CN113253206A - Variable polarization monopulse radar target angle estimation method, system, device and medium - Google Patents

Abstract

The invention discloses a target angle estimation method, system, device and medium of a variable-polarization monopulse radar. The method includes: acquiring target echo signals of four channels of the variable-polarization monopulse radar; non-linear digital beamforming to obtain the first horizontal polarization component, the first vertical polarization component, the second horizontal polarization component, and the second vertical polarization component of each channel, and generate the first high-resolution distance of each channel image and the second high-resolution range image; determine the sum-difference signal pair of the four polarization channels according to the first high-resolution range image and the second high-resolution range image; determine the target polarization scattering matrix according to the sum-difference signal pair, And estimate the target azimuth and target elevation angle of each polarization channel. The invention improves the accuracy of target polarization parameter measurement and angle estimation of the variable-polarization monopulse radar, and can be widely used in the field of radar technology.

Description

Target angle estimation method, system, device and medium for variable polarization monopulse radar

technical field

The invention relates to the technical field of radar, in particular to a target angle estimation method, system, device and medium of a variable polarization monopulse radar.

Background technique

At present, the monopulse technology is a relatively mature technology, which can enable the tracking radar to obtain strong anti-jamming capability, and can also determine the direction of the target through the sum-difference pattern. In order to further suppress the interference and obtain the polarization information of the target at the same time, the full polarization detection technology is gradually introduced into the monopulse radar.

The polarization modes include H-horizontal polarization and V-vertical polarization, which represent the vibration direction of the electric field. A radar system using H and V linear polarizations uses a pair of symbols to represent the transmit and receive polarizations and can therefore have the following four polarizations—HH, VV, HV, VH, where:

(1) HH- is used for horizontal transmission and horizontal reception;

(2) VV- for vertical transmission and vertical reception;

(3) HV - for vertical transmission and horizontal reception;

(4) VH- is used for horizontal transmission and vertical reception.

The variable-polarization technology is a technology that realizes full-polarization detection based on sequentially rotating sub-arrays. When the radar transmits, by adjusting the weight of each channel, any form of polarized electromagnetic waves can be synthesized in space. When the radar is receiving, through digital beamforming technology, the radar can receive the target echo with any polarization base. Compared with the dual-polarization technology, the variable-polarization technology only utilizes half of the channels, which can reduce the cost and complexity of the system.

For the four-channel variable-polarization monopulse radar, the polarization information and angle information of the target in the received signal are nonlinearly coupled due to the number and type of data channels. Therefore, the existing linear digital beamforming methods will lead to errors in the measurement and angle estimation of the target's polarization parameters.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve one of the technical problems existing in the prior art at least to a certain extent.

Therefore, an object of the embodiments of the present invention is to provide a method for estimating the target angle of a variable-polarization monopulse radar, so as to improve the accuracy of the target polarization parameter measurement and angle estimation of the variable-polarization monopulse radar.

Another object of the embodiments of the present invention is to provide a target angle estimation system for a variable-polarization monopulse radar.

In order to achieve the above technical purpose, the technical solutions adopted in the embodiments of the present invention include:

In a first aspect, an embodiment of the present invention provides a method for estimating a target angle of a variable-polarization monopulse radar, including the following steps:

Obtain the target echo signals of the four channels of the variable polarization monopulse radar;

According to the target echo signal, two kinds of nonlinear digital beam synthesis are respectively performed to obtain the first horizontal polarization component, the first vertical polarization component, the second horizontal polarization component, and the second vertical polarization component of each channel, and generating a first high-resolution range image and a second high-resolution range image of each channel;

Determine the sum-difference signal pair of the four polarization channels according to the first high-resolution range image and the second high-resolution range image;

The target polarization scattering matrix is determined according to the sum-difference signal pair, and the target azimuth angle and target elevation angle of each polarization channel are estimated.

Further, in an embodiment of the present invention, the method for estimating the target angle of the variable-polarization monopulse radar further comprises the following steps:

Determine whether the variable polarization monopulse radar transmits horizontal polarization or vertical polarization, and determines whether the variable polarization monopulse radar receives horizontal polarization or vertical polarization.

Further, in an embodiment of the present invention, when it is determined that the variable polarization monopulse radar transmits horizontal polarization, the first horizontal polarization component is:

表示第n个通道的第一水平极化分量，

表示第n个通道的目标回波信号，n＝1、2、3、4，

且

且

in,

represents the first horizontally polarized component of the nth channel,

Represents the target echo signal of the nth channel, n=1, 2, 3, 4,

and

and

The first vertical polarization component is:

表示第n个通道的第一垂直极化分量；in,

represents the first vertically polarized component of the nth channel;

The first high-resolution range image is generated from the first horizontal polarization component and the first vertical polarization component.

Further, in an embodiment of the present invention, when it is determined that the variable polarization monopulse radar transmits horizontal polarization, the second horizontal polarization component is:

表示第n个通道的第二水平极化分量，

表示第n个通道的目标回波信号，n＝1、2、3、4，

表示变极化单脉冲雷达发射垂直极化时第n个通道的目标回波信号；in,

represents the second horizontally polarized component of the nth channel,

Represents the target echo signal of the nth channel, n=1, 2, 3, 4,

Represents the target echo signal of the nth channel when the variable-polarization monopulse radar transmits vertical polarization;

The second vertically polarized component is:

表示第n个通道的第二垂直极化分量；in,

represents the second vertically polarized component of the nth channel;

The second high-resolution range image is generated from the second horizontally polarized component and the second vertically polarized component.

