RCS Test Echo Calibration Method Based on Directional Filtering and Related System

Abstract

The present invention belongs to the field of communication, and discloses a method for calibrating the RCS test echo based on directional filtering and related systems. By placing the target and the positioning ball at designated positions and combining with the scanning angle and the number of angles of the radar, the relative position between the test environment and the antenna is accurately calibrated, thereby improving the accuracy of the measurement results. Scanning the target multiple times according to the scanning angle and the number of angles can cover different angles and directions to ensure comprehensive acquisition of echo data. The present invention obtains the initial distance index from the echo data, which can effectively screen out key data, reduce the complexity of subsequent data processing, and improve the processing efficiency. The present invention adopts the directional filtering method to effectively reduce noise interference, enhance the target signal, make the phase calibration factor more accurate, and further improve the effect of subsequent data calibration.

Description

Technical Field

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

[0002] In the test of Rich Communication Service (RCS) in converged communication, the traditional method is that the radar antenna always aims at the center position of the target. At the same time, the relative trajectory between the antenna and the target must be a standard circular arc with the target center as the origin and the distance from the target center to the antenna position as the standard, and it must be a 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 while the radar makes a circular motion, then it is basically impossible to require that the trajectory of the radar motion is a standard circular arc without any error. Thus, during the movement, there is a certain deviation between the actual position of the radar antenna and the ideal position, and this deviation will cause a serious phase error between the actual echo of the target and the standard echo. This error will cause the RCS test result to be distorted. Summary of the Invention

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

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides an RCS test echo calibration method based on directional filtering, including the following steps:

[0006] Calibrate the test environment;

[0007] Place the target in the test environment, and according to the target size, place the positioning ball at the required position in the test environment;

[0008] Preset the scanning angle and the number of scanning angles of the radar according to the test requirements;

[0009] Scan the target according to the scanning angle and the number of scanning angles, and receive the echo data after scanning;

[0010] Obtain the initial distance index according to the echo data;

[0011] Process the echo data based on the initial distance index by using the directional filtering method to obtain the phase calibration factor;

[0012] Based on the phase calibration factor, the echo data is calibrated and background cancelled to obtain the final echo signal.

[0013] A further improvement of the present invention lies in that the specific method for calibrating the test environment is as follows:

[0014] Place the target at the position to be tested in the test environment, and place a positioning ball beside the target;

[0015] Shield the target and test the positioning ball under different test environments;

[0016] Use the positioning ball instead of the target to make the center position of the positioning ball coincide with the center position of the target;

[0017] Obtain the data of the current test environment as the calibration data of the test environment, and take out the target.

[0018] A further improvement of the present invention lies in that the specific method for placing the target in the test environment and placing the positioning ball at the required position in the test environment according to the target size is as follows:

[0019]

[0020]

[0021] Wherein, is the X-axis coordinate of the positioning ball placed in the test environment, is 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.

[0022] A further improvement of the present invention lies in that the specific method for presetting the scan angle and the number of scan angles of the radar according to the test requirements is as follows:

[0023] The scan angle of the radar is obtained as follows:

[0024]

[0025] Wherein, is the starting angle of the radar, is the scan step of the radar, , is the number of scan angles of the radar, and the scan step of the radar is obtained as follows:

[0026]

[0027] Wherein, is the speed of light, is the highest frequency of the radar;

[0028] The number of scanning angles of the radar The acquisition method is as follows:

[0029]

[0030]

[0031] Among them, is the termination angle of the radar, is the scanning angle span threshold, and the scanning angle span threshold The acquisition method is as follows:

[0032]

[0033] Among them, is the distance from the positioning ball to the target center, is the maximum reception distance of the target, is the diameter of the target, is the X-axis coordinate of the positioning ball placed in the test environment, is the Y-axis coordinate of the positioning ball placed in the test environment.

[0034] 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;

[0035] The first echo data is the echo data of the positioning ball;

[0036] The second echo data is the echo data of the background and the positioning ball;

[0037] The third echo data is the echo data of the background, the positioning ball, and the target.

[0038] A further improvement of the present invention is that the calculation method of the initial distance index is as follows:

[0039]

[0040] Among them, is the initial distance index, is the initial distance index variable, is the transform length of the inverse discrete Fourier transform.

