in, is the reference frequency, , is the number of scanning frequencies, is the frequency interval, is the maximum detection distance of the radar.

[0057] When generating each set of data, the radar position at each scanning angle ( ), which is expressed as follows:

[0058] in, is the maximum receiving distance of the target, is the scanning angle of the radar, express A random number in the range [-0.01, 0.01], express A random number in the range [-0.01, 0.01].

[0059] Embodiment 7: This embodiment limits the specific implementation of S5 in Embodiment 1.

[0060] According to the echo data, the calculation method of the initial distance index is as follows:

[0061] in, is the initial distance index, is the initial distance index variable, is the transform length of the inverse discrete Fourier transform.

[0062] Maximum unambiguous distance It is expressed as:

[0063] Radial distance discrete value It is expressed as follows:

[0064] in, , is the transform length of the inverse discrete Fourier transform.

[0065] At each scanning angle , select the radial distance discrete value In and The distance between the lower positioning ball and the radar The closest value is . Embodiment 8: This embodiment limits the specific implementation of S6 in Embodiment 1.

[0066] The specific method of using the directional filtering method to process the echo data based on the initial distance index and obtain the phase calibration factor is as follows: Echo data for positioning balls Perform frequency-based inverse discrete Fourier transform IDFT to obtain the transformed echo data .

[0067] For each scanning angle , first find the echo data after the change The actual peak index of the spherical , where the distance from the initial index The most recent peak index is recorded as the actual peak index .

[0068] According to the actual peak index Constructing a rectangular window , rectangular window It is expressed as follows:

[0069] in, is the length of the window, is the index variable.

[0070] After the transformation, the echo data To perform directional filtering, the method is as follows:

[0071] Filtered echo data is the result of time domain multiplication, and the filtered echo data Make the length The inverse discrete Fourier transform IDFT is used to obtain the echo data after the secondary transformation. ; According to the echo data after secondary transformation, the phase calibration factor is obtained , the method is as follows:

[0072] in, Indicates the wave number.

[0073] By analogy, we can get the echo data of the background and positioning ball. Calibration factor , as well as echo data of background, positioning ball and target Calibration factor .

[0074] Embodiment 9: This embodiment limits the specific implementation of S7 in Embodiment 1.

[0075] Based on the phase calibration factor, the echo data is calibrated and the background is cancelled to obtain the final echo signal. The specific method is as follows: For echo data including positioning ball , background and positioning ball echo data , as well as echo data of background, positioning ball and target ,) to perform echo calibration and obtain three types of echo data calibrated signals. The calibration method is as follows:

[0076]

[0077]

[0078] in, It is the calibration signal of the echo data of the positioning ball. It is the calibration signal for the echo data of the background and positioning ball. It is the calibration signal for the echo data of background, positioning ball and target.

[0079] The background cancellation is performed on the signals after calibration of the three echo data to obtain the final echo signal. The background cancellation method is as follows:

[0080] in, is the final echo signal of the positioning ball. is the final echo signal of the target.

[0081] Embodiment 10: See also Figure 3 and Figure 4 According to the contents of all the above embodiments, the position of the positioning ball and the distance from the positioning ball to the origin O are determined. , the target is at the origin O.

[0082] Assume the target size diameter D = 2 meters, and construct the distance from the positioning ball to the origin O The data is used to generate 36 scattering points with a scattering value of 1 meter at an angle interval of 10° on a circle with a center at the origin O and a radius of D / 2.

[0083] At the same time, assume that the distance from the positioning ball to the origin O is Meters, starting angle of the radar , and get the placement position of the positioning ball. The scattering value of the positioning ball is 10dB lower than the scattering value of the scattering point.

[0084] A background interference ball is set up, with the center at the origin O and a radius of 5 meters, to generate 10 scattering points with an angle interval of 60°, whose scattering value is 10dB lower than that of the positioning ball.

[0085] Set the target maximum receiving distance Meters, maximum unambiguous distance rice Determine the scanning step of the radar that meets the conditions , , and the number of sweep angles , and generate three sets of data.

[0086] The three sets of echo data are compared to obtain the final echo signal of the positioning ball. and the final echo signal of the target .

[0087] Final echo signal for the set piece and the final echo signal of the target Perform spherical wave ring scattering extrapolation technology CNFFFT transformation (Circular Near-field to Far-field Transformation) to obtain the transformed positioning ball data With the transformed target data ,make And compared with the ideal far-field echo data containing only the target scattering points Subtracting, expressed as:

[0088] in, Indicates the scanning angle error.

[0089] The simulation results are as follows Figure 5 As shown, the scanning angle error obtained by the invention is significantly lower than that of the traditional method, which further illustrates the superiority of the invention.

[0090] Embodiment 11: See also Figure 6 As shown, the present invention also provides an electronic device 100 for an RCS test echo calibration method based on directional filtering; the electronic device 100 includes a memory 101, at least one processor 102, a computer program 103 stored in the memory 101 and executable on the at least one processor 102, and at least one communication bus 104.

[0091] The memory 101 can be used to store the computer program 103, and the processor 102 implements the steps of the RCS test echo calibration method based on directional filtering described in Example 1 by running or executing the computer program stored in the memory 101 and calling the data stored in the memory 101. The memory 101 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data (such as audio data) created according to the use of the electronic device 100, etc. In addition, the memory 101 can include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

[0092] The at least one processor 102 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 102 may be a microprocessor or any conventional processor, etc. The processor 102 is the control center of the electronic device 100, and uses various interfaces and lines to connect various parts of the entire electronic device 100.