Further, in an embodiment of the present invention, in the step of determining the sum-difference signal pair of four polarization channels according to the first high-resolution range image and the second high-resolution range image, the Specifically include:

Selecting a scattering point with a higher signal-to-noise ratio in the first high-resolution range image and the second high-resolution range image to generate a third high-resolution range image;

determining a third horizontal polarization component and a third vertical polarization component of each channel according to the third high-resolution range image;

determining a sum-difference signal pair of four polarization channels according to the third horizontal polarization component and the third vertical polarization component;

Wherein, the polarization channel includes HH polarization channel, VH polarization channel, HV polarization channel and VV polarization channel, and the HH polarization channel indicates that the variable polarization monopulse radar transmits horizontal polarization and receives horizontal polarization , the VH polarization channel represents that the variable-polarization monopulse radar transmits horizontal polarization and receives vertical polarization, the HV polarization channel represents that the variable-polarization monopulse radar sends vertical polarization and receives horizontal polarization, and the VV The polarization channel indicates that the variable polarization monopulse radar transmits vertical polarization and receives vertical polarization.

Further, in an embodiment of the present invention, the sum-difference signal pair is:

以及

分别表示HH极化通道的和信号、方位差信号以及俯仰差信号，

以及

分别表示VH极化通道的和信号、方位差信号以及俯仰差信号，

以及

分别表示HV极化通道的和信号、方位差信号以及俯仰差信号，

以及

分别表示VV极化通道的和信号、方位差信号以及俯仰差信号，

表示变极化单脉冲雷达发送水平极化时第n个通道的第三水平极化分量，

表示变极化单脉冲雷达发送水平极化时第n个通道的第三垂直极化分量，

表示变极化单脉冲雷达发送垂直极化时第n个通道的第三水平极化分量，

表示变极化单脉冲雷达发送垂直极化时第n个通道的第三垂直极化分量。in,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the HH polarization channel, respectively,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the VH polarization channel, respectively,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the HV polarization channel, respectively,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the VV polarization channel, respectively,

represents the third horizontal polarization component of the nth channel when the variable polarization monopulse radar transmits horizontal polarization,

represents the third vertical polarization component of the nth channel when the variable polarization monopulse radar transmits the horizontal polarization,

represents the third horizontal polarization component of the nth channel when the variable polarization monopulse radar transmits vertical polarization,

It represents the third vertical polarization component of the nth channel when the variable polarization monopulse radar transmits vertical polarization.

Further, in an embodiment of the present invention, the target polarization scattering matrix is:

Among them, M represents the target polarization scattering matrix;

The target azimuth is:

分别表示HH极化通道、VH极化通道、HV极化通道、VV极化通道的目标方位角，k_HH、k_VH、k_VV、k_VV分别表示HH极化通道、VH极化通道、HV极化通道、VV极化通道的和差波束鉴角曲线斜率，Re(·)表示取实部；in,

represent the target azimuth angles of the HH polarization channel, VH polarization channel, HV polarization channel, and VV polarization channel, respectively, k _HH , k _VH , k _VV , and k _VV represent the HH polarization channel, VH polarization channel, HV polarization channel, respectively. The slope of the sum-difference beam discrimination curve of the polarization channel and the VV polarization channel, Re( ) represents the real part;

The target pitch angle is:

分别表示HH极化通道、VH极化通道、HV极化通道、VV极化通道的目标俯仰角。in,

Indicate the target pitch angles of the HH polarization channel, VH polarization channel, HV polarization channel, and VV polarization channel, respectively.

In a second aspect, an embodiment of the present invention provides a variable polarization monopulse radar target angle estimation system, including:

The target echo signal acquisition module is used to acquire the target echo signals of the four channels of the variable polarization monopulse radar;

A nonlinear digital beam synthesis module, configured to perform two kinds of nonlinear digital beam synthesis respectively according to the target echo signal to obtain the first horizontal polarization component, the first vertical polarization component, and the second horizontal polarization component of each channel , a second vertically polarized component, and generate a first high-resolution range image and a second high-resolution range image of each channel;

a sum-difference signal pair determination module, configured to determine a sum-difference signal pair of four polarization channels according to the first high-resolution range image and the second high-resolution range image;

The target angle estimation module is used to determine the target polarization scattering matrix according to the sum-difference signal pair, and estimate the target azimuth angle and target elevation angle of each polarization channel.

In a third aspect, an embodiment of the present invention provides a device for estimating a target angle of a variable-polarization monopulse radar, including:

at least one processor;

at least one memory for storing at least one program;

When the at least one program is executed by the at least one processor, the at least one processor is made to implement the above-mentioned method for estimating the target angle of a variable-polarization monopulse radar.

In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, in which a program executable by a processor is stored, and the program executable by the processor is used to execute the above one when executed by the processor Target angle estimation method for variable polarization monopulse radar.

