A method for determining ambiguity in millimeter wave radar angle measurement

Abstract

The present invention provides a method for determining the ambiguity of millimeter wave radar angle measurement, comprising the following steps: obtaining the maximum ranging range of the radar, calculating the unambiguous pitch angle measurement range within different ranging ranges according to the maximum ranging range and the pitch angle measurement range of the target; obtaining measured circular scanning data in azimuth and pitch directions through circular scanning, obtaining and correcting the synthetic antenna pattern according to the measured circular scanning data in azimuth and pitch directions, and obtaining the corrected synthetic antenna pattern; determining the relationship between the corrected synthetic antenna pattern and the maximum detection distance according to the radar equation and the maximum detection distance; drawing the relationship with the unambiguous pitch angle measurement range within different ranging ranges in the same Pos coordinate diagram, obtaining the intersection in the Pos coordinate diagram, determining the actual unambiguous pitch angle measurement range according to the intersection and converting it into a distance range. The present invention can determine the actual unambiguous pitch angle measurement range, and ensure the reliability of the estimated pitch angle.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter wave radars, and in particular to a method for determining ambiguity in angle measurement of millimeter wave radars. Background Art

[0002] In the forward-facing vehicle-mounted millimeter-wave radar, if a high target such as an overpass cannot be identified, the high target will be identified as an obstacle, which will directly affect the warning function. In order to realize the height recognition function of the vehicle-mounted millimeter-wave radar and accurately identify the high target, it is necessary to add the measurement of the target pitch angle information to the vehicle-mounted millimeter-wave radar. At the same time, the millimeter-wave radar can also realize the three-dimensional estimation of the target through the measurement of the target pitch angle information, breaking through the limitation that the traditional millimeter-wave radar can only identify two-dimensional targets. However, the few vehicle-mounted millimeter-wave radars with height measurement function also inevitably have problems such as inaccurate pitch angle estimation, low angle measurement resolution and unavailable target height information.

[0003] When designing the height measurement function of the vehicle-mounted millimeter-wave radar, it is realized through the wireless layout of the radar. However, since the angle between the height target and the radar in the actual scene does not need to cover the ±90° range, and considering the influence of the array aperture on the angle measurement resolution, only a small number of array elements are designed for height measurement, and the spacing between the array elements is usually set to exceed half a wavelength. Such a design usually makes the unambiguous range of pitch angle measurement smaller. When the target angle exceeds the unambiguous angle measurement range, the angle will be folded; and it is impossible to determine whether it is folded and its folding factor based on the estimated result of the target pitch angle alone, resulting in the inability to determine the target's true pitch angle.

[0004] Therefore, there is an urgent need for a method that can determine the unambiguous range of the target pitch angle and ensure that the estimated target pitch angle is accurate and reliable. Summary of the invention

[0005] Based on this, it is necessary to provide a method for determining the ambiguity of millimeter-wave radar angle measurement in response to the above technical problems.

[0006] A method for determining the ambiguity of millimeter wave radar angle measurement comprises the following steps: obtaining the maximum ranging range of the radar, and calculating the unambiguous pitch angle measurement ranges within different ranging ranges according to the maximum ranging range and the pitch angle measurement range of the target; obtaining measured azimuth ring scanning data and measured pitch angle measurement data by ring scanning, analyzing and obtaining a synthetic antenna pattern according to the measured azimuth ring scanning data and the measured pitch angle measurement data, and performing correction to obtain a corrected synthetic antenna pattern; determining a relationship between the corrected synthetic antenna pattern and the maximum detection distance according to a radar equation and a maximum detection distance; plotting the relationship with the unambiguous pitch angle measurement ranges within different ranging ranges in the same Pos coordinate diagram, obtaining an intersection in the Pos coordinate diagram, determining an actual unambiguous pitch angle measurement range according to the intersection, and converting the actual unambiguous pitch angle measurement range into a distance range.

