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

Abstract

The present invention discloses a one-dimensional phased array radar and a calibration method and system thereof. The calibration method includes performing solar feature recognition on radar volume scan data to obtain first solar intensity information and its corresponding first relative azimuth, first relative pitch angle, and volume scan time; determining a sector scan range based on the last first relative azimuth, controlling radar rotation and starting sector scan based on the sector scan range; performing solar feature recognition on the sector scan data to obtain second solar intensity information and its corresponding second relative azimuth, second relative pitch angle, and sector scan time; calculating azimuth deviation and pitch deviation based on the radar geographic location, all first relative azimuths, first relative pitch angles, volume scan time, second relative azimuth, second relative pitch angle, and sector scan time; and calibrating the radar based on the azimuth deviation and pitch deviation. The present invention improves calibration efficiency and accuracy.

Description

Technical Field

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

[0002] Throughout the lifecycle of a radar system, antenna pointing deviation remains a key factor limiting its performance. Ideally, a radar antenna should maintain stable and accurate pointing during scanning, but in practice, it is often affected by a variety of factors. Improper installation, mechanical wear, temperature fluctuations, sensor failure, motor or drive system issues, external environmental interference (such as vibration and wind), control system algorithm errors, geomagnetic deviation, and structural fatigue can cause radar azimuth and elevation deviations. Furthermore, mechanical structural precision limitations (such as bearing clearance and manufacturing tolerances of transmission components) can cause antenna axis wobble, leading to antenna pointing deviation. Long-term operation and vibration can cause components to loosen or deform, further affecting accuracy. Sensor errors, external vibration, shock, or resonance can also cause deviations. To mitigate these issues, regular inspection, calibration, and maintenance are crucial. While radar antennas are rigorously calibrated at the factory to ensure accurate pointing, manufacturing precision limitations, calibration equipment tolerances, operator variability, and environmental factors can ultimately lead to deviations in calibration results.

[0003] To address these issues, existing technologies have proposed various compensation measures. Electronic scanning technology overcomes the angular errors caused by mechanical scanning to a certain extent, but performance fluctuations of electronic components may still affect it. While using mathematical models for prediction and correction can address deviations to a certain extent, the computational complexity is high, the data accuracy and integrity requirements are extremely high, and the model adaptability is limited. Dual-antenna alternating scanning methods, while reducing radar angular deviation, increase equipment cost and system complexity.

[0004] Currently, solar calibration, a commonly used radar calibration method, faces numerous challenges in practical application. Due to differences in radar hardware structure and signal processing methods produced by different manufacturers, as well as the varying operating conditions of each radar in different operating environments, existing solar calibration methods are difficult to standardize and lack universality and reference value. This necessitates developing a customized calibration plan for each radar, increasing calibration complexity and cost while reducing efficiency. Summary of the Invention

[0005] The purpose of the present invention is to provide a one-dimensional phased array radar and a calibration method and system thereof, so as to solve the problem that when using the existing solar method for radar calibration, a special calibration scheme needs to be formulated for 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, comprising:

[0007] Acquire multiple continuous radar volume scan data; each circle of scanning corresponds to one radar volume scan data;

[0008] Perform solar feature recognition on each radar volume scan data to obtain 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 first relative azimuth angles, first relative elevation angles, and volume scan times;

[0009] When the continuity check passes, the sector scan range is determined according to the last first relative azimuth, and the radar is controlled to rotate and start sector scanning based on the sector scan range;

[0010] Acquire a plurality of continuous sector scan data, wherein each reciprocating scan corresponds to two sector scan data;

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

[0012] When the continuity check passes, an integrity check is performed based on all first solar intensity information and its corresponding first relative azimuth angle, first relative pitch angle, and volume scan time, as well as all second solar intensity information and its corresponding second relative azimuth angle, second relative pitch angle, and sector scan time;

[0013] When the integrity check passes, the azimuth deviation and elevation deviation are calculated based on the radar's geographical location, all first relative azimuth angles, first relative elevation angles, body scan time, second relative azimuth angles, second relative elevation angles, and sector scan time;

[0014] Radar calibration is performed according to the azimuth deviation and the elevation deviation.

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

[0016] Set the calibration start time;

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

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

[0019] Determine the pitch angle to start detecting according to the radar scanning mode;

[0020] The binary method is used to find the time when the sun reaches the pitch angle for starting detection within a specified time range, thereby obtaining the calibration start time.

