Rcs extraction method and system based on eccentric calibration body calibration synchronization

Abstract

The application belongs to the field of RCS test, and discloses an RCS extraction method and system based on eccentric calibration body calibration synchronization. The application selects an eccentric calibration body meeting the frequency band requirement, so that a circular characteristic can be formed in rotation, thereby accurately extracting background data without additional background test, and reducing background uncertainty. The actual distance between the rotation center and the feed source is obtained, and the echo is power compensated in combination with the eccentric scattering distance model, so that the amplitude error caused by the distance fluctuation is effectively eliminated. Further, the eccentric deviation is estimated and the phase error is corrected by using the relationship between the phase and the eccentric position, so that the accuracy of the calibration signal is improved. In combination with filtering denoising and background deduction, the real and stable calibration signal can be obtained, so that the radar scattering cross section calculation of the target body is more accurate. The method simultaneously realizes background extraction and calibration, and significantly improves the efficiency and accuracy of the radar scattering cross section test.

Description

Technical Field

[0001] This invention belongs to the field of RCS testing, specifically relating to an RCS extraction method and system based on calibration synchronization of an eccentric calibration body. Background Technology

[0002] Radar Cross Section (RCS) testing typically relies on a vector network analyzer and an RF link to perform measurements by acquiring background echo, calibration body echo, and target echo separately. Current mainstream methods generally require three independent tests to obtain a complete dataset. Furthermore, higher test accuracy demands higher requirements on instrument signal processing speed, scan time, and data stability, significantly increasing the overall test cycle. In actual testing, operators need to remove the calibration body to reacquire background data, making it difficult to maintain a consistent background environment and causing background echo fluctuations, thus affecting the final RCS inversion accuracy. To improve test efficiency, the industry has proposed solutions such as parallel testing with multiple vector network analyzers, high-speed receivers, and linear frequency modulated signals. However, these solutions have limitations such as increased RF link complexity, higher equipment costs, enhanced mutual interference between feed sources, greater system debugging difficulty, and the difficulty in balancing high-speed system stability and accuracy. Therefore, under current technological conditions, it remains difficult to simultaneously achieve high efficiency and high accuracy without increasing test hardware costs. Summary of the Invention

[0003] The purpose of this invention is to overcome the problems of low efficiency, high background uncertainty and difficulty in achieving accuracy in existing RCS testing, and to provide an RCS extraction method and system based on synchronous calibration of an eccentric calibration body.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] In a first aspect, the present invention provides an RCS extraction method based on calibration synchronization of an eccentric calibration body, comprising the following steps:

[0006] Select the required eccentric calibration body according to the target frequency band;

[0007] Based on the eccentric calibration body and the test turntable, a far-field transceiver feed test system was set up. The far-field transceiver feed test system was used to test the eccentric calibration body and the target body, and the echo signal of the eccentric calibration body and the echo signal of the target body were obtained.

[0008] The echo signal of the eccentric calibration body is processed to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the far-field transceiver feed test system. Based on the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed, the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable is obtained. Based on the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable, the echo signal of the eccentric calibration body is power compensated to obtain the compensated calibration echo signal.

[0009] The compensated calibration echo signal is processed to obtain the deviation position parameters between the center of the eccentric calibration body and the rotation center of the eccentric calibration body. The eccentric calibration body is corrected according to the deviation position parameters to obtain accurate calibration data.

[0010] Extract background data from the compensated calibrated echo signal;

[0011] Based on the background data, the accurate calibration data and the echo signal of the target are processed to obtain the radar cross section of the target.

[0012] A further improvement of this invention lies in the following method for selecting the required eccentric calibration body according to the target frequency band:

[0013] Based on the principle of background extraction from a fitted circle, an eccentric calibration body is selected such that the difference between the maximum and minimum radial distances between the scattering point of the eccentric calibration body and the feed source is greater than or equal to half of the lowest frequency wavelength.

[0014] A further improvement of this invention lies in setting up a far-field transceiver feed test system based on an eccentric calibration body and a test turntable. The specific method for using the far-field transceiver feed test system to test the eccentric calibration body and the target body to obtain the echo signal of the eccentric calibration body and the echo signal of the target body is as follows:

[0015] Based on the eccentric calibrator and the test turntable, a far-field transceiver feed test system is set up. In the far-field transceiver feed test system, the eccentric calibrator rotates around the rotation center of the test turntable, and far-field transceiver feeds are deployed at the required positions.