[0041] A further improvement of the present invention is that the specific method for obtaining the phase calibration factor is as follows:

[0042] Perform an inverse discrete Fourier transform on the echo data to obtain the echo data after the first transformation;

[0043] Obtain the actual peak index of the echo data after the first transformation;

[0044] Construct a rectangular window according to the actual peak index;

[0045] Perform directional filtering on the echo data after the first transformation based on the rectangular window to obtain the filtered echo data;

[0046] Perform an inverse discrete Fourier transform on the filtered echo data again to obtain the echo data after the second transformation;

[0047] Obtain the phase calibration factor according to the echo data after the second transformation.

[0048] In a second aspect, the present invention provides an RCS test echo calibration system based on directional filtering, including:

[0049] A calibration module for calibrating the test environment;

[0050] A positioning module for placing the target in the test environment and placing the positioning ball at the required position in the test environment according to the target size;

[0051] A parameter setting module for presetting the scan angle and the number of scan angles of the radar according to the test requirements;

[0052] A data receiving module for scanning the target according to the scan angle and the number of scan angles and receiving the scanned echo data;

[0053] An index acquisition module for obtaining the initial distance index according to the echo data;

[0054] A phase calibration factor acquisition module for processing the echo data based on the initial distance index by using the directional filtering method to obtain the phase calibration factor;

[0055] An echo signal calibration module for performing echo calibration and background cancellation on the echo data based on the phase calibration factor to obtain the finally calibrated echo signal.

[0056] In a third aspect, the present invention provides an electronic device, including a memory and a processor, where the memory stores a computer program, and the processor executes the steps of the RCS test echo calibration method based on directional filtering.

[0057] In a fourth aspect, the present invention provides a storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the RCS test echo calibration method based on directional filtering are implemented.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] The present invention ensures the accurate calibration of the relative position between the test environment and the antenna by placing the target and the positioning ball at the specified positions and combining the scanning angle and the number of angles of the radar, thereby improving the accuracy of the measurement results. By scanning the target multiple times according to the scanning angle and the number, different angles and directions can be covered to ensure the comprehensive acquisition of echo data. The present invention obtains the initial distance index from the echo data, which can effectively screen out key data, reduce the complexity of subsequent data processing, and improve the processing efficiency. The present invention adopts the directional filtering method to effectively reduce noise interference, enhance the target signal, make the phase calibration factor more accurate, and further improve the effect of subsequent data calibration. The present invention calibrates and 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 results. The echo signal processed comprehensively by the present invention is more accurate and can provide high-precision data support for the performance evaluation of subsequent radar or antenna systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 is a flowchart of the present invention;

[0061] Figure 2 is a system diagram of the present invention;

[0062] Figure 3 is a relationship diagram of the positioning ball and the target coordinate system XOY;

[0063] Figure 4 is a position diagram of the positioning ball and the background interference ball;

[0064] Figure 5 is a comparison diagram of the scanning angle error of Example 10;

[0065] Figure 6 is a system diagram of Example 11. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0066] To further understand the content of the present invention, the following describes the present invention in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention and not for limiting it.

[0067] Example 1:

[0068] Refer to Figure 1 , the RCS test echo calibration method based on directional filtering includes the following steps:

[0069] S1, calibrate the test environment.

[0070] S2, place the target in the test environment, and place the positioning ball at the required position in the test environment according to the target size.

[0071] S3. Preset the scanning angle and the number of scanning angles of the radar according to the test requirements.

[0072] S4. Scan the target according to the scanning angle and the number of scanning angles, and receive the echo data after scanning.

[0073] S5. Obtain the initial distance index according to the echo data.

[0074] S6. Process the echo data by using the directional filtering method based on the initial distance index to obtain the phase calibration factor.

[0075] S7. Perform echo calibration and background cancellation on the echo data based on the phase calibration factor to obtain the finally calibrated echo signal.

[0076] Embodiment 2:

[0077] See Figure 2 , the RCS test echo calibration system based on directional filtering includes:

[0078] The calibration module is used to calibrate the test environment;

[0079] The positioning module is used to place the target in the test environment and place the positioning ball at the required position in the test environment according to the target size;

[0080] The parameter setting module is used to preset the scanning angle and the number of scanning angles of the radar according to the test requirements;

[0081] The 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;

[0082] The index obtaining module is used to obtain the initial distance index according to the echo data;

[0083] The phase calibration factor obtaining module is used to process the echo data by using the directional filtering method based on the initial distance index to obtain the phase calibration factor;

[0084] 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 finally calibrated echo signal.

