A target fusion method of airborne phased array radar

Abstract

The application discloses a target fusion method of airborne phased array radar and belongs to the technical field of radar signal fusion. Parameter information of each wave position when a target is detected is stored into a target cache pool, a target is taken out from the target cache pool and is set as a reference target for comparison with other targets in the target cache pool, whether the target meets a fusion condition is judged according to comparison of relative distance, azimuth angle, pitch angle and amplitude information of the target and the reference target, all targets under the same wave position meeting the fusion condition are reserved one into a fusion target pool, and other targets are deleted from the target cache pool. The application scheme detects and processes the targets under the same wave position through circulation, compares and judges the targets through setting a comparison threshold value, fuses the targets meeting the fusion condition, and reduces the possibility that the same target in the target pool is repeatedly intercepted in the interception stage.

Description

Technical Field

[0001] This invention relates to the field of radar signal fusion technology, and specifically to a target fusion method for airborne phased array radar. Background Technology

[0002] Airborne phased array radars possess technological advantages such as beam agility, multi-target tracking, and multi-functional multiplexing, making them core sensors in modern avionics systems. However, in complex electromagnetic environments, factors such as antenna pattern sidelobes, clutter residue, electronic interference, and scanning methods can cause multiple repeated detections of the same target at different wavelengths. This leads to target point redundancy and track correlation errors, severely reducing the radar system's detection performance and data reliability.

[0003] Existing radar signal fusion technology employs the following approach: scanning the field of view according to a designed wavefront sequence. After a target is detected at each wavefront, its range and angle information are saved to a target pool. Once all wavefronts have been scanned, it is confirmed whether a valid target exists in the target pool. If a target is found, it is selected for interception and tracking; otherwise, the search is repeated according to the designed wavefront sequence. In existing solutions, to ensure complete field of view coverage, the wavefront design typically considers a certain degree of overlap between adjacent wavefronts to prevent targets in the wavefront "gaps" from being missed. However, this results in targets in the overlapping areas between wavefronts being detected and saved in the target pool across multiple wavefronts. During subsequent interception of targets in the pool, the same target may be repeatedly detected, especially when there are multiple targets or multiple target tracking requirements, thus affecting detection accuracy.

[0004] Public document (CN113391274A) discloses a method for searching low-altitude targets using airborne phased array radar. Utilizing prior knowledge such as the DEM (Distributed Image Model) and takeoff / landing zone location, combined with an airborne radar search model, it eliminates the influence of ground clutter on low-altitude targets. Furthermore, by employing an intelligent optimization algorithm to optimize the search data rate for each beam position, it achieves rapid and accurate search for aerial targets. However, this method still fails to account for the problem of multiple targets with the same beam position, thus affecting the accuracy of detection.

[0005] Public document (CN121432417A) discloses a ground target elimination method, medium, and electronic equipment for low-altitude sounding using a two-dimensional phased array. It transmits a single-frame waveform composed of a spatial sounding wave and a ground sidelobe elimination wave. The detection point with the highest power is selected as the effective detection point of the spatial sounding wave, while the remaining monitoring points are identified as ground sidelobe detection points and eliminated. From the detection points of the spatial sounding wave, effective detection points with power exceeding that of the effective detection points due to ground sidelobe elimination waves are eliminated. However, this method can only eliminate sidelobe targets and cannot address the problem of the same target appearing multiple times on different wave positions. Summary of the Invention

[0006] The purpose of this invention is to propose a target fusion method for airborne phased array radar based on existing technology. This method can fuse the same target appearing on different wave positions during the search process, which solves the problem of the same target appearing repeatedly on different wave positions and meets the requirements of real-time processing.

[0007] This invention is achieved through the following technical solution:

[0008] A target fusion method for airborne phased array radar includes:

[0009] The parameter information of each wave position when the target is detected is stored in the target cache pool;

[0010] Take a target from the target cache pool and set it as a reference target for comparison with other targets in the target cache pool;

[0011] Based on the comparison of the relative distance, azimuth, pitch angle, and amplitude information between the target and the reference target, it is determined whether the target meets the fusion conditions;

[0012] All targets that meet the fusion criteria are retained in the fusion target pool, and the other targets are removed from the target cache pool.

[0013] In the above technical solution, once the reference target is retrieved from the target cache pool, it will not be returned to the target cache pool.

[0014] In the above technical solution, if the target cache pool is empty after the reference target is retrieved, the reference target is put into the fusion target pool.

[0015] In the above technical solution, all targets in the target cache pool are compared with the reference target in turn. When none of them meet the fusion conditions, the reference target is put into the fusion target pool.