[0016] The far-field transceiver feed scans and acquires the echo signals corresponding to the eccentric calibration body at various rotation angles. These echo signals of the eccentric calibration body include background data and eccentric calibration body data.

[0017] The eccentric calibration body was replaced with the target body and tested in a far-field transceiver feed test system. The echo signals of the target body at various rotation angles were obtained and used as the echo signals of the target body.

[0018] A further improvement of this invention lies in processing the echo signal of the eccentric calibration body to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the far-field transceiver feed test system. Based on the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed, the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable is obtained. Power compensation is then performed on the echo signal of the eccentric calibration body based on this relationship. The specific method for obtaining the compensated calibration echo signal is as follows:

[0019] The echo signal of the eccentric calibration body is obtained, and the inverse Fourier transform of the echo signal of the eccentric calibration body is performed to obtain the one-dimensional range image displayed in the two-dimensional image.

[0020] By removing the RF line loss in the one-dimensional distance image, the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the far-field transceiver feed test system is obtained.

[0021] Obtain the eccentricity distance, radius, and rotation angle of the test turntable of the eccentric calibrator. Combine this with the actual distance between the rotation center of the eccentric calibrator and the far-field transceiver feed to obtain the relationship between the actual scattering distance of the eccentric calibrator and the rotation angle of the test turntable.

[0022] The amplitude of the echo signal of the eccentric calibrator as a function of the rotation angle is obtained. Based on the relationship between the actual scattering distance of the eccentric calibrator and the rotation angle of the test turntable, the power of the echo signal of the eccentric calibrator is compensated to obtain the compensated calibration echo signal.

[0023] A further improvement of this invention lies in processing the compensated calibration echo signal to obtain the deviation position parameters between the center of the eccentric calibration body and the rotation center of the eccentric calibration body. The specific method for correcting the eccentric calibration body based on these deviation position parameters to obtain accurate calibration data is as follows:

[0024] The echo signal of the compensated eccentric calibration body is obtained, and the relationship between the phase and the eccentric position of the eccentric calibration body is analyzed.

[0025] Based on the relationship between the phase of the eccentric calibrator and its eccentric position, the phase error of the eccentric calibrator at different eccentric positions is obtained;

[0026] The phase error of the eccentric calibration body at different eccentric positions is estimated by least squares method to obtain the position parameters of the eccentric calibration body relative to the rotation center of the eccentric calibration body;

[0027] The phase of the eccentric calibrator is corrected by using the offset position parameter of the eccentric calibrator rotation center to obtain accurate calibration data.

[0028] A further improvement of this invention lies in the following specific method for extracting background data from the compensated calibrated echo signal:

[0029] The compensated calibration echo signal is acquired, the noisy complex signal in the compensated calibration echo signal is extracted, and the noisy complex signal is filtered to remove noise and interference signals, so as to obtain a signal that retains the auxiliary measurement signal and the background signal.

[0030] Background data is extracted from the signals that retain both the auxiliary measurement signal and the background signal by using the principle of fitted circle background extraction.

[0031] A further improvement of this invention lies in the following method for processing accurate calibration data and the echo signal of the target object based on background data to obtain the radar cross section of the target object:

[0032] Acquire the echo signal of the target object, and use background data to perform background cancellation on the echo signal of the target object to obtain the calibration signal of the target object after background cancellation;

[0033] Obtain the echo signal of the eccentric calibration body from the accurate calibration data, and use the background data to perform background cancellation on the echo signal of the eccentric calibration body to obtain the calibration signal of the eccentric calibration body after background cancellation.

[0034] The calibration algorithm is used to process the calibration signal of the target object after background cancellation and the calibration signal of the eccentric calibration object after background cancellation to obtain the radar cross section of the target object.

[0035] Secondly, the present invention provides an RCS extraction system based on calibration synchronization of an eccentric calibration body, comprising:

[0036] The eccentric calibration body selection module is used to select the required eccentric calibration body according to the target frequency band;

[0037] The test module is used to set up a far-field transceiver feed test system based on an eccentric calibration body and a test turntable. The far-field transceiver feed test system is used to test the eccentric calibration body and the target body to obtain the echo signal of the eccentric calibration body and the echo signal of the target body.

[0038] The signal compensation module is used to process the echo signal of the eccentric calibration body to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the far-field transceiver feed test system. Based on the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed, the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable is obtained. Based on the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable, the power compensation of the echo signal of the eccentric calibration body is performed to obtain the compensated calibration echo signal.

[0039] The signal correction module is used to process the compensated calibration echo signal to obtain the deviation position parameters between the center of the eccentric calibration body and the rotation center of the eccentric calibration body. Based on the deviation position parameters, the eccentric calibration body is corrected to obtain accurate calibration data.

