阅读说明：本技术 一种基于四臂螺旋天线的二维测角方法 (Two-dimensional angle measurement method based on four-arm helical antenna ) 是由 魏宪举 陈玲 王鹏 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种基于四臂螺旋天线的二维测角方法,涉及雷达技术领域,该方法利用基于四臂螺旋天线的被动测向系统对不同角度处的样本目标进行测向采集得到角度信息及其对应的原始天线波束的样本数据,计算四个原始天线波束的和波束和差波束并分别对和波束和差波束进行不同的波束运算得到四个偏轴正交波束,利用和波束、差波束和四个偏轴正交波束得到第一参数、第二参数和第三参数,基于处理后的样本数据采用最小二乘法拟合得到角度信息与第一参数、第二参数和第三参数之间的测角函数关系,然后可以利用测角函数关系进行测角,这种二维拟合修正测角的方法可以有效提高测角的精度。(The invention discloses a two-dimensional angle measurement method based on a quadrifilar helix antenna, relating to the technical field of radar, the method comprises the steps of carrying out direction-finding acquisition on sample targets at different angles by using a passive direction-finding system based on a four-arm helical antenna to obtain angle information and sample data of original antenna beams corresponding to the angle information, calculating sum beams and difference beams of the four original antenna beams, carrying out different beam operations on the sum beams and the difference beams respectively to obtain four off-axis orthogonal beams, obtaining a first parameter, a second parameter and a third parameter by using the sum beams, the difference beams and the four off-axis orthogonal beams, fitting by using a least square method based on the processed sample data to obtain a measured angle function relation between the angle information and the first parameter, the second parameter and the third parameter, and then angle measurement can be carried out by utilizing the angle measurement function relation, and the method for correcting the angle measurement through two-dimensional fitting can effectively improve the precision of the angle measurement.)

1. A two-dimensional angle measurement method based on a quadrifilar helix antenna is characterized by comprising the following steps:

carrying out direction finding on sample targets at different angles by using a passive direction finding system based on a four-arm helical antenna, and determining angle information of the sample targets and four corresponding original antenna beams acquired through the four-arm helical antenna in each direction finding to obtain a group of sample data;

calculating sum beams and difference beams of four original antenna beams for each group of sample data, and performing different beam operations on the sum beams and the difference beams respectively to obtain four off-axis orthogonal beams; obtaining a first parameter according to the sum beam and the difference beam, determining a second parameter according to two off-axis orthogonal beams and the sum beam of one group of opposite angles, and determining a third parameter according to two off-axis orthogonal beams and the sum beam of the other group of opposite angles to obtain processed sample data;

fitting by adopting a least square method based on the processed sample data to obtain an angle measurement function relation between the angle information and the first parameter, the second parameter and the third parameter;

and acquiring four original antenna beams of the target to be measured by using a passive direction-finding system based on a four-arm helical antenna, determining corresponding first parameters, second parameters and third parameters, and inputting the first parameters, the second parameters and the third parameters into the angle-measuring function relation to obtain angle information of the target to be measured.

2. The method of claim 1, wherein obtaining the first parameter from the sum beam and the difference beam comprises determining the first parameter asWhere Δ is the difference beam, Σ is the sum beam, and the symbol | | | represents the amplitude of the beam.

3. The method of claim 1, wherein determining the second parameter from one set of two diagonal off-axis orthogonal beams and a sum beam and determining the third parameter from the other set of two diagonal off-axis orthogonal beams and a sum beam comprises:

determining the second parameter asDetermining the third parameter asWhere B1 and B3 are a set of two diagonal off-axis orthogonal beams, B2 and B4 are another set of two diagonal off-axis orthogonal beams, Σ is the sum beam, and the symbol | | | represents the amplitude of the beam.

4. The method of claim 1, wherein the least squares fit is used to obtain the angle-measuring functional relationship between the angle information and the first, second and third parameters based on the processed sample data, including according toThe form fitting of (1) obtains a goniometric functional relationship between the angle information and a first parameter k1, a second parameter k2 and a third parameter k3, i, j, m are parameters, i + j + m is less than or equal to 3, and lambda (i, j, m) is a coefficient.

5. The method according to any of claims 1-4, wherein said calculating a sum beam and a difference beam of four original antenna beams and performing different beam operations on said sum beam and difference beam to obtain four off-axis orthogonal beams comprises:

determining sum beams of sigma-P1-j P2-P3+ j P4, difference beams of delta-P1-P2 + P3-P4, and P1, P2, P3 and P4 as four original antenna beams respectively;

four off-axis orthogonal beams B1, B2, B3 and B4 are determined asWhere B1 and B3 are a set of two diagonal off-axis orthogonal beams and B2 and B4 are another set of two diagonal off-axis orthogonal beams.