[0016] In the above technical solution, when comparing a target in the cache pool with a reference target, it is determined whether the target is located in a neighboring position of the reference target:

[0017] When the target is not in a neighboring position of the reference target, the next target in the buffer pool is automatically switched for comparison with the reference target;

[0018] When the target is in a neighboring position of the reference target, the absolute value of the difference between the target parameters and the reference target parameters is taken. If the absolute value is not greater than the set threshold value, it is determined that the fusion condition is met.

[0019] In the above technical solution, the fusion conditions include:

[0020] The absolute value of the difference between the measured distances of the target and the reference target is not greater than a set threshold value.

[0021] The absolute value of the difference between the measured azimuth angles of the target and the reference target is not greater than the set threshold value.

[0022] The absolute value of the difference between the measured pitch angles of the target and the reference target is not greater than the set threshold value.

[0023] In the above technical solution, the preferred approach is that when the target is not in the vicinity of the reference target, the target is determined to be an independent target, and the target is retained in the target cache pool.

[0024] When a target meets the fusion conditions, it is removed from the target cache pool and used for fusion with the reference target.

[0025] In the above technical solutions, the preferred approach is when the target meets the fusion conditions:

[0026] If the magnitude of the target is not greater than the magnitude of the reference target, remove the target from the target cache pool;

[0027] If the magnitude of the target is greater than that of the reference target, remove the target from the target cache pool and replace it with the reference target.

[0028] In the above technical solution, during the fusion process of a wave position, when the target buffer pool is detected to be empty, the result in the fusion target pool is moved to the target buffer pool and the detection of the next wave position begins.

[0029] In the above technical solution, after all wave positions are detected, the final fusion result is contained in the fusion target pool.

[0030] In radar systems, beamwidth is defined as the angle between the two half-power points of the beam. When using amplitude-comparison angle measurement, the target angle is usually required to be within the beamwidth. Therefore, when searching and detecting within a certain field of view, to meet the angle measurement conditions and prevent the target from being missed, the scanning positions are designed to overlap to a certain extent. The higher the overlap rate, the more positions are required to scan the same field of view, which means a longer search time. Usually, an appropriate overlap rate is selected based on the search time and field of view required by the system design to ensure that the search time is not too long while guaranteeing full coverage of the field of view. However, position overlap means that when the target angle is at the point of overlap between adjacent positions, it will be detected in multiple positions, resulting in a target appearing multiple times in the detection results when the search is completed.

[0031] The principle of the technical solution of this invention is that whenever a target is detected by a wave position during the search, it is first saved to the target pool, and a target fusion operation is performed. The same target that appears multiple times in the target pool is fused according to whether the targets in the target pool are adjacent wave positions and whether the spatial relationship corresponding to the measurement information is less than a certain threshold.

[0032] This invention is executed when a target is detected at each wave position, which solves the problem of multiple detections of the same target caused by beam overlap and avoids the problem of long computation time caused by too many accumulated targets when all wave position searches are completed.

[0033] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0034] This application's solution detects and processes targets under the same wave position in a loop. By setting a comparison threshold, it continuously compares and judges the targets that meet the criteria for fusion, and then fuses them, thereby reducing the possibility of the same target in the target pool being repeatedly intercepted when entering the interception stage.

[0035] Multi-wavelength joint processing, through correlation judgment of neighboring wavelengths, enables effective identification of repeating targets across wavelengths, improving fusion coverage; multi-parameter joint judgment, by fusing multi-dimensional information such as range, azimuth, elevation, and amplitude, improves the accuracy of fusion judgment; dynamic updating of reference targets through amplitude comparison effectively eliminates false targets caused by sidelobe false targets and clutter residue, improving the reliability of target detection; and the use of single-pass fusion logic loop processing reduces algorithm complexity and meets the performance requirements of real-time processing of airborne radar. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0037] Figure 1 This is a flowchart illustrating the existing technology.

[0038] Figure 2 This is a flowchart illustrating the technology of this solution;

[0039] Figure 3 A flowchart illustrating the process for determining fusion conditions;

[0040] Figure 4 A flowchart illustrating the fusion conditions;

[0041] Figure 5This is a schematic diagram of the radar scanning range wave position design in this embodiment. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0043] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0044] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0045] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features for a similar purpose, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0046] like Figure 1The diagram illustrates the process flow of the prior art. In the prior art, after system startup, it first enters a wave position traversal search mode, sequentially scanning the signal space according to a preset wave position division. Each wave position scan verifies the existence of a target signal matching the characteristics. If a signal is found, it is automatically stored in the target pool for information archiving. If no signal is found, the system directly enters the search phase for judgment. After a single wave position is detected, it checks whether all preset wave positions have been scanned. If not, it returns to the search phase to continue detecting the next wave position, achieving full-range traversal. After the full wave position scan is completed, it checks whether the target pool has a valid record. If no valid target is found, a new round of search is restarted to ensure continuous detection. If a target exists, the system enters the final interception phase, sorting the multi-source target information in the target pool by confidence and priority, selecting the optimal target, and then performing the final interception operation to complete the entire closed-loop process.