[0040] The background data extraction module is used to extract background data from the compensated calibrated echo signal.

[0041] The calibration processing module is used to process the calibration data and the echo signal of the target object based on the accurate background data to obtain the radar cross section of the target object.

[0042] Thirdly, the present invention provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, characterized in that the processor, when executing the computer program, implements an RCS extraction method based on eccentric calibration volume calibration synchronization.

[0043] Fourthly, the present invention provides a storage medium storing a computer program thereon, wherein the computer program, when executed by a processor, implements an RCS extraction method based on eccentric calibration volume calibration synchronization.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] This invention selects an eccentric calibration body that meets the scattering distance fluctuation requirements according to the target frequency band, ensuring that the eccentric calibration body generates sufficient radial distance change during rotation, so that the echo from the eccentric scattering point on the complex plane exhibits a circle-fitting characteristic. This circle-fitting characteristic allows background noise to be accurately separated from the echo data through circle fitting, avoiding the problems of traditional background acquisition relying on additional tests or multiple scans of the site environment, significantly reducing background uncertainty and improving the stability and repeatability of the test. This invention processes the eccentric calibration body to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed, and based on this, constructs a functional relationship between the actual scattering distance of the eccentric calibration body and the rotation angle. This invention implements targeted power compensation, normalizing the intensity of the echo signal across the entire angular domain, effectively eliminating amplitude errors caused by eccentricity, distance variations, and system path differences, and improving the consistency and comparability of the echo data. This invention analyzes the mathematical relationship between the phase and eccentricity position in the compensated calibration echo signal to estimate the offset position parameters between the center and rotation center of the eccentric calibration body, and corrects the eccentric calibration body accordingly. This process enables the eccentric calibration body to achieve equivalent centroid alignment in the signal space, eliminating the systematic phase shift caused by eccentricity and ensuring higher accuracy of the obtained calibration data, providing a reliable reference for subsequent background subtraction and radar cross section (RCS) calculation. This invention removes noise and external interference through filtering techniques and utilizes stable background data extracted from the compensated calibration echo signal, eliminating the need for additional site measurements during background modeling and significantly shortening the testing process. After background removal, the target's echo signal can be accurately recovered against a clean background and used together with the calibration data in the RCS calibration algorithm to achieve high-precision radar cross section calculation. In summary, this invention can not only simultaneously complete the background extraction and calibration data extraction processes, reducing the workload of on-site testing and improving the efficiency of RCS testing, but also significantly reduce the uncertainty of the background and systematic errors through key technologies such as distance compensation, phase correction and background separation, thereby improving the accuracy and stability of RCS measurement. It is particularly suitable for RCS testing scenarios with complex environmental reflections and unstable site backgrounds. Attached Figure Description

[0046] Figure 1 This is a flowchart of the present invention;

[0047] Figure 2 This is a system diagram of the present invention;

[0048] Figure 3 This is a schematic diagram of a test scenario for an eccentric calibration body.

[0049] Figure 4This is a schematic diagram of the distance calibration of the eccentric calibration body; where (a) is a schematic diagram of the result before the distance calibration of the calibration body, and (b) is a schematic diagram of the result after the distance calibration of the calibration body;

[0050] Figure 5 This is a schematic diagram of background data extraction for a fitted circle;

[0051] Figure 6 This is a schematic diagram comparing the results of the present invention with those of an ideal simulation.

[0052] Figure 7 This is a system diagram of Example 6. Detailed Implementation

[0053] To further understand the content of this invention, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the invention.

[0054] Example 1:

[0055] See Figure 1 The RCS extraction method based on calibration synchronization of an eccentric calibration body includes the following steps:

[0056] S1, Select the required eccentric calibration body according to the target frequency band.

[0057] S2. Based on the eccentric calibration body and the test turntable, a far-field transceiver feed test system is set up. The far-field transceiver feed test system is used to test the eccentric calibration body and the target body to obtain the echo signal of the eccentric calibration body and the echo signal of the target body.

[0058] S3. Process the echo signal of the eccentric calibration body to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the field transceiver feed test system. Based on the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed, obtain the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable. Based on the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable, perform power compensation on the echo signal of the eccentric calibration body to obtain the compensated calibration echo signal.

[0059] S4 processes the compensated calibration echo signal to obtain the deviation position parameters between the center of the eccentric calibration body and the rotation center of the eccentric calibration body. Based on the deviation position parameters, the eccentric calibration body is corrected to obtain accurate calibration data.