[0021] Furthermore, solar feature recognition is performed 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 signal 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;

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

[0025] Based on the identified data segments, calculating the actual solar pitch information and the solar pitch information detected by the radar;

[0026] Determine whether the difference between the actual solar pitch information and the solar pitch information detected by the radar is within a reasonable range;

[0027] When the difference between the actual solar pitch information and the solar pitch information detected by the radar is within a reasonable range, the maximum solar radiation signal is found from each data segment, and the maximum solar radiation signal is used as the first solar intensity information or the second solar intensity information of each data segment.

[0028] Furthermore, the fan scanning range is (the last first relative azimuth angle±the first angle threshold, the last first relative azimuth angle+the second angle threshold), wherein 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, the azimuth deviation and the elevation deviation are calculated according to the radar geographic location, all first relative azimuth angles, first relative elevation angles, body scan time, second relative azimuth angles, second relative elevation angles, and sector scan time, specifically including:

[0031] Calculate a first absolute azimuth and a first absolute elevation angle according to the radar's geographic location and the scanning time; calculate a first azimuth deviation according to the first relative azimuth and the first absolute azimuth, and calculate a first elevation deviation according to the first relative elevation angle and the first absolute elevation angle;

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

[0033] The final azimuth deviation is obtained by averaging all the first azimuth deviations and the second azimuth deviations; the final pitch deviation is obtained by averaging all the first pitch deviations and the second pitch deviations.

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

[0035] ;

[0036] ;

[0037] in, Indicates the first absolute pitch angle or the second absolute pitch angle; Indicates the radar latitude; Indicates declination, which is calculated based on the corresponding body scan time or sector scan time; Indicates the local hour angle; represents the Greenwich hour angle; represents the radar longitude;

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

[0039] ;

[0040] in, Indicates the first absolute azimuth or the second absolute azimuth.

[0041] Based on the same concept, the present invention further provides a one-dimensional phased array radar, which is calibrated using the one-dimensional phased array radar calibration method 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 multiple continuous radar volume scan data transmitted by the radar; wherein each circle scan corresponds to one radar volume scan data; receive and cache multiple continuous 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 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 first relative azimuth angles, first relative elevation angles, and volume scan times;

[0047] When the continuity check passes, the sector scan range is determined according to the last first relative azimuth, and the radar controller controls the radar to rotate and start sector scanning based on the sector scan range;

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

[0049] When the continuity check passes, an integrity check is performed based on all the first solar intensity information and the corresponding first relative azimuth angle and first relative pitch angle, and all the second solar intensity information and the corresponding second relative azimuth angle and second relative pitch angle;

[0050] When the integrity check passes, the azimuth deviation and elevation deviation are calculated based on the radar's geographical location, all first relative azimuth angles, first relative elevation angles, body scan time, second relative azimuth angles, second relative elevation angles, and sector scan time;

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

[0052] The client is used to:

[0053] Start or stop calibration, so that the radar controller will control the radar to start body scanning when calibration starts.

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

[0055] The present invention uses the sun as the calibration radiation source and performs calibration with the help of the sun's azimuth and elevation information, avoiding the need to purchase and maintain expensive calibration equipment and reducing calibration and maintenance costs. The sun's true azimuth and elevation information can be quickly obtained based on the radar's geographical location and scanning time, and the calibration deviation can be calculated. This method greatly simplifies the calibration process, shortens the calibration time, and improves the calibration efficiency. There is no need to formulate a special calibration plan based on the radar, which improves the versatility of the solar method calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0057] Figure 1 is a schematic model diagram of the sun's position based on the horizon in an embodiment of the present invention;

[0058] Figure 2 is a flow chart of a one-dimensional phased array radar calibration method according to an embodiment of the present invention;

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

[0060] Figure 4 It is the final azimuth deviation scatter plot in the embodiment of the present invention. DETAILED DESCRIPTION

[0061] The following is a clear and complete description of the technical solutions of the present invention in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

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

[0063] Existing solar calibration methods struggle to achieve a unified standard and lack universality and reference value. This necessitates developing a customized calibration solution for each radar, increasing calibration complexity and cost while reducing efficiency. To address these technical issues, the present invention provides a one-dimensional phased array radar and a calibration method and system thereof. These methods utilize the sun as a calibration radiation source and utilize the sun's azimuth and elevation information to achieve automatic calibration, simplifying the calibration process, shortening calibration time, and improving calibration efficiency.