[0007] Further, the maximum ranging range of the radar is obtained, and according to the maximum ranging range and the target pitch angle measurement range, the unambiguous Pos coordinate range of the pitch angle within different ranging ranges is calculated, which specifically includes:

[0008] The maximum ranging range and pitch element spacing of the radar are obtained, and the phase difference generated by the target pitch angle is calculated according to the target pitch angle and the pitch element spacing. The formula is:

[0009]

[0010] Where H is the pitch array element spacing, is the target pitch angle, λ is the wavelength;

[0011] Let the target pitch angle measurement range be [-η,η], then:

[0012]

[0013] According to the maximum ranging range and the pitch angle measurement range, the unambiguous pitch angle measurement range of different ranging ranges is calculated.

[0014] Furthermore, the method of using a circular scanning method to obtain measured circular scanning data in azimuth and measured circular scanning data in elevation, analyzing and obtaining a synthetic antenna pattern based on the measured circular scanning data in azimuth and measured circular scanning data in elevation, and performing correction to obtain a corrected synthetic antenna pattern specifically includes: using an azimuth circular scanning method to measure the measured circular scanning data in azimuth of the azimuth angle and the antenna gain; using an elevation circular scanning method to measure the measured circular scanning data in azimuth of the elevation angle and the antenna gain; obtaining a synthetic antenna pattern in azimuth and elevation based on the measured circular scanning data in azimuth and measured circular scanning data in elevation; and collecting fixed-point data in azimuth and elevation to correct the synthetic antenna pattern to obtain a corrected synthetic antenna pattern.

[0015] Furthermore, the relationship between the modified synthetic antenna pattern and the maximum detection distance is determined according to the radar equation and the maximum detection distance, specifically including: the radar equation is:

[0016]

[0017] Where P t is the transmitting power, G is the antenna gain, λ is the wavelength, σ is the target radar cross-sectional area, S imin is the minimum detectable signal power;

[0018] Assume existence Then, in combination with the corrected synthetic antenna pattern, the relationship between the maximum detection distance and the corrected synthetic antenna pattern is obtained as follows:

[0019]

[0020] Where K is a constant, To correct the composite antenna pattern, θ is the azimuth angle, is the pitch angle.

[0021] Furthermore, the relationship and the unambiguous pitch angle measurement ranges in different ranging ranges are plotted in the same Pos coordinate diagram, an intersection in the Pos coordinate diagram is obtained, an actual unambiguous pitch angle measurement range is determined according to the intersection, and the actual unambiguous pitch angle measurement range is converted into a distance range, specifically comprising: drawing a three-dimensional diagram of azimuth-pitch angle-effective range according to a relationship between the maximum detection distance and the azimuth and pitch angle; converting the three-dimensional coordinates of azimuth-pitch angle-effective range into Pos coordinates, plotting a Pos coordinate diagram, converting the unambiguous pitch angle measurement ranges of different ranging ranges into corresponding Pos coordinates, and plotting the converted Pos coordinates in the Pos coordinate diagram; obtaining an intersection in the diagram according to the Pos coordinate diagram, determining the actual unambiguous pitch angle measurement range according to the intersection, and converting the actual unambiguous pitch angle measurement range into a distance range.

[0022] Furthermore, the three-dimensional coordinates of azimuth angle-pitch angle-operating range are converted into Pos coordinates by the formula:

[0023] xPos=range*cos(pitch)*cos(azim);

[0024] yPos=range*cos(pitch)*sin(azim);

[0025] zPos = range * sin(pitch);

[0026] Among them, pitch is the pitch angle, azim is the azimuth angle, and range is the effective distance.

[0027] Further, the method of obtaining an intersection in the graph according to the Pos coordinate graph, determining an actual pitch angle unambiguous angle measurement range according to the intersection, and converting the actual pitch angle unambiguous angle measurement range into a distance range specifically includes: obtaining an intersection in the graph and a corresponding Pos coordinate according to the Pos coordinate graph, the intersection being the actual pitch angle unambiguous angle measurement range; selecting the nearest point and the farthest point of the intersection, and calculating and obtaining a minimum actual unambiguous angle measurement distance and a maximum actual unambiguous angle measurement distance according to the Pos coordinates of the nearest point and the farthest point, and the calculation formula is:

[0028]

[0029]

[0030]

[0031] Wherein, xPos′, yPos′ and zPos′ are the Pos coordinates of the intersection part, and R is the actual unambiguous angle measurement distance; the interval range formed by the minimum actual unambiguous angle measurement distance and the maximum actual unambiguous angle measurement distance is recognized as the distance range of the actual pitch angle unambiguous angle measurement.