[0093] The memory 101 in the electronic device 100 stores a plurality of instructions to implement the RCS test echo calibration method based on directional filtering, and the processor 102 can execute the plurality of instructions to implement: Calibrate the test environment; The target is placed in the test environment, and the positioning ball is placed at the desired position in the test environment according to the target size; According to the test requirements, preset the radar's scanning angle and number of scanning angles; Scan the target according to the scanning angle and the number of scanning angles, and receive the echo data after scanning; According to the echo data, the initial distance index is obtained; Directional filtering method is used to process echo data based on the initial distance index to obtain the phase calibration factor; Based on the phase calibration factor, the echo data is subjected to echo calibration and background cancellation to obtain the final echo signal.

[0094] Embodiment 12: If the module / unit integrated in the electronic device 100 is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory and read-only memory (ROM, Read-Only Memory).

[0095] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0096] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0097] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0098] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0099] 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 above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. The RCS test echo calibration method based on directional filtering is characterized by: The following steps are involved: Calibrate the test environment; The target is placed in the test environment, and the positioning ball is placed at the desired position in the test environment according to the target size; According to the test requirements, preset the radar's scanning angle and number of scanning angles; Scan the target according to the scanning angle and the number of scanning angles, and receive the echo data after scanning; According to the echo data, the initial distance index is obtained; Directional filtering method is used to process echo data based on the initial distance index to obtain the phase calibration factor; Based on the phase calibration factor, the echo data is subjected to echo calibration and background cancellation to obtain the final echo signal.

2. The RCS test echo calibration method based on directional filtering according to claim 1 is characterized in that: The specific method for calibrating the test environment is as follows: Place the target at the location to be tested in the test environment and place a positioning ball next to the target; Shield the target and test the set-piece in different test environments; A positioning ball is used to replace the target, so that the center position of the positioning ball coincides with the center position of the target; Get the data of the current test environment as the calibration data of the test environment and take out the target.

3. The RCS test echo calibration method based on directional filtering according to claim 1 is characterized in that: Place the target in the test environment. Depending on the target size, the specific method for placing the positioning ball at the required position in the test environment is as follows: in, The X-axis coordinate of the positioning ball placed in the test environment, The Y-axis coordinate of the positioning ball placed in the test environment, is the distance between the positioning ball and the target center, is the current scan angle.

4. The RCS test echo calibration method based on directional filtering according to claim 1 is characterized in that: According to the test requirements, the specific method of presetting the radar's scanning angle and number of scanning angles is as follows: Radar scanning angle The method to obtain is as follows: in, is the starting angle of the radar, is the scanning step of the radar, , is the number of scanning angles of the radar, and the scanning step of the radar The method to obtain is as follows: in, is the speed of light, is the highest frequency of the radar; Number of radar scanning angles The method to obtain is as follows: in, is the radar termination angle, is the scanning angle span threshold, scanning angle span threshold The method to obtain is as follows: in, is the distance between the positioning ball and the target center, is the maximum receiving distance of the target, is the diameter of the target, The X-axis coordinate of the positioning ball placed in the test environment, The Y-axis coordinate of the positioning ball in the test environment.

5. The RCS test echo calibration method based on directional filtering according to claim 1 is characterized in that: The echo data after scanning includes first echo data, second echo data and third echo data; The first echo data is the echo data of the positioning ball; The second echo data is the echo data of the background and positioning ball; The third echo data are the echo data of the background, positioning ball and target.

6. The RCS test echo calibration method based on directional filtering according to claim 1 is characterized in that: The initial distance index is calculated as follows: in, is the initial distance index, is the initial distance index variable, is the transform length of the inverse discrete Fourier transform.

7. The RCS test echo calibration method based on directional filtering according to claim 1 is characterized in that: The specific method for obtaining the phase calibration factor is as follows: Performing inverse discrete Fourier transform on the echo data to obtain the echo data after primary transformation; Get the actual peak index of the echo data after the primary transformation; Construct a rectangular window based on the actual peak index; Directional filtering is performed on the echo data after the primary transformation based on a rectangular window to obtain filtered echo data; Performing inverse discrete Fourier transform on the filtered echo data again to obtain echo data after secondary transformation; The phase calibration factor is obtained according to the echo data after the secondary transformation.

8. The RCS test echo calibration system based on directional filtering is characterized by: include: A calibration module, used to calibrate the test environment; A positioning module is used to place the target in the test environment and place the positioning ball at a desired position in the test environment according to the target size; Parameter setting module, used to preset the radar scanning angle and number of scanning angles according to test requirements; A data receiving module is used to scan the target according to the scanning angle and the number of scanning angles, and receive the echo data after scanning; An index acquisition module is used to obtain an initial distance index based on the echo data; A phase calibration factor acquisition module is used to process the echo data based on the initial distance index using a directional filtering method to obtain a phase calibration factor; The echo signal calibration module is used to perform echo calibration and background cancellation on the echo data based on the phase calibration factor to obtain the final calibrated echo signal.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the RCS test echo calibration method based on directional filtering described in any one of claims 1 to 7 are implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the RCS test echo calibration method based on directional filtering described in any one of claims 1 to 7 are implemented.

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