阅读说明：本技术 基于波束指向优化的提高三坐标雷达比幅测角精度的方法 (Method for improving amplitude-comparison angle measurement precision of three-coordinate radar based on beam pointing optimization ) 是由 潘瑞云 刘军华 孟凡 贾倩茜 于 2021-07-02 设计创作，主要内容包括：本发明提出一种基于波束指向优化的提高三坐标雷达比幅测角精度的方法。现代三坐标雷达不论是频扫体制还是相控阵体制,在测量目标仰角时会用到比幅测角方法。通常的比幅测角方法,在良好信号条件下测角精度只能达到波束宽度的1/10左右,本方法利用优化后的波束指向可显著提高比幅测角精度,比幅测角的仰角精度可达到波束宽度的1/20。(The invention provides a method for improving amplitude-comparison angle measurement precision of a three-coordinate radar based on beam pointing optimization. No matter the modern three-coordinate radar is in a frequency scanning system or a phased array system, an amplitude comparison angle measurement method can be used when the target elevation angle is measured. The common amplitude comparing angle measuring method has the advantages that the angle measuring precision can only reach about 1/10 of the beam width under the good signal condition, the amplitude comparing angle measuring precision can be obviously improved by utilizing the optimized beam pointing, and the elevation angle precision of the amplitude comparing angle measuring method can reach 1/20 of the beam width.)

1. The method for improving the amplitude comparison angle measurement precision of the three-coordinate radar based on beam pointing optimization is characterized by comprising the following steps of:

calculating the beam width according to the physical elements and radio frequency parameters of the phased array antenna; calculating the number of simultaneously formed wave beams according to the elevation angle coverage range designed by the radar; setting a first beam direction according to the initial beam direction; continuously and iteratively determining the direction of the next beam according to a beam overlapping criterion and a beam width change rule, and determining the directions of all beams under the current frequency; repeating the steps and determining the beam directions of other frequencies.

2. The method for improving the amplitude measurement accuracy of the three-coordinate radar based on the beam pointing optimization according to claim 1, wherein: calculating the beam pointing interval includes:

step 1: obtaining radar parameter antenna pitching feed number N, array element spacing s, light speed c and antenna inclination angle fai, and initializing a radar model according to the parameters;

step 2: obtaining parameters used at this time, receiving a beam weighting broadening coefficient u, radio frequency Fr and a first beam elevation angle pointing theta 1, and initializing the calculated beam pointing;

and step 3: calculating the beam width beta of the first beam pointing₁；

And 4, step 4: calculating the pointing angle on of the next beam, k being the overlap factor, theta_n＝θ_n-1+β_n-1*k；

And 5: judging whether the elevation angle coverage is met, and ending if the pointing angle meets the elevation angle coverage; and if the elevation coverage is not met, repeating the step 3 and the step 4 until the elevation coverage is met, and finally determining the pointing angles of all the receiving beams.

Technical Field

The invention belongs to the general technical field of radars.

Background

The target elevation angle accuracy is an important index of the three-coordinate radar, and is generally in direct proportion to the width of an antenna beam, and the narrower the antenna beam is, the higher the elevation angle accuracy is. The target elevation accuracy is typically calculated using a stacked beam amplitude versus angle method. However, the narrower the antenna beam, the larger the antenna aperture, and may cause problems in terms of fittability, weight, and processing difficulty in radar design. Therefore, under the condition that the aperture of the antenna is certain, the technical index of the radar can be improved to a great extent by improving the angle measurement precision, or the radar antenna can be made smaller under the condition that the technical index of the radar is met. Under a certain antenna aperture, the improvement of the radar angle measurement precision is the content of continuous research of the radar overall technology.

Disclosure of Invention

The three-coordinate radar measures the target elevation angle by adopting a method of receiving simultaneous multi-beam and amplitude-comparing angle measurement, and the measurement precision of the elevation angle is limited by a plurality of parameters. In order to improve the elevation angle measurement accuracy of the three-coordinate radar under the condition of determining the aperture of the antenna, the invention provides a method for improving the amplitude-to-amplitude angle measurement accuracy of the three-coordinate radar based on beam pointing optimization, so that the elevation angle measurement accuracy is improved to 1/20 of the beam width.