[0060] S5, extract the background data from the compensated calibrated echo signal.

[0061] S6, based on the background data, processes the accurate calibration data and the echo signal of the target to obtain the radar cross section of the target.

[0062] This embodiment selects an eccentric calibration body that meets the frequency band requirements, enabling it to form a fittable circular characteristic during rotation. This allows for accurate extraction of background data without additional background testing, reducing background uncertainty. Power compensation of the echo is performed using an eccentric scattering range model, effectively eliminating amplitude errors caused by range fluctuations. Furthermore, the relationship between phase and eccentric position is utilized to estimate the eccentric deviation and correct phase errors, improving the accuracy of the calibration signal. Combining filtering and background subtraction yields a true and stable calibration signal, making the calculation of the target's radar cross section more accurate. This method simultaneously extracts background data and calibration data, significantly improving the efficiency and accuracy of radar cross section testing.

[0063] Example 2:

[0064] See Figure 2 An RCS extraction system based on eccentric calibration synchronization includes:

[0065] The eccentric calibration body selection module is used to select the required eccentric calibration body according to the target frequency band.

[0066] The test module is used to set up a far-field transceiver test system based on an eccentric calibration body and a test turntable. The far-field transceiver test system is used to test the eccentric calibration body and the target body to obtain the echo signal of the eccentric calibration body and the echo signal of the target body.

[0067] The signal compensation module processes the echo signal of the eccentric calibration body to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the far-field transceiver feed test system. Based on the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed, the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable is obtained. Based on the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable, the power of the echo signal of the eccentric calibration body is compensated to obtain the compensated calibration echo signal.

[0068] The signal correction module is used to process the compensated calibration echo signal to obtain the deviation position parameters between the center of the eccentric calibration body and the rotation center of the eccentric calibration body. Based on the deviation position parameters, the eccentric calibration body is corrected to obtain accurate calibration data.

[0069] The background data extraction module is used to extract background data from the compensated calibrated echo signal.

[0070] The calibration processing module is used to process accurate calibration data and the echo signal of the target object based on background data to obtain the radar cross section of the target object.

[0071] Example 3:

[0072] This embodiment provides an RCS extraction method based on calibration synchronization of an eccentric calibration body. The method involves setting up a far-field transceiver feed test system to acquire echo signals from both the eccentric calibration body and the target object. It then sequentially performs operations such as eccentric calibration body selection, echo signal range compensation, phase error correction, background data extraction, and target object radar cross section calculation. This achieves synchronous extraction of background data and calibration data, ultimately yielding an accurate target object radar cross section.

[0073] Step 1: Select the required eccentric calibration body according to the target frequency band. When selecting the eccentric calibration body, the principle of background extraction by fitting a circle is adopted to ensure that the difference between the maximum and minimum radial distances between the scattering point of the eccentric calibration body and the feed source is greater than or equal to half of the lowest frequency wavelength, so as to ensure that the fluctuation of the scattering distance under different rotation angles meets the background fitting requirements.

[0074] Step two involves setting up a far-field transceiver feed test system based on an eccentric calibration body and a test turntable. In this system, the eccentric calibration body rotates around the rotation center of the test turntable, and far-field transceiver feeds are positioned at the desired locations. The echo signals of the eccentric calibration body at various rotation angles are acquired through far-field transceiver feed scanning, obtaining the echo signals of the eccentric calibration body. These echo signals include background data and eccentric calibration body data. Subsequently, the eccentric calibration body is replaced with a target object, and the same test procedure is performed in the far-field transceiver feed test system to obtain the echo signals of the target object at various rotation angles. These echo signals are then used as the target object's echo signals.

[0075] Step 3: Acquire the echo signal of the eccentric calibration body and perform an inverse Fourier transform on it to obtain a one-dimensional range image for the two-dimensional image display. Perform RF line loss removal processing on the one-dimensional range image to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed. Obtain the eccentric distance, radius, and rotation angle of the test turntable of the eccentric calibration body. Combine this with the actual distance between the rotation center and the far-field transceiver feed to obtain the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable. Further obtain the amplitude value of the echo signal of the eccentric calibration body as a function of angle. Combine this with the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable to perform power compensation on the echo signal of the eccentric calibration body to obtain the compensated calibration echo signal.