[0032] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: obtaining the maximum ranging range of the radar, calculating the unambiguous measuring range of the pitch angle in different ranging ranges according to the maximum ranging range and the pitch angle measuring range of the target, obtaining the measured ring scanning data in the azimuth direction and the measured ring scanning data in the pitch direction by means of ring scanning, analyzing and obtaining the synthetic antenna pattern according to the measured ring scanning data in the azimuth direction and the pitch direction, and performing correction to obtain the corrected synthetic antenna pattern; determining the relationship between the corrected synthetic antenna pattern and the maximum detection distance according to the radar equation and the maximum detection distance, plotting the relationship with the unambiguous measuring range of the pitch angle in different ranging ranges in the same Pos coordinate diagram, obtaining the intersection in the Pos coordinate diagram, determining the actual unambiguous measuring range of the pitch angle according to the intersection, and converting the actual unambiguous measuring range of the pitch angle into the distance range, realizing the determination of the actual unambiguous measuring range of the pitch angle, thereby judging whether the estimated pitch angle is accurate and reliable, facilitating the estimation of the target height and the like according to the accurate pitch angle, and thus improving the performance of the radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flowchart of a method for determining ambiguity in millimeter-wave radar angle measurement in one embodiment;

[0034] Figure 2is an unambiguous pitch angle measurement range for different distance ranges in one embodiment;

[0035] Figure 3 An array composite antenna pattern in one embodiment;

[0036] Figure 4 is a schematic diagram of a Pos coordinate diagram in one embodiment;

[0037] Figure 5 for Figure 4 Schematic diagram from another angle. DETAILED DESCRIPTION

[0038] In order to make the present invention more clearly understood, the present invention is further described in detail below through specific implementation modes in combination with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] like Figure 1 As shown, a method for determining the ambiguity of millimeter wave radar angle measurement is provided, comprising the following steps:

[0040] Step S101, obtaining the maximum ranging range of the radar, and calculating the unambiguous pitch angle measurement range within different ranging ranges according to the maximum ranging range and the target pitch angle measurement range.

[0041] Specifically, after the actual vehicle-mounted millimeter-wave radar antenna layout is designed, the maximum detection distance can be obtained according to the radar antenna layout plan, and the unambiguous measurement range of the pitch angle within different measurement ranges can be calculated according to the target pitch angle measurement range and the maximum detection distance.

[0042] In one embodiment, step S101 specifically includes: obtaining the maximum ranging range and pitch element spacing of the radar, and calculating the phase difference generated by the target pitch angle according to the target pitch angle and the pitch element spacing, and the formula is:

[0043]

[0044] Where H is the pitch array element spacing, is the target pitch angle, λ is the wavelength; let the target pitch angle measurement range be [-η,η], then:

[0045]

[0046] According to the maximum ranging range and the pitch angle measurement range, the pitch angle unambiguous range of different ranging ranges is calculated.

[0047] Specifically, since the range of the wave path phase change does not exceed π, and the pitch element spacing H exceeds half a wavelength, the pitch angle measurement range is [-η,η]. If the angle measurement range is exceeded, angle folding will occur, resulting in ambiguity. According to the maximum ranging range in the vehicle-mounted millimeter-wave radar antenna layout scheme, the unambiguous pitch angle measurement range of different ranging ranges is calculated. Figure 2 The shaded part in the middle shows the unambiguous pitch angle measurement range at different distance ranges.

[0048] Step S102, using a circular scanning method to obtain measured circular scanning data in azimuth and measured circular scanning data in elevation, analyzing and obtaining a synthetic antenna pattern based on the measured circular scanning data in azimuth and measured circular scanning data in elevation, and performing correction to obtain a corrected synthetic antenna pattern.