The advantages and beneficial effects of the present invention will, in part, be given in the following description, and in part will become apparent from the following description, or be learned by practice of the present invention:

The embodiment of the present invention performs two nonlinear digital beam synthesis on the target echo signal to obtain two sets of high-resolution range images, and then forms a sum-difference signal pair in the HH, VH, HV and VV polarization channels, and then according to the sum and difference signal pairs are formed. The estimation results of the target polarization scattering matrix and the target angle are obtained from the difference signal pair, which improves the accuracy of the target polarization parameter measurement and angle estimation of the variable-polarization monopulse radar.

Description of drawings

In order to explain the technical solutions in the embodiments of the present invention more clearly, the following descriptions are given to the accompanying drawings that are used in the embodiments of the present invention. It should be understood that the accompanying drawings in the following introduction are only for the convenience of clearly expressing the technology of the present invention. For some of the embodiments in the solution, for those skilled in the art, other drawings can also be obtained from these drawings without the need for creative work.

1 is a flowchart of steps of a method for estimating a target angle of a variable polarization monopulse radar according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a space coordinate system of a variable polarization monopulse radar according to an embodiment of the present invention;

3 is a schematic diagram of a four-channel polarization distribution of a variable-polarization monopulse radar according to an embodiment of the present invention;

FIG. 4 is a schematic diagram showing the comparison of high-resolution range images obtained after four kinds of digital beam synthesis of targets provided in an embodiment of the present invention;

5 is a schematic diagram of comparison of azimuth angle estimation results of a target in four polarization channels according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of comparison of pitch angle estimation results of a target in four polarization channels according to an embodiment of the present invention;

7 is a structural block diagram of a target angle estimation system for variable polarization monopulse radar according to an embodiment of the present invention;

FIG. 8 is a structural block diagram of an apparatus for estimating a target angle of a variable-polarization monopulse radar according to an embodiment of the present invention.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the present invention, and should not be construed as a limitation of the present invention. The numbers of the steps in the following embodiments are only set for the convenience of description, and the sequence between the steps is not limited in any way, and the execution sequence of each step in the embodiments can be adapted according to the understanding of those skilled in the art Sexual adjustment.

In the description of the present invention, the meaning of multiple is two or more. If the first and second are described, they are only for the purpose of distinguishing technical features, and should not be understood as indicating or implying relative importance or implicit Indicates the number of the indicated technical features or implicitly indicates the order of the indicated technical features. Also, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

Firstly, the space coordinate system and four-channel polarization distribution of the variable-polarization monopulse radar are introduced.

表示波束方向γ在xoy平面的投影与x轴的夹角。Figure 2 is a schematic diagram of the space coordinate system of the variable-polarization monopulse radar. The antenna is located on the xy plane, and the electromagnetic wave propagates in the positive direction of the z-axis. The horizontal polarization is defined as the positive direction of the x-axis, and the vertical polarization is the positive direction of the y-axis. direction, e represents the angle between the beam direction γ and the z-axis, ele represents the angle between the projection of the beam direction γ on the yoz plane and the z-axis (that is, the azimuth angle), azi represents the projection of the beam direction γ on the xoz plane and the z-axis The included angle (that is, the pitch angle),

Indicates the angle between the projection of the beam direction γ on the xoy plane and the x-axis.

Figure 3 is a schematic diagram of the four-channel polarization distribution of the variable-polarization monopulse radar, where channels 1 and 4 are -45° linear polarization, and channels 2 and 3 are 45° linear polarization. On the basis of the orthogonal polarization base, the radar can transmit or receive any polarized electromagnetic wave. The embodiment of the present invention adopts a dual-coordinate radar, which can measure the azimuth angle and the elevation angle of the target at the same time.

In monopulse radar, the antennas have the same phase center, but a deflection angle in azimuth and elevation. The orientation diagram of the four units in Figure 3 can be expressed as:

F ₁ (ξ _azi , ξ _ele )=F(ξ _azi +Δ _H , ξ _ele +Δ _V )

F ₂ (ξ _azi , ξ _ele )=F(ξ _azi -Δ _H , ξ _ele +Δ _V )

F ₃ (ξ _azi , ξ _ele )=F(ξ _azi +Δ _H , ξ _ele -Δ _V )

F ₄ (ξ _azi , ξ _ele )=F(ξ _azi -Δ _H , ξ _ele -Δ _V )

Among them, _ΔH and _ΔV are the deflection angles of the beam in azimuth and elevation angles, ξ _azi and ξ _ele represent the elevation and azimuth angles, respectively, and F(ξ _azi , ξ _ele ) points to the positive direction of the z-axis. Since _ΔH and _ΔV are negligible compared with π, and F is axisymmetric and centrosymmetric, the Qinler expansion of each pattern in the above formula can be performed as follows:

where F′ _H (Δ _H , Δ _V ) and F′ _V (Δ _H , Δ _V ) are the partial derivatives of F (Δ _H , Δ _V ) along the H and V directions, respectively, and F″ _H (Δ _H , Δ V ) _V ) and F″ _v (Δ _H ,Δ _V ) are the second-order partial derivatives of F (Δ _H ,Δ _V ) along the H and V directions, respectively.

In the embodiment of the present invention, the variable polarization monopulse radar can generate sum and difference signals in any polarization channel, obtain target polarization parameter information through the sum channel, and obtain the angle estimation results in each polarization channel through the monopulse angle measurement method .