[0076] Step four involves acquiring the compensated calibration echo signal and analyzing the relationship between the phase and eccentric position of the eccentric calibration body. Based on this relationship, the phase error of the eccentric calibration body at different eccentric positions is obtained. The phase error at these positions is then estimated using the least squares method to obtain the deviation parameters between the eccentric calibration body and the rotation center. Based on these deviation parameters, the phase of the eccentric calibration body is corrected to obtain accurate calibration data.

[0077] Step 5: Obtain the compensated calibration echo signal, extract the noisy complex signal, and filter the noisy complex signal to obtain a signal that retains the auxiliary measurement signal and the background signal. Then, the background data in the signal is extracted using the fitted circle background extraction principle to obtain stable background data related to the eccentric calibration body.

[0078] Step six: Acquire the echo signal of the target object. Perform background cancellation on the target object's echo signal using background data to obtain the target object's calibration signal after background cancellation. Acquire the echo signal of the eccentric calibration body from the accurate calibration data. Perform background cancellation on the eccentric calibration body's echo signal using background data to obtain the eccentric calibration body's calibration signal after background cancellation. Input the target object's calibration signal and the eccentric calibration body's calibration signal after background cancellation into the calibration algorithm for processing, and finally obtain the target object's radar cross section.

[0079] Through the above steps, this embodiment can simultaneously extract calibration data and background data, realize echo signal power compensation and phase correction, and improve the calibration accuracy after background subtraction and the accuracy of the target's radar cross section.

[0080] Example 4:

[0081] This embodiment includes the following steps:

[0082] Step 1: Select a suitable eccentric calibration body according to the frequency band. Calculate the eccentric calibration body based on the principle of background extraction using a fitted circle, ensuring that the difference between the maximum and minimum radial distances between the scattering point of the eccentric calibration body and the feed source is greater than or equal to half of the lowest frequency wavelength.

[0083] As the test turntable rotates, the phase changes with the turntable's rotation angle. The difference between the farthest and nearest radial distances of the echo pair... When the following conditions are met:

[0084]

[0085] The set of points formed by the real and imaginary parts of the echo signal can be represented as a circle in the XOY coordinate system. In the absence of background noise, the echo amplitude deviation caused by the radial distance is negligible compared to the distance between the test turntable and the center of rotation; the center of the circle is at the origin. When background noise is introduced, the distance between the center of the circle and the origin becomes the background echo value; this is the principle behind using a fitted circle to extract background noise. At the speed of light, This is the lowest frequency.

[0086] In actual testing, a metal sphere offset from the center of rotation is placed on the test turntable as an eccentric calibration body, and an eccentric peach-shaped structure is designed on the top of the test turntable as an eccentric calibration body. The value of the eccentricity is... Half of it. For example, above 1GHz, The center distance of the eccentric calibrator from the rotation center needs to be ≥75mm, and at the same time, the scattering value of the eccentric calibrator is at least 20dB higher than the background.

[0087] Step two: Based on the eccentric calibration body and the test turntable, a far-field transceiver feed test system is set up so that the eccentric calibration body rotates around the rotation center of the test turntable. The far-field transceiver feed scans and collects the echo signals corresponding to the eccentric calibration body at various rotation angles, which serve as the echo signals of the eccentric calibration body. The echo signals of the eccentric calibration body also contain background data. and eccentric calibration data However, different algorithms are needed to extract them separately, then remove the eccentric calibration body, place the target body for rotation testing, and obtain the echo signal T of the target body.

[0088] Step 3: Perform an inverse Fourier transform on the echo signal from the eccentric calibration body to obtain a one-dimensional range image displayed in the two-dimensional image. Remove the RF line loss from the one-dimensional range image to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed. The actual scattering distance of the eccentric calibrator The rotation angle of the test turntable has the following functional relationship:

[0089]

[0090] in, The eccentricity distance of the eccentric calibration body. The radius of the eccentric calibration body, To test the rotation angle of the turntable, the echo signal T of the target object is:

[0091]

[0092] in, This represents the amplitude of the echo signal from the eccentric calibrator as a function of angle. Based on the relationship between the actual scattering distance of the eccentric calibrator and the rotation angle of the test turntable, power compensation is performed on the echo signal from the eccentric calibrator to obtain the compensated echo signal. :

[0093]

[0094] in, The operating frequency of the eccentric calibrator. It is a natural constant.

[0095] Step 4: Obtain the distance between the center of the eccentric calibration body and the center of rotation. The angle between the line connecting the center of the eccentric calibration body and the center of the test turntable and a certain zero-angle line. Test the angular velocity of the turntable rotation The included angle is obtained. .