[0064] Figure 1A schematic model of the sun's position based on the horizon is shown, where Az = 0° represents north, Az = 90° represents east, Az = 180° represents south, and Az = 270° represents west. The semicircular structure above the horizon represents the sky. The angle between the straight line pointing from the radar to the sun and the horizon is the elevation angle Alt, and the angle between the projection of the straight line pointing from the radar to the sun on the horizon and due north is the azimuth angle Az. Figure 1 The azimuth and elevation angles are used to visually present the spatial position relationship between the sun and the horizon and the radar. Figure 1 The radar is set in the southern hemisphere for demonstration purposes. Combined with its actual geographical location (the northern hemisphere), the sun rises in the east and sets in the west. Therefore, when calibrating the radar, its azimuth rotation usually follows the range of 90° to 180°, and the pitch angle increases in the morning and decreases in the afternoon, providing a reference basis for subsequent calibration.

[0065] Example 1

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

[0067] Step S1: Acquire multiple continuous radar volume scan data.

[0068] Before calibration, a calibration start time is set and a timed task is automatically initiated. When the calibration start time is reached, the radar is controlled to switch to calibration mode, at which point the radar shuts down its signal transmission function, enters a silent state, and initiates a low-speed 360° omnidirectional scanning mode (i.e., volume scanning), passively receiving solar radiation signals. Each completed volume scan (i.e., one full sweep) generates a radar volume scan data point. In this embodiment, at least 10 consecutive radar volume scan data points are acquired. Acquiring solar radiation signals through volume scanning ensures comprehensive, full-range, and comprehensive acquisition of solar radiation signals, avoiding potential loss of solar radiation signals due to significant deviations that may occur during radar installation.

[0069] Once the tester confirms that the current weather and external environment meet the solar calibration requirements, they set the calibration start time and wait for the calibration task to automatically execute. For example, the tester confirms that the weather conditions in the radar area meet the requirements for visible sunlight (sunny, cloudy, etc.).

[0070] To ensure accurate radar elevation calibration, the calibration start time is determined by taking into account the fact that the solar radiation signal moves from one end of the antenna array normal to the other during the entire calibration process. Specifically, the optimal radar calibration start time can be accurately calculated by integrating the time of day, the radar scanning pattern, and the real-time position of the sun, using celestial mechanics models and complex algorithms. In this embodiment, the specific calculation process for the optimal radar calibration start time is as follows:

[0071] Step S1.1: Determine the starting pitch angle for detection based on the radar scanning mode. Usually, the starting pitch angle for detection is half of the total pitch angle of the scan, that is, the normal angle. The normal angle refers to the angle perpendicular to the sun facing the radar array.

[0072] Step S1.2: Use the binary search method to find the time when the sun arrives to start detecting the pitch angle within a specified time range (for example, morning or afternoon). Subtract 20 minutes from this time to obtain the optimal radar calibration start time.

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

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

[0075] Radar volume scan data contains a large amount of internal noise and a small amount of weak solar radiation signals. To perform solar signature recognition on the solar radiation signals, wavelet denoising and adaptive filtering are first used to filter out the internal noise in the radar volume scan data. In a specific embodiment of the present invention, solar signature recognition is performed on each radar volume scan data, specifically including:

[0076] Step S2.1: Calculate the average value of the solar radiation signal in each radar volume scan data, filter out the solar radiation signals below the average value, and retain 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 recognized data segments satisfy the normal distribution characteristics.

[0078] Among them, the normal distribution characteristics include: the difference between the maximum and minimum values ​​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 operating mode and speed are fixed).

[0079] Step S2.3: Based on the data segments obtained in step S2.2, calculate the true solar pitch information and the solar pitch information detected by the radar, and determine whether the difference between the true solar pitch information and the solar pitch information detected by the radar is within a reasonable range, and remove 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 actual solar pitch information and the solar pitch information detected by the radar is within the range of 0~10°, the data segment is not removed; otherwise, the data segment is removed.

[0081] Step S2.4: Find 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] The first relative azimuth, first relative pitch angle, and volume scanning time corresponding to the first solar intensity information can be determined based on the identified first solar intensity information. Each first solar intensity information corresponds to a first relative azimuth, a first relative pitch angle, and a volume scanning time.