[0085] Embodiment 3:

[0086] This embodiment defines the specific implementation manner of S1 in Embodiment 1.

[0087] The specific method for calibrating the test environment is as follows:

[0088] Step 1. Place the target at the position to be tested in the test environment and place the positioning ball beside the target.

[0089] Step 2, Shield the target and test the positioning ball in different test environments.

[0090] Step 3, Use the positioning ball to replace the target and make the center position of the positioning ball coincide with the center position of the target.

[0091] Step 4, Obtain the data of the current test environment as the calibration data of the test environment and take out the target.

[0092] Assume that the coordinate system of the target is the XOY coordinate system, and the diameter of the target size is Take the rotation center of the target as the origin O(0, 0).

[0093] Given that the distance from the positioning ball to the origin O is and satisfy and , is the maximum unambiguous distance.

[0094] Example 4:

[0095] This example limits the specific implementation manner of S2 in Example 1.

[0096] See 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:

[0097] Let the circle formed by the targets with the center at the origin O be circle 1, and the ray be the ray passing through the origin O and making an angle with the positive half-axis of the X-axis of , and the ray be the ray obtained by rotating the ray clockwise by 90° around the origin O and intersecting circle 1 at point A. Taking point A as the rotation center, rotate the ray clockwise by 90 degrees to obtain a ray. Let the straight line be parallel to this ray, and the equation of the straight line is expressed as the same as .

[0098]

[0099] According to the distance from the positioning ball to the origin O being , determine the equation of circle 2 with the center at the origin O and a radius of :

[0100]

[0101] Among them, is the X-axis coordinate of the positioning ball placed in the test environment, is the Y-axis coordinate of the positioning ball placed in the test environment, is the distance between the positioning ball and the center of the target, is the current scanning angle.

[0102] Combined with the equation of the straight line and the equation of circle 2, the required position of the positioning ball placed in the test environment can be obtained .

[0103] Example 5:

[0104] This example defines the specific implementation manner of S3 in Example 1.

[0105] According to the test requirements, the specific method for presetting the scanning angle and the number of scanning angles of the radar is as follows:

[0106] The method for obtaining the scanning angle of the radar is as follows:

[0107]

[0108] Among them, 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 method for obtaining the scanning step of the radar is as follows:

[0109]

[0110] Among them, , is the highest frequency of the radar;

[0111] The method for obtaining the number of scanning angles of the radar is as follows:

[0112]

[0113]

[0114] Among them, is the termination angle of the radar, is the scanning angle span threshold, and the method for obtaining the scanning angle span threshold is as follows:

[0115]

[0116] Among them, is the maximum receiving distance of the target, is the diameter of the target.

[0117] Example 6:

[0118] This embodiment defines the specific implementation manner of S4 in Embodiment 1.

[0119] According to the scanning angle and the number of scanning angles, the target is scanned, and the echo data after scanning is received. The echo data after scanning includes the echo data of the positioning ball , the echo data of the background and the positioning ball , and the echo data of the background, the positioning ball and the target , is the radar scanning frequency, and the calculation method is as follows:

[0120]

[0121]

[0122] Among them, is the reference frequency, , is the number of scanning frequencies, is the frequency interval, is the maximum detection distance of the radar.

[0123] Under the generation of each group of data, the radar position at each scanning angle ( ) is expressed as follows:

[0124]

[0125] Among them, is the maximum reception distance of the target, is the scanning angle of the radar, represents a random number in the range [-0.01, 0.01], represents a random number in the range [-0.01, 0.01].

[0126] Embodiment 7:

[0127] This embodiment defines the specific implementation manner of S5 in Embodiment 1.

[0128] According to the echo data, the calculation method for obtaining the initial distance index is as follows:

[0129]

[0130] Among them, is the initial distance index, is the initial distance index variable, is the transform length of the inverse discrete Fourier transform.

[0131] Maximum unambiguous range It is expressed as:

[0132]

[0133] Radial distance discrete values It is expressed as follows:

[0134]

[0135] Wherein, , is the transform length of the inverse discrete Fourier transform.

