Method and device for measuring complex scattering function of radar target

Abstract

The invention discloses a method and device for measuring a complex scattering function of a radar target, and relates to the field of microwave stealth technology and active microwave remote sensing, and the method comprises the steps: constructing a generalized radar equation represented by a complex voltage for a radar detection target; according to the generalized radar equation, fitting to obtain a relation curve of the amplitude and the distance of the complex scattering function and a relation curve of the phase and the distance; performing low-pass filtering processing on the relation curve of the amplitude and the distance and the relation curve of the phase and the distance; and for the relation curve of the amplitude and the distance after filtering and the relation curve of the phase and the distance after filtering, obtaining the amplitude and the phase of the complex scattering function at the infinite far field by adopting a polynomial fitting and limit taking method. According to the invention, the method can directly and accurately measure the complex scattering function of any small to-be-measured target (including a standard device), and does not need an RCS standard device with a known standard value in the measurement process.

Description

TECHNICAL FIELD

[0001] The present application relates to the fields of microwave stealth technology and active microwave remote sensing, and particularly relates to a radar target complex scattering function measurement method and device. BACKGROUND

[0002] In the fields of microwave stealth technology and active microwave remote sensing, it is necessary to accurately obtain electromagnetic scattering information of a target to be measured. However, it is found by modern measurement instrument research that, although ideal instruments (including ideal radars) do not exist, accurate calibration methods can be used in combination with corresponding precision calibration pieces to achieve precision calibration of the measurement instrument, so that the error is kept within a sufficiently small range. For precision measurement systems such as microwave stealth target precision measurement systems and active microwave remote sensing, it is impossible to perform accurate measurement without precision calibration methods and supporting standard devices with standard values. In the early stage, a standard metal sphere was usually used in the field of microwave stealth measurement technology, and a three-corner reflector was usually used in the field of active microwave remote sensing. The standard value of the radar cross section (RCS) or the scattering function can be obtained by full-wave analysis modeling and simulation calculation. However, as the measurement accuracy improves, some complex standard devices (whose shape is difficult to accurately model) such as a dragon lens with a dielectric material and an active RCS standard device are needed. However, complex standard devices cannot be modeled and simulated by full-wave analysis methods, and are usually measured by a comparison method, that is, by measuring a target to be measured and a standard device with a known standard value, and then by measuring the difference between the return intensities to obtain the RCS or the scattering function (Scattering function-SF) of the target to be measured. However, this method inevitably increases the measurement uncertainty. Therefore, it is of great significance to accurately measure the complex scattering function of a radar target. SUMMARY

[0003] The purpose of the present application is to provide a radar target complex scattering function measurement method and device, which solves the problem of precision measurement of standard devices and standard scattering functions of small targets to be measured.

[0004] To achieve the above purpose, the present application provides the following solutions: In a first aspect, the present application provides a radar target complex scattering function measurement method, comprising: For radar detection targets, a generalized radar equation represented by complex voltage is constructed; the generalized radar equation contains impedance mismatch correction; According to the generalized radar equation, the amplitude-distance relationship curve of the complex scattering function and the phase-distance relationship curve of the complex scattering function are fitted; The amplitude-distance relationship curve and the phase-distance relationship curve are subjected to low-pass filtering processing, and the filtered amplitude-distance relationship curve and the filtered phase-distance relationship curve are obtained, respectively. The amplitude and phase of the complex scattering function at infinity are obtained by using polynomial fitting and taking the limit on the curves showing the relationship between the filtered amplitude and distance, as well as the curves showing the relationship between the filtered phase and distance.

[0005] Secondly, this application provides a system for measuring the complex scattering function of a radar target, comprising: The generalized radar equation construction module is used to construct generalized radar equations in terms of complex voltages for radar-detected targets; the generalized radar equations include impedance mismatch corrections; The fitting module is used to fit the curves of the amplitude of the complex scattering function versus the distance and the curves of the phase of the complex scattering function versus the distance based on the generalized radar equation. The filtering module is used to perform low-pass filtering on the amplitude-distance relationship curve and the phase-distance relationship curve, respectively, to obtain the filtered amplitude-distance relationship curve and the filtered phase-distance relationship curve. The polynomial fitting and limit module is used to obtain the amplitude and phase of the complex scattering function at infinity by using polynomial fitting and limit taking on the relationship curves of the amplitude versus distance and the phase versus distance after filtering.

