Multiplicative error polarization calibration method, device and medium based on loose angle constraints

Abstract

The present invention discloses a multiplicative error polarization calibration method, device and medium based on loose angle constraints, which belongs to the technical field of full polarization radar and is used to solve the technical problem that the existing radar error polarization calibration method is difficult to apply to broadband full polarization radar systems with different isolation degrees, and the attitude constraint control of the calibration body in the radar is relatively complex, which is not conducive to the efficiency of polarization calibration. The method includes: performing consistency calculation on the main channel elements between the metal ball and the 45° metal wire to obtain a consistency result; calculating the metal echo of the 45° metal wire to obtain 45° metal wire echo data and 0° metal wire echo data; reconstructing the radar system polarization error matrix through partial system error parameters and system residual error parameters corresponding to the 0° metal wire echo data to obtain a reconstructed system error parameter matrix; compensating other targets in the broadband full polarization radar system and obtaining optimized polarization information.

Description

Technical Field

[0001] The present application relates to the technical field of full polarization radar, and in particular to a multiplicative error polarization calibration method, device and medium based on loose angle constraints. Background Art

[0002] A large number of studies have shown that polarization information has important application value in the fields of radar detection, tracking and parameter inversion. Therefore, many radar systems have introduced full polarization measurement systems, such as polarimetric synthetic aperture radar, full polarization ground penetrating radar and insect radar. However, in practical applications, full polarization insect radar often faces polarization errors. These errors mainly come from the amplitude and phase imbalance of the polarization channel and antenna crosstalk. Polarization errors will significantly affect the accuracy of the measurement results. Therefore, effective polarization calibration is an indispensable part of the application of polarization information.

[0003] Traditional mainstream passive polarization calibration methods usually consider narrowband radar systems, while broadband fully polarized radar systems will introduce additional multiplicative errors, and traditional mainstream polarization calibration methods will fail. There are two main ways to currently use polarization calibration methods for broadband radar systems: one is to use multiple calibration bodies to solve polarization errors, which has strict requirements on the attitude of the calibration body. Only when the calibration body strictly meets a specific attitude can effective polarization calibration be completed. However, in the field environment, it is often a great challenge to maintain the precise attitude of the calibration body and accurately align it with the center of the radar beam. In order to overcome attitude control, for example, a step-by-step polarization calibration method for a fully polarized radar based on a metal ball and a metal wire (CN202211393037.6) is disclosed. This polarization calibration method uses metal balls and metal wires to gradually calibrate the system error, and uses the results of the metal ball calibration to determine the metal wire attitude. However, this method ignores the antenna crosstalk in the system error model and is only effective for high-isolation radar systems. For radar systems with general system isolation, this polarization calibration method has a large error. Summary of the invention

[0004] The embodiments of the present application provide a multiplicative error polarization calibration method, device and medium based on loose angle constraints, which are used to solve the following technical problems: the existing radar error polarization calibration method is difficult to apply to broadband fully polarized radar systems with different isolation levels, and the attitude constraint control of the calibration body in the radar is relatively complex, which is not conducive to the efficiency of polarization calibration.

[0005] The present application embodiment adopts the following technical solutions:

[0006] On the one hand, an embodiment of the present application provides a multiplicative error polarization calibration method based on loose angle constraints, including: performing radar measurement processing on a metal wire and a metal ball respectively through a broadband fully polarized radar system; performing consistency calculation on the main channel elements between the metal ball and the 45° metal wire according to the polarization scattering matrix of the measurement target measured by the metal wire and the metal ball to obtain a consistency result; calculating the metal echo of the 45° metal wire according to the consistency result to obtain 45° metal wire echo data; determining 0° metal wire echo data based on the 45° metal wire echo; reconstructing the radar system polarization error matrix through partial system error parameters corresponding to the 45° metal wire echo data and system residual error parameters corresponding to the 0° metal wire echo data to obtain a reconstructed system error parameter matrix; compensating other targets in the broadband fully polarized radar system through the reconstructed system error parameter matrix and the true scattering matrix, and obtaining optimized polarization information.

