One-dimensional phased array radar and calibration method and system thereof

Abstract

The invention discloses a one-dimensional phased array radar and a calibration method and system thereof, and the method comprises the steps: carrying out the solar feature recognition of radar body scanning data, and obtaining first solar intensity information, and a first relative azimuth angle, a first relative pitch angle and body scanning time corresponding to the first solar intensity information; determining a sector scanning range according to the last first relative azimuth angle, and controlling the radar to rotate and start sector scanning based on the sector scanning range; performing solar feature recognition on the sector scanning data to obtain second solar intensity information and a second relative azimuth angle, a second relative pitch angle and sector scanning time corresponding to the second solar intensity information; calculating azimuth deviation and pitch deviation according to the radar geographic position, all the first relative azimuth angles, the first relative pitch angles, the body scanning time, the second relative azimuth angles, the second relative pitch angles and the sector scanning time; and performing radar calibration according to the azimuth deviation and the pitching deviation. The calibration efficiency and the calibration precision are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar calibration, and particularly relates to a one-dimensional phased array radar and its calibration method and system, aiming to solve the problem of radar antenna pointing deviation and improve the accuracy and reliability of radar detection. Background Art

[0002] Throughout the entire life cycle of a radar system, antenna pointing deviation has always been a key factor restricting its performance. Ideally, the radar antenna should maintain a stable and accurate pointing during the scanning process, but in actual operation, it is often affected by various factors. Inaccurate installation, mechanical wear, temperature changes, sensor failures, motor or drive system problems, external environmental interferences (such as vibrations, wind), control system algorithm errors, geomagnetic deviation, and structural fatigue may cause azimuth deviation and pitch deviation of the radar. In addition, the accuracy limitations of the mechanical structure (such as bearing clearances and manufacturing errors of transmission components) may also cause the antenna shaft to swing, thereby resulting in antenna pointing deviation. Long-term operation and vibrations can cause components to loosen or deform, further affecting the accuracy. Sensor errors, external vibrations, shocks, or resonance phenomena may also cause deviations. To reduce these problems, regular inspections, calibrations, and maintenance are crucial. Although the radar antenna is strictly calibrated at the factory to ensure accurate pointing, due to the accuracy limitations in the manufacturing process, the errors of the calibration equipment itself, as well as operator differences and environmental factors, the calibration results may ultimately deviate.

[0003] In response to these problems, various compensation measures have been proposed in the prior art. Electronic scanning technology overcomes the angular errors brought by mechanical scanning to a certain extent, but the performance fluctuations of electronic components may still affect it; using mathematical models for prediction and correction can solve the deviation to a certain extent, but the computational complexity is high, and the requirements for data accuracy and integrity are extremely high, and the model adaptability is also limited; the dual-antenna alternating scanning method can reduce the radar angular deviation, but it increases the equipment cost and system complexity.

[0004] Currently, the solar method calibration, as a commonly used radar calibration method, faces many challenges in practical applications. Due to the differences in the hardware structures and signal processing methods of radars produced by different manufacturers, and the different working states of each radar in different operating environments, the existing solar method calibration methods are difficult to unify standards, lacking universality and referenceability. This makes it necessary to develop special calibration schemes for each radar's specific situation during radar calibration, increasing the complexity and cost of calibration and reducing the calibration efficiency. Summary of the Invention

[0005] The object of the present invention is to provide a one-dimensional phased array radar and its calibration method and system, so as to solve the problem that when calibrating the radar using the existing solar method, it is necessary to formulate a special calibration plan according to the specific situation of each radar, which increases the calibration complexity and cost and reduces the calibration efficiency.

[0006] The present invention solves the above technical problems through the following technical solutions: A one-dimensional phased array radar calibration method includes:

[0007] Obtain a plurality of consecutive radar volume scan data; wherein, each circle of scan corresponds to one radar volume scan data;

[0008] Perform solar feature recognition on each radar volume scan data to obtain the first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle and volume scan time; perform continuity verification based on all the first relative azimuth angles, first relative elevation angles and volume scan times;

[0009] When the continuity verification passes, determine the fan scan range according to the last first relative azimuth angle, and control the radar to rotate and start fan scanning based on the fan scan range;

[0010] Obtain a plurality of consecutive fan scan data; wherein, each reciprocating scan corresponds to two fan scan data;

[0011] Perform solar feature recognition on each fan scan data to obtain the second solar intensity information and its corresponding second relative azimuth angle, second relative elevation angle and fan scan time; perform continuity verification based on all the second relative azimuth angles, second relative elevation angles and volume scan times;

[0012] When the continuity verification passes, perform integrity verification based on all the first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle and volume scan time, and all the second solar intensity information and its corresponding second relative azimuth angle, second relative elevation angle and fan scan time;

[0013] When the integrity verification passes, calculate the azimuth deviation and elevation deviation according to the radar geographical location, all the first relative azimuth angles, first relative elevation angles, volume scan times, second relative azimuth angles, second relative elevation angles and fan scan times;

[0014] Perform radar calibration according to the azimuth deviation and elevation deviation.

[0015] Further, before calibration, the calibration method further includes:

[0016] Set the calibration start time;

[0017] When the calibration start time is reached, control the radar to switch to the calibration mode, the radar enters the silent state, and starts volume scanning.

[0018] Furthermore, the specific calculation process of the calibration start time is as follows:

[0019] Determine the starting detection elevation angle according to the radar scanning mode;

[0020] Use the bisection method to find the moment when the sun reaches the starting detection elevation angle within the specified time range, and then obtain the calibration start time.