[0006] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method for measuring the complex scattering function of a radar target.

[0007] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the aforementioned method for measuring the complex scattering function of a radar target.

[0008] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the aforementioned method for measuring the complex scattering function of a radar target.

[0009] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a method and apparatus for measuring the complex scattering function of a radar target. For the first time, it clearly presents a complete analytical expression of the generalized radar equation in terms of complex voltage, including reflections from the radar antenna and the transmitting and receiving antennas. Because it uses complex numbers, it provides a perfect theoretical and computational formula for target background cancellation. Furthermore, compared to conventional radar equations, it considers phase information and multiple reflections between the antenna and the target. In addition, this application can directly and accurately measure the complex scattering function (the amplitude of which is the RCS) of any small target (including a standard), accurately quantifying the scattering characteristics of the target to incident electromagnetic waves, achieving precise measurement of the complex scattering function of the target, and eliminating the need for a standard RCS with a known value during the measurement process. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 A flowchart illustrating a method for measuring the complex scattering function of a radar target, provided in Embodiment 1 of this application; Figure 2 A schematic diagram of the target to be measured located directly in front of the radar antenna, as provided in Embodiment 1 of this application; Figure 3 A schematic diagram of a theoretical model of the target under test located in front of the radar antenna's line of sight, provided in Embodiment 1 of this application; Figure 4 This is a schematic diagram of SF varying with distance, provided in Embodiment 1 of this application; Figure 5 A schematic diagram illustrating the intense fluctuations introduced by multiple reflections between the target under test and the radar antenna, and the antenna reflection, as provided in Embodiment 1 of this application; Figure 6 A schematic diagram showing the change and filtering effect of the amplitude of SF after local magnification in Embodiment 1 of this application; Figure 7 This is a schematic diagram showing the phase local magnification change and filtering effect of the SF provided in Embodiment 1 of this application; Figure 8 This is a schematic diagram of the flat panel in the Ku band provided in Embodiment 1 of this application; Figure 9 The validity verification process of the measurement method provided in Embodiment 1 of this application; Figure 10This is a schematic diagram showing the change of SF of a 200mm×200mm metal plate as a function of distance, calculated using the electromagnetic moment method, as provided in Embodiment 1 of this application. Figure 11 A schematic diagram comparing the amplitude measurement results of SF based on the measurement method of this application with the user simulation results provided in Embodiment 1 of this application; Figure 12 A schematic diagram comparing the phase measurement results of SF based on the measurement method of this application with the user simulation results provided in Embodiment 1 of this application; Figure 13 This is a functional module diagram of a radar target complex scattering function measuring device provided in Embodiment 2 of this application; Detailed Implementation

[0012] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0013] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0014] Example 1 like Figure 1 As shown, this embodiment provides a method for measuring the complex scattering function of a radar target. The method is illustrated using frequency domain measurement as an example, but it can also be applied to time domain measurement. The method includes: S1: For each frequency point in the radar detection band, construct a generalized radar equation expressed in terms of complex voltages. The generalized radar equation includes impedance mismatch correction.

[0015] like Figure 2 As shown, the target under test (RCS standard) is located directly in front of the radar antenna, and the distance between the antenna aperture and the reference surface of the target under test is... Based on this model, the generalized radar equation expressed in terms of complex voltage is derived, and the complex scattering function is then calculated using this analytical expression based on the measurement results.

[0016] The derived expression for the generalized radar equation is as follows: (1) in, This represents the complex voltage at the output of the radar antenna; This represents the complex voltage fed into the radar antenna; This represents the reflection coefficient at the input of the radar antenna; Indicates the target under test in the incident wave Scattering function under component Quantity; Indicates the target under test in the incident wave Scattering function under component Quantity; Indicates the target under test in the incident wave Scattering function under component Quantity; Indicates the target under test in the incident wave Scattering function under component Quantity; Represented as the antenna aperture in the radar echo Scattering function under component Quantity; Indicates wavelength; Represents the space wave number of radio waves. ; This represents the distance between the radar antenna aperture and the reference point of the target being measured, in meters (m). Indicates the imaginary number identifier; Indicates the radar antenna aperture in the radar echo Scattering function under component Quantity; Indicates the radar antenna aperture in the radar echo Scattering function under component Quantity; Indicates the radar antenna aperture in the radar echo Scattering function under component Quantity; Represents the complex transfer function of the radar antenna Components, amplitude in meters (m), phase in degrees (°); Represents the complex transfer function of the radar antenna Components, amplitude in meters (m), phase in degrees (°); Indicates ratio Higher-order components. All parameters in the formula are in complex form.