[0007] The embodiment of the present application performs polarization calibration on a broadband fully polarized radar system. The use of multi-angle metal wires and metal balls can realize the solution of all polarization errors of the broadband fully polarized radar system. Compared with the prior art, the present application considers a complete system error model and is applicable to broadband fully polarized radar systems with different isolation levels. In addition, the present application determines the posture of the metal wire by using the consistency of the ratio of the main channel of the scattering matrix of the metal ball and the metal wire at a specific angle, which greatly reduces the constraints on the posture of the calibration body and facilitates engineering implementation.

[0008] In a feasible implementation manner, before performing consistency calculation on the main channel element between the metal ball and the 45° metal wire according to the polarization scattering matrix of the measurement target measured by the metal wire and the metal ball to obtain the consistency result, the method further includes: , obtain the polarization scattering matrix M of the measurement target; where, , , , , , , as well as The subscripts h and v in represent horizontal polarization and vertical polarization, respectively; represents the four-channel elements of the polarization scattering matrix of the measurement target, represents the wave number, Indicates the distance between the radar and the target. is the four-channel element of the channel gain matrix, represents the Hadamard product, , , and Represents the amplitude and phase imbalance factor in the receiving channel and the transmitting channel, and Respectively represent the amplitude and phase imbalance of the antenna H channel and V channel, and Both represent the cross-polarization level between different channels of the antenna. represents the four-channel element of the target's true polarization scattering matrix, Represents the additive error generated by noise and clutter; optimizes the single error term of the polarization scattering matrix of the measurement target; according to , and obtain the optimized measurement target polarization scattering matrix ;in, is the system error matrix, Included , , , , and Represent six error parameters respectively, and , , ; is the true polarization scattering matrix.

[0009] In a feasible implementation manner, according to the polarization scattering matrix of the measurement target measured by the metal wire and the metal ball, a consistency calculation is performed on the main channel element between the metal ball and the 45° metal wire to obtain a consistency result, specifically including: according to , and obtain the theoretical relative polarization scattering matrix of the metal sphere ;according to , the first theoretical relative polarization scattering matrix of the 45° wire is obtained ; The theoretical relative polarization scattering matrix of the metal ball and the first theoretical relative polarization scattering matrix of the 45° metal wire are combined with the polarization scattering matrix of the measurement target to obtain the main channel ratio of the metal ball to the 45° metal wire; wherein, according to , and obtain consistent results; among them, , , as well as ; is an error parameter of the polarization scattering matrix of the measurement target, is based on the error parameters in the polarization scattering matrix of the measurement target Intermediate amount; the consistency result represents that the ratio between the main channel elements between the metal ball and the 45° metal wire is the same.

[0010] In a feasible implementation, based on the consistency result, the metal echo of the 45° metal wire is calculated to obtain the 45° metal wire echo data, specifically including: using a broadband fully polarized radar system, calculating and processing the metal wire echo at different angles, and generating metal wire echo data sets at different angles; based on the consistency result, performing data query processing on the metal wire echo data sets at different angles to obtain the 45° metal wire echo data.

[0011] In a feasible implementation manner, based on the 45° metal wire echo, the 0° metal wire echo data is determined, specifically comprising: based on the uniform rotation of the radar antenna in the broadband fully polarized radar system, the 45° metal wire is angle-forwarded to obtain the 0° metal wire; based on the consistency result, data query processing is performed on the metal wire echo data sets at different angles to obtain the 0° metal wire echo data.