1 , an embodiment of the present invention provides a method for estimating a target angle of a variable-polarization monopulse radar, which specifically includes the following steps:

S101 , acquiring target echo signals of four channels of the variable-polarization monopulse radar.

Specifically, when the radar transmits, ignoring the spatial attenuation, the far-field electric field vectors of the four channels can be expressed as:

与

分别表示水平和垂直方向的极化基。当四个通道的权重为(1+j0，1+j0，1+j0，1+j0)时，由上式和前述各个方向图的泰勒展开式可知，雷达发射水平极化电磁波可以表示为：in,

and

represent the polarization bases in the horizontal and vertical directions, respectively. When the weights of the four channels are (1+j0, 1+j0, 1+j0, 1+j0), it can be seen from the above formula and the Taylor expansion of each of the aforementioned patterns that the radar transmits horizontally polarized electromagnetic waves can be expressed as:

Similarly, when the weights of the four channels are (-1+j0, 1+j0, 1+j0, -1+j0), the vertically polarized electromagnetic waves emitted by the radar can be expressed as:

When the radar receives, the electric field vector of the antenna echo can be assumed to be

where p and q are the horizontal and vertical polarization components of the echo. At this time, the received signals of the four channels are as follows:

Wherein, Sn ( _n =1, 2, 3, 4) represents the received signal of the nth channel.

S102. Perform two kinds of nonlinear digital beam synthesis respectively according to the target echo signal to obtain a first horizontal polarization component, a first vertical polarization component, a second horizontal polarization component, and a second vertical polarization component of each channel, and A first high-resolution range image and a second high-resolution range image are generated for each channel.

Further as an optional implementation manner, the method for estimating the target angle of the variable-polarization monopulse radar further comprises the following steps:

Determine whether the variable polarization monopulse radar transmits horizontal polarization or vertical polarization, and determines whether the variable polarization monopulse radar receives horizontal polarization or vertical polarization.

Specifically, the variable-polarization monopulse radar according to the embodiment of the present invention includes four polarization modes: HH, VH, HV, and VV, where HH represents transmitting horizontal polarization and receiving horizontal polarization, and VH represents transmitting horizontal polarization and receiving vertical polarization. , HV means transmit vertical polarization and receive horizontal polarization, VV means transmit vertical polarization and receive vertical polarization.

Definition α _n (n=1, 2, 3, 4) and β _n (n=1, 2, 3, 4) represent the horizontal and vertical polarization components of the echo at channel n, and satisfy the following equations:

Among them, the superscripts H and V indicate the horizontal or vertical polarization of the radar emission.

Combining the expressions of the received signals of the four channels obtained above, it can be known that when the radar transmits the horizontal polarization, the received signals of the four channels are as follows:

Similarly, when the radar transmits vertical polarization, the four channels receive signals as follows:

And because channels 1 and 2 measure the same azimuth angle as channels 3 and 4 respectively, and channels 1 and 3 measure the same pitch angle as channels 2 and 4 respectively, there are:

Among them, k ₁ and k ₂ are constants to be solved.

Further as an optional embodiment, when it is determined that the variable polarization monopulse radar transmits the horizontal polarization, the first horizontal polarization component is:

表示第n个通道的第一水平极化分量，

表示第n个通道的目标回波信号，n＝1、2、3、4，

且

且

in,

represents the first horizontally polarized component of the nth channel,

Represents the target echo signal of the nth channel, n=1, 2, 3, 4,

and

and

The first vertically polarized component is:

表示第n个通道的第一垂直极化分量；in,

represents the first vertically polarized component of the nth channel;

The first high-resolution range image is generated from the first horizontal polarization component and the first vertical polarization component.

The accuracy of the first high-resolution range image can be determined from the signal-to-noise ratio of the HH ² -VH ² and HV ² -VV ² channels.

Similarly, when it is determined that the variable polarization monopulse radar transmits vertical polarization, the first horizontal polarization component is;

表示第n个通道的第一水平极化分量，

表示第n个通道的目标回波信号，n＝1、2、3、4，

且

in,

represents the first horizontally polarized component of the nth channel,

Represents the target echo signal of the nth channel, n=1, 2, 3, 4,

and

The first vertically polarized component is:

表示第n个通道的第一垂直极化分量。in,

represents the first vertically polarized component of the nth channel.

Further as an optional embodiment, when it is determined that the variable polarization monopulse radar transmits the horizontal polarization, the second horizontal polarization component is:

表示第n个通道的第二水平极化分量，

表示第n个通道的目标回波信号，n＝1、2、3、4，

表示变极化单脉冲雷达发射垂直极化时第n个通道的目标回波信号；in,

represents the second horizontally polarized component of the nth channel,

Represents the target echo signal of the nth channel, n=1, 2, 3, 4,

Represents the target echo signal of the nth channel when the variable-polarization monopulse radar transmits vertical polarization;

The second vertically polarized component is:

表示第n个通道的第二垂直极化分量；in,

represents the second vertically polarized component of the nth channel;

The second high-resolution range image is generated from the second horizontal polarization component and the second vertical polarization component.

Specifically, according to the reciprocity theory, the received signals in the HV and VH polarized channels are the same, so there are:

α ^V = β ^H

And since the polarization ratios of the echoes arriving at each channel are the same, there are:

The second horizontal polarization component and the second vertical polarization component can be obtained by combining the expressions of the received signals of the four channels obtained above, thereby obtaining a second high-resolution range image. The accuracy of the second high-resolution range image can be determined according to the signal-to-noise ratio of the HH-VV channel.