Technical Field

The invention relates to the technical field of radars, in particular to a two-dimensional angle measurement method based on a four-arm helical antenna.

Background

The dual-mode spiral broadband direction-finding system is mainly applied to an ultra-wideband passive direction-finding system, a dual-mode quadrifilar spiral antenna is commonly used in the passive direction-finding system, a quadrifilar spiral can determine an azimuth angle and a pitch angle through the relationship between two symmetrical arms so as to achieve the purpose of direction finding, the traditional passive direction-finding system based on the quadrifilar spiral antenna mainly utilizes a sum mode (M1 mode) and a difference mode (M2 mode) radiated by an antenna to determine an angle-finding result based on a pre-made lookup table, the curves of the sum mode and the difference mode of the quadrifilar spiral antenna are shown in figure 1, but the amplitude comparison and the phase comparison of the quadrifilar spiral antenna in a phase-finding angle are greatly influenced by the environment, and the situation of inaccurate angle.

Disclosure of Invention

The invention provides a two-dimensional angle measurement method based on a quadrifilar helix antenna aiming at the problems and the technical requirements, and the technical scheme of the invention is as follows:

a two-dimensional angle measurement method based on a quadrifilar helix antenna comprises the following steps:

carrying out direction finding on sample targets at different angles by using a passive direction finding system based on a four-arm helical antenna, and determining angle information of the sample targets and four corresponding original antenna beams acquired through the four-arm helical antenna in each direction finding to obtain a group of sample data;

calculating sum beams and difference beams of four original antenna beams for each group of sample data, and performing different beam operations on the sum beams and the difference beams respectively to obtain four off-axis orthogonal beams; obtaining a first parameter according to the sum beam and the difference beam, determining a second parameter according to two off-axis orthogonal beams and the sum beam of one group of opposite angles, and determining a third parameter according to two off-axis orthogonal beams and the sum beam of the other group of opposite angles to obtain processed sample data;

fitting by adopting a least square method based on the processed sample data to obtain an angle measurement function relation between the angle information and the first parameter, the second parameter and the third parameter;

and acquiring four original antenna beams of the target to be measured by using a passive direction-finding system based on a four-arm helical antenna, determining corresponding first parameters, second parameters and third parameters, and inputting the corresponding first parameters, second parameters and third parameters into an angle-measuring function relation to obtain angle information of the target to be measured.

The further technical scheme is that the first parameter is obtained according to the sum beam and the difference beam, and the first parameter is determined to beWhere Δ is the difference beam, Σ is the sum beam, and the symbol | | | represents the amplitude of the beam.

The further technical scheme is that the method determines a second parameter according to one group of two diagonal off-axis orthogonal beams and a sum beam, and determines a third parameter according to the other group of diagonal two off-axis orthogonal beams and the sum beam, and comprises the following steps:

determining the second parameter asDetermining a third parameter asWhere B1 and B3 are a set of two diagonal off-axis orthogonal beams, B2 and B4 are another set of two diagonal off-axis orthogonal beams, Σ is a sum beam, and the symbol | | | represents the amplitude of the beam.

The further technical scheme is that the least square method is adopted to fit based on the processed sample data to obtain the angle measurement function relation between the angle information and the first parameter, the second parameter and the third parameter, including the angle measurement function relation according to the methodThe form fitting of (1) obtains a goniometric functional relationship between the angle information and a first parameter k1, a second parameter k2 and a third parameter k3, i, j, m are parameters, i + j + m is less than or equal to 3, and lambda (i, j, m) is a coefficient.

The further technical scheme is that the method comprises the steps of calculating sum beams and difference beams of four original antenna beams and performing different beam operations on the sum beams and the difference beams respectively to obtain four off-axis orthogonal beams, and comprises the following steps:

determining sum beams of sigma-P1-j P2-P3+ j P4, difference beams of delta-P1-P2 + P3-P4, and P1, P2, P3 and P4 as four original antenna beams respectively;

four off-axis orthogonal beams B1, B2, B3 and B4 are determined asWhere B1 and B3 are a set of two diagonal off-axis orthogonal beams and B2 and B4 are another set of two diagonal off-axis orthogonal beams.