[0012] In a feasible implementation manner, before reconstructing the radar system polarization error matrix by using partial system error parameters corresponding to the 45° wire echo data and system residual error parameters corresponding to the 0° wire echo data to obtain a reconstructed system error parameter matrix, the method further includes: combining the 45° wire echo data and the 0° wire echo data with the measurement target polarization scattering matrix for calculation processing; , obtain the first part of the system error parameters in the partial system error parameters ;in, is the second intermediate quantity related to the 45° metal wire in the polarization scattering matrix of the measurement target, and ; is the first intermediate quantity related to the 45° metal wire in the polarization scattering matrix array of the measurement target, and ; is an error parameter of the polarization scattering matrix of the measurement target, is based on the error parameters in the polarization scattering matrix of the measurement target Intermediate quantity; according to , obtain the second part of the system error parameters in the partial system error parameters ;in, is the third intermediate quantity related to the 45° metal wire in the polarization scattering matrix of the measurement target, and ; is based on the error parameters in the polarization scattering matrix of the measurement target Intermediate quantity; according to , obtain the third part of the system error parameters in the partial system error parameters ;in, is the fourth intermediate quantity related to the 45° metal wire in the measurement target polarization scattering matrix, and ; is based on the error parameters in the polarization scattering matrix of the measurement target Intermediate quantity; wherein the partial system error parameters include: the first partial system error parameters, the second partial system error parameters and the third partial system error parameters; according to , and obtain the residual error parameters of the system ;in, is the second intermediate quantity related to the 0° metal wire in the polarization scattering matrix of the measurement target, and ; is the third intermediate quantity related to the 0° metal wire in the measurement target polarization scattering matrix, and .

[0013] In a feasible implementation manner, the radar system polarization error matrix is ​​reconstructed by using partial system error parameters corresponding to the 45° wire echo data and system residual error parameters corresponding to the 0° wire echo data to obtain a reconstructed system error parameter matrix, specifically comprising: , and obtain the reconstruction system error parameter matrix ;in, is the residual error parameter of the system; is the first partial system error parameter among the partial system error parameters; is a second part of the system error parameters in the part of the system error parameters; is the third partial system error parameter among the partial system error parameters.

[0014] In a feasible implementation manner, by reconstructing the system error parameter matrix and the real scattering matrix, compensating other targets in the broadband full-polarization radar system and obtaining optimized polarization information specifically includes: , get the real scattering matrix ;in, is the reconstruction system error parameter matrix; M is the measurement target polarization scattering matrix.

[0015] In a second aspect, an embodiment of the present application also provides a multiplicative error polarization calibration device based on loose angle constraints, the device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor so that the at least one processor can execute a multiplicative error polarization calibration method based on loose angle constraints as described in any of the above-mentioned embodiments.

[0016] In the third aspect, an embodiment of the present application also provides a non-volatile computer storage medium, characterized in that the storage medium is a non-volatile computer-readable storage medium, and the non-volatile computer-readable storage medium stores at least one program, each of which includes instructions, and when the instructions are executed by the terminal, the terminal executes a multiplicative error polarization calibration method based on loose angle constraints described in any of the above-mentioned embodiments.

[0017] The present application provides a method, device and medium for polarization calibration of multiplicative errors based on loose angle constraints. Compared with the prior art, the present application has the following beneficial effects:

[0018] The embodiment of the present application performs polarization calibration on a broadband fully polarized radar system. The use of multi-angle metal wires and metal balls can realize the solution of all polarization errors of the broadband fully polarized radar system. Compared with the prior art, the present application considers a complete system error model and is applicable to broadband fully polarized radar systems with different isolation levels. In addition, the present application determines the posture of the metal wire by using the consistency of the ratio of the main channel of the scattering matrix of the metal ball and the metal wire at a specific angle, which greatly reduces the constraints on the posture of the calibration body and facilitates engineering implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0020] Figure 1 A flow chart of a multiplicative error polarization calibration method based on loose angle constraints provided in an embodiment of the present application;

[0021] Figure 2 A curve showing the variation of the four-channel echo amplitude of a metal wire with the angle under ideal conditions in a simulation experiment provided in an embodiment of the present application;