Similarly, when it is determined that the variable polarization monopulse radar transmits vertical polarization, the second horizontal polarization component is:

表示第n个通道的第二水平极化分量，

表示第n个通道的目标回波信号，n＝1、2、3、4，

表示变极化单脉冲雷达发射水平极化时第n个通道的目标回波信号；in,

represents the second horizontally polarized component of the nth channel,

Represents the target echo signal of the nth channel, n=1, 2, 3, 4,

Represents the target echo signal of the nth channel when the variable-polarization monopulse radar transmits horizontal polarization;

The second vertically polarized component is:

表示第n个通道的第二垂直极化分量。in,

represents the second vertically polarized component of the nth channel.

S103. Determine the sum-difference signal pair of the four polarization channels according to the first high-resolution range image and the second high-resolution range image.

Further as an optional implementation manner, step S103 specifically includes the following steps:

S1031, selecting a scattering point with a higher signal-to-noise ratio in the first high-resolution range image and the second high-resolution range image to generate a third high-resolution range image;

S1032, determining the third horizontal polarization component and the third vertical polarization component of each channel according to the third high-resolution range image;

S1033, determine the sum-difference signal pair of the four polarization channels according to the third horizontal polarization component and the third vertical polarization component;

Among them, the polarization channel includes HH polarization channel, VH polarization channel, HV polarization channel and VV polarization channel. HH polarization channel means that the variable polarization monopulse radar transmits horizontal polarization and receives horizontal polarization, VH polarization The channel indicates that the variable polarization monopulse radar transmits horizontal polarization and receives vertical polarization, the HV polarization channel indicates that the variable polarization monopulse radar transmits vertical polarization and receives horizontal polarization, and the VV polarization channel indicates that the variable polarization monopulse radar Transmit vertical polarization and receive vertical polarization.

In the embodiment of the present invention, after the horizontal and vertical polarization components of the target echo reaching each channel are obtained through two nonlinear digital beamforming methods, a higher signal-to-noise ratio is selected at the same position of the two sets of high-resolution range images. The scattered points are used as the HRRP data of the third high-resolution range image, and the subsequent angle estimation is performed on this basis, thereby improving the accuracy of the target angle estimation.

Optionally, it is also possible to select scattering points higher than 14db from the two sets of high-resolution range images for single-pulse angle measurement, and take the average of the target angle estimation results obtained from the two sets of high-resolution range images as the final result. result.

Further as an optional implementation manner, the sum-difference signal pair is:

以及

分别表示HH极化通道的和信号、方位差信号以及俯仰差信号，

以及

分别表示VH极化通道的和信号、方位差信号以及俯仰差信号，

以及

分别表示HV极化通道的和信号、方位差信号以及俯仰差信号，

以及

分别表示VV极化通道的和信号、方位差信号以及俯仰差信号，

表示变极化单脉冲雷达发送水平极化时第n个通道的第三水平极化分量，

表示变极化单脉冲雷达发送水平极化时第n个通道的第三垂直极化分量，

表示变极化单脉冲雷达发送垂直极化时第n个通道的第三水平极化分量，

表示变极化单脉冲雷达发送垂直极化时第n个通道的第三垂直极化分量。in,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the HH polarization channel, respectively,

as well as

respectively represent the sum signal, azimuth difference signal and pitch difference signal of the VH polarization channel,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the HV polarization channel, respectively,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the VV polarization channel, respectively,

represents the third horizontal polarization component of the nth channel when the variable polarization monopulse radar transmits horizontal polarization,

represents the third vertical polarization component of the nth channel when the variable polarization monopulse radar transmits the horizontal polarization,

represents the third horizontal polarization component of the nth channel when the variable polarization monopulse radar transmits vertical polarization,

It represents the third vertical polarization component of the nth channel when the variable polarization monopulse radar transmits vertical polarization.

S104: Determine the target polarization scattering matrix according to the sum-difference signal pair, and estimate the target azimuth angle and target elevation angle of each polarization channel.

Further as an optional implementation manner, the target polarization scattering matrix is:

Among them, M represents the target polarization scattering matrix;

The target azimuth is:

分别表示HH极化通道、VH极化通道、HV极化通道、VV极化通道的目标方位角，k_HH、k_VH、k_HV、k_VV分别表示HH极化通道、VH极化通道、HV极化通道、VV极化通道的和差波束鉴角曲线斜率，Re(·)表示取实部；in,

Respectively represent the target azimuth angles of HH polarization channel, VH polarization channel, HV polarization channel, VV polarization channel, k _HH , k _VH , k _HV , k _VV represent HH polarization channel, VH polarization channel, HV polarization channel, respectively The slope of the sum-difference beam discrimination curve of the polarization channel and the VV polarization channel, Re( ) represents the real part;

The target pitch angle is:

分别表示HH极化通道、VH极化通道、HV极化通道、VV极化通道的目标俯仰角。in,

Indicate the target pitch angles of the HH polarization channel, VH polarization channel, HV polarization channel, and VV polarization channel, respectively.