[0083] The relative azimuth (i.e., the first relative azimuth and the second relative azimuth) and relative elevation (i.e., the first relative elevation and the second relative elevation) of this embodiment are the azimuth and elevation of solar radiation signals passively received by the radar when the signal transmission function is turned off. The absolute azimuth (i.e., the first absolute azimuth and the second absolute azimuth) and absolute elevation (i.e., the first absolute elevation and the second absolute elevation) of this embodiment are the true azimuth and true elevation of the sun calculated according to the solar azimuth and elevation calculation formula based on the radar's geographic location and the corresponding scanning time.

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

[0085] In order to ensure the accuracy and reliability of solar feature recognition, solar feature recognition is performed on multiple continuous 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 pitch angle and volume scan time; and continuity verification is performed based on the first relative azimuth angle, first relative pitch angle and volume scan time of multiple continuous radar volume scan data.

[0086] In a specific embodiment of the present invention, the continuity check is performed based on all the first relative azimuth angles, the first relative pitch angles, and the body scan time, specifically including:

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

[0088] In this embodiment, the specific operation of eliminating abnormal values ​​is: calculating the average value of all the first relative azimuth angles, and eliminating the first relative azimuth angles that are beyond the range of the average value, for example, the first relative azimuth angles that are beyond the range of ±5° of the average value; calculating the average value of all the first relative pitch angles, and eliminating the first relative pitch angles that are beyond the range of the average value, for example, the first relative pitch angles that are beyond the range of ±5° of the average value.

[0089] Step S3.2: Determine whether the amount of data obtained in step S3.1 reaches the first quantity threshold. If so, proceed to step S3.3; otherwise, the calibration fails and the calibration is exited.

[0090] In this embodiment, for 10 consecutive radar volume scan data, if the first relative azimuth angle, the first relative pitch angle and the volume scan time of at least 5 radar volume scan data can be obtained, then go to step S3.3; otherwise, the calibration fails and exits 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 pitch angle changes continuously in the correct direction. If so, the continuity check is passed.

[0092] The sun is in the southern hemisphere of the radar and moves from east to west, that is, from 90° to 180°. This process is used to determine whether the first relative azimuth angle changes continuously. The sun rises in the morning as an accumulation, and sets in the afternoon as a decrement. This process is used to determine whether the first relative elevation angle changes continuously.

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

[0094] In a specific embodiment of the present invention, the fan scanning range is (the last first relative azimuth angle ± the first angle threshold, the last first relative azimuth angle + the second angle threshold). Figure 2 As shown, considering the radar's geographical location, the sun is in the south and rises in the east and sets in the west, the second angle threshold must be greater than the first angle threshold. To ensure sufficient coverage, the first angle threshold is set to 10° and the second angle threshold is set to 20°.

[0095] Step S5: Acquire a plurality of continuous sector scan data.

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

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

[0098] Sector scan data contains a large amount of internal noise and a small amount of weak solar radiation signals. In order to perform solar feature recognition on the solar radiation signals, the internal noise in the sector scan data is first filtered out. In a specific embodiment of the present invention, solar feature recognition is performed on each sector scan data, specifically including:

[0099] Step S6.1: Calculate the average value of the solar radiation signal 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 segments satisfy the normal distribution characteristics.

[0101] Among them, the normal distribution characteristics include: the difference between the maximum and minimum values ​​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 operating mode and speed are fixed).

[0102] Step S6.3: Based on the data segments obtained in step S6.2, calculate the true solar pitch information and the solar pitch information detected by the radar, and determine whether the difference between the true solar pitch information and the solar pitch 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 actual solar pitch information and the solar pitch information detected by the radar is within the range of 0~10°, 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 characteristic signal.

[0105] The second relative azimuth angle, second relative pitch angle, and sector sweep time corresponding to the second solar intensity information can be determined based on the identified second solar intensity information. Each second solar intensity information corresponds to a second relative azimuth angle, a second relative pitch angle, and a sector sweep time.

[0106] Step S7: Perform continuity check based on all the second relative azimuth angles, second relative elevation angles and sector scan times.

[0107] In order to ensure the accuracy and reliability of solar feature identification, solar feature identification is performed on multiple consecutive fan-scan data to obtain the second solar intensity information of each fan-scan data and its corresponding second relative azimuth angle, second relative pitch angle and fan-scan time; and continuity verification is performed based on the second relative azimuth angle, second relative pitch angle and fan-scan time of multiple consecutive fan-scan data.

