阅读说明：本技术 一种雷达测量目标角度的实验方法 (Experimental method for measuring target angle by radar ) 是由 颜卫忠 陈栋志 孔凡伟 钱婧怡 白旭东 于 2020-12-10 设计创作，主要内容包括：本发明实施例提供了一种雷达测量目标角度的实验方法,其特征在于,包括步骤：步骤1:架设雷达,选取经过雷达的第一条线,即中轴线,然后根据选取的夹角,在中轴线的两侧根据夹角选取两条标记线,所述标记线用于标记目标移动的轨迹；步骤2：雷达天线指向校准；步骤3：将目标放置在标记线上,利用雷达测量目标的角度；步骤4：对每一个角度标记线上测量的角度数据进行处理,即得到目标角度。测量的目标角度先平均,再减去天线主轴指向角度,记为最终目标角度。(The embodiment of the invention provides an experimental method for measuring a target angle by a radar, which is characterized by comprising the following steps: step 1, erecting a radar, selecting a first line passing through the radar, namely a central axis, and then selecting two marking lines on two sides of the central axis according to the included angle according to the selected included angle, wherein the marking lines are used for marking the moving track of a target; step 2: calibrating the orientation of the radar antenna; and step 3: placing the target on a marking line, and measuring the angle of the target by using a radar; and 4, step 4: and processing the angle data measured on each angle marking line to obtain the target angle. The measured target angles are averaged, and then the pointing angle of the main shaft of the antenna is subtracted, and the result is recorded as a final target angle.)

1. An experimental method for measuring a target angle by a radar is characterized by comprising the following steps:

step 1, erecting a radar, selecting a first line passing through the radar, namely a central axis, and then selecting two marking lines on two sides of the central axis according to the included angle according to the selected included angle, wherein the marking lines are used for marking the moving track of a target;

step 2: calibrating the orientation of the radar antenna;

and step 3: placing the target on a marking line, and measuring the angle of the target by using a radar;

and 4, step 4: and processing the angle data measured on each angle marking line to obtain the target angle. The measured target angles are averaged, and then the pointing angle of the main shaft of the antenna is subtracted, and the result is recorded as a final target angle.

2. The experimental method for radar measurement of target angle as claimed in claim 1, wherein in step 2, the calibration body is placed on the central axis, the antenna pointing direction is continuously adjusted, and the angle of the calibration body is measured, so that the angle of the calibration body is smaller than the threshold value δ, and the angle of the calibration body is recorded as θ_T。

3. The experimental method for radar measurement of target angle according to claim 2, wherein in step 2, the target (calibration body) angle θ on the central axis of the system is measured for the first time₀If the target angle is less than the threshold value delta, i.e. | theta₀|<δ, no correction is needed. Otherwise, when theta₀>0, the radar antenna needs to rotate clockwise, and conversely, the radar antenna needs to rotate anticlockwise. After the antenna is fixed, the target angle theta is measured again₁. The direction of the antenna is repeatedly adjusted until the angle is theta_i|<Delta, then the calibration is completed and the direction of the antenna main axis is recorded as theta_T＝θ_i。

4. The experimental method for radar measurement of target angle according to claim 2, wherein in step 3,

to measure a continuously moving object, the object is moved along the marking line and the angle measurement data is recorded.

5. The experimental method for radar measurement of target angle according to claim 4, wherein in step 2, the angle error threshold δ is set according to the angle measurement accuracy.

6. The experimental method for radar measurement of target angle as claimed in claim 5, wherein in step 2, the radar antenna orientation needs to be recalibrated when the test environment or test condition changes.

7. The experimental method for radar measurement of target angle as claimed in claim 6, wherein in step 4, the measured target angle is averaged and then the antenna main axis pointing angle θ is subtracted_TAnd is recorded as a final target angle.

Technical Field

The invention belongs to the field of radar target measurement, and relates to an experimental method for measuring a target angle by a radar.