The beneficial technical effects of the invention are as follows:

the application discloses a two-dimensional angle measurement method based on a four-arm helical antenna, the method is based on the original four original antenna beams to construct and obtain three intermediate parameters, then the minimum multiplication fitting is adopted to obtain the functional relation between angle information and the intermediate parameters, and the method for correcting the angle measurement through the two-dimensional fitting can effectively improve the precision of the angle measurement.

Drawings

Fig. 1 is a schematic diagram of a quadrifilar helix antenna and the mode and differential mode curves.

Fig. 2 is a flow chart of a two-dimensional angle measurement method disclosed in the present application.

Fig. 3 is a graph illustrating a first parameter obtained by the present application.

Detailed Description

The following further describes the embodiments of the present invention with reference to the drawings.

The application discloses a two-dimensional angle measurement method based on a quadrifilar helix antenna, which comprises two parts, an angle measurement function relation fitting part and an actual angle measurement part, and please refer to a flow chart shown in figure 2. The angle measuring function relation fitting part mainly comprises the following steps:

step S1, a passive direction finding system based on the quadrifilar helix antenna is used for carrying out direction finding on sample targets at different angles, and angle information of the sample targets and four corresponding original antenna beams P1, P2, P3 and P4 acquired through the quadrifilar helix antenna are determined in each direction finding to obtain a group of sample data. The angle information in this application includes an azimuth angle α and a pitch angle β, and a set of sample data obtained at each direction finding can be represented as { (α, β), (P1, P2, P3, P4) }.

Step S2, performing data processing on each group of sample data to obtain processed sample data, and constructing three intermediate parameters k1, k2, and k3 by mainly using four original antenna beams P1, P2, P3, and P4 in each group of sample data, which specifically includes the following steps:

1. the sum beam Σ and the difference beam Δ of the four original antenna beams P1, P2, P3, P4 are calculated. The calculation formula adopted is as follows: sigma-P1-j P2-P3+ j P4, delta-P1-P2 + P3-P4, j is an imaginary number.

2. Carrying out different beam operations on the sum beam sigma and the difference beam delta to obtain four off-axis orthogonal beams B1, B2, B3 and B4, wherein the four off-axis orthogonal beams form two groups of diagonal off-axis orthogonal beams, and the adopted calculation formula is thatWhere B1 and B3 are a set of two diagonal off-axis orthogonal beams and B2 and B4 are another set of two diagonal off-axis orthogonal beams.

3. The first parameter k1 is obtained from the sum beam Σ and the difference beam Δ, and the amplitude ratio between the difference beam Δ and the sum beam Σ is k1, i.e. k1The symbol | | | represents the amplitude of the beam. The obtained curve of the first parameter k1 is schematically shown in fig. 3.

4. The second parameter k2 is determined from one set of two diagonal off-axis orthogonal beams and the sum beam and the third parameter k3 is determined from the other set of two diagonal off-axis orthogonal beams and the sum beam. The ratio of the amplitude difference of the two off-axis orthogonal beams of one set of opposite corners to the amplitude of the sum beam Σ is used as the second parameter k2, and the ratio of the amplitude difference of the two off-axis orthogonal beams of the other set of opposite corners to the amplitude of the sum beam Σ is used as the third parameter k3, that is, the ratio of the amplitude difference of the two off-axis orthogonal beams of the other set of opposite corners to the amplitude of the sum beam Σ

Therefore, each group of sample data can be processed to obtain corresponding processed sample data, where the processed sample data at least includes angle information of a sample target and a corresponding relationship between three intermediate parameters k1, k2, and k3 obtained by processing corresponding four original antenna beams, that is, each group of processed sample data can be represented as { (α, β), (k1, k2, k3) }.

And step S3, obtaining an angle measurement functional relation between the angle information and the first parameter k1, the second parameter k2 and the third parameter k3 by adopting least square fitting based on the processed sample data. The application is in accordance withThe form fitting of (1) to obtain the angle measurement function relation, i, j, m is a parameter, i + j + m is less than or equal to 3, and lambda (i, j, m) is a coefficient.

After the angle measurement function relationship is obtained through the fitting in the steps S1-S3, the actual angle measurement can be performed by using the angle measurement function relationship, for a target to be measured requiring angle measurement, four original antenna beams of the target to be measured are obtained by using a passive direction finding system based on a quadrifilar helical antenna, corresponding first parameters, second parameters and third parameters are determined according to the method, the angle measurement function relationship is input to obtain angle information of the target to be measured, and the azimuth angle and the pitch angle of the target to be measured are also obtained.

What has been described above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiment. It is to be understood that other modifications and variations directly derivable or suggested by those skilled in the art without departing from the spirit and concept of the present invention are to be considered as included within the scope of the present invention.