[0021] Furthermore, perform solar feature recognition on each radar volume scan data or sector scan data, specifically including:

[0022] Perform filtering processing on each radar volume scan data or each sector scan data;

[0023] Calculate the average value of the solar radiation signals in the filtered radar volume scan data or sector scan data, and filter out the solar radiation signals below the average value, retaining the solar radiation signals above the average value;

[0024] Perform solar feature recognition on the retained data to identify data segments that meet the normal distribution characteristics;

[0025] Based on the identified data segments, calculate the true solar elevation information and the solar elevation information detected by the radar;

[0026] Judge whether the difference between the true solar elevation information and the solar elevation information detected by the radar is within a reasonable range;

[0027] When the difference between the true solar elevation information and the solar elevation information detected by the radar is within a reasonable range, find the maximum solar radiation signal from each data segment, and use the maximum solar radiation signal as the first solar intensity information or the second solar intensity information for each data segment.

[0028] Furthermore, the sector scan range is (the last first relative azimuth angle ± the first angle threshold, the last first relative azimuth angle + the second angle threshold), where the second angle threshold is greater than the first angle threshold.

[0029] Furthermore, the first angle threshold is 10°, and the second angle threshold is 20°.

[0030] Furthermore, calculate the azimuth deviation and elevation deviation according to the radar geographical location, all the first relative azimuth angles, the first relative elevation angles, the volume scan time, the second relative azimuth angles, the second relative elevation angles, and the sector scan time, specifically including:

[0031] Calculate the first absolute azimuth angle and the first absolute elevation angle according to the radar geographical location and the volume scan time; calculate the first azimuth deviation according to the first relative azimuth angle and the first absolute azimuth angle, and calculate the first elevation deviation according to the first relative elevation angle and the first absolute elevation angle;

[0032] Calculate the second absolute azimuth angle and the second absolute elevation angle according to the radar geographical location and the sector scan time; calculate the second azimuth deviation according to the second relative azimuth angle and the second absolute azimuth angle, and calculate the second elevation deviation according to the second relative elevation angle and the second absolute elevation angle;

[0033] Average all the first azimuth deviations and the second azimuth deviations to obtain the final azimuth deviation; average all the first elevation deviations and the second elevation deviations to obtain the final elevation deviation.

[0034] Furthermore, the specific calculation formula for the first absolute elevation angle or the second absolute elevation angle is:

[0035] ;

[0036] ;

[0037] Wherein, represents the first absolute elevation angle or the second absolute elevation angle; represents the radar latitude; represents the declination, and the declination is calculated according to the corresponding volume scan time or sector scan time; represents the local hour angle; represents the Greenwich hour angle; represents the radar longitude;

[0038] The specific calculation formula for the first absolute azimuth angle or the second absolute azimuth angle is:

[0039] ;

[0040] Wherein, represents the first absolute azimuth angle or the second absolute azimuth angle.

[0041] Based on the same concept, the present invention also provides a one-dimensional phased array radar, and the one-dimensional phased array radar is calibrated by using the one-dimensional phased array radar calibration method as described above.

[0042] Based on the same concept, the present invention also provides a one-dimensional phased array radar calibration system, including a receiving module, a processing module and a client;

[0043] The receiving module is used for:

[0044] Receive and cache a plurality of consecutive radar volume scan data transmitted by the radar; wherein, each circle of scan corresponds to one radar volume scan data; receive and cache a plurality of consecutive sector scan data transmitted by the radar; wherein, each reciprocating scan corresponds to two sector scan data;

[0045] The processing module is used for:

[0046] Perform solar feature recognition on each radar volume scan data to obtain the first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle, and volume scan time; perform continuity verification based on all the first relative azimuth angles, first relative elevation angles, and volume scan times;

[0047] When the continuity verification passes, determine the sector scan range according to the last first relative azimuth angle, and enable the radar controller to control the radar to rotate and start sector scan based on the sector scan range;

[0048] Perform solar feature recognition on each sector scan data to obtain the second solar intensity information and its corresponding second relative azimuth angle, second relative elevation angle, and sector scan time; perform continuity verification based on all the second relative azimuth angles, second relative elevation angles, and sector scan times;

[0049] When the continuity verification passes, perform integrity verification based on all the first solar intensity information and its corresponding first relative azimuth angle and first relative elevation angle, and all the second solar intensity information and its corresponding second relative azimuth angle and second relative elevation angle;

[0050] When the integrity verification passes, calculate the azimuth deviation and elevation deviation according to the radar geographical location, all the first relative azimuth angles, first relative elevation angles, volume scan times, second relative azimuth angles, second relative elevation angles, and sector scan times;

[0051] Perform radar calibration according to the azimuth deviation and elevation deviation;

[0052] The client is used for:

[0053] Start or stop calibration, and enable the radar controller to control the radar to start volume scan at the beginning of calibration.

[0054] Compared with the prior art, the advantages of the present invention are as follows:

[0055] The present invention uses the sun as a calibration radiation source and performs calibration by means of the azimuth information and elevation information of the sun, avoiding the need to purchase and maintain expensive calibration equipment, reducing the calibration cost and maintenance cost; according to the radar geographical location and scan time, the true azimuth information and true elevation information of the sun can be quickly obtained, and then the calibration deviation can be calculated. This method greatly simplifies the calibration process, shortens the calibration time, improves the calibration efficiency, and does not require a special calibration scheme to be formulated according to the radar, improving the versatility of the solar method calibration. Description of the Drawings

[0056] To more clearly illustrate the technical solution of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only one embodiment of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0057] Figure 1 It is a schematic model diagram of the sun position based on the ground plane in the embodiment of the present invention;

[0058] Figure 2 It is a flowchart of the one-dimensional phased array radar calibration method in the embodiment of the present invention;

[0059] Figure 3 It is a schematic diagram of the regular change of the final pitch deviation in the embodiment of the present invention;

[0060] Figure 4 It is a scatter plot of the final azimuth deviation in the embodiment of the present invention. Specific Embodiments

[0061] The following will clearly and completely describe the technical solution in the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0062] The following will detail the technical solution of the present application with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0063] The existing sun method calibration method is difficult to unify the standard, lacks universality and referenceability, which makes it necessary to develop a special calibration plan for each radar when calibrating the radar, increasing the complexity and cost of calibration and reducing the calibration efficiency. To solve the above technical problems, the present invention provides a one-dimensional phased array radar and its calibration method and system, using the sun as the calibration radiation source, and realizing automatic calibration by means of the azimuth information and pitch information of the sun, simplifying the calibration process, shortening the calibration time, and improving the calibration efficiency.