[0136] At each scanning angle , select the radial distance discrete value among those that is closest to the distance between the positioning ball and the radar at . Denote it as . .

[0137] Embodiment 8:

[0138] This embodiment defines the specific implementation manner of S6 in Embodiment 1.

[0139] The specific method for processing the echo data by using the directional filtering method based on the initial distance index to obtain the phase calibration factor is as follows:

[0140] Perform an inverse discrete Fourier transform IDFT based on frequency on the echo data of the positioning ball to obtain the transformed echo data .

[0141] For each scanning angle , first find the actual peak index of the positioning ball in the transformed echo data . Among them, the peak index closest to the initial distance index is denoted as the actual peak index .

[0142] Construct a rectangular window according to the actual peak index . The rectangular window is expressed as follows:

[0143]

[0144] Wherein, is the length of the window, is the index variable.

[0145] Perform directional filtering on the transformed echo data by the following method:

[0146]

[0147] Filtered echo data is the result after time-domain multiplication, for the filtered echo data perform an inverse discrete Fourier transform IDFT of length to obtain the echo data after the second transformation ;

[0148] According to the echo data after the second transformation, obtain the phase calibration factor , the method is as follows:

[0149]

[0150] wherein, represents the wave number.

[0151] And so on, the calibration factors of the echo data of the background and the positioning ball can be obtained , and the calibration factors of the echo data of the background, the positioning ball and the target , and the calibration factors of the echo data of the background, the positioning ball and the target .

[0152] Embodiment 9:

[0153] This embodiment defines the specific implementation manner of S7 in Embodiment 1.

[0154] Based on the phase calibration factor, perform echo calibration and background cancellation on the echo data to obtain the final echo signal, the specific method is as follows:

[0155] For the echo data including the positioning ball , the echo data of the background and the positioning ball , and the echo data of the background, the positioning ball and the target , ) perform echo calibration to obtain the signals after calibration of the three echo data, and the calibration method is as follows:

[0156]

[0157]

[0158]

[0159] wherein, is the calibration signal of the echo data of the positioning ball, is the calibration signal of the echo data of the background and the positioning ball, is the calibration signal of the echo data of the background, the positioning ball and the target. ​

[0160] Perform background cancellation on the calibrated signals of the three types of echo data to obtain the final echo signal. The background cancellation method is as follows:

[0161]

[0162] Among them, is the final echo signal of the positioning ball, is the final echo signal of the target.

[0163] Example 10:

[0164] Refer to Figure 3 and Figure 4 , and determine the position of the positioning ball and the distance from the positioning ball to the origin O according to the content of all the above embodiments , and the position of the target is at the origin O.

[0165] Assume that the target size diameter D = 2 meters, and construct the data of the distance from the positioning ball to the origin O. On a circle with the origin O as the center and a radius of D / 2, 36 scattering points with a scattering value of 1 meter are generated at an angular interval of 10°.

[0166] At the same time, assume that the distance from the positioning ball to the origin O is meters, and the starting angle

[0167] of the radar is

[0168] to obtain the placement position of the positioning ball. The scattering value of the positioning ball is 10 dB lower than that of the scattering point. Set background interference balls. On a circle with the origin O as the center and a radius of 5 meters, 10 scattering points with a scattering value 10 dB lower than that of the positioning ball are generated at an angular interval of 60°. meters

[0169] Determine the scanning step , , and the number of scanning angles that meet the conditions, and generate three sets of echo data.

[0170] Calibrate the three sets of echo data to finally obtain the final echo signal of the positioning ball and the final echo signal of the target.

[0171] For the final echo signal of the positioning ball and the final echo signal Perform the CNFFFT transform (Circular Near-field to Far-Field Transformation) of the spherical wave ring scattering extrapolation technique respectively to obtain the transformed positioning sphere data and the transformed target data , let and subtract it from the ideal far-field echo data that only contains the target scattering points , which is expressed as:

[0172]

[0173] wherein represents the scan angle error

[0174] The simulation results are as Figure 5 shown. The scan angle error obtained by this invention is significantly lower than that of the traditional method, further illustrating the superiority of this invention

[0175] Example 11:

[0176] Please refer to Figure 6 shown. The present invention also provides an electronic device 100 for the 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

[0177] The memory 101 can be used to store the computer program 103. The processor 102 realizes 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 mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system, application programs required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area can store data created according to the use of the electronic device 100 (such as audio data, etc.). In addition, the memory 101 can include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices

[0178] The at least one processor 102 may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 102 may be a microprocessor or the processor 102 may also be any conventional processor, etc. The processor 102 is the control center of the electronic device 100, and connects various parts of the entire electronic device 100 through various interfaces and lines.