[0108] In a specific embodiment of the present invention, the continuity check is performed based on all the second relative azimuth angles, the second relative pitch angles, and the sector sweep time, specifically including:

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

[0110] In this embodiment, the specific operation of eliminating abnormal values ​​is: calculating the average value of all second relative azimuth angles, and eliminating second relative azimuth angles that are beyond the range of the average value, for example, second relative azimuth angles that are beyond the range of ±5° of the average value; calculating the average value of all second relative pitch angles, and eliminating second relative pitch angles that are beyond the range of the average value, for example, second relative pitch angles that are beyond the range of ±5° of the average value.

[0111] Step S7.2: Determine whether the amount of data obtained in step S7.1 reaches a second threshold value. If so, proceed to step S7.3; otherwise, the calibration fails and the calibration is exited.

[0112] In this embodiment, if the second relative azimuth angle, the second relative pitch angle and the volume scan time of at least 40 sector scan data can be obtained, then the process goes to step S7.3; otherwise, the calibration fails and the process is exited.

[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 pitch angle changes continuously in the correct direction. If so, the continuity check is passed.

[0114] The sun is in the southern hemisphere of the radar and moves from east to west, that is, from 90° to 180°. This process is used to determine whether the second relative azimuth angle changes continuously. The sun rises in the morning as an accumulation, and sets in the afternoon as a decrement. This process is used to determine whether the second relative elevation angle changes continuously.

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

[0116] In a specific embodiment of the present invention, integrity verification is performed based on all first solar intensity information and its corresponding first relative azimuth angle, first relative pitch angle, and volume scan time, as well as all second solar intensity information and its corresponding second relative azimuth angle, second relative pitch angle, and sector scan time, specifically including:

[0117] Step S8.1: Calculate the azimuth deviation and the elevation deviation based on the radar geographic location, all first relative azimuth angles, first relative elevation angles, body scan time, second relative azimuth angles, second relative elevation angles, and sector scan time.

[0118] In a specific embodiment of the present invention, the azimuth deviation and the elevation deviation are calculated based on the radar geographical location, all first relative azimuth angles, first relative elevation angles, body scan time, second relative azimuth angles, second relative elevation angles, and sector scan time, specifically including:

[0119] Step S8.11: Calculate a first absolute azimuth angle and a first absolute elevation angle according to the radar geographic location and the volume scanning 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] in, represents the time parameter, Julian day time representing the body scan time, represents the geometric mean ecliptic longitude, represents the center difference, Indicates the solar ecliptic longitude, represents right ascension, Indicates the obliquity of the ecliptic. represents declination, represents the Greenwich hour angle, Indicates universal time, represents the local hour angle, represents the radar longitude, Indicates the first absolute pitch angle; represents the radar latitude, Indicates the first absolute azimuth.

[0133] Step S8.12: Calculate a first azimuth deviation based on the first relative azimuth angle and the first absolute azimuth angle, and calculate a 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 and the first absolute azimuth is the first azimuth deviation, and the absolute value of the difference between the first relative elevation angle and the first absolute elevation angle is the first elevation deviation. Each set of first relative azimuth, first relative elevation angle, and volume scan time corresponds to one first azimuth deviation and one first elevation deviation.

[0135] Step S8.13: Calculate the second absolute azimuth angle and the second absolute elevation angle according to the radar geographic location and the sector scanning time.

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

[0137] Step S8.14: Calculate a second azimuth deviation based on the second relative azimuth angle and the second absolute azimuth angle, and calculate a 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 and the second absolute azimuth is the second azimuth deviation, and the absolute value of the difference between the second relative elevation angle and the second absolute elevation angle is the second elevation deviation. Each set of second relative azimuth, second relative elevation angle, and sector time corresponds to one second azimuth deviation and one second elevation deviation.

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

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

[0141] Figure 3 The figure shows the regular changes of the final pitch deviation. The horizontal axis represents the number of volume scans and sector scans. The change rate of the final pitch deviation is equal to the difference between the two final pitch deviations. Figure 4 A scatter plot of the final azimuth deviation is shown, where the horizontal axis represents the number of volume scans and sector scans, and the mean range of the final azimuth deviation is the mean of all final azimuth deviations ±1°.

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

[0143] If the calibration time exceeds 1 hour and the integrity check fails, the calibration is considered failed and the system will exit the calibration process. The radar will be restored to its pre-calibration state and the reason for the calibration failure will be returned.