Background

Signals generated by a radar transmitter are radiated outwards through a transmitting antenna, the signals are reflected or scattered after encountering a target, and a receiving antenna of the radar transmits received reflected signals (echo signals) to a radar receiver to complete processing such as frequency conversion, filtering, amplification and the like, so that intermediate frequency signals are formed. The intermediate frequency signal is sampled and processed by a digital signal processor to complete the measurement of target parameters. The radar is able to measure the distance and speed of a target and, if there are multiple receive antennas or the antenna beam is steerable, the angle of the target. The radar system has different systems aiming at different application scenes, and common radars comprise a linear frequency modulation continuous wave radar, a Doppler radar, a pulse radar and the like.

For a static target, only the main shaft of the radar antenna is required to be coincided with a target measurement coordinate system, the target angle measurement is simpler, and the angle measurement error can be determined according to the difference between the radar angle measurement value and the actual angle value. For the verification of the angle measurement error of the continuously moving target, the real-time change of the angle brings difficulty to the measurement, and the limited angle measurement precision also causes larger error of the measurement result, so that the target moves along a fixed angle, and the experiment complexity can be reduced. In addition, regardless of the target in any motion state, the antenna orientation needs to be calibrated before measurement. However, the radar angle measurement method is rarely introduced in the literature, so that a method for determining radar angle measurement errors of targets in different motion states is necessary.

Disclosure of Invention

Aiming at the problems of complicated process, large error and low reliability of the current radar target angle measurement, the experimental method for measuring the target angle by the radar is provided.

An experimental method for measuring a target angle by a radar is characterized by comprising the following steps:

step 1, erecting a radar, selecting a first line passing through the radar, namely a central axis, and then selecting two marking lines on two sides of the central axis according to the included angle according to the selected included angle, wherein the marking lines are used for marking the moving track of a target;

step 2: calibrating the orientation of the radar antenna;

and step 3: placing the target on a marking line, and measuring the angle of the target by using a radar;

and 4, step 4: and processing the angle data measured on each angle marking line to obtain the target angle. The measured target angles are averaged, and then the pointing angle of the main shaft of the antenna is subtracted, and the result is recorded as a final target angle.

Preferably, in the step 2, a calibration body is placed on the central axis, the pointing direction of the antenna is continuously adjusted, and the angle of the calibration body is measured, so that the angle of the calibration body is smaller than a threshold value delta, and the angle of the calibration body is recorded as theta_T。

Preferably, in the step 2, the target angle θ on the central axis of the system is measured for the first time₀If the target angle is less than the threshold value delta, i.e. | theta₀|<δ, no correction is needed. Otherwise, when theta₀>0, the radar antenna needs to rotate clockwise, and conversely, the radar antenna needs to rotate anticlockwise. After the antenna is fixed, the target angle theta is measured again₁. The direction of the antenna is repeatedly adjusted until the angle is theta_i|<Delta, then the calibration is completed and the direction of the antenna main axis is recorded as theta_T＝θ_i。

Preferably, in step 3, in order to measure the continuously moving object, the object is moved along the mark line, and the angle measurement data is recorded.

Preferably, in step 2, the angle error threshold δ needs to be set according to the angle measurement precision.

Preferably, in step 2, when the test environment or the test condition changes, the radar antenna orientation needs to be recalibrated.

Preferably, in step 4, the measured target angles are averaged, and then the antenna main axis pointing angle θ is subtracted_TAnd is recorded as a final target angle.

The invention provides an experimental method for measuring a target angle by a radar, which can better ensure the accuracy of target angle measurement by combining with a processing technology of radar echo signals.

The beneficial effects of the invention include:

(1) can be used as a radar angle measurement calibration system

A calibration body is placed on the central axis of the angle measurement system, the pointing direction of the antenna is continuously adjusted, the angle of the calibration body is measured, the angle of the calibration body is smaller than a threshold value delta, and therefore the angle measurement error of the system is smaller than delta. In addition, by processing the angle data measured on each of the mark lines, the angle measurement error can be further reduced.