[0096] exist At time t, the distance from the eccentric calibrator to the feed source is ,get:

[0097]

[0098] because, Then, after Taylor expansion, we get:

[0099]

[0100] Assume the feed source transmits a signal for:

[0101]

[0102] Ignoring the movement of the target object during the two-way propagation of the electromagnetic wave, the received signal is:

[0103]

[0104] in, The imaginary unit, The angular frequency of the signal transmitted by the feed source. The initial phase of the feed signal is denoted as . The operating wavelength of the feed source. The total phase term of the echo signal. .

[0105] Phase error mainly comes from The second term is estimated using the least squares method, taking into account the distance d between the center of the eccentric calibration body and the rotation center, and the included angle. An estimation is performed to obtain the error term in the phase term of the calibration body echo signal. Then, the influence of this error term is eliminated to obtain accurate calibration body data.

[0106] Step 5: Obtain the compensated calibration echo signal and extract the noisy complex signal from the compensated calibration echo signal. for:

[0107]

[0108] in, The amplitude of the echo signal from the eccentric calibration body. The amplitude of the background echo. For the phase of the background echo, The echo signal is from an eccentric calibration body and contains amplitude and phase information. The background signal contains amplitude and phase information; N represents noise; and L represents external interference. The noise N and external interference L components are filtered to retain only the echo signal from the eccentric calibration body. and background signals The received signal consists of two parts, after filtering. for:

[0109]

[0110] The filtered received signal It can be written in the form of an orthogonal signal consisting of an in-phase component I and a quadrature component Q, as follows:

[0111]

[0112]

[0113]

[0114] Therefore:

[0115]

[0116] and

[0117]

[0118] in, To receive the in-phase component of the signal, To receive orthogonal components of the signal, For the in-phase component of the eccentric calibration body signal, For the orthogonal components of the eccentric calibration volume signal, The background signal is in-phase component. These are the quadrature components of the background signal.

[0119] The trajectory of signal S in the IQ plane is a circle or arc with its center deviating from the origin, the position of the center... It is the IQ component of the background signal that is the radius of the circle. To assist in the amplitude of the calibration body signal, the center position of the circle represents the IQ component of the background clutter, and the radius of the circle is the RCS amplitude of the eccentric calibration body, thereby simultaneously obtaining the estimated values ​​of the IQ components of the eccentric calibration body echo and the background clutter.

[0120] Step 6: Acquire the echo signal of the target object using background data. Background cancellation of the target's echo signal:

[0121]

[0122]

[0123] in, For the calibration signal of the target body, This is the calibration signal for the eccentric calibration body.

[0124] The calibration signal of the target calibration signal with eccentric calibrator The input is processed by a calibration algorithm to obtain the radar cross section of the target.

[0125] Example 5:

[0126] This embodiment simulates the above embodiment using the high-frequency electromagnetic structure simulation software Ansys HFSS2020 and the mathematical modeling and simulation software Matlab 2022b. In the high-frequency electromagnetic structure simulation software Ansys HFSS2020, a radar echo simulation scenario is set. It is assumed that the distance between the feed source and the test rotation center is 20m, the distance between the center of the eccentric calibration body and the test rotation center is 150mm, the frequency band is set to 1-4GHz, and the frequency interval is 10MHz.

[0127] The above embodiments are implemented in detail. Steps one and two are modeled in the high-frequency electromagnetic structure simulation software Ansys HFSS2020, while steps three, four, five, and six are performed in the mathematical modeling and simulation software Matlab 2022b. In step two, background noise is set during simulation to simulate the real test environment. The radar cross section result of the target obtained in step six is ​​compared with the ideal simulated radar cross section value.

[0128] As can be seen from steps one and two of the simulation, two rotation test processes were simulated. The calibration data and background data are based on the first rotation test of the eccentric calibration body in step two. The target data is based on the second rotation test of the target in step two, which effectively shortens the test time in a real-world testing scenario.

[0129] from Figure 3 This shows the actual simulation test scenario of the eccentric calibration body. Figure 4 As can be seen from the distance calibration data, the eccentric calibration echo data obtained through distance calibration is represented by a straight line perpendicular to the distance coordinate axis in the distance image plane, indicating that the distance between the feed and the eccentric calibration body remains constant. Figure 5 As can be seen, the echo data from the eccentric calibration body can be presented as a circle in the XOY coordinate system after each frequency point is rotated once. From Figure 6 As can be seen from the results, the radar cross section extracted by the present invention is basically consistent with the value of the ideal simulation. The radar cross section value obtained by the present invention has some fluctuations due to the background noise set in the simulation.