[0144] Step S9: When the integrity check passes, the azimuth deviation and pitch deviation are calculated based on the radar's geographic location, all first relative azimuth angles, first relative pitch angles, body scan time, second relative azimuth angles, second relative pitch angles and sector scan time. For the specific calculation process, please refer to steps S8.11 to S8.15.

[0145] Step S10: performing radar calibration according to the azimuth deviation and the pitch deviation.

[0146] The formulas for calculating the true azimuth and elevation of the sun (i.e., formulas (1) to (11)) are based on precise astronomical and geographic coordinate conversion principles, fully considering factors such as the Earth's rotation and revolution, the radar's geographic location, and scanning time. By accurately calculating the true azimuth and true elevation of the sun, a stable and reliable benchmark is provided for radar antenna beam pointing calibration. As a natural calibration source with stable radiation characteristics, the precise calculation of the sun's true azimuth and elevation information provides an objective reference standard for radar calibration. During calibration, the solar azimuth and elevation information detected by the radar (i.e., relative azimuth and relative elevation) is compared with the true solar azimuth and elevation information (i.e., absolute azimuth and absolute elevation). This allows for an accurate assessment of the radar antenna's pointing deviation, providing an accurate basis for subsequent calibration adjustments.

[0147] Using the sun as the calibration radiation source, calibration is performed using formulas for calculating the sun's true azimuth and elevation, along with radar scan data. This eliminates the need to purchase and maintain expensive specialized calibration equipment. Traditional calibration methods often require the use of high-precision, specialized equipment, which is not only costly but also difficult to maintain and operate. This method only requires the radar's geographic location (longitude and latitude) and accurate scanning time. Combined with the formulas for calculating the sun's true azimuth and elevation, this method can quickly derive the sun's true azimuth and elevation, allowing calibration to proceed. This approach greatly simplifies the calibration process, lowers the technical barriers to entry, and makes calibration easier to implement and promote.

[0148] The formula for calculating the sun's true azimuth and elevation features rapid calculation speed, enabling the calculation to be completed in a short period of time. When the radar needs calibration, the radar is activated to scan and acquire solar radiation data. The detected solar azimuth and elevation are then quickly determined based on this data. Calibration is then performed using this information, significantly reducing calibration time and improving efficiency. Furthermore, because the calibration process relies solely on the radar's spatiotemporal information, it is not restricted to specific sites or equipment. Whether at a remote field weather station or a military radar base in a diverse geographic location, radar calibration can be performed anytime and anywhere, as long as accurate spatiotemporal information is available, ensuring the radar remains in optimal working condition. Furthermore, the formula supports online updates, allowing adjustments based on the latest astronomical data and geographic information to ensure the accuracy of the calculation results.

[0149] This invention enables precise calibration of the radar's pitch and azimuth angles, strictly controlling deviations to within 0.2°. This high-precision calibration significantly improves the accuracy of the radar antenna's pointing, enabling the radar to more accurately determine the target's position and motion parameters when detecting a target, thereby enhancing the radar's detection accuracy and reliability. In the field of meteorological monitoring, this technology can more accurately monitor meteorological changes, providing more reliable data support for weather forecasts. In the field of military defense, it can more accurately identify and track targets, enhancing national defense security capabilities.

[0150] A simple, easy-to-use calibration interface allows for one-click calibration on and off. Upon completion of the calibration process, the system immediately generates and displays deviation results, eliminating the need for complex manual intervention and data processing. The operational process can be flexibly optimized and automated based on different application scenarios and user needs. This not only improves efficiency and reduces human error, but also lowers the need for operator expertise, making radar calibration more convenient and efficient. Furthermore, the automated process enables remote calibration, facilitating the unified management and calibration of radars distributed across different locations.

[0151] The present invention can perform azimuth and elevation calibration corrections on radars anywhere, anytime, in sunny weather conditions. This flexibility enables radars to quickly adapt to different working environments and task requirements, adjusting their own status in a timely manner to ensure good working performance in a variety of complex situations. Whether it is minor deviations that occur during long-term operation or the need for recalibration after equipment relocation, the present invention can quickly complete calibration and ensure the stable operation of the radar system. In addition, the present invention also supports the simultaneous calibration of multiple radars, further improving calibration efficiency and management convenience.

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

[0153] Example 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 calibrated radar and the processing module, and the processing module is connected to the calibrated radar.