[0064] Figure 1It shows a schematic model of the sun's position based on the ground plane. Az = 0° represents the north direction, Az = 90° represents the east direction, Az = 180° represents the south direction, Az = 270° represents the west direction. The semi-circular arc structure above the ground plane represents the sky. The angle between the straight line of the radar pointing to the sun and the ground plane is the elevation angle Alt, and the angle between the projection of the straight line of the radar pointing to the sun on the ground plane and the due north direction is the azimuth angle Az. Figure 1 The spatial position relationship between the sun, the ground plane, and the radar is visually presented through the azimuth angle and the elevation angle. Figure 1 The radar is set in the southern hemisphere for demonstration. Considering the actual geographical location (the northern hemisphere), the sun follows the law of rising in the east and setting in the west. Therefore, during radar calibration, its azimuth rotation usually follows the range of 90° to 180°, and the pitch angle shows the change characteristics of increasing in the morning and decreasing in the afternoon, providing a reference basis for subsequent calibration.

[0065] Embodiment 1

[0066] Figure 2 It shows a one-dimensional phased array radar and the flowchart of its calibration method. As Figure 2 shown, the calibration method includes the following steps:

[0067] Step S1: Obtain a plurality of consecutive radar volume scan data.

[0068] Before calibration, set the calibration start time, automatically start the timing task. When the calibration start time is reached, control the radar to switch to the calibration mode. At this time, the radar closes the signal emission function, enters the silent state, and starts the low-speed 360° omnidirectional scanning mode (i.e., volume scan), and receives the solar radiation signal in a passive manner. Each time a volume scan is completed (i.e., scanning one circle), a radar volume scan data is obtained. In this embodiment, at least 10 consecutive radar volume scan data are obtained. By performing volume scan to obtain the solar radiation signal, it realizes all-round pitch and obtains the solar radiation signal without omission, avoiding the loss of solar radiation signal caused by possible large deviations during the radar installation process.

[0069] When the tester confirms that the current weather and external environment meet the requirements of solar method calibration, set the calibration start time and wait for the calibration task to be automatically executed. For example, the tester determines that the weather conditions in the area where the radar is located meet the requirements of visible sunlight (sunny, cloudy, etc.).

[0070] To ensure the accuracy of radar calibration in pitch, when determining the calibration start time, consider that during the entire calibration process, the solar radiation signal moves from one end of the normal direction of the antenna array to the other end. Specifically, the optimal calibration start time of the radar can be accurately calculated by comprehensively considering the current time of the day, the radar scanning mode, and the real-time position of the sun, and applying the celestial mechanics model and complex algorithms. In this embodiment, the specific calculation process of the optimal calibration start time of the radar is as follows:

[0071] Step S1.1: Determine the starting detection elevation angle according to the radar scanning mode. Usually, the starting detection elevation angle is half of the total scanning elevation angle, that is, the normal angle. The normal angle refers to the angle when the sun is directly facing the vertical direction of the radar array surface.

[0072] Step S1.2: Use the bisection method to find the moment when the sun reaches the starting detection elevation angle within a specified time range (such as in the morning or afternoon). Subtract 20 minutes from this moment to obtain the optimal calibration start time of the radar.

[0073] The purpose of determining the optimal calibration start time of the radar is to move the solar radiation signal from one side of the normal direction of the radar array surface to the other side, enhancing the accuracy of scanning.

[0074] Step S2: Perform solar feature recognition on each radar volume scan data to obtain the first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle, and volume scan time.

[0075] The radar volume scan data contains a large amount of internal noise of the machine and a small amount of weak solar radiation signals. In order to perform solar feature recognition on the solar radiation signals, first use wavelet denoising, adaptive filtering, etc. to filter out the internal noise of the machine in the radar volume scan data. In the specific implementation manner of the present invention, performing solar feature recognition on each radar volume scan data specifically includes:

[0076] Step S2.1: Calculate the average value of the solar radiation signals in each radar volume scan data, and filter out the solar radiation signals below the average value, retaining the solar radiation signals above the average value.

[0077] Step S2.2: Perform solar feature recognition on the data obtained in Step S2.1, and the identified data segment satisfies the normal distribution characteristics.

[0078] Among them, the normal distribution characteristics include: the difference between the maximum value and the minimum value in the data segment is greater than 1 (empirical value), the peak data is located in the middle area of the data segment, and the width of the data segment is greater than 10 data points (empirical value after the radar operation mode and rotation speed are fixed).

[0079] Step S2.3: Based on the data segment obtained in Step S2.2, calculate the true solar elevation information and the solar elevation information detected by the radar, and determine whether the difference between the true solar elevation information and the solar elevation information detected by the radar is within a reasonable range, removing the data segments outside the reasonable range.

[0080] In this embodiment, the reasonable range is set to 0~10°. That is, if the difference between the true solar elevation information and the solar elevation information detected by the radar is within the range of 0~10°, then this data segment is not removed; otherwise, this data segment is removed.