[0022] Figure 3 A curve showing the variation of amplitude inconsistency, phase inconsistency and polarization isolation of the main channel of a metal ball with the signal-to-noise ratio after algorithm calibration in a simulation experiment provided in an embodiment of the present application;

[0023] Figure 4 A schematic diagram of the structure of a multiplicative error polarization calibration device based on loose angle constraints provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0025] The present application embodiment provides a multiplicative error polarization calibration method based on loose angle constraints, such as Figure 1 As shown, the multiplicative error polarization calibration method based on loose angle constraints specifically includes steps S101-S106:

[0026] It should be noted that the present application provides a multiplicative error polarization calibration method based on loose angle constraints, which can solve all polarization errors of a broadband fully polarized radar system by using multi-angle metal wires and metal balls. This technology not only overcomes the difficulty of attitude control, but also does not simplify the system model. It can achieve good calibration effects for broadband fully polarized radars with different isolation levels, and helps fully polarized radar systems obtain more accurate polarization information.

[0027] The present application is a multiplicative error polarization calibration method based on loose angle constraints. The basic idea is, first, to model a broadband fully polarized radar system; then, to determine the wire posture by measuring the consistency of the ratio of the main channel of the scattering matrix using a metal ball and a metal wire at a specific angle; finally, to complete the calibration of the complete polarization error model of the broadband fully polarized radar system by using two metal wires at specific angles to compensate for the channel amplitude and phase inconsistency and antenna crosstalk.

[0028] S101. Perform radar measurement on the metal wire and the metal ball respectively through a broadband fully polarized radar system.

[0029] First, place the metal wire directly above the radar, point the radar vertically to the sky, and measure the metal wire at different angles by rotating the azimuth, and measure the metal ball. That is, the radar needs to be used to measure the PSM of the metal wire and the PSM of the metal ball at different angles.

[0030] S102, performing consistency calculation on the main channel elements between the metal ball and the 45-degree metal wire according to the polarization scattering matrix of the measurement target measured by the metal wire and the metal ball, and obtaining a consistency result.

[0031] Specifically, first according to , and obtain the polarization scattering matrix M of the measured target. Among them, , , , , , , as well as The subscripts h and v in represent horizontal polarization and vertical polarization, respectively; represents the four-channel element of the polarization scattering matrix of the measurement target, represents the wave number, Indicates the distance between the radar and the target. is the four-channel element of the channel gain matrix, represents the Hadamard product, , , and Represents the amplitude and phase imbalance factor in the receiving channel and the transmitting channel, and Respectively represent the amplitude and phase imbalance of the antenna H channel and V channel, and Both represent the cross-polarization level between different channels of the antenna. represents the four-channel element of the target's true polarization scattering matrix, Represents the additive error caused by noise and clutter.

[0032] As a feasible implementation method, in order to simplify the system model, and can be considered equal, It can be weakened by background subtraction and other techniques, so it is assumed in the following that the influence of measurement noise and clutter errors has been eliminated. The polarization scattering matrix M of the measured target is transformed into:

[0033] In addition, we can define , , , , , .in is a constant term common to all elements of the scattering matrix. It can be obtained by measuring a standard metal sphere when performing absolute calibration. Since we are more concerned with the relative relationship between the elements of the scattering matrix, we will no longer consider it in the subsequent analysis. .

[0034] The target polarization scattering matrix after the above transformation can be simplified as follows:

[0035] .

[0036] It can be seen that is the system error matrix, Include , , , , and In practice, we find that some error terms are coupled with each other, and it is impossible to find the solution of a single error term. .

[0037] Furthermore, optimization processing of the single error term is performed on the polarization scattering matrix of the measurement target.

[0038] Further, according to , and obtain the optimized measurement target polarization scattering matrix .in, is the system error matrix, Included , , , , and Represent six error parameters respectively, and , , ; is the true polarization scattering matrix.

[0039] Further, according to , and the theoretical relative polarization scattering matrix of the metal sphere is obtained .

[0040] Further, according to , the first theoretical relative polarization scattering matrix of the 45° wire is obtained .