[0155] The receiving module is used to: receive and cache multiple continuous radar volume scan data transmitted by the radar; wherein each circle scan corresponds to one radar volume scan data; receive and cache multiple continuous 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 first solar intensity information and its corresponding first relative azimuth angle, first relative pitch angle, and volume scan time; and perform continuity verification based on all first relative azimuth angles, first relative pitch angles, and volume scan times;

[0157] When the continuity check passes, the sector scan range is determined according to the last first relative azimuth, and the radar controller controls 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 second solar intensity information and its corresponding second relative azimuth angle, second relative pitch angle, and sector scan time; perform continuity verification based on all second relative azimuth angles, second relative pitch angles, and sector scan times;

[0159] When the continuity check passes, an integrity check is performed based on all the first solar intensity information and the corresponding first relative azimuth angle and first relative pitch angle, and all the second solar intensity information and the corresponding second relative azimuth angle and second relative pitch angle;

[0160] When the integrity check passes, the azimuth deviation and elevation deviation are calculated based on the radar's geographical location, all first relative azimuth angles, first relative elevation angles, body scan time, second relative azimuth angles, second relative elevation angles, and sector scan time;

[0161] Radar calibration is performed according to the azimuth deviation and the elevation deviation.

[0162] The client is used to start or stop calibration, so that the radar controller can control the radar to start volume scanning when calibration starts.

[0163] As the entry point for radar scan data, the receiving module possesses powerful data processing and buffering capabilities, enabling rapid and stable reception of the massive amounts of radar scan data reported in real time by the radar. During data reception, the radar scan data undergoes preliminary format conversion and preprocessing to remove noise and invalid data, providing a high-quality data foundation for subsequent precise processing.

[0164] The processing module is the core control hub of the entire calibration system, responsible for client-side control of multiple radars and their coordinated operation. By utilizing advanced algorithms and intelligent scheduling strategies, it achieves unified management and coordinated operation of multiple radars. During calibration, the processing module precisely controls the radar's scanning parameters and operating mode based on client instructions and the real-time status of each radar, ensuring a smooth calibration process. Furthermore, the processing module possesses data fusion and analysis capabilities, enabling comprehensive processing of multi-radar data to enhance calibration accuracy and reliability.

[0165] The client provides users with an intuitive and convenient interface, serving as a crucial window for interaction with the system. Through the client, users can view radar monitoring data, calibration results, and other information in real time, as well as perform operations such as parameter settings and task initiation. Furthermore, the client features data visualization, displaying radar scan data and calibration results in charts and maps, allowing users to intuitively understand the radar's operating status and calibration results.

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

[0167] The present invention constructs an integrated calibration system structure 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 is responsible for the 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 users and the system, the client provides an intuitive and convenient operation interface, which not only clearly displays various key information, but also supports 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 collaboration between the various parts of the system, laying a solid foundation for the smooth implementation of radar calibration work.

[0168] The above disclosure is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, and they should all be covered by the scope of protection of the present invention.

Claims

1. A one-dimensional phased array radar calibration method, characterized in that: The calibration method comprises: Acquire multiple continuous radar volume scan data; each circle of scanning corresponds to one radar volume scan data; Performing solar feature recognition on each radar volume scan data to obtain first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle, and volume scan time; performing continuity verification based on all first relative azimuth angles, first relative elevation angles, and volume scan times; wherein the continuity verification refers to determining whether the first relative azimuth angle and the first relative elevation angle continuously change in the correct direction; When the continuity check passes, the sector scan range is determined according to the last first relative azimuth, and the radar is controlled to rotate and start sector scanning based on the sector scan range; Acquire a plurality of continuous sector scan data, wherein each reciprocating scan corresponds to two sector scan data; Perform solar feature recognition on each sector scan data to obtain second solar intensity information and its corresponding second relative azimuth angle, second relative pitch angle, and sector scan time; perform continuity verification based on all second relative azimuth angles, second relative pitch angles, and sector scan times; When the continuity check passes, the azimuth deviation and elevation deviation are calculated based on the radar's geographical location, all first relative azimuth angles, first relative elevation angles, body scan time, second relative azimuth angles, second relative elevation angles, and sector scan time; Determine whether the pitch deviation changes regularly and whether its rate of change is within its mean range, and determine whether the azimuth deviation is within its mean range. If so, the integrity check passes; When the integrity check passes, radar calibration is performed according to the azimuth deviation and the elevation deviation.