[0017] The derivation of formula (1) is as follows: like Figure 2 As shown, the target under test is located directly in front of the radar antenna's line of sight, and the distance from the target's reference plane to the antenna aperture is [distance missing]. The above model can be extended to, for example... Figure 3 The model shown. Figure 3 In Chinese, the meanings of each symbol are as follows: Input radio frequency voltage of the radar antenna; Characteristic impedance is, typically ; Input impedance of the radar antenna; F1: Reference plane for radar antenna input signal; The scattering function matrix of the target under test; : The radio frequency voltage input from the radar antenna to the radar receiver; , : These represent the complex electric field strength (indicating the electromagnetic waves radiated by the radar antenna striking the target.) Components and Quantity; , : These are the complex electric field strengths of the electromagnetic waves scattered by the target reaching the radar antenna aperture. Components and Quantity.

[0018] Wave impedance in air, typically .

[0019] If we consider the radar antenna as a "3-port network", then according to microwave network theory, we have: (2) Based on the meaning of the scattering function matrix of the target, we have: (3) Solving the above formulas simultaneously, we get: (4) In the formula: (5) (6) (7) Equations (4) to (7) can be simplified to: (8) Bundle and Substituting into equation (8), we can obtain equation (1).

[0020] S2: Based on the generalized radar equation, the curves showing the relationship between the amplitude and distance of the complex scattering function and the phase and distance of the complex scattering function are obtained by fitting.

[0021] Specifically, step S2 includes: (1) When the radar antenna is linearly polarized (its cross-polarization component can be ignored), the generalized radar equation is simplified and transformed to obtain the transformed equation; the parameters in the transformed equation include the reflection coefficient obtained when there is a target, the reflection coefficient obtained when there is no target, the range and the complex scattering function; the range refers to the distance between the radar and the target.

[0022] The expression for the deformation equation is: (9) In the formula: The reflection coefficient obtained when there is a target to be measured; The reflection coefficient obtained when there is no target to be measured; The distance between the radar and the target being measured; Radio wave space wavenumber ; Wavelength, measured in meters (m); The target under test in the incident wave Scattering function under component Quantity; : Complex transfer function of radar antenna Quantity; : Coefficients obtained from polynomial fitting.

[0023] The polynomial in the above formula Specific number of items It needs to be based on the distance to be measured. Reflection coefficient Monotonicity of the envelope and near-field scattering function It is determined by the monotonicity of the envelope. Usually... .

[0024] (2) Obtain the first dataset when there is a target to be measured and the second dataset when there is no target to be measured; the first dataset includes the reflection coefficients obtained at different distances and with the corresponding target to be measured; the second dataset includes the reflection coefficients obtained when there is no target to be measured.

[0025] The process of measuring the reflection coefficient with and without a target: (1) Accurately install the target and radar antenna to ensure that the attitude error is less than 0.05°.

[0026] (2) Accurately measure the reflection coefficient when there is no target to be measured. and By changing the distance between the radar and the target, a series of measurement data at different distances can be obtained.

[0027] (3) Substitute the data from the first and second datasets into the deformation equation and fit the curve of the relationship between the amplitude and distance of the complex scattering function (e.g., Figure 4 (a) The curve corresponding to BeforeFilter in the figure) and the curve showing the relationship between the phase and distance of the complex scattering function (e.g.) Figure 4 (b) The curve corresponding to BeforeFilter in the figure. Figure 4 In this context, the radar cross section (RCS) is the amplitude in the complex scattering function. This application employs background noise cancellation technology (i.e., the aforementioned vector subtraction) to reduce background scattering and radar antenna reflection. Theoretically, vector subtraction can only eliminate most of the background scattering, but some remains. Furthermore, strong multiple reflections exist between the antenna and the target, necessitating subsequent data filtering and polynomial fitting.

[0028] S3: Perform low-pass filtering on the amplitude-distance relationship curve and the phase-distance relationship curve to obtain the filtered amplitude-distance relationship curve and the filtered phase-distance relationship curve, respectively.