The steps of the embodiments of the present invention are described above. The embodiment of the present invention performs two nonlinear digital beam synthesis on the target echo signal to obtain two sets of high-resolution range images, and then forms a sum-difference signal pair in the HH, VH, HV and VV polarization channels, and then according to the sum and difference signal pairs are formed. The estimation results of the target polarization scattering matrix and the target angle are obtained from the difference signal pair, which improves the accuracy of the target polarization parameter measurement and angle estimation of the variable-polarization monopulse radar.

The estimation result of the embodiment of the present invention is verified below with reference to a specific embodiment.

The radar is set at a distance of 20 meters from the ground, the turntable is on the ground, 150 meters away from the radar, and the vehicle is placed in the center of the turntable. The rotation angle range of the turntable is set from 0 degrees to 360 degrees. The radar measures the high-resolution range image (HRRP) of the vehicle every 3 seconds, records the target HRRP of the four physical channels, and selects the scattering points with a signal-to-noise ratio greater than 14dB in the HRRP as the data for subsequent processing.

The sum-difference signal pair is obtained by processing the traditional linear digital beamforming method as follows:

分别表示雷达发送水平极化时的和信号、方位差信号、俯仰差信号，Sn(n＝1，2，3，4)表示通道n的目标回波信号。根据上式可知，通过线性数字波束合成得到的和差通道数据均不满足预期，从而会导致后续的极化测量和目标角度估计结果不准确。in,

Respectively represent the sum signal, azimuth difference signal, and pitch difference signal when the radar sends horizontal polarization, and Sn (n=1, 2, 3, 4) represents the target echo signal of channel n. According to the above formula, the sum-difference channel data obtained by linear digital beamforming does not meet expectations, which will lead to inaccurate results of subsequent polarization measurement and target angle estimation.

After processing by the two nonlinear digital beamforming methods in the embodiment of the present invention, the obtained first high-resolution range image (corresponding to Non-linear DBF I in the figure) and the second high-resolution range image (corresponding to Non-linear DBF II in the figure) ), the third high-resolution range image (corresponding to Non-linearDBFⅠ+Ⅱ in the figure) and the high-resolution range image (corresponding to linearDBF in the figure) obtained by traditional linear digital beam synthesis are shown in Figure 4, where, Figure 4(a) shows the high-resolution range image obtained after four kinds of digital beamformation in the HH polarization channel, and Figure 4(b) shows the high-resolution distance image obtained after four kinds of digital beamformation in the VH polarization channel Figure 4(c) shows the high-resolution range image obtained after four kinds of digital beamforming in the HV polarization channel, and Figure 4(d) shows the high-resolution range image obtained after four kinds of digital beamforming in the VV polarization channel rate distance image. It can be seen that the difference between the HH and VV channels of the high-resolution range images obtained after the four kinds of digital beamforming is smaller than that of the VH and HV channels, because the echo intensity of the VH and HV channels is smaller than that of the HH and VV channels.

Figure 5 is a schematic diagram of the comparison of the azimuth angle estimation results of the target in the four polarization channels, in which Figure 5(a), Figure 5(b), Figure 5(c), and Figure 5(d) correspond to LinearDBF, Non-linearDBFⅠ, Non-linearDBFⅡ, Non-linearDBFⅠ+Ⅱ, the azimuth angle estimation results after four kinds of digital beam synthesis. Figure 6 is a schematic diagram showing the comparison of the pitch angle estimation results of the target in the four polarization channels, in which Figure 6(a), Figure 6(b), Figure 6(c), and Figure 6(d) correspond to LinearDBF, Non-linearDBFⅠ, Non-linearDBFⅡ, Non-linearDBFⅠ+Ⅱ, these four digital beamforming results of pitch angle estimation.

It can be seen from Figure 5 and Figure 6 that the angle data of all polarization channels in nonlinear digital beamforming is more consistent than that in linear digital beamforming. For Non-linear DBFI, because the signals in the VH and HV channels are similar, the signal in the VV channel is lower than that in the HH channel, which indicates that the signal-to-noise ratio of the HV2-VV2 channel is lower than that of the ^{HH2 -} VH2 channel, so the HV channel has a lower signal-to-noise ratio than the ^{HH2 -} VH2 channel. The worst results. For Non-linearDBFII, the angle estimation results between different polarization channels are more consistent than Non-linearDBFI, because the signal-to-noise ratio of HH-VV channel is higher than that of HV ² -VV ² channel. For Non-linear DBFI+II, since the embodiment of the present invention selects the scattering point with higher signal-to-noise ratio at the same position of the two sets of high-resolution range images as the HRRP data of the third high-resolution range image, and on this basis For the subsequent angle estimation, the consistency between each polarization channel is better than Non-linearDBFⅠ and Non-linearDBFⅡ.

Referring to FIG. 7 , an embodiment of the present invention provides a target angle estimation system for a variable-polarization monopulse radar, including:

The target echo signal acquisition module is used to acquire the target echo signals of the four channels of the variable polarization monopulse radar;

The nonlinear digital beam synthesis module is used to perform two kinds of nonlinear digital beam synthesis respectively according to the target echo signal to obtain the first horizontal polarization component, the first vertical polarization component, the second horizontal polarization component, the first horizontal polarization component, and the first horizontal polarization component of each channel. Two vertically polarized components, and generate a first high-resolution range image and a second high-resolution range image of each channel;

a sum-difference signal pair determination module, configured to determine the sum-difference signal pair of the four polarization channels according to the first high-resolution range image and the second high-resolution range image;

The target angle estimation module is used to determine the target polarization scattering matrix according to the sum-difference signal pair, and estimate the target azimuth angle and target elevation angle of each polarization channel.