[0081] Step S2.4: Search for the maximum solar radiation signal in each data segment obtained in Step S2.3, and use the maximum solar radiation signal as the first solar intensity information of each data segment, that is, the solar characteristic signal.

[0082] Based on the identified first solar intensity information, the corresponding first relative azimuth angle, first relative elevation angle, and volume scan time can be determined. Each first solar intensity information corresponds to a first relative azimuth angle, a first relative elevation angle, and a volume scan time.

[0083] In this embodiment, the relative azimuth angle (i.e., the first relative azimuth angle and the second relative azimuth angle) and the relative elevation angle (i.e., the first relative elevation angle and the second relative elevation angle) are the azimuth angle and elevation angle of the solar radiation signal passively received by the radar when the signal transmission function is turned off; the absolute azimuth angle (i.e., the first absolute azimuth angle and the second absolute azimuth angle) and the absolute elevation angle (i.e., the first absolute elevation angle and the second absolute elevation angle) in this embodiment are the true azimuth angle and true elevation angle of the sun calculated according to the solar azimuth and elevation calculation formula based on the radar geographical location and the corresponding scan time.

[0084] Step S3: Perform continuity verification based on all the first relative azimuth angles, first relative elevation angles, and volume scan times.

[0085] To ensure the accuracy and reliability of solar characteristic recognition, solar characteristic recognition is performed on continuous multiple radar volume scan data to obtain the first solar intensity information of each radar volume scan data and its corresponding first relative azimuth angle, first relative elevation angle, and volume scan time; and continuity verification is performed based on the first relative azimuth angles, first relative elevation angles, and volume scan times of continuous multiple radar volume scan data.

[0086] In the specific implementation manner of the present invention, performing continuity verification based on all the first relative azimuth angles, first relative elevation angles, and volume scan times specifically includes:

[0087] Step S3.1: Integrate and remove outliers from all the first relative azimuth angles, first relative elevation angles, and volume scan times.

[0088] In this embodiment, the specific operation of removing outliers is as follows: Calculate the average value of all the first relative azimuth angles, and remove the first relative azimuth angles that exceed the range of this average value, for example, the first relative azimuth angles that exceed the range of this average value ±5°; calculate the average value of all the first relative elevation angles, and remove the first relative elevation angles that exceed the range of this average value, for example, the first relative elevation angles that exceed the range of this average value ±5°.

[0089] Step S3.2: Determine whether the number of data obtained in step S3.1 reaches the first quantity threshold. If so, proceed to step S3.3; otherwise, mark the calibration as failed and exit the calibration.

[0090] In this embodiment, for 10 consecutive radar volume scan data, if at least 5 sets of the first relative azimuth angle, the first relative elevation angle, and the volume scan time of the radar volume scan data can be obtained, proceed to step S3.3; otherwise, mark the calibration as failed and exit the calibration.

[0091] Step S3.3: Based on the data obtained in step S3.1, determine whether the first relative azimuth angle changes continuously in the correct direction and whether the first relative elevation angle changes continuously in the correct direction. If so, pass the continuity check.

[0092] When the sun is in the southern hemisphere of the radar and moves from east to west, that is, in the cumulative process from 90° to 180°, determine whether the first relative azimuth angle changes continuously according to this process. In the morning, the rising sun is for accumulation, and in the afternoon, the setting sun is for subtraction. Determine whether the first relative elevation angle changes continuously according to this process.

[0093] Step S4: When the continuity check passes, determine the sector scan range based on the last first relative azimuth angle, and control the radar to rotate and start sector scanning based on the sector scan range.

[0094] In the specific embodiment of the present invention, the sector scan range is (the last first relative azimuth angle ± the first angle threshold, the last first relative azimuth angle + the second angle threshold). As Figure 2 shown, considering the geographical location of the radar, the sun is in the south, and the characteristics of rising in the east and setting in the west, the second angle threshold should be greater than the first angle threshold. To ensure sufficient area coverage, the first angle threshold is set to 10°, and the second angle threshold is set to 20°.

[0095] Step S5: Obtain a plurality of consecutive sector scan data.

[0096] Sector scanning is a reciprocating scan within the sector scan range. For each completed reciprocating scan, two sector scan data are obtained. In this embodiment, at least 40 consecutive sector scan data are obtained.

[0097] Step S6: Perform solar feature recognition on each sector scan data to obtain the second solar intensity information and its corresponding second relative azimuth angle, second relative elevation angle, and sector scan time.

[0098] The sector scan data contains a large amount of in-aircraft noise and a small amount of weak solar radiation signals. In order to perform solar feature recognition on the solar radiation signals, first filter out the in-aircraft noise in the sector scan data. In the specific embodiment of the present invention, performing solar feature recognition on each sector scan data specifically includes:

[0099] Step S6.1: Calculate the average value of the solar radiation signals in each sector scan data, filter out the solar radiation signals below the average value, and retain the solar radiation signals above the average value.

[0100] Step S6.2: Perform solar feature recognition on the data obtained in Step S6.1, and the recognized data segment satisfies the normal distribution characteristics.

[0101] Among them, the normal distribution characteristics include: the difference between the maximum value and the minimum value in the data segment is greater than 1 (empirical value), the peak data is located in the middle area of the data segment, and the width of the data segment is greater than 10 data points (empirical value after the radar operation mode and rotation speed are fixed).

[0102] Step S6.3: Based on the data segment obtained in Step S6.2, calculate the true solar elevation information and the solar elevation information detected by the radar, and determine whether the difference between the true solar elevation information and the solar elevation information detected by the radar is within a reasonable range, and remove the data segments outside the reasonable range.

[0103] In this embodiment, the reasonable range is set to 0~10°, that is, if the difference between the true solar elevation information and the solar elevation information detected by the radar is within the range of 0~10°, then the data segment is not removed; otherwise, the data segment is removed.