[0029] like Figure 5 As shown, due to multiple reflections between the target and the antenna, and between the antenna and the microwave signal source, the reflection coefficients (amplitude and phase) measured at the antenna port subsequently fluctuate drastically with distance, exceeding 10 dB. This fluctuation poses significant challenges to the measurement results. Therefore, the following filtering technique is proposed to address the multiple reflections between the target and the radar antenna.

[0030] The amplitude versus distance curve was filtered using low-pass filtering techniques to obtain a filtered amplitude versus distance curve, such as... Figure 4 The curve corresponding to AfterFilter in (a) is shown in the enlarged view below. Figure 6 The green curve is shown.

[0031] The phase-distance relationship curve is filtered using low-pass filtering techniques to obtain the filtered phase-distance relationship curve, such as... Figure 4 The curve corresponding to AfterFilter in (b) is shown in the enlarged view below. Figure 7 The green curve is shown.

[0032] S4: For the relationship curves of amplitude versus distance and phase versus distance after filtering, the amplitude and phase of the complex scattering function at infinity at each frequency point are obtained by using polynomial fitting and then taking the limit.

[0033] Scattering function ( ,in, The scattering function of the target is given, with amplitude in meters and phase in degrees. Let be the electric field of the plane wave incident on the target reference point, with an amplitude of V / m and a phase of °; The electromagnetic field strength (with amplitude V / m and phase °) of the electromagnetic wave scattered by the target reaching the plane wave reference point is defined at an infinite distance. However, in actual measurements, the distance between the radar antenna and the target cannot be infinite. In practice, to ensure the received echo field strength... Sufficient power for accurate measurements, and limitations of microwave anechoic chamber size, measurement distance. It always needs to be limited to a certain range. In fact, even if the far-field distance is satisfied... (here The size of the antenna or target. The phase error introduced is as high as 22.5° (where the wavelength is 160 nm). To address the field gradient error introduced over a finite distance, a polynomial fitting and limit method is used to obtain the SF at infinity. Specifically, step S4 includes: (1) Fit the relationship curve between the filtered amplitude and distance using a cubic or quartic polynomial to obtain the amplitude-distance polynomial fitting result, such as Figure 4 The curve corresponding to Poly in (a) is shown in the magnified view of its local area. Figure 6 The blue curve in the image.

[0034] (2) Take the limit of the amplitude-distance polynomial fitting result to obtain the amplitude of the complex scattering function at infinity at each frequency point. For example Figure 4 The curve corresponding to Infinite in (a) shows the amplitude of the complex scattering function at infinity at a certain frequency. Figure 8 The complex scattering function at each frequency point is shown, where (a) is the amplitude at infinity at each frequency point.

[0035] (3) A cubic polynomial is used to fit the relationship curve between the filtered phase and the distance to obtain the phase-distance polynomial fitting result, such as... Figure 4 The curve corresponding to Poly in (b) is shown in the magnified view of its local area. Figure 7 The blue curve in the image.

[0036] (4) Take the limit of the phase-range polynomial fitting results to obtain the phase of the complex scattering function at infinity at each frequency point. For example... Figure 4 The curve corresponding to Infinite in (b) shows the phase of the complex scattering function at infinity at a certain frequency. Figure 8(b) represents the phase at infinity at each frequency point.

[0037] This application presents, for the first time, a complete analytical expression of the generalized radar equation in terms of complex voltage, which includes reflections from the radar antenna and the transmitting and receiving antennas. Because it uses complex numbers, it provides a perfect theoretical and computational formula for target background cancellation. In contrast, conventional radar equations measure the radar cross section (RCS), which lacks phase information and does not consider multiple reflections between the antenna and the target. Furthermore, by measuring the distance-dependent SF (sensory fraction), a solid foundation is provided for eliminating multiple reflections between the radar antenna and the target; this measurement also provides a solid foundation for measuring the SF at infinite distances from finite distances. Moreover, the method in this application accurately measures the SF of the target without requiring a known RCS standard during the measurement process.