(2) Adapted for measurement of other target parameters

Besides angle measurement, the experimental method is also suitable for target distance, speed and multi-target multi-parameter measurement.

The above description describes in detail embodiments of the present patent. It is emphasized that the invention is not limited to the specific embodiments described above, but that various modifications and extensions can be made by a person skilled in the relevant art within the scope of the claims without this affecting the essence of the invention.

Drawings

FIG. 1 is a schematic diagram of an experimental system for measuring a target angle by a radar in the present invention.

FIG. 2 is a schematic diagram of the angle measurement error of the stationary target according to the present invention.

Fig. 3 is a schematic diagram of the angle measurement of the moving object in the present invention.

Fig. 4 is a radar chart of angle measurement of a moving target in the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

The invention mainly provides an experimental method for measuring target angles by a radar aiming at targets in different motion states, which comprises the following steps:

step 1, erecting a radar, and selecting a first line passing through the radar, namely a central axis. And marking lines with different angles are drawn on the ground according to the selected central axis, so that the rear target can be conveniently placed or moved.

And 2, calibrating the orientation of the radar antenna. Placing a calibration body on the central axis of the angle measurement system, continuously adjusting the pointing direction of the antenna and measuring the angle of the calibration body to make the angle of the calibration body less than a threshold value delta and marking the angle of the calibration body as theta_T。

According to an embodiment of the present invention, in the step 2, the radar antenna pointing calibration step includes: firstly measuring target angle theta on central axis of system₀If the target angle is less than the threshold value delta, i.e. | theta₀|<δ, no correction is needed. Otherwise, when theta₀>0, the radar antenna needs to rotate clockwise, and conversely, the radar antenna needs to rotate anticlockwise. After the antenna is fixed, the target angle theta is measured again₁. The direction of the antenna is repeatedly adjusted until the angle is theta_i|<Delta, then the calibration is completed and the direction of the antenna main axis is recorded as theta_T＝θ_i。

In step 2, the angle error threshold δ needs to be set according to the angle measurement precision.

In step 2, when the test environment or the test condition changes, the radar antenna orientation needs to be recalibrated.

And 3, placing the target on a mark line at any angle in the radar beam range, and measuring the angle of the target by using the radar. In step 3, in order to measure the continuously moving target, the platform on which the target is located is moved along the fixed angle marking line, and the angle measurement data is recorded.

And 4, processing the angle data measured on each angle marking line to obtain the target angle. According to an embodiment of the present invention, in the step 4, the measured target angles are averaged, and then the antenna main axis pointing angle θ is subtracted_TAnd is recorded as a final target angle.

The experimental method for measuring the target angle by the radar can better ensure the accuracy of the measurement of the target angle. The embodiments of the present application will be described below with reference to specific examples.

With reference to fig. 1 to 4, the specific implementation of the present invention is as follows:

step 1, selecting a first line passing through a radar in space, namely a central axis, and drawing marking lines at different angles on the ground according to a relation tan theta (L/H), so that a target at the back can be conveniently placed or moved, as shown in fig. 1.

And 2, calibrating the orientation of the radar antenna. Placing a calibration body on the central axis, continuously adjusting the pointing direction of the antenna and measuring the angle of the calibration body to make the angle of the calibration body smaller than a threshold value delta, and recording the angle of the calibration body as theta_T. The radar antenna pointing calibration steps are as follows: target angle theta on central axis of primary angle measurement system₀If the target angle is less than the threshold value delta, i.e. | theta₀|<δ, no correction is needed. Otherwise, when theta₀>0, the radar antenna needs to rotate clockwise, and conversely, the radar antenna needs to rotate anticlockwise. After the antenna is fixed, the target angle theta is measured again₁. The direction of the antenna is repeatedly adjusted until the angle is theta_i|<Delta, then the calibration is completed and the direction of the antenna main axis is recorded as theta_T＝θ_i. The angle error threshold δ needs to be set according to the angle measurement accuracy.