[0041] Furthermore, the theoretical relative polarization scattering matrix of the metal ball and the first theoretical relative polarization scattering matrix of the 45° metal wire are combined with the measured target polarization scattering matrix to obtain the main channel ratio of the metal ball and the 45° metal wire. Polarization scattering matrix relative to the first theory Substitute the optimized measurement target polarization scattering matrix .

[0042] Among them, according to , and get the consistent result. Among them, , , as well as ; is an error parameter for measuring the target polarization scattering matrix. is the error parameter in the polarization scattering matrix of the measured target. Intermediate amount; consistency results represent the same ratio between the main channel elements between the metal ball and the 45° wire.

[0043] S103. Calculate the metal echo of the 45° metal wire according to the consistency result to obtain 45° metal wire echo data.

[0044] Specifically, the broadband fully polarized radar system is used to calculate and process the wire echoes at different angles, and generate wire echo data sets at different angles. Then, based on the consistency results, data query processing is performed on the wire echo data sets at different angles to obtain 45° wire echo data.

[0045] As a feasible implementation method, it can be seen from the formula corresponding to the consistency result that the ratio of the main channel elements of the measured 45° metal wire and metal ball scattering matrices is the same, so this ratio consistency can be used to obtain the 45° metal wire echo in the metal wire echo data at different angles.

[0046] S104 . Determine 0° metal wire echo data based on the 45° metal wire echo.

[0047] Specifically, based on the uniform rotation of the radar antenna in the broadband fully polarized radar system, the 45° wire is angle-forwarded to obtain the 0° wire. Then, based on the consistency results, data query processing is performed on the echo data sets of wires at different angles to obtain the 0° wire echo data.

[0048] As a feasible implementation, since the radar antenna rotates at a constant speed, the 0° wire echo can be obtained by pushing the 45° wire azimuth forward by 45°. Thus, the echo data of the 0° wire and the 45° wire can be obtained.

[0049] S105 , reconstructing the radar system polarization error matrix by using partial system error parameters corresponding to the 45° metal wire echo data and system residual error parameters corresponding to the 0° metal wire echo data to obtain a reconstructed system error parameter matrix.

[0050] Specifically, the 45° metal wire echo data and the 0° metal wire echo data are combined with the measurement target polarization scattering matrix for calculation and processing.

[0051] In one embodiment, the 45° metal wire echo data and the 0° metal wire echo data are substituted into the measurement target polarization scattering matrix, and 1) about the 45° metal wire can be obtained: ; ; as well as . 2) About 0° wire: ; ; ; .

[0052] Furthermore, after combining the formulas in the above embodiments, we can get , get the first part of the system error parameters in the partial system error parameters .in, is to measure the second intermediate quantity about the 45° wire in the target polarization scattering matrix, and ; To measure the first intermediate quantity of the 45° wire in the target polarization scattering matrix array, and ; is an error parameter for measuring the target polarization scattering matrix. is the error parameter in the polarization scattering matrix of the measured target. Intermediate amount.

[0053] Further, according to , get the second part of the system error parameters in the partial system error parameters .in, To measure the third intermediate quantity about the 45° wire in the target polarization scattering matrix, and ; is the error parameter in the polarization scattering matrix of the measured target. Intermediate amount.

[0054] Further, according to , and obtain the third part of the system error parameters in the partial system error parameters .in, is to measure the fourth intermediate quantity about the 45° wire in the target polarization scattering matrix, and ; is the error parameter in the polarization scattering matrix of the measured target. Intermediate amount.

[0055] The partial system error parameters include: a first partial system error parameter, a second partial system error parameter and a third partial system error parameter.

[0056] Further, according to , and obtain the system residual error parameters .in, is to measure the second intermediate quantity about the 0° metal wire in the target polarization scattering matrix, and ; is to measure the third intermediate quantity about the 0° wire in the target polarization scattering matrix, and At this point, the solution of all polarization errors in the broadband fully polarized radar system has been completed.