[0049] Specifically, under ideal conditions, when the target is facing the radar, that is, when the azimuth and elevation angles are both 0, the antenna pattern has the strongest energy, and as the azimuth angle gradually increases, the energy of the azimuth antenna pattern gradually decreases. Similarly, as the elevation angle gradually increases, the energy of the elevation antenna pattern gradually decreases, and the azimuth antenna pattern and the elevation antenna pattern are symmetrical about 0 degrees in azimuth and 0 degrees in elevation, respectively. Depending on the antenna layout design of the radar, the energy attenuation of the antenna pattern is different. Generally speaking, the antenna design requires that the energy attenuation within the angle measurement FOV (field angle of view) range be reduced as much as possible, and the energy attenuation within the non-angle measurement FOV range is faster.

[0050] However, in actual design, the angle measurement FOV will leave redundancy, making the designed angle measurement range slightly larger than the actual angle measurement range. At the same time, taking into account the influence of various factors such as hardware interference, array element mutual coupling effect, and antenna characteristics, the actual antenna pattern is not ideal. It is necessary to obtain a synthetic antenna pattern based on the measured circular scanning data in the azimuth and elevation directions of the radar, and to correct the synthetic antenna pattern to obtain a corrected synthetic antenna pattern.

[0051] In one embodiment, step S102 specifically includes: using azimuth circular scanning to measure azimuth angle and antenna gain measured circular scanning data in azimuth direction; using elevation circular scanning to measure elevation angle and antenna gain measured circular scanning data in azimuth direction; calculating the composite antenna radiation pattern in azimuth and elevation direction based on the azimuth measured circular scanning data and the elevation measured circular scanning data; collecting fixed-point data in azimuth and elevation direction to correct the composite antenna radiation pattern to obtain a corrected composite antenna radiation pattern.

[0052] Specifically, in order to obtain a more accurate synthetic antenna radiation pattern, the measured azimuth ring scan data is obtained through the azimuth ring scan test, and the corresponding relationship G between the azimuth angle θ and the antenna gain is obtained. Azim(θ); obtain the measured pitch scan data through the pitch scan test to get the pitch angle Relationship with antenna gain The composite antenna pattern in azimuth and elevation is calculated as The fixed-point data in azimuth and elevation are collected to correct the synthetic antenna pattern to obtain the corrected synthetic antenna pattern. Corrected composite antenna pattern Figure 3 shown.

[0053] Step S103, determining a relationship between the corrected synthetic antenna pattern and the maximum detection distance according to the radar equation and the maximum detection distance.

[0054] Specifically, according to the radar equation and the maximum detection distance of the radar, in combination with the corrected synthetic antenna pattern, a relationship between the corrected synthetic antenna pattern and the maximum detection distance is determined.

[0055] In one embodiment, step S103 specifically includes: the radar equation is:

[0056]

[0057] Among them, P t is the transmitting power, G is the antenna gain, λ is the wavelength, σ is the target radar cross-sectional area, S imin is the minimum detectable signal power; assuming there is Combined with the corrected synthetic antenna pattern, the relationship between the maximum detection distance and the corrected synthetic antenna pattern is obtained as follows:

[0058]

[0059] Where K is a constant, To correct the composite antenna pattern, θ is the azimuth angle, is the pitch angle.

[0060] Specifically, according to the radar equation and the obtained maximum detection range of the radar, combined with the corrected synthetic antenna pattern, when determining the relationship between the corrected synthetic antenna pattern and the maximum detection range, it is assumed that the relationship between the transmit power, wavelength, target radar cross-sectional area and minimum detectable signal power in the radar equation is a constant, denoted as K, and only the relationship between the maximum detection range and the corrected synthetic antenna pattern is considered, then the relationship between the maximum detection range and the corrected synthetic antenna pattern is obtained.

[0061] Step S104, plotting the relationship and the pitch angle unambiguous measurement ranges in different distance measurement ranges in the same Pos coordinate diagram, obtaining the intersection part in the Pos coordinate diagram, determining the actual pitch angle unambiguous measurement range according to the intersection part, and converting the actual pitch angle unambiguous measurement range into a distance range.