[0130] Example 6:

[0131] See Figure 7 The present invention also provides an electronic device 100 based on an RCS extraction method for eccentric calibration body calibration synchronization; 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.

[0132] The memory 101 can be used to store the computer program 103. The processor 102 implements the steps of the RCS extraction method based on eccentric calibration synchronization described in Embodiment 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 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the electronic device 100 (such as audio data), etc. In addition, the memory 101 may include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other non-volatile solid-state storage device.

[0133] The at least one processor 102 may be a Central Processing Unit (CPU), or 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 any conventional processor. The processor 102 is the control center of the electronic device 100, connecting various parts of the electronic device 100 via various interfaces and lines.

[0134] The memory 101 in the electronic device 100 stores multiple instructions to implement an RCS extraction method based on eccentric calibration volume synchronization, and the processor 102 can execute the multiple instructions to achieve the following:

[0135] Select the required eccentric calibration body according to the target frequency band;

[0136] Based on the eccentric calibration body and the test turntable, a far-field transceiver feed test system was set up. The far-field transceiver feed test system was used to test the eccentric calibration body and the target body, and the echo signal of the eccentric calibration body and the echo signal of the target body were obtained.

[0137] The echo signal of the eccentric calibration body is processed to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the far-field transceiver feed test system. Based on the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed, the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable is obtained. Based on the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable, the echo signal of the eccentric calibration body is power compensated to obtain the compensated calibration echo signal.

[0138] The compensated calibration echo signal is processed to obtain the deviation position parameters between the center of the eccentric calibration body and the rotation center of the eccentric calibration body. The eccentric calibration body is corrected according to the deviation position parameters to obtain accurate calibration data.

[0139] Extract background data from the compensated calibrated echo signal;

[0140] Based on the background data, the accurate calibration data and the echo signal of the target are processed to obtain the radar cross section of the target.

[0141] Example 7:

[0142] If the modules / units integrated in the electronic device 100 are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, and a read-only memory (ROM).

[0143] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied 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.

[0144] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0145] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0146] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0147] 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 it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do 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. An RCS extraction method based on calibration synchronization of an eccentric calibration body, characterized in that, Includes the following steps: The required eccentric calibration body is selected based on the target frequency band, and the specific method is as follows: Based on the principle of background extraction of fitted circles, an eccentric calibration body is selected such that the difference between the maximum and minimum radial distances between the scattering point of the eccentric calibration body and the feed source is greater than or equal to half of the lowest frequency wavelength. Based on the eccentric calibration body and the test turntable, a far-field transceiver feed test system was set up. The far-field transceiver feed test system was used to test the eccentric calibration body and the target body, and the echo signal of the eccentric calibration body and the echo signal of the target body were obtained. The echo signal of the eccentric calibration body is processed to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the far-field transceiver feed test system. Based on the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed, the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable is obtained. Based on the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable, the echo signal of the eccentric calibration body is power compensated to obtain the compensated calibration echo signal. The compensated calibration echo signal is processed to obtain the deviation position parameters between the center of the eccentric calibration body and the rotation center of the eccentric calibration body. The eccentric calibration body is corrected according to the deviation position parameters to obtain accurate calibration data. The background data is extracted from the compensated calibrated echo signal using the following method: The compensated calibration echo signal is acquired, the noisy complex signal in the compensated calibration echo signal is extracted, and the noisy complex signal is filtered for noise and interference signals to obtain a signal that retains the auxiliary measurement signal and the background signal. Background data is extracted from the signals that retain both the auxiliary measurement signal and the background signal using the principle of fitted circle background extraction. Based on the background data, the accurate calibration data and the echo signal of the target are processed to obtain the radar cross section of the target.

2. The RCS extraction method based on eccentric calibration volume synchronization according to claim 1, characterized in that, Based on an eccentric calibration body and a test turntable, a far-field transceiver feed test system was set up. The eccentric calibration body and the target body were tested using the far-field transceiver feed test system. The specific method for obtaining the echo signals of the eccentric calibration body and the target body is as follows: Based on the eccentric calibrator and the test turntable, a far-field transceiver feed test system is set up. In the far-field transceiver feed test system, the eccentric calibrator rotates around the rotation center of the test turntable, and far-field transceiver feeds are deployed at the required positions. The far-field transceiver feed scans and acquires the echo signals corresponding to the eccentric calibration body at various rotation angles. These echo signals of the eccentric calibration body include background data and eccentric calibration body data. The eccentric calibration body was replaced with the target body and tested in a far-field transceiver feed test system. The echo signals of the target body at various rotation angles were obtained and used as the echo signals of the target body.