The contents in the above method embodiments are all applicable to the present system embodiments, the specific functions implemented by the present system embodiments are the same as the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

Referring to FIG. 8 , an embodiment of the present invention provides a device for estimating a target angle of a variable-polarization monopulse radar, including:

at least one processor;

at least one memory for storing at least one program;

When the above-mentioned at least one program is executed by the above-mentioned at least one processor, the above-mentioned at least one processor is made to realize the above-mentioned method for estimating the target angle of a variable-polarization monopulse radar.

The contents in the above method embodiments are all applicable to the present device embodiments, the specific functions implemented by the present device embodiments are the same as the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

Embodiments of the present invention further provide a computer-readable storage medium, in which a program executable by a processor is stored, and when executed by the processor, the program executable by the processor is used to execute the above-mentioned variable polarization monopulse radar Target angle estimation method.

A computer-readable storage medium according to an embodiment of the present invention can execute a method for estimating a target angle of a variable-polarization monopulse radar provided by the method embodiment of the present invention, and can execute any combination of implementation steps of the method embodiment. Corresponding functions and beneficial effects.

The embodiment of the present invention also discloses a computer program product or computer program, where the computer program product or computer program includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. A processor of the computer device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions to cause the computer device to perform the method shown in FIG. 1 .

In some alternative implementations, the functions/operations noted in the block diagrams may occur out of the order noted in the operational diagrams. For example, two blocks shown in succession may, in fact, be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/operations involved. Furthermore, the embodiments presented and described in the flowcharts of the present invention are provided by way of example in order to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of the various operations are altered and in which sub-operations described as part of larger operations are performed independently.

Furthermore, although the invention is described in the context of functional modules, it is to be understood that, unless stated to the contrary, one or more of the above-described functions and/or features may be integrated in a single physical device and/or In software modules, or one or more functions and/or features may be implemented in separate physical devices or software modules. It will also be appreciated that a detailed discussion of the actual implementation of each module is not necessary to understand the present invention. Rather, given the attributes, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the modules will be within the routine skill of the engineer. Accordingly, those skilled in the art, using ordinary skill, can implement the invention as set forth in the claims without undue experimentation. It is also to be understood that the specific concepts disclosed are illustrative only and are not intended to limit the scope of the invention, which is to be determined by the appended claims along with their full scope of equivalents.

If the above functions are implemented in the form of software functional units and sold or used as independent products, they may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present invention can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the above-mentioned methods in various embodiments of the present invention. The aforementioned storage medium includes: U disk, removable hard disk, Read-Only Memory (ROM, Read-Only Memory), Random Access Memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes .

The logic and/or steps represented in flowcharts or otherwise described herein, for example, may be considered an ordered listing of executable instructions for implementing the logical functions, may be embodied in any computer-readable medium, For use with, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch instructions from and execute instructions from an instruction execution system, apparatus, or apparatus) or equipment. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport the program for use by or in connection with an instruction execution system, apparatus, or apparatus.

More specific examples (non-exhaustive list) of computer readable media include the following: electrical connections with one or more wiring (electronic devices), portable computer disk cartridges (magnetic devices), random access memory (RAM), Read Only Memory (ROM), Erasable Editable Read Only Memory (EPROM or Flash Memory), Fiber Optic Devices, and Portable Compact Disc Read Only Memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the above-mentioned program can be printed, as it is possible, for example, by optically scanning the paper or other medium, followed by editing, interpretation or other suitable means if necessary Processing is performed to obtain the above program electronically and then stored in computer memory.

It should be understood that various parts of the present invention may be implemented in hardware, software, firmware or a combination thereof. In the above-described embodiments, various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or a combination of the following techniques known in the art: Discrete logic circuits, application specific integrated circuits with suitable combinational logic gates, Programmable Gate Arrays (PGA), Field Programmable Gate Arrays (FPGA), etc.

In the above description of the present specification, reference to the description of the terms "one embodiment/example", "another embodiment/example" or "certain embodiments/examples" etc. means the description in conjunction with the embodiment or example. Particular features, structures, materials, or characteristics are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, The scope of the invention is defined by the claims and their equivalents.

The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above-mentioned embodiments, and those skilled in the art can also make various equivalent deformations or replacements on the premise of not violating the spirit of the present invention. Equivalent modifications or substitutions are included within the scope defined by the claims of the present application.