[0104] Step S6.4: Find the maximum solar radiation signal in each data segment obtained in Step S6.3, and use the maximum solar radiation signal as the second solar intensity information of each data segment, that is, the solar feature signal.

[0105] According to the recognized second solar intensity information, the corresponding second relative azimuth angle, second relative elevation angle and sector scan time can be determined. Each second solar intensity information corresponds to a second relative azimuth angle, a second relative elevation angle and a sector scan time.

[0106] Step S7: Perform continuity verification according to all the second relative azimuth angles, second relative elevation angles and sector scan times.

[0107] To ensure the accuracy and reliability of solar feature recognition, perform solar feature recognition on multiple consecutive sector scan data to obtain the second solar intensity information of each sector scan data and its corresponding second relative azimuth angle, second relative elevation angle and sector scan time; and perform continuity verification according to the second relative azimuth angles, second relative elevation angles and sector scan times of multiple consecutive sector scan data.

[0108] In the specific implementation manner of the present invention, performing continuity verification according to all the second relative azimuth angles, second relative elevation angles and sector scan times specifically includes:

[0109] Step S7.1: Integrate all the second relative azimuth angles, second relative elevation angles, and sector scan times, and eliminate outliers.

[0110] In this embodiment, the specific operation of outlier elimination is as follows: Calculate the average value of all the second relative azimuth angles, and eliminate the second relative azimuth angles that exceed the range of this average value, such as the second relative azimuth angles that exceed the range of this average value ±5°; Calculate the average value of all the second relative elevation angles, and eliminate the second relative elevation angles that exceed the range of this average value, such as the second relative elevation angles that exceed the range of this average value ±5°.

[0111] Step S7.2: Determine whether the number of data obtained in Step S7.1 reaches the second quantity threshold. If so, proceed to Step S7.3; otherwise, the calibration fails and the calibration exits.

[0112] In this embodiment, if at least 40 second relative azimuth angles, second relative elevation angles, and volume scan times of sector scan data can be obtained, proceed to Step S7.3; otherwise, the calibration fails and the calibration exits.

[0113] Step S7.3: Based on the data obtained in Step S7.1, determine whether the second relative azimuth angle changes continuously in the correct direction and whether the second relative elevation angle changes continuously in the correct direction. If so, pass the continuity check.

[0114] The sun is in the southern hemisphere of the radar and moves from east to west, that is, the accumulation process from 90° to 180°. Determine whether the second relative azimuth angle changes continuously according to this process. In the morning, the sun rises for accumulation, and in the afternoon, the sun sets for subtraction. Determine whether the second relative elevation angle changes continuously according to this process.

[0115] Step S8: When the continuity check passes, perform an integrity check based on all the first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle, and volume scan time, as well as all the second solar intensity information and its corresponding second relative azimuth angle, second relative elevation angle, and sector scan time.

[0116] In the specific implementation manner of the present invention, perform an integrity check based on all the first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle, and volume scan time, as well as all the second solar intensity information and its corresponding second relative azimuth angle, second relative elevation angle, and sector scan time. Specifically, it includes:

[0117] Step S8.1: Calculate the azimuth deviation and elevation deviation according to the radar geographical location, all the first relative azimuth angles, first relative elevation angles, volume scan times, second relative azimuth angles, second relative elevation angles, and sector scan times.

[0118] In a specific embodiment of the present invention, the azimuth deviation and pitch deviation are calculated based on the radar geographical location, all the first relative azimuth angles, the first relative pitch angles, the volume scan time, the second relative azimuth angles, the second relative pitch angles, and the sector scan time. Specifically, it includes:

[0119] Step S8.11: Calculate the first absolute azimuth angle and the first absolute pitch angle according to the radar geographical location and the volume scan time.

[0120] In this embodiment, the specific calculation formulas for the first absolute azimuth angle and the first absolute pitch angle are:

[0121] (1)

[0122] (2)

[0123] (3)

[0124] (4)

[0125] (5)

[0126] (6)

[0127] (7)

[0128] (8)

[0129] (9)

[0130] (10)

[0131] (11)

[0132] Wherein, represents the time parameter, represents the Julian day time of the volume scan time, represents the geometric mean ecliptic longitude, represents the equation of the center, represents the apparent ecliptic longitude of the sun, represents the right ascension, represents the obliquity of the ecliptic, represents the declination, represents the Greenwich hour angle, represents the universal time, represents the local hour angle, represents the radar longitude, represents the first absolute pitch angle; represents the radar latitude, Indicates the first absolute azimuth angle.

[0133] Step S8.12: Calculate the first azimuth deviation based on the first relative azimuth angle and the first absolute azimuth angle, and calculate the first pitch deviation based on the first relative pitch angle and the first absolute pitch angle.

[0134] The absolute value of the difference between the first relative azimuth angle and the first absolute azimuth angle is the first azimuth deviation, and the absolute value of the difference between the first relative pitch angle and the first absolute pitch angle is the first pitch deviation. Each set of the first relative azimuth angle, the first relative pitch angle, and the volume scan time corresponds to a first azimuth deviation and a first pitch deviation.

[0135] Step S8.13: Calculate the second absolute azimuth angle and the second absolute pitch angle based on the radar geographical location and the sector scan time.

[0136] Similarly, the second absolute azimuth angle and the second absolute pitch angle can be calculated according to Formulas (1) to (11).

[0137] Step S8.14: Calculate the second azimuth deviation based on the second relative azimuth angle and the second absolute azimuth angle, and calculate the second pitch deviation based on the second relative pitch angle and the second absolute pitch angle.