3. The RCS extraction method based on eccentric calibration volume synchronization according to claim 1, characterized in that, The echo signal of the eccentric calibration body is processed to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the far-field transceiver feed test system. Based on the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed, the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable is obtained. Power compensation is then performed on the echo signal of the eccentric calibration body based on this relationship. The specific method for obtaining the compensated calibration echo signal is as follows: The echo signal of the eccentric calibration body is obtained, and the inverse Fourier transform of the echo signal of the eccentric calibration body is performed to obtain the one-dimensional range image displayed in the two-dimensional image. By removing the RF line loss in the one-dimensional distance image, the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the far-field transceiver feed test system is obtained. Obtain the eccentricity distance, radius, and rotation angle of the test turntable of the eccentric calibrator. Combine this with the actual distance between the rotation center of the eccentric calibrator and the far-field transceiver feed to obtain the relationship between the actual scattering distance of the eccentric calibrator and the rotation angle of the test turntable. The amplitude of the echo signal of the eccentric calibrator as a function of the rotation angle is obtained. Based on the relationship between the actual scattering distance of the eccentric calibrator and the rotation angle of the test turntable, the power of the echo signal of the eccentric calibrator is compensated to obtain the compensated calibration echo signal.

4. The RCS extraction method based on eccentric calibration volume synchronization according to claim 1, characterized in that, The compensated calibration echo signal is processed to obtain the offset position parameters between the center of the eccentric calibration body and its rotation center. The eccentric calibration body is then corrected based on these offset position parameters to obtain accurate calibration data. The specific method for this is as follows: The echo signal of the compensated eccentric calibration body is obtained, and the relationship between the phase and the eccentric position of the eccentric calibration body is analyzed. Based on the relationship between the phase of the eccentric calibrator and the eccentric position, the phase error of the eccentric calibrator at different eccentric positions is obtained; The phase error of the eccentric calibration body at different eccentric positions is estimated by least squares method to obtain the position parameters of the eccentric calibration body relative to the rotation center of the eccentric calibration body; The phase of the eccentric calibrator is corrected by using the offset position parameter of the eccentric calibrator rotation center to obtain accurate calibration data.

5. The RCS extraction method based on eccentric calibration volume synchronization according to claim 1, characterized in that, The specific method for obtaining the radar cross section of the target object by processing accurate calibration data and the echo signal of the target object based on background data is as follows: Acquire the echo signal of the target object, and use background data to perform background cancellation on the echo signal of the target object to obtain the calibration signal of the target object after background cancellation; Obtain the echo signal of the eccentric calibration body from the accurate calibration data, and use the background data to perform background cancellation on the echo signal of the eccentric calibration body to obtain the calibration signal of the eccentric calibration body after background cancellation. The calibration algorithm is used to process the calibration signal of the target object after background cancellation and the calibration signal of the eccentric calibration object after background cancellation to obtain the radar cross section of the target object.

6. An RCS extraction system based on eccentric calibration synchronization, and based on the RCS extraction method based on eccentric calibration synchronization as described in claim 1, characterized in that, include: The eccentric calibration body selection module is used to select the required eccentric calibration body according to the target frequency band; The test module is used to set up a far-field transceiver feed test system based on an eccentric calibration body and a test turntable. The far-field transceiver feed test system is used to test the eccentric calibration body and the target body to obtain the echo signal of the eccentric calibration body and the echo signal of the target body. The signal compensation module is used to process the echo signal of the eccentric calibration body to obtain the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed in the far-field transceiver feed test system. Based on the actual distance between the rotation center of the eccentric calibration body and the far-field transceiver feed, the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable is obtained. Based on the relationship between the actual scattering distance of the eccentric calibration body and the rotation angle of the test turntable, the power compensation of the echo signal of the eccentric calibration body is performed to obtain the compensated calibration echo signal. The signal correction module is used to process the compensated calibration echo signal to obtain the deviation position parameters between the center of the eccentric calibration body and the rotation center of the eccentric calibration body. Based on the deviation position parameters, the eccentric calibration body is corrected to obtain accurate calibration data. The background data extraction module is used to extract background data from the compensated calibrated echo signal. The calibration processing module is used to process accurate calibration data and the echo signal of the target object based on background data to obtain the radar cross section of the target object.

7. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the RCS extraction method based on eccentric calibration synchronization as described in any one of claims 1 to 5.

8. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the RCS extraction method based on eccentric calibration synchronization as described in any one of claims 1 to 5.

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