[0038] like Figure 9 As shown, to verify the effectiveness of the measurement method in this application, the electromagnetic moment method is used for modeling and simulation calculations of simple standard instruments such as metal plates to obtain their scattered electric field. Then, based on... The near-field SF as a function of distance can be calculated. From the curve, we can then obtain its far-field SF, such as Figure 10 As shown. Since the phase of the calculated SF does not converge, a sufficiently long SF distance can usually be used. Figure 11 The amplitude measurement results of SF using the method of this application are shown in comparison with user simulation results; Figure 12 The phase measurement results of SF using the method of this application are shown in comparison with the user simulation results. Figure 11 and Figure 12 In the diagram, the black curve represents the amplitude and phase of the SF obtained using the Electromagnetic Moment Method (MoM) simulation; the red curve represents the amplitude and phase of the SF measured using the method of measurement from this invention. Figure 11 and Figure 12 As can be seen, the amplitude difference is less than 0.5 dB and the phase difference is less than 5°, indicating that the results match very well and verifying the accuracy of the measurement method obtained in this application. Therefore, it can be concluded that the verification method of electromagnetic moment method used in this application achieves perfect agreement between the measurement results and simulation results, demonstrating that the measurement method provided in this application is feasible and has a very high level of maturity. Figure 9 If the difference does not meet the requirements, the preparation of the standard body and horn antenna must be returned, and the measurement must be repeated, including the processing of the standard body and the metrological calibration of the complex transfer function of the standard gain horn antenna.

[0039] This application also provides an application scenario in which the aforementioned method for measuring the complex scattering function of radar targets is applied. Specifically, the method for measuring the complex scattering function of radar targets provided in this embodiment can be applied in the design scenario of stealth unmanned aerial vehicles (UAVs). This scenario includes a complex scattering function measurement stage for the UAV under test and a UAV optimization stage; the complex scattering function measurement stage is used to accurately quantify the scattering characteristics of the UAV to incident electromagnetic waves; the UAV optimization stage optimizes the UAV structure based on the scattering characteristics to reduce its detectability. The method for measuring the complex scattering function of radar targets provided in this embodiment belongs to the complex scattering function measurement stage of the UAV under test.

[0040] Example 2 Based on the same inventive concept, this embodiment also provides a complex scattering function measurement system for radar targets, used to implement the aforementioned method for measuring the complex scattering function of radar targets. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations of one or more embodiments of the complex scattering function measurement system for radar targets provided below can be found in the limitations of the complex scattering function measurement method for radar targets described above, and will not be repeated here. Figure 13 As shown, a system for measuring the complex scattering function of a radar target is provided, comprising: The generalized radar equation construction module M1 is used to construct a generalized radar equation in terms of complex voltages for radar-detected targets; the generalized radar equation includes impedance mismatch correction.

[0041] The fitting module M2 is used to fit the curves of the relationship between the amplitude and the distance of the complex scattering function and the relationship between the phase and the distance of the complex scattering function according to the generalized radar equation.

[0042] The filtering module M3 is used to perform low-pass filtering on the amplitude-distance relationship curve and the phase-distance relationship curve, respectively, to obtain the filtered amplitude-distance relationship curve and the filtered phase-distance relationship curve.

[0043] The polynomial fitting and limit module M4 is used to obtain the amplitude and phase of the complex scattering function at infinity by using polynomial fitting and limit method on the relationship curves of the amplitude versus distance and the phase versus distance after filtering.

[0044] Example 3 In this embodiment, a computer device is provided, which may be a server or a terminal. The computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores generalized radar equations and the amplitude and phase of the complex scattering function at infinity at each frequency point. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for measuring the complex scattering function of a radar target. In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0045] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0046] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0047] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods.

[0048] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for measuring the complex scattering function of a radar target, characterized in that, include: For radar-detected targets, a generalized radar equation expressed in terms of complex voltage is constructed; The generalized radar equations include impedance mismatch corrections; Based on the generalized radar equation, the curves relating the amplitude of the complex scattering function to the distance and the curves relating the phase of the complex scattering function to the distance are obtained by fitting. Low-pass filtering was applied to the amplitude-distance and phase-distance curves to obtain the filtered amplitude-distance and phase-distance curves, respectively. The amplitude and phase of the complex scattering function at infinity are obtained by using polynomial fitting and taking the limit on the curves showing the relationship between the filtered amplitude and distance, as well as the curves showing the relationship between the filtered phase and distance.