And 3, placing the target on a mark line at any angle in the radar beam range, and measuring the angle of the target by using the radar. In order to measure the continuously moving target, the platform on which the target is positioned moves along a fixed angle marking line, and angle measurement data is recorded.

And 4, processing the angle data measured on each angle marking line to obtain the target angle. The measured target angles are averaged and then the antenna main shaft pointing angle theta is subtracted_TAnd is recorded as a final target angle.

The technical solution of the present invention is further described in detail by two examples. The embodiments are all implemented on the premise of the technical scheme of the invention, and the embodiments and specific operation processes are given in the embodiments, but the protection scope of the invention is not limited to the following two embodiments.

Example 1: a stationary target.

The present embodiment is specifically described with reference to fig. 1 to 2:

step 1, building an experimental system for measuring target angles by a radar. Firstly, erecting a radar, determining a central axis of a measurement system, taking H as 5 meters, determining offset L of different angles (± 9 °, ± 7 °, ± 5 °, ± 3 °) according to a relation L as H · tan theta, connecting the radar to a ground projection and offset point, and drawing a marking line, which is shown in figure 1.

And 2, calibrating the orientation of the radar antenna. Placing a calibration body on the central axis of the angle measurement system, continuously adjusting the pointing direction of the antenna and measuring the angle of the calibration body to ensure that the angle of the calibration body is less than a threshold value delta (delta is 1 degree), and recording the angle of the calibration body as theta_T。

And 3, placing the target on a mark line with a plurality of angles (+/-9 degrees, +/-7 degrees, +/-5 degrees and +/-3 degrees) in the radar beam range, and measuring the angle of the target by utilizing the radar.

Step 4, subtracting the antenna main shaft pointing angle theta from a group of angle data measured at each angle_TThen, averaging is carried out, and the actual angle is subtracted to obtain the angle measurement error. The measurement results are shown in fig. 2.

Example 2: and moving the object.

The present embodiment is specifically described with reference to fig. 1, 3 and 4:

step 1, erecting a radar, determining a main shaft, selecting a first line, namely a central axis, near the main shaft, and drawing marking lines with different angles (respectively minus 6 degrees and plus or minus 3 degrees) on the ground.

And 2, calibrating the orientation of the radar antenna. If the test environment or test conditions are not changed, the radar antenna orientation does not need to be recalibrated. The threshold value δ is set to 1 °.

And 3, placing the target on a marking line with a certain angle (-6 degrees, -3 degrees and +3 degrees) in the radar beam range, reciprocating the moving platform along the marking line, and measuring the angle of the target by using the radar. The schematic test diagram is shown in fig. 3.

Step 4, subtracting the antenna main shaft pointing angle theta from a group of angle data measured at each angle_TThen, averaging is carried out, and the actual angle is subtracted to obtain the angle measurement error. The measurement results are shown in fig. 4.

The test results of different angles are counted, and the angle measurement result is shown as 4. The average angle measurement errors of three angles of-6 degrees, -3 degrees and 3 degrees are respectively 0.494 degrees, 0.565 degrees and 0.516 degrees and are all less than 1 degree. Note that the 3dB beamwidth of the radar antenna in this embodiment is 30 °.

The beneficial effects of the invention include:

1) can be used as a radar angle measurement calibration system

A calibration body is placed on the central axis of the angle measurement system, the pointing direction of the antenna is continuously adjusted, the angle of the calibration body is measured, the angle of the calibration body is smaller than a threshold value delta, and therefore the angle measurement error of the system is smaller than delta. In addition, by processing the angle data measured on each of the mark lines, the angle measurement error can be further reduced.

2) Adapted for measurement of other target parameters

Besides angle measurement, the experimental method is also suitable for target distance, speed and multi-target multi-parameter measurement.

The above description describes in detail embodiments of the present patent. It is emphasized that the invention is not limited to the specific embodiments described above, but that various modifications and extensions can be made by a person skilled in the relevant art within the scope of the claims without this affecting the essence of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.