[0057] Further, according to , and obtain the reconstructed system error parameter matrix .in, is the system residual error parameter; is the first partial system error parameter among the partial system error parameters; is the second partial system error parameter in the partial system error parameters; It is the third part of the system error parameters.

[0058] S106, performing compensation processing on other targets in the broadband full-polarization radar system by reconstructing the system error parameter matrix and the real scattering matrix, and obtaining optimized polarization information.

[0059] Specifically, according to , and obtain the true scattering matrix .in, is the reconstructed system error parameter matrix; M is the measured target polarization scattering matrix.

[0060] In one embodiment, in order to verify the multiplicative error polarization calibration method based on loose angle constraints, simulation experiments were performed under different signal-to-noise ratio conditions, and the calibration effect was verified using a metal ball. Figure 2 This is a curve showing how the amplitude of a metal wire's four-channel echo changes with angle under ideal conditions in a simulation experiment provided in an embodiment of the present application. Figure 3 The curves of amplitude inconsistency, phase inconsistency and polarization isolation of the main channel of the metal ball after algorithm calibration in a simulation experiment provided by the embodiment of the present application with the signal-to-noise ratio are shown. Figure 2 as well as Figure 3 The effect shown in this application takes into account the complete system error model and is applicable to broadband full-polarization radar systems with different isolation levels. The consistency of the ratio of the main channel of the metal ball and the metal wire scattering matrix at a specific angle is used to determine the metal wire posture, which greatly reduces the constraints on the calibration body posture and facilitates engineering implementation.

[0061] In addition, the embodiment of the present application also provides a multiplicative error polarization calibration device based on loose angle constraints, such as Figure 4 As shown, the multiplicative error polarization calibration device 400 based on loose angle constraints specifically includes:

[0062] At least one processor 401. And a memory 402 in communication with the at least one processor 401. The memory 402 stores instructions that can be executed by the at least one processor 401, so that the at least one processor 401 can execute:

[0063] The wideband fully polarized radar system is used to perform radar measurement on the metal wire and the metal ball respectively.

[0064] According to the polarization scattering matrix of the measurement target measured by the metal wire and the metal ball, the consistency calculation of the main channel elements between the metal ball and the 45° metal wire is performed to obtain the consistency result;

[0065] According to the consistency result, the metal echo of the 45° metal wire is calculated to obtain the 45° metal wire echo data;

[0066] Based on the 45° wire echo, the 0° wire echo data is determined;

[0067] The radar system polarization error matrix is ​​reconstructed by using partial system error parameters corresponding to the 45° metal wire echo data and system residual error parameters corresponding to the 0° metal wire echo data to obtain a reconstructed system error parameter matrix;

[0068] By reconstructing the system error parameter matrix and the real scattering matrix, other targets in the broadband full-polarization radar system are compensated and the optimized polarization information is obtained.

[0069] At the same time, an embodiment of the present application also provides a non-volatile computer storage medium, which is a non-volatile computer-readable storage medium. The non-volatile computer-readable storage medium stores at least one program, and each program includes instructions. When the instructions are executed by the terminal, the terminal can execute: through a broadband full-polarization radar system, radar measurement processing is performed on the metal wire and the metal ball respectively; according to the polarization scattering matrix of the measurement target measured by the metal wire and the metal ball, the consistency calculation is performed on the main channel element between the metal ball and the 45° metal wire to obtain a consistency result; according to the consistency result, the metal echo of the 45° metal wire is calculated to obtain the 45° metal wire echo data; based on the 45° metal wire echo, the 0° metal wire echo data is determined; through the partial system error parameters corresponding to the 45° metal wire echo data and the system residual error parameters corresponding to the 0° metal wire echo data, the radar system polarization error matrix is ​​reconstructed to obtain a reconstructed system error parameter matrix; by reconstructing the system error parameter matrix and the real scattering matrix, other targets in the broadband full-polarization radar system are compensated, and optimized polarization information is obtained.