[0062] Specifically, the relationship between the maximum detection distance and the corrected synthetic antenna gain is plotted in the same Pos coordinate diagram as the unambiguous angle measurement range of the elevation angle in different ranging ranges, such as Figure 4 and Figure 5 As shown, determine the intersection part in the Pos coordinate map, and calculate the actual pitch unambiguous angle measurement range based on the intersection part. The actual pitch unambiguous angle measurement range is as follows: Figure 4 The part selected by the white line, that is, the points in this part are all recognized as the pitch unambiguous angle measurement range, and the points in the rest of the part are recognized as having angle folding, which causes the target angle to be blurred and the real pitch angle of the target cannot be determined.

[0063] according to Figure 4 and Figure 5 It can be seen that when the radar detects a long-distance target, the range of the synthetic antenna pattern is smaller than the measurement range of the target pitch angle [η, -η]. At this time, the target pitch angle will not be folded, and the correct pitch angle can be obtained as long as the target energy meets the cfar (Constant False Alarm Rate) detection threshold requirement; when the radar detects a close-range target, the range of the synthetic antenna pattern exceeds the target pitch angle measurement range [η, -η]. At this time, the target pitch angle is large and angle folding may occur. Since the folding multiple is unknown and the folded angle is mixed with the unfolded angle, it is determined that the target pitch angle is unreliable at this time, that is, it is still in a fuzzy state.

[0064] In one embodiment, step S104 specifically includes: drawing a three-dimensional graph of azimuth-pitch angle-effective distance according to the relationship between the maximum detection distance and the azimuth and pitch angle; converting the three-dimensional coordinates of azimuth-pitch angle-effective distance into Pos coordinates, drawing a Pos coordinate graph, and converting the unambiguous measurement ranges of the pitch angles of different ranging ranges into corresponding Pos coordinates, and drawing the converted Pos coordinates in the Pos coordinate graph; obtaining the intersection part in the graph according to the Pos coordinate graph, determining the unambiguous measurement range of the actual pitch angle according to the intersection part, and converting the actual unambiguous measurement range of the pitch angle into a distance range.

[0065] Specifically, according to the relationship between the maximum detection distance and the azimuth and pitch angle, a three-dimensional graph of azimuth-pitch angle-effective distance is drawn; according to the relationship between the three-dimensional coordinates and the Pos coordinates, the three-dimensional coordinates are converted into Pos coordinates, and a Pos coordinate graph of the three-dimensional graph of azimuth-pitch angle-effective distance is drawn, such as Figure 4 and Figure 5The black circle part in the figure; and convert the unambiguous angle measurement range of the pitch angle of different ranging ranges into the corresponding Pos coordinates, and plot the converted Pos coordinates in the Pos coordinate diagram of azimuth angle-pitch angle-effective distance, such as Figure 4 and Figure 5 The upper and lower plane parts in the figure are obtained according to the Pos coordinate diagram to obtain the intersection between the two. It is determined that the points in the intersection are in the actual unambiguous angle measurement range, and the points outside the intersection are the fuzzy angle measurement range. That is, the unambiguous angle measurement range of the actual pitch angle is determined according to the intersection, and it is converted into a distance range, so as to determine the actual unambiguous angle measurement distance of the millimeter-wave radar.

[0066] The three-dimensional coordinates of azimuth angle, elevation angle and range are converted into Pos coordinates using the following formula:

[0067] xPos=range*cos(pitch)*cos(azim);

[0068] yPos=range*cos(pitch)*sin(azim);

[0069] zPos = range * sin(pitch);

[0070] In the formula, pitch is the pitch angle, azim is the azimuth angle, and range is the effective distance.

[0071] Among them, the intersection part in the figure is obtained according to the Pos coordinate diagram, the actual pitch angle unambiguous measurement range is determined according to the intersection part, and the actual pitch angle unambiguous measurement range is converted into a distance range, specifically including: obtaining the intersection part in the figure and the corresponding Pos coordinates according to the Pos coordinate diagram, the intersection part is the actual pitch angle unambiguous measurement range; selecting the nearest point and the farthest point of the intersection part, and calculating the minimum actual unambiguous measurement distance and the maximum actual unambiguous measurement distance according to the Pos coordinates of the nearest point and the farthest point, and the calculation formula is:

[0072]

[0073]

[0074]

[0075] Wherein, xPos′, yPos′ and zPos′ are the Pos coordinates of the intersection part, and R is the actual unambiguous angle measurement distance; the interval range formed by the minimum actual unambiguous angle measurement distance and the maximum actual unambiguous angle measurement distance is recognized as the distance range of the actual unambiguous angle measurement of the pitch angle.