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

3. The one-dimensional phased array radar calibration method according to claim 2, characterized in that: The specific calculation process of the calibration start time is: Determine the pitch angle to start detecting according to the radar scanning mode; The binary method is used to find the time when the sun reaches the pitch angle for starting detection within a specified time range, thereby obtaining the calibration start time.

4. The one-dimensional phased array radar calibration method according to claim 1, characterized in that: Perform solar feature recognition on each radar volume scan data or sector scan data, including: Perform filtering processing on each radar volume scan data or each sector scan data; Calculate the average value of the solar radiation signal 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 meet normal distribution characteristics; Based on the identified data segments, calculating the actual solar pitch information and the solar pitch information detected by the radar; Determine whether the difference between the actual solar pitch information and the solar pitch information detected by the radar is within a reasonable range; When the difference between the actual solar pitch information and the solar pitch information detected by the radar is within a reasonable range, the maximum solar radiation signal is found from each data segment, and the maximum solar radiation signal is used 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, characterized in that: The sector scanning range is (the last first relative azimuth angle±the first angle threshold, the last first relative azimuth angle+the second angle threshold), wherein the second angle threshold is greater than the first angle threshold.

6. The one-dimensional phased array radar calibration method according to claim 5, characterized in that: 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 elevation deviation based on the radar's geographic location, all first relative azimuth angles, first relative elevation angles, body scan time, second relative azimuth angle, second relative elevation angle, and sector scan time, specifically including: Calculate a first absolute azimuth and a first absolute elevation angle according to the radar's geographic location and the scanning time; calculate a first azimuth deviation according to the first relative azimuth and the first absolute azimuth, and calculate a first elevation deviation according to the first relative elevation angle and the first absolute elevation angle; Calculate a second absolute azimuth and a second absolute elevation angle according to the radar geographic location and the sector scanning time; calculate a second azimuth deviation according to the second relative azimuth and the second absolute azimuth, and calculate a second elevation deviation according to the second relative elevation angle and the second absolute elevation angle; The final azimuth deviation is obtained by averaging all the first azimuth deviations and the second azimuth deviations; the final pitch deviation is obtained by averaging all the first pitch deviations and the second pitch deviations.

8. The one-dimensional phased array radar calibration method according to claim 7, characterized in that: The specific calculation formula of the first absolute pitch angle or the second absolute pitch angle is: ； ； in, Indicates the first absolute pitch angle or the second absolute pitch angle; Indicates the radar latitude; Indicates declination, which is calculated based on the corresponding body scan time or sector scan time; Indicates the local hour angle; represents the Greenwich hour angle; represents the radar longitude; The specific calculation formula of the first absolute azimuth angle or the second absolute azimuth angle is: ； in, Indicates the first absolute azimuth or the second absolute azimuth.

9. A one-dimensional phased array radar, characterized in that: The one-dimensional phased array radar is calibrated using the one-dimensional phased array radar calibration method according to 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: Receive and cache multiple continuous radar volume scan data transmitted by the radar; wherein each circle scan corresponds to one radar volume scan data; receive and cache multiple continuous 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 first solar intensity information and its corresponding first relative azimuth angle, first relative elevation angle, and volume scan time; performing continuity verification based on all first relative azimuth angles, first relative elevation angles, and volume scan times; wherein the continuity verification refers to determining whether the first relative azimuth angle and the first relative elevation angle continuously change in the correct direction; When the continuity check passes, the sector scan range is determined according to the last first relative azimuth, and the radar controller controls the radar to rotate and start sector scanning based on the sector scan range; Perform solar feature recognition on each sector scan data to obtain second solar intensity information and its corresponding second relative azimuth angle, second relative pitch angle, and sector scan time; perform continuity verification based on all second relative azimuth angles, second relative pitch angles, and sector scan times; When the continuity check passes, the azimuth deviation and elevation deviation are calculated based on the radar's geographical location, all first relative azimuth angles, first relative elevation angles, body scan time, second relative azimuth angles, second relative elevation angles, and sector scan time; Determine whether the pitch deviation changes regularly and whether its rate of change is within its mean range, and determine whether the azimuth deviation is within its mean range. If so, the integrity check passes; When the integrity check passes, performing radar calibration according to the azimuth deviation and the elevation deviation; The client is used to: Start or stop calibration, so that the radar controller will control the radar to start body scanning when calibration starts.

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