[0070] The embodiment of the present application performs polarization calibration on a broadband fully polarized radar system. The use of multi-angle metal wires and metal balls can realize the solution of all polarization errors of the broadband fully polarized radar system. Compared with the prior art, the present application considers a complete system error model and is applicable to broadband fully polarized radar systems with different isolation levels. In addition, the present application determines the posture of the metal wire by using the consistency of the ratio of the main channel of the scattering matrix of the metal ball and the metal wire at a specific angle, which greatly reduces the constraints on the posture of the calibration body and facilitates engineering implementation.

[0071] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device and non-volatile computer storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0072] The devices and media provided in the embodiments of the present application correspond one-to-one to the methods. Therefore, the devices and media also have similar beneficial technical effects as the corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the devices and media will not be repeated here.

[0073] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0074] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0075] Memory may include non-permanent storage in a computer-readable medium, in the form of random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0076] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0077] The above describes specific embodiments of the present application. In some cases, the actions or steps recorded in the specification can be performed in an order different from that in the embodiment and still achieve the desired results. In addition, the process depicted in the accompanying drawings does not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0078] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the embodiments of the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present application should be included in the scope of the specification of the present application.

Claims

1. A multiplicative error polarization calibration method based on loose angle constraints, characterized in that: The method comprises: The wideband fully polarized radar system is used to perform radar measurement on the metal wire and the metal ball respectively. According to the polarization scattering matrix of the measurement target measured by the metal wire and the metal ball, a consistency calculation is performed on the main channel element between the metal ball and the 45-degree metal wire to obtain a consistency result; According to the consistency result, the metal echo of the 45° metal wire is calculated to obtain the 45° metal wire echo data; Based on the 45° wire echo, determining 0° wire echo data; Combining the 45° metal wire echo data and the 0° metal wire echo data with the measurement target polarization scattering matrix for calculation and processing; according to , obtain the first part of the system error parameters in the partial system error parameters ;in, is the second intermediate quantity related to the 45° metal wire in the polarization scattering matrix of the measurement target, and ; is the first intermediate quantity related to the 45° metal wire in the polarization scattering matrix array of the measurement target, and ; is the error parameter of the polarization scattering matrix of the measurement target, is an error parameter based on the polarization scattering matrix of the measurement target; according to , obtain the second part of the system error parameters in the partial system error parameters ;in, is the third intermediate quantity related to the 45° metal wire in the measurement target polarization scattering matrix, and ; is an error parameter based on the polarization scattering matrix of the measurement target; according to , obtain the third part of the system error parameters in the partial system error parameters ;in, is the fourth intermediate quantity related to the 45° metal wire in the measurement target polarization scattering matrix, and ; is an error parameter based on the polarization scattering matrix of the measurement target; The partial system error parameters include: the first partial system error parameters, the second partial system error parameters and the third partial system error parameters; according to , and obtain the residual error parameters of the system ;in, is the second intermediate quantity related to the 0° metal wire in the polarization scattering matrix of the measurement target, and ; is the third intermediate quantity related to the 0° metal wire in the measurement target polarization scattering matrix, and ; The radar system polarization error matrix is ​​reconstructed by using partial system error parameters corresponding to the 45° metal wire echo data and system residual error parameters corresponding to the 0° metal wire echo data to obtain a reconstructed system error parameter matrix, which specifically includes: according to , and obtain the reconstruction system error parameter matrix ;in, is the residual error parameter of the system; is the first partial system error parameter among the partial system error parameters; is a second part of the system error parameters in the part of the system error parameters; is a third partial system error parameter among the partial system error parameters; By reconstructing the system error parameter matrix and the real scattering matrix, compensation processing is performed on other targets in the broadband full-polarization radar system, and optimized polarization information is obtained.