[0076] Specifically, when calculating the distance range of the actual pitch unambiguous angle measurement according to the intersection part in the Pos coordinate map, the intersection part and the corresponding Pos coordinates in the map are obtained according to the Pos coordinate map, and the intersection part is the actual pitch angle unambiguous angle measurement range; the nearest point and the farthest point of the intersection part are selected, and the minimum actual unambiguous angle measurement distance and the maximum actual unambiguous angle measurement distance are calculated according to the Pos coordinates of the nearest point and the farthest point. When calculating, the distance calculation formula can be obtained according to the relationship between the three-dimensional coordinates and the Pos coordinates. Any calculation formula in the above formula can be used to calculate the minimum and maximum actual unambiguous angle measurement distances, and the interval range of the minimum and maximum actual unambiguous angle measurement distances is recognized as the distance range of the actual pitch angle unambiguous angle measurement, so that the reliability of the pitch angle measurement of the millimeter wave radar within this distance range can be determined.

[0077] In this embodiment, the maximum ranging range of the radar is obtained, and the unambiguous measuring range of the pitch angle in different ranging ranges is calculated according to the maximum ranging range and the pitch angle measuring range of the target. The measured ring scanning data in azimuth and pitch are obtained by ring scanning. According to the measured ring scanning data in azimuth and pitch, a synthetic antenna pattern is analyzed and corrected to obtain a corrected synthetic antenna pattern. According to the radar equation and the maximum detection distance, a relationship between the corrected synthetic antenna pattern and the maximum detection distance is determined, and the relationship and the unambiguous measuring range of the pitch angle in different ranging ranges are plotted in the same Pos coordinate diagram, and the intersection part in the Pos coordinate diagram is obtained. According to the intersection part, the actual unambiguous measuring range of the pitch angle is determined, and the actual unambiguous measuring range of the pitch angle is converted into a distance range, so that the actual unambiguous measuring range of the pitch angle is determined, thereby judging whether the estimated pitch angle is accurate and reliable, and facilitating the estimation of the target height and the like according to the accurate pitch angle, thereby improving the performance of the radar.

[0078] The above contents are further detailed descriptions of the present invention in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A method for determining ambiguity in millimeter wave radar angle measurement, characterized in that: The following steps are involved: Obtaining the maximum ranging range of the radar, and calculating the unambiguous pitch angle measurement range within different ranging ranges according to the maximum ranging range and the target pitch angle measurement range; Acquire measured azimuth circular scanning data and measured elevation circular scanning data by means of circular scanning, and obtain a synthetic antenna pattern by analyzing and correcting the azimuth circular scanning data and the elevation circular scanning data to obtain a corrected synthetic antenna pattern; Determine a relationship between the modified synthetic antenna pattern and the maximum detection distance according to the radar equation and the maximum detection distance; The relationship and the unambiguous pitch angle measurement ranges in different distance measurement ranges are plotted in the same Pos coordinate diagram, the intersection in the Pos coordinate diagram is obtained, the actual unambiguous pitch angle measurement range is determined according to the intersection, and the actual unambiguous pitch angle measurement range is converted into a distance range.

2. The method for determining ambiguity in millimeter wave radar angle measurement according to claim 1, characterized in that: The obtaining of the maximum ranging range of the radar and calculating the unambiguous Pos coordinate range of the pitch angle measurement within different ranging ranges according to the maximum ranging range and the pitch angle measurement range of the target include: The maximum ranging range and pitch element spacing of the radar are obtained, and the phase difference generated by the target pitch angle is calculated according to the target pitch angle and the pitch element spacing. The formula is: Where H is the pitch array element spacing, is the target pitch angle, λ is the wavelength; Let the target pitch angle measurement range be [-η,η], then: According to the maximum ranging range and the pitch angle measurement range, the unambiguous pitch angle measurement range of different ranging ranges is calculated.