[0138] The absolute value of the difference between the second relative azimuth angle and the second absolute azimuth angle is the second azimuth deviation, and the absolute value of the difference between the second relative pitch angle and the second absolute pitch angle is the second pitch deviation. Each set of the second relative azimuth angle, the second relative pitch angle, and the sector scan time corresponds to a second azimuth deviation and a second pitch deviation.

[0139] Step S8.15: Calculate the average value of all the first azimuth deviations and the second azimuth deviations to obtain the final azimuth deviation; calculate the average value of all the first pitch deviations and the second pitch deviations to obtain the final pitch deviation.

[0140] Step S8.2: Monitor whether the final pitch deviation changes regularly and whether its change rate is within its average value range; monitor whether the final azimuth deviation is within its average value range.

[0141] Figure 3 Shows the regular change of the final pitch deviation. The abscissa represents the serial number of the volume scan and the sector scan. The change rate of the final pitch deviation is equal to the difference between the two consecutive final pitch deviations. Figure 4 Shows the scatter plot of the final azimuth deviation. The abscissa represents the serial number of the volume scan and the sector scan. The average value range of the final azimuth deviation is the average value of all the final azimuth deviations ±1°.

[0142] When the final pitch deviation shows regular changes and its change rate is within the range of its mean value, and the final azimuth deviation is within the range of its mean value, it indicates that the integrity check has passed.

[0143] When the calibration duration exceeds 1 hour and the integrity check cannot be passed, it is also considered that the calibration fails this time. The calibration is exited, the radar is restored to the operating state before calibration, and the reason for the calibration failure is returned.

[0144] Step S9: When the integrity check passes, calculate the azimuth deviation and pitch deviation based on the radar geographical location, all the first relative azimuth angles, first relative pitch angles, volume scan time, second relative azimuth angles, second relative pitch angles, and sector scan time. The specific calculation process is shown in Steps S8.11 to S8.15.

[0145] Step S10: Perform radar calibration based on the azimuth deviation and pitch deviation.

[0146] The calculation formulas for the true azimuth and pitch information of the sun (i.e., Formulas (1) to (11)) are based on the precise astronomical and geographical coordinate conversion principles, fully considering factors such as the rotation and revolution of the earth, as well as the radar geographical location and scan time. Through the precise calculation of the true azimuth angle and true pitch angle of the sun, it provides a stable and reliable benchmark for the calibration of the radar antenna beam pointing. The sun, as a natural calibration source with stable radiation characteristics, the precise calculation of its true azimuth and pitch information provides an objective reference standard for radar calibration. When performing calibration, comparing the sun azimuth and pitch information detected by the radar (i.e., relative azimuth angle and relative pitch angle) with the true azimuth and pitch information of the sun (i.e., absolute azimuth angle and absolute pitch angle) can accurately evaluate the pointing deviation of the radar antenna and provide an accurate basis for subsequent calibration adjustment.

[0147] Using the sun as the calibration radiation source and performing calibration with the calculation formulas for the true azimuth and pitch information of the sun and the radar scan data avoids the need to purchase and maintain expensive special calibration equipment. Traditional calibration methods often require the use of high-precision special equipment, which is not only costly but also difficult to maintain and operate. The present invention only needs to obtain the radar geographical location (longitude, latitude) and accurate scan time, and combine the calculation formulas for the true azimuth and pitch information of the sun to quickly obtain the true azimuth and pitch information of the sun, and then carry out the calibration work. This method greatly simplifies the calibration process, reduces the technical threshold of the calibration work, and makes the calibration work easier to implement and promote.

[0148] The calculation formula for the true azimuth and elevation information of the sun features fast calculation and can obtain the formula for the true azimuth and elevation information of the sun in a short time. When the radar needs to be calibrated, the radar is started to scan to obtain solar radiation data. Based on the solar radiation data, the detected azimuth and elevation information of the sun are quickly determined, and then calibration is performed in combination with the true azimuth and elevation information of the sun, greatly shortening the calibration time and improving the calibration efficiency. At the same time, since the calibration process only depends on the spatio-temporal information of the radar and is not restricted by specific sites and equipment, whether it is a remote field weather station or a military radar base in different geographical locations, as long as accurate spatio-temporal information can be obtained, radar calibration can be carried out anytime and anywhere to ensure that the radar always maintains a good working state. In addition, the calculation formula for the true azimuth and elevation information of the sun also supports online update and can be adjusted according to the latest astronomical data and geographical information to ensure the accuracy of the calculation results.

[0149] The present invention can perform refined calibration on the elevation and azimuth angles of the radar, strictly controlling the deviation value within 0.2°. This high-precision calibration significantly improves the accuracy of the radar antenna pointing, enabling the radar to more accurately determine the position and motion parameters of the target when detecting the target, and enhancing the detection accuracy and reliability of the radar. In the field of meteorological monitoring, it can more accurately monitor meteorological changes and provide more reliable data support for weather forecasting; in the field of national defense and military, it can more precisely identify and track targets and enhance the national defense security guarantee ability.

[0150] A simple and easy-to-use calibration operation interface can be set up, adopting an operation method of one-key opening or closing of calibration. After the calibration process is completed, the system can immediately generate and display the deviation results without complex manual intervention and data processing processes. The operation process can be flexibly optimized according to different application scenarios and user requirements to achieve automatic configuration. This not only improves work efficiency, reduces human operation errors, but also reduces the requirements for the professional skills of operators, making the radar calibration work more convenient and efficient. At the same time, the automated operation process can also achieve remote calibration, facilitating the unified management and calibration of radars distributed in different regions.