2. The method for measuring the complex scattering function of a radar target according to claim 1, characterized in that, The expression for the generalized radar equation is: in, This represents the complex voltage at the output of the radar antenna; This represents the complex voltage fed into the radar antenna; This represents the reflection coefficient at the input of the radar antenna; Indicates the target under test in the incident wave Scattering function under component Quantity; Indicates the target under test in the incident wave Scattering function under component Quantity; Indicates the target under test in the incident wave Scattering function under component Quantity; Indicates the target under test in the incident wave Scattering function under component Quantity; Represented as the radar antenna aperture in the radar echo Scattering function under component Quantity; Indicates wavelength; Indicates the space wavenumber of radio waves; This indicates the distance between the radar antenna aperture and the reference point of the target being measured; Indicates the imaginary number identifier; Indicates the radar antenna aperture in the radar echo Scattering function under component Quantity; Indicates the radar antenna aperture in the radar echo Scattering function under component Quantity; Indicates the antenna aperture in the radar echo Scattering function under component Quantity; Represents the complex transfer function of the radar antenna Quantity; Represents the complex transfer function of the radar antenna Quantity; Indicates ratio Higher-order components.

3. The method for measuring the complex scattering function of a radar target according to claim 1, characterized in that, Based on the generalized radar equations, the relationship curves between the amplitude and range of the complex scattering function and between the phase and range of the complex scattering function are obtained through fitting, specifically including: When the radar antenna is linearly polarized, the generalized radar equation is simplified and transformed to obtain the transformed equation. The parameters in the transformed equation include the reflection coefficient obtained when there is a target, the reflection coefficient obtained when there is no target, the range, and the complex scattering function. The range refers to the distance between the radar and the target. Acquire a first dataset with a target to be measured and a second dataset without a target to be measured; the first dataset includes reflectance coefficients obtained at different distances with a target to be measured; the second dataset includes reflectance coefficients obtained without a target to be measured. Substituting the data from the first and second datasets into the deformation equation, we can obtain the curves showing the relationship between the amplitude and distance of the complex scattering function and the relationship between the phase and distance of the complex scattering function.

4. The method for measuring the complex scattering function of a radar target according to claim 3, characterized in that, The expression for the deformation equation is: in, The reflection coefficient is obtained when there is a target to be measured; The reflection coefficient is obtained when there is no target to be measured; Indicates the distance between the radar and the target being measured; Indicates the space wavenumber of radio waves; Indicates wavelength; Indicates the target under test in the incident wave Scattering function under component Quantity; Represents the complex transfer function of the radar antenna Quantity; The coefficients are represented by ; N represents the number of terms in the polynomial.

5. The method for measuring the complex scattering function of a radar target according to claim 1, characterized in that, The amplitude and phase of the filtered curves versus distance, and the phase versus distance curves, are obtained by polynomial fitting and taking the limit to derive the amplitude and phase of the complex scattering function at infinity. Specifically, this includes: The relationship curve between the filtered amplitude and distance is fitted using a cubic or quartic polynomial to obtain the amplitude-distance polynomial fitting result; By taking the limit of the amplitude-distance polynomial fitting result, the amplitude of the complex scattering function at infinity is obtained; A cubic polynomial was used to fit the relationship curve between the filtered phase and the distance, and the phase-distance polynomial fitting result was obtained. By taking the limit of the phase-range polynomial fitting result, the phase of the complex scattering function at infinity is obtained.

6. A system for measuring the complex scattering function of a radar target, characterized in that, include: The generalized radar equation construction module is used to construct generalized radar equations in terms of complex voltages for radar-detected targets. The generalized radar equations include impedance mismatch corrections; The fitting module is used to fit the curves of the amplitude of the complex scattering function versus the distance and the curves of the phase of the complex scattering function versus the distance based on the generalized radar equation. The filtering module is used to perform low-pass filtering on the amplitude-distance relationship curve and the phase-distance relationship curve, respectively, to obtain the filtered amplitude-distance relationship curve and the filtered phase-distance relationship curve. The polynomial fitting and limit module is used to obtain the amplitude and phase of the complex scattering function at infinity by using polynomial fitting and limit taking on the relationship curves of the amplitude versus distance and the phase versus distance after filtering.

7. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the method for measuring the complex scattering function of a radar target according to any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the method for measuring the complex scattering function of a radar target as described in any one of claims 1-5.

9. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the method for measuring the complex scattering function of a radar target as described in any one of claims 1-5.

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