[0179] 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. The processor 102 can execute the plurality of instructions to implement:

[0180] Calibrate the test environment;

[0181] Place the target in the test environment, and according to the target size, place the positioning ball at the required position in the test environment;

[0182] Preset the scan angle and the number of scan angles of the radar according to the test requirements;

[0183] Scan the target according to the scan angle and the number of scan angles, and receive the echo data after scanning;

[0184] Obtain the initial distance index according to the echo data;

[0185] Process the echo data based on the initial distance index by using the directional filtering method to obtain the phase calibration factor;

[0186] Perform echo calibration and background cancellation on the echo data based on the phase calibration factor to obtain the final echo signal.

[0187] Embodiment 12:

[0188] If the modules / units integrated in the electronic device 100 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, to implement all or part of the processes in the above-described embodiment methods of the present invention, it can also be completed by a computer program instructing relevant hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-described method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, and read-only memory (ROM, Read-Only Memory).

[0189] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of an all-hardware embodiment, an all-software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can 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.

[0190] The present invention is described with reference to the 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 can be implemented by computer program instructions, and the combination of processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the specified functions in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0191] These computer program instructions can also be stored in a computer-readable memory capable of guiding a computer or other programmable data processing devices to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured product including an instruction device, and the instruction device implements the specified functions in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0192] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus, so that a series of operation steps are performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions for implementing the functions specified in one process or a plurality of processes and / or blocks Figure 1 one process or a plurality of processes and / or blocks Figure 1 steps of the functions specified in one block or a plurality of blocks.

[0193] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific embodiments of the present invention. Any modification or equivalent replacement without departing from the spirit and scope of the present invention shall be covered by the protection scope 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 specific method 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; 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, and the calculation method is as follows: in, is the initial distance index, is the initial distance index variable, is the transform length of the inverse discrete Fourier transform; Maximum unambiguity distance It is expressed as: Radial distance discrete value It is expressed as follows: in, , is the transform length of the inverse discrete Fourier transform, is the maximum receiving distance of the target; 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 ; The directional filtering method is used to process the echo data based on the initial distance index to obtain the phase calibration factor. The specific method is as follows: Echo data for positioning balls Perform frequency-based inverse discrete Fourier transform IDFT to obtain the transformed echo data ; 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 distance index The most recent peak index is recorded as the actual peak index ; According to the actual peak index Constructing a rectangular window , rectangular window It is expressed as follows: in, is the length of the window, is the index variable; After the transformation, the echo data To perform directional filtering, the method is as follows: 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: in, represents the wave number; 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 ; 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: 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.

3. 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 diameter of the target.

4. 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.

5. The RCS test echo calibration system based on directional filtering is characterized by: include: The calibration module is used to calibrate the test environment. The specific method 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; 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; The index acquisition module is used to obtain the initial distance index calculation method based on the echo data as follows: in, is the initial distance index, is the initial distance index variable, is the transform length of the inverse discrete Fourier transform; Maximum unambiguity distance It is expressed as: Radial distance discrete value It is expressed as follows: in, , is the transform length of the inverse discrete Fourier transform, is the maximum receiving distance of the target; 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 ; The phase calibration factor acquisition module is used to process the echo data based on the initial distance index using the directional filtering method to obtain the phase calibration factor. The specific method is as follows: Echo data for positioning balls Perform frequency-based inverse discrete Fourier transform IDFT to obtain the transformed echo data ; 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 distance index The most recent peak index is recorded as the actual peak index ; According to the actual peak index Constructing a rectangular window , rectangular window It is expressed as follows: in, is the length of the window, is the index variable; After the transformation, the echo data To perform directional filtering, the method is as follows: 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: in, represents the wave number; 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 ; 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.

6. 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 4 are implemented.

7. 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 4 are implemented.

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