[0151] Under sunny weather conditions, the present invention can perform azimuth and elevation calibration corrections on radars everywhere at any time. This flexibility enables the radar to quickly adapt to different working environments and task requirements, timely adjust its own state, and ensure good working performance in various complex situations. Whether it is the small deviation that occurs during long-term operation or the situation that requires re-calibration after equipment relocation, the calibration can be quickly completed through the present invention to ensure the stable operation of the radar system. In addition, the present invention also supports simultaneous calibration of multiple radars, further improving the calibration efficiency and management convenience.

[0152] The solar radiation signal is less affected by interference factors such as atmospheric refraction, which can effectively improve the calibration accuracy.

[0153] Embodiment 2

[0154] The one-dimensional phased array radar calibration system provided by the embodiment of the present invention includes a receiving module, a processing module, and a client. The receiving module is connected to the radar to be calibrated and the processing module, and the processing module is connected to the radar to be calibrated.

[0155] The receiving module is used to: receive and cache a plurality of consecutive radar volume scan data transmitted by the radar; wherein, each circle of scan corresponds to one radar volume scan data; receive and cache a plurality of consecutive sector scan data transmitted by the radar; wherein, each reciprocating scan corresponds to two sector scan data.

[0156] The processing module is used to: perform solar feature recognition on each radar volume scan data to obtain the first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle, and volume scan time; perform continuity verification based on all the first relative azimuth angles, first relative elevation angles, and volume scan times;

[0157] When the continuity verification passes, determine the sector scan range according to the last first relative azimuth angle, and enable the controller of the radar to control the radar to rotate and start sector scanning based on the sector scan range;

[0158] Perform solar feature recognition on each sector scan data to obtain the second solar intensity information and its corresponding second relative azimuth angle, second relative elevation angle, and sector scan time; perform continuity verification based on all the second relative azimuth angles, second relative elevation angles, and sector scan times;

[0159] When the continuity verification passes, perform integrity verification based on all the first solar intensity information and its corresponding first relative azimuth angle and first relative elevation angle, and all the second solar intensity information and its corresponding second relative azimuth angle and second relative elevation angle;

[0160] When the integrity verification passes, calculate the azimuth deviation and elevation deviation according to the radar geographical location, all the first relative azimuth angles, first relative elevation angles, volume scan times, second relative azimuth angles, second relative elevation angles, and sector scan times;

[0161] Perform radar calibration according to the azimuth deviation and elevation deviation.

[0162] The client is used to: start or stop calibration, and enable the controller of the radar to control the radar to start volume scanning at the start of calibration.

[0163] As the entrance of radar scanning data, the receiving module has powerful data processing and buffering capabilities, and can quickly and stably receive the massive radar scanning data reported by the radar in real time. In the process of receiving data, the radar scanning data will be initially converted into a format and preprocessed to remove noise and invalid data, providing a high-quality data foundation for subsequent accurate processing.

[0164] The processing module is the core control center of the entire calibration system, and undertakes the important tasks of client control of multiple radars and radar collaborative operation. By using advanced algorithms and intelligent scheduling strategies, unified management and collaborative work of multiple radars are achieved. During calibration, the processing module accurately controls the scanning parameters and working mode of the radar according to the client's instructions and the real-time status of each radar to ensure the smooth progress of the calibration process. At the same time, the processing module also has data fusion and analysis capabilities, and can comprehensively process the data of multiple radars to improve the accuracy and reliability of calibration.

[0165] The client provides users with an intuitive and convenient operation interface and is an important window for users to interact with the system. Through the client, users can view various information such as radar monitoring data and calibration results in real time, and can also perform operations such as parameter setting and task initiation. In addition, the client also has data visualization functions, which can display radar scanning data and calibration results in the form of charts, maps, etc., so that users can intuitively understand the working status and calibration effect of the radar.

[0166] In some specific implementations, the one-dimensional phased array radar calibration system may be combined with features of the one-dimensional phased array radar calibration method in the embodiments of the present invention, and vice versa, which will not be described in detail herein.

[0167] The present invention constructs an integrated calibration system mechanism including a receiving module, a processing module and a client. The receiving module has a powerful data processing capability and can efficiently process the massive scanning data reported by the radar in real time, providing an accurate basis for subsequent analysis. The processing module is the "smart brain" of the system, which undertakes the important task of precise control and coordinated operation of multiple radars. Through intelligent algorithms and efficient scheduling strategies, it ensures the tacit cooperation between the radars and improves the overall work efficiency. As a bridge for the interaction between the user and the system, the client provides an intuitive and convenient operation interface, which can not only clearly display various key information, but also support a variety of interaction methods to meet the operating habits of different users and realize the user's flexible control of the radar. This architectural design ensures close cooperation between the various parts of the system and lays a solid foundation for the smooth development of radar calibration work.

[0168] The above-disclosed is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or variations, which should all be covered within the protection scope of the present invention.

Claims

1. A one-dimensional phased array radar calibration method, characterized in that The calibration method includes: Obtain a plurality of consecutive radar volume scan data; where each circle of scanning corresponds to one radar volume scan data; Perform solar feature recognition on each radar volume scan data to obtain the first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle, and volume scan time; perform continuity verification based on all the first relative azimuth angles, first relative elevation angles, and volume scan times; When the continuity verification passes, determine the sector scan range according to the last first relative azimuth angle, and control the radar to rotate and start sector scanning based on the sector scan range; Obtain a plurality of consecutive sector scan data; where each reciprocating scan corresponds to two sector scan data; Perform solar feature recognition on each sector scan data to obtain the second solar intensity information and its corresponding second relative azimuth angle, second relative elevation angle, and sector scan time; perform continuity verification based on all the second relative azimuth angles, second relative elevation angles, and volume scan times; When the continuity verification passes, perform integrity verification based on all the first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle, and volume scan time, and all the second solar intensity information and its corresponding second relative azimuth angle, second relative elevation angle, and sector scan time; When the integrity verification passes, calculate the azimuth deviation and elevation deviation according to the radar geographical location, all the first relative azimuth angles, first relative elevation angles, volume scan times, second relative azimuth angles, second relative elevation angles, and sector scan times; Perform radar calibration according to the azimuth deviation and elevation deviation.