2. The multiplicative error polarization calibration method based on loose angle constraints according to claim 1, characterized in that: Before performing consistency calculation on the main channel elements between the metal ball and the 45° metal wire according to the polarization scattering matrix of the measurement target measured by the metal wire and the metal ball to obtain a consistency result, the method further includes: according to , obtain the polarization scattering matrix M of the measurement target; where, , , , , , , as well as The subscripts h and v in represent horizontal polarization and vertical polarization, respectively; represents the four-channel elements of the polarization scattering matrix of the measurement target, represents the wave number, Indicates the distance between the radar and the target. is the four-channel element of the channel gain matrix, represents the Hadamard product, , , and Represents the amplitude and phase imbalance factor in the receiving channel and the transmitting channel, and Respectively represent the amplitude and phase imbalance of the antenna H channel and V channel, and Both represent the cross-polarization level between different channels of the antenna. represents the four-channel element of the target's true polarization scattering matrix, Represents the additive error caused by noise and clutter; Performing optimization processing on a single error term on the polarization scattering matrix of the measurement target; according to , and obtain the optimized measurement target polarization scattering matrix ;in, is the system error matrix, Included , , , , and Represent six error parameters respectively, and , , ; is the true polarization scattering matrix.

3. The multiplicative error polarization calibration method based on loose angle constraints according to claim 1, characterized in that: According to the polarization scattering matrix of the measurement target measured by the metal wire and the metal ball, a consistency calculation is performed on the main channel element between the metal ball and the 45° metal wire to obtain a consistency result, specifically including: according to , and obtain the theoretical relative polarization scattering matrix of the metal sphere ; according to , the first theoretical relative polarization scattering matrix of the 45° wire is obtained ; The theoretical relative polarization scattering matrix of the metal ball and the first theoretical relative polarization scattering matrix of the 45° metal wire are combined with the polarization scattering matrix of the measurement target to obtain the main channel ratio of the metal ball to the 45° metal wire; Among them, according to , and obtain consistent results; among them, , , as well as ; is an error parameter of the polarization scattering matrix of the measurement target, is based on the error parameters in the polarization scattering matrix of the measurement target Intermediate quantity; The consistency result represents that the ratio between the main channel elements between the metal ball and the 45° metal wire is the same.

4. The method for polarization calibration of multiplicative errors based on loose angle constraints according to claim 1, characterized in that: According to the consistency result, the metal echo of the 45° metal wire is calculated to obtain the 45° metal wire echo data, which specifically includes: The broadband fully polarized radar system is used to calculate and process the metal wire echoes at different angles, and generate metal wire echo data sets at different angles. Based on the consistency result, data query processing is performed on the different angle wire echo data sets to obtain the 45° wire echo data.

5. The method for polarization calibration of multiplicative errors based on loose angle constraints according to claim 1, characterized in that: Based on the 45° wire echo, the 0° wire echo data is determined, specifically including: Based on the uniform rotation of the radar antenna in the broadband fully polarized radar system, the 45° metal wire is subjected to an angle forward processing to obtain a 0° metal wire; Based on the consistency result, data query processing is performed on the wire echo data sets at different angles to obtain the 0° wire echo data.

6. The method for polarization calibration of multiplicative errors based on loose angle constraints according to claim 1, characterized in that: By reconstructing the system error parameter matrix and the real scattering matrix, compensating other targets in the broadband full-polarization radar system and obtaining optimized polarization information specifically include: according to , get the real scattering matrix ;in, is the reconstruction system error parameter matrix; M is the measurement target polarization scattering matrix.

7. A multiplicative error polarization calibration device based on loose angle constraints, characterized in that: The device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, so that the at least one processor can execute the multiplicative error polarization calibration method based on loose angle constraints according to any one of claims 1-6.

8. A non-volatile computer storage medium, characterized in that: The storage medium is a non-volatile computer-readable storage medium, and the non-volatile computer-readable storage medium stores at least one program, each of which includes instructions, and when the instructions are executed by the terminal, the terminal executes the multiplicative error polarization calibration method based on loose angle constraints according to any one of claims 1-6.

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