Claims (10)

1. a variable polarization monopulse radar target angle estimation method, is characterized in that, comprises the following steps: Obtain the target echo signals of the four channels of the variable polarization monopulse radar; According to the target echo signal, two kinds of nonlinear digital beam synthesis are respectively performed to obtain the first horizontal polarization component, the first vertical polarization component, the second horizontal polarization component, and the second vertical polarization component of each channel, and generating a first high-resolution range image and a second high-resolution range image of each channel; Determine the sum-difference signal pair of the four polarization channels according to the first high-resolution range image and the second high-resolution range image; The target polarization scattering matrix is determined according to the sum-difference signal pair, and the target azimuth angle and target elevation angle of each polarization channel are estimated. 2. a kind of variable polarization monopulse radar target angle estimation method according to claim 1, is characterized in that, described variable polarization monopulse radar target angle estimation method also comprises the following steps: Determine whether the variable polarization monopulse radar transmits horizontal polarization or vertical polarization, and determines whether the variable polarization monopulse radar receives horizontal polarization or vertical polarization. 3. a kind of variable polarization monopulse radar target angle estimation method according to claim 2 is characterized in that, when determining that the variable polarization monopulse radar transmits horizontal polarization, the first horizontal polarization component is:

in,

represents the first horizontally polarized component of the nth channel,

Represents the target echo signal of the nth channel, n=1, 2, 3, 4,

and

and

The first vertical polarization component is:

in,

represents the first vertically polarized component of the nth channel; The first high-resolution range image is generated from the first horizontal polarization component and the first vertical polarization component. 4. a kind of variable polarization monopulse radar target angle estimation method according to claim 2 is characterized in that, when determining that the variable polarization monopulse radar transmits horizontal polarization, the second horizontal polarization component is:

in,

represents the second horizontally polarized component of the nth channel,

Represents the target echo signal of the nth channel, n=1, 2, 3, 4,

Represents the target echo signal of the nth channel when the variable-polarization monopulse radar transmits vertical polarization; The second vertically polarized component is:

in,

represents the second vertically polarized component of the nth channel; The second high-resolution range image is generated from the second horizontally polarized component and the second vertically polarized component. 5. The method for estimating the target angle of a variable-polarization monopulse radar according to claim 1, characterized in that, according to the first high-resolution range image and the second high-resolution range image, the four The step of the sum-difference signal pair of the polarization channels specifically includes: Selecting a scattering point with a higher signal-to-noise ratio in the first high-resolution range image and the second high-resolution range image to generate a third high-resolution range image; determining a third horizontal polarization component and a third vertical polarization component of each channel according to the third high-resolution range image; determining a sum-difference signal pair of four polarization channels according to the third horizontal polarization component and the third vertical polarization component; Wherein, the polarization channel includes HH polarization channel, VH polarization channel, HV polarization channel and VV polarization channel, and the HH polarization channel indicates that the variable polarization monopulse radar transmits horizontal polarization and receives horizontal polarization , the VH polarization channel represents that the variable-polarization monopulse radar transmits horizontal polarization and receives vertical polarization, the HV polarization channel represents that the variable-polarization monopulse radar sends vertical polarization and receives horizontal polarization, and the VV The polarization channel indicates that the variable polarization monopulse radar transmits vertical polarization and receives vertical polarization. 6. a kind of variable polarization monopulse radar target angle estimation method according to claim 5, is characterized in that, described sum-difference signal pair is:

in,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the HH polarization channel, respectively,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the VH polarization channel, respectively,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the HV polarization channel, respectively,

as well as

Represent the sum signal, azimuth difference signal and pitch difference signal of the VV polarization channel, respectively,

represents the third horizontal polarization component of the nth channel when the variable polarization monopulse radar transmits horizontal polarization,

represents the third vertical polarization component of the nth channel when the variable polarization monopulse radar transmits the horizontal polarization,

represents the third horizontal polarization component of the nth channel when the variable polarization monopulse radar transmits vertical polarization,

It represents the third vertical polarization component of the nth channel when the variable polarization monopulse radar transmits vertical polarization. 7. a kind of variable polarization monopulse radar target angle estimation method according to claim 6, is characterized in that, described target polarization scattering matrix is:

Among them, M represents the target polarization scattering matrix; The target azimuth is:

in,

Respectively represent the target azimuth angles of HH polarization channel, VH polarization channel, HV polarization channel, VV polarization channel, k _HH , k _VH , k _HV , k _VV represent HH polarization channel, VH polarization channel, HV polarization channel, respectively The slope of the sum-difference beam discrimination curve of the polarization channel and the VV polarization channel, Re( ) represents the real part; The target pitch angle is:

in,

Indicate the target pitch angles of the HH polarization channel, VH polarization channel, HV polarization channel, and VV polarization channel, respectively. 8. A variable polarization monopulse radar target angle estimation system, characterized in that, comprising: The target echo signal acquisition module is used to acquire the target echo signals of the four channels of the variable polarization monopulse radar; A nonlinear digital beam synthesis module, configured to perform two kinds of nonlinear digital beam synthesis respectively according to the target echo signal to obtain the first horizontal polarization component, the first vertical polarization component, and the second horizontal polarization component of each channel , a second vertically polarized component, and generate a first high-resolution range image and a second high-resolution range image of each channel; a sum-difference signal pair determination module, configured to determine a sum-difference signal pair of four polarization channels according to the first high-resolution range image and the second high-resolution range image; The target angle estimation module is used to determine the target polarization scattering matrix according to the sum-difference signal pair, and estimate the target azimuth angle and target elevation angle of each polarization channel. 9. A variable polarization monopulse radar target angle estimation device, characterized in that, comprising: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method for estimating a target angle of a variable polarization monopulse radar according to any one of claims 1 to 7. 10. A computer-readable storage medium in which a processor-executable program is stored, wherein the processor-executable program, when executed by the processor, is used to execute any one of claims 1 to 7 A method for estimating the target angle of a variable-polarization monopulse radar described in Item 1.

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