2. The one-dimensional phased array radar calibration method according to claim 1, wherein Before calibration, the calibration method further includes: Set the calibration start time; When the calibration start time is reached, control the radar to switch to the calibration mode, the radar enters the silent state, and starts volume scanning.

3. The one-dimensional phased array radar calibration method according to claim 2, wherein The specific calculation process of the calibration start time is: Determine the start detection elevation angle according to the radar scan mode; Use the bisection method to find the moment when the sun reaches the start detection elevation angle within the specified time range, and thus obtain the calibration start time.

4. The one-dimensional phased array radar calibration method according to claim 1, wherein Performing solar feature recognition on each radar volume scan data or sector scan data specifically includes: Perform filtering processing on each radar volume scan data or each sector scan data; Calculate the average value of the solar radiation signals in the filtered radar volume scan data or sector scan data, filter out the solar radiation signals below the average value, and retain the solar radiation signals above the average value; Perform solar feature recognition on the retained data to identify data segments that satisfy the normal distribution characteristics; Based on the identified data segments, calculate the true solar elevation information and the solar elevation information detected by the radar; Judge whether the difference between the true solar elevation information and the solar elevation information detected by the radar is within a reasonable range; When the difference between the true solar elevation information and the solar elevation information detected by the radar is within a reasonable range, find the maximum solar radiation signal from each data segment, and use the maximum solar radiation signal as the first solar intensity information or the second solar intensity information of each data segment.

5. The one-dimensional phased array radar calibration method according to claim 1, wherein The sector scan range is (the last first relative azimuth angle ± the first angle threshold, the last first relative azimuth angle + the second angle threshold), where the second angle threshold is greater than the first angle threshold.

6. The one-dimensional phased array radar calibration method according to claim 5, wherein The first angle threshold is 10°, and the second angle threshold is 20°.

7. The one-dimensional phased array radar calibration method according to any one of claims 1 to 6, characterized in that Calculate the azimuth deviation and pitch deviation according to the radar geographical location, all the first relative azimuth angles, first relative pitch angles, volume scan time, second relative azimuth angles, second relative pitch angles, and sector scan time. Specifically, it includes: Calculate the first absolute azimuth angle and first absolute pitch angle according to the radar geographical location and volume scan time; calculate the first azimuth deviation according to the first relative azimuth angle and the first absolute azimuth angle, and calculate the first pitch deviation according to the first relative pitch angle and the first absolute pitch angle; Calculate the second absolute azimuth angle and second absolute pitch angle according to the radar geographical location and sector scan time; calculate the second azimuth deviation according to the second relative azimuth angle and the second absolute azimuth angle, and calculate the second pitch deviation according to the second relative pitch angle and the second absolute pitch angle; Take the average of all the first azimuth deviations and second azimuth deviations to obtain the final azimuth deviation; take the average of all the first pitch deviations and second pitch deviations to obtain the final pitch deviation.

8. The one-dimensional phased array radar calibration method according to claim 7, wherein The specific calculation formula for the first absolute pitch angle or the second absolute pitch angle is: ； ； Wherein, represents the first absolute pitch angle or the second absolute pitch angle; represents the radar latitude; represents the declination, which is calculated according to the corresponding volume scan time or sector scan time; represents the local hour angle; represents the Greenwich hour angle; represents the radar longitude; The specific calculation formula for the first absolute azimuth angle or the second absolute azimuth angle is: ； Among them, represents the first absolute azimuth angle or the second absolute azimuth angle.

9. A one-dimensional phased array radar, characterized in that, The one-dimensional phased array radar is calibrated by using the one-dimensional phased array radar calibration method described in any one of claims 1 to 8.

10. One-dimensional phased array radar calibration system, characterized in that, The calibration system includes a receiving module, a processing module, and a client; The receiving module is used for: Receiving and caching a continuous plurality of radar volume scan data transmitted by the radar; wherein, each circle of scanning corresponds to one radar volume scan data; receiving and caching a continuous plurality of sector scan data transmitted by the radar; wherein, each reciprocating scan corresponds to two sector scan data; The processing module is used for: Performing solar feature recognition on each radar volume scan data to obtain the first solar intensity information and its corresponding first relative azimuth angle, first relative pitch angle, and volume scan time; performing continuity verification according to all the first relative azimuth angles, first relative pitch angles, and volume scan time; When the continuity verification passes, determine the sector scan range according to the last first relative azimuth angle, and enable the controller of the radar to control the radar to rotate and start sector scanning based on the sector scan range; Performing solar feature recognition on each sector scan data to obtain the second solar intensity information and its corresponding second relative azimuth angle, second relative pitch angle, and sector scan time; performing continuity verification according to all the second relative azimuth angles, second relative pitch angles, and sector scan time; When the continuity verification passes, perform integrity verification according to all the first solar intensity information and its corresponding first relative azimuth angle and first relative pitch angle, and all the second solar intensity information and its corresponding second relative azimuth angle and second relative pitch angle; When the integrity verification passes, calculate the azimuth deviation and pitch deviation according to the radar geographical location, all the first relative azimuth angles, first relative pitch angles, volume scan time, second relative azimuth angles, second relative pitch angles, and sector scan time; Perform radar calibration according to the azimuth deviation and pitch deviation; The client is used for: Starting or stopping calibration, and enabling the controller of the radar to control the radar to start volume scanning at the beginning of calibration.

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