The technical scheme for realizing the invention comprises the following steps:

calculating the beam width according to the physical elements and radio frequency parameters of the phased array antenna; calculating the number of simultaneously formed wave beams according to the elevation angle coverage range designed by the radar; setting a first beam direction according to the initial beam direction; continuously and iteratively determining the direction of the next beam according to a beam overlapping criterion and a beam width change rule, and determining the directions of all beams under the current frequency; repeating the steps and determining the beam directions of other frequencies.

Further, calculating the beam pointing interval comprises:

step 1: obtaining radar parameter antenna pitching feed number N, array element spacing s, light speed c and antenna inclination angle fai, and initializing a radar model according to the parameters;

step 2: obtaining parameters used at this time, receiving a beam weighting broadening coefficient u, radio frequency Fr and a first beam elevation angle pointing theta 1, and initializing the calculated beam pointing;

and step 3: calculating the beam width beta of the first beam pointing₁；

And 4, step 4: calculating the pointing angle on of the next beam, k being the overlap factor, theta_n＝θ_n-1+β_n-1*k；

And 5: judging whether the elevation angle coverage is met, and ending if the pointing angle meets the elevation angle coverage; and if the elevation coverage is not met, repeating the step 3 and the step 4 until the elevation coverage is met, and finally determining the pointing angles of all the receiving beams.

The beneficial effects of the invention include:

under the condition that the aperture of the antenna is fixed, namely under the condition that the number of array elements is determined, the method can improve the angle measurement precision by one time. Or at the initial stage of radar design, the number of radar array elements can be reduced by half under the condition that the accuracy meets the requirement. The method has a very positive effect on the adaptability, economy, flexibility and the like of radar design.

Drawings

FIG. 1 is a system process flow diagram of the present invention.

Fig. 2 is a schematic beam pointing diagram of the present invention.

Detailed Description

The invention is further explained below with reference to the figures and examples.

The invention provides a method for improving amplitude comparison angle measurement precision of a three-coordinate radar based on beam pointing optimization, which mainly comprises the following steps: calculating the beam width according to the physical elements, radio frequency parameters and the like of the phased array antenna; calculating the number of simultaneously formed wave beams according to the elevation angle coverage range designed by the radar; setting a first beam direction according to the initial beam direction; continuously and iteratively determining the direction of the next beam according to a beam overlapping criterion and a beam width change rule, and determining the directions of all beams under the current frequency; repeating the steps and determining the beam directions of other frequencies. The method for improving amplitude ratio angle measurement mainly calculates accurate beam pointing angles theta 1-theta n, and comprises the following steps: confirming the coverage of elevation angle, antenna parameters, array element spacing, array element number, confirming the weighting coefficient of received wave beam, signal radio frequency and initial wave beam pointing, and calculating the wave beam pointing interval, as shown in fig. 1:

step 1: obtaining radar parameter antenna pitching feed number N, array element spacing s, light speed c and antenna inclination angle fai, and initializing a radar model according to the parameters;

step 2: obtaining parameters used at this time, receiving a beam weighting broadening coefficient u, radio frequency Fr and a first beam elevation angle pointing theta 1, and initializing the calculated beam pointing;

and step 3: calculating the beam width beta of the first beam pointing₁，

δ₁Is the angle at which the beam is pointing away from normal, and λ c/Fr.

And 4, step 4: the pointing angle thetan of the next beam is calculated.

k is an overlap coefficient, and a value of 0.82-0.85 is generally selected to maximize the precision.

θ_n＝θ_n-1+β_n-1*k

And 5: judging whether the elevation angle coverage is met, and ending if the pointing angle meets the elevation angle coverage; and if the elevation coverage is not met, repeating the step 3 and the step 4 until the elevation coverage is met, and calculating all the pointing angles theta 1-theta n as shown in figure 2.

By introducing the calculated receiving beam pointing parameters into the radar design and carrying out amplitude comparison angle measurement calculation, the angle measurement precision of the three-coordinate radar is obviously improved.