3. The method for determining ambiguity in millimeter wave radar angle measurement according to claim 2, characterized in that: The method of obtaining measured azimuth ring-scan data and measured elevation ring-scan data by ring-scanning, analyzing and obtaining a synthetic antenna pattern according to the measured azimuth ring-scan data and measured elevation ring-scan data, and performing correction to obtain a corrected synthetic antenna pattern specifically includes: Azimuth circular scanning is used to measure the azimuth angle and antenna gain in the azimuth direction. The pitch circular scan is used to measure the pitch angle and the azimuth measured circular scan data of the antenna gain; Acquire a synthetic antenna pattern in the azimuth direction and the elevation direction according to the measured circular scanning data in the azimuth direction and the measured circular scanning data in the elevation direction; The fixed-point data in the azimuth and elevation directions are collected to correct the synthetic antenna pattern to obtain a corrected synthetic antenna pattern.

4. The method for determining ambiguity in millimeter wave radar angle measurement according to claim 3, characterized in that: Determining the relationship between the modified synthetic antenna pattern and the maximum detection distance according to the radar equation and the maximum detection distance specifically includes: The radar equation is: Where P t is the transmitting power, G is the antenna gain, λ is the wavelength, σ is the target radar cross-sectional area, S imin is the minimum detectable signal power; Assume existence Then, in combination with the corrected synthetic antenna pattern, the relationship between the maximum detection distance and the corrected synthetic antenna pattern is obtained as follows: Where K is a constant, To correct the composite antenna pattern, θ is the azimuth angle, is the pitch angle.

5. The method for determining ambiguity in millimeter wave radar angle measurement according to claim 1, characterized in that: The step of plotting the relationship and the unambiguous pitch angle measurement ranges in different distance measurement ranges in the same Pos coordinate diagram, obtaining the intersection in the Pos coordinate diagram, determining the actual unambiguous pitch angle measurement range according to the intersection, and converting the actual unambiguous pitch angle measurement range into a distance range specifically includes: According to the relationship between the maximum detection distance and the azimuth and elevation angles, draw a three-dimensional graph of azimuth-elevation-effective distance; The three-dimensional coordinates of azimuth angle-pitch angle-effective range are converted into Pos coordinates, a Pos coordinate diagram is drawn, and the unambiguous angle measurement ranges of the pitch angles of different ranging ranges are converted into corresponding Pos coordinates, and the converted Pos coordinates are drawn in the Pos coordinate diagram; An intersection portion in the Pos coordinate graph is obtained according to the Pos coordinate graph, an unambiguous angle measurement range of an actual pitch angle is determined according to the intersection portion, and the unambiguous angle measurement range of the actual pitch angle is converted into a distance range.

6. A method for determining ambiguity in millimeter wave radar angle measurement according to claim 5, characterized in that: The three-dimensional coordinates of azimuth angle-pitch angle-effective distance are converted into Pos coordinates, and the formula is: xPos=range*cos(pitch)*cos(azim); yPos=range*cos(pitch)*sin(azim); zPos = range * sin(pitch); Among them, pitch is the pitch angle, azim is the azimuth angle, and range is the effective distance.

7. The method for determining ambiguity in millimeter wave radar angle measurement according to claim 6, characterized in that: The step of obtaining an intersection portion in the Pos coordinate graph according to the Pos coordinate graph, determining an unambiguous angle measurement range of an actual pitch angle according to the intersection portion, and converting the unambiguous angle measurement range of the actual pitch angle into a distance range specifically includes: According to the Pos coordinate graph, an intersection portion in the graph and a corresponding Pos coordinate are obtained, wherein the intersection portion is an unambiguous angle measurement range of the actual pitch angle; The nearest point and the farthest point of the intersection are selected, and the minimum actual unambiguous angular measurement distance and the maximum actual unambiguous angular measurement distance are calculated according to the Pos coordinates of the nearest point and the farthest point. The calculation formula is: Where xPos′, yPos′ and zPos′ are the Pos coordinates of the intersection part, and R is the actual unambiguous angle measurement distance; The interval range formed by the minimum actual unambiguous angle measurement distance and the maximum actual unambiguous angle measurement distance is determined as the distance range of the actual unambiguous angle measurement of the pitch angle.

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