[0047] This implementation example Figure 2 As shown, the specific process is as follows:

[0048] S1: Target parameter cache

[0049] When a target is detected at each wave position, the measured target parameters, including distance, azimuth, elevation, amplitude information, wave position number, and adjacent wave position numbers, are stored at the beginning of the target cache pool. The target cache pool uses a dynamic linked list structure for storage, supporting fast target insertion, query, and deletion operations.

[0050] S2: Verify the selection of the reference target and whether the cache pool is empty.

[0051] A target is retrieved from the target cache pool and set as a reference target. This reference target is used for comparison with other targets in the target cache pool, and once retrieved, it will not be returned to the target cache pool. The target that appears first in the target cache pool is preferentially selected as the initial reference target.

[0052] If the target cache pool is empty after retrieving the reference target, the reference target is moved to the merged target pool, such as... Figure 3 As shown.

[0053] If there are still other targets in the target cache pool after the reference target is retrieved, then traverse the remaining targets in the target cache pool.

[0054] S3: Traverse the targets in the cached target pool and determine their relevance.

[0055] During the traversal, the remaining targets in the target cache pool are compared with the reference target in turn, and it is determined whether the target is in the vicinity of the reference target based on each comparison.

[0056] When the target is not in the vicinity of the reference target, automatically switch to the next target in the target buffer pool;

[0057] When the target is in a neighboring position to the reference target, compare the absolute values ​​of the differences in measured distance, azimuth, and elevation angles between the target and the reference target to see if they are all greater than a set threshold. If all are satisfied, then the conditions for fusion between the target and the reference target are met. Figure 3 As shown.

[0058] The rules for determining adjacent positions are as follows: the azimuth difference between the position of the target and the position of the reference target is no greater than 1 position beamwidth, and the elevation difference is no greater than 1 position beamwidth. This range covers the main lobe overlap area during phased array radar beam scanning, ensuring that cross-position repeating targets can be included in the fusion decision range.

[0059] S4: Calculate the fusion conditions and perform fusion processing, such as... Figure 4 As shown,

[0060] When the fusion conditions are not met, it means that the target and the reference target are independent targets. Therefore, both the target and the reference target are kept in the target cache pool.

[0061] When the fusion condition is met, if the amplitude of the current target is not greater than the amplitude of the reference target, it means that the target used for comparison may be the same target detected by the residual wave position and the same target as the reference target. The target used for comparison will be deleted from the target cache pool.

[0062] When the fusion conditions are met, if the amplitude of the current target is greater than that of the reference target, it means that the reference target may be the same target detected by the residual wave position as the target used for comparison. The target used for comparison will replace the reference target and will be deleted from the target cache pool.

[0063] S5: Operate based on the number of targets in the target cache pool;

[0064] If the target cache pool is empty after the current target is deleted from the target cache pool, it means that the target traversal is complete, and then proceed to the next step.

[0065] After deleting the current target from the target cache pool, if the target cache pool is not empty, return to S3 to continue traversing.

[0066] S6: Reference target entry

[0067] After merging, if the target cache pool is not empty, return to S2 and determine a new reference target for a new round of traversal;

[0068] After fusion, if the target cache pool is empty, it means that all traversal has been completed. Save the reference target to the final fusion target pool and proceed to the next step.

[0069] S7: Output Results

[0070] Move the structures in the target pool to the target cache pool, ready for use during the next wavelet detection.

[0071] After all wave positions have been detected and fused, the targets stored in the fusion target pool are the final fusion results. Example 1

[0072] Three targets were set: target one at a distance of 3500m, azimuth 0°, and elevation 0°; target two at a distance of 3510m, azimuth -1.63°, and elevation 0°; and target three at a distance of 3495m, azimuth 1.63°, and elevation 0°.

[0073] like Figure 5 As shown in the figure below, the scanning range and wave position design are as follows. Each red circle represents a wave position, with a total of 91 wave positions. The beamwidth is 1.6°, the scanning range is ±5° in both azimuth and elevation, the overlap rate of adjacent wave positions is 28.5%, and the number at the center of the wave position represents the scanning order. The fusion distance threshold is set to DIST_THRESHOLD=10m, and the fusion angle threshold is set to ANGLE_THRESHOLD=0.8°.

[0074] Based on the wave position design, the neighboring wave positions for each wave position number can be listed as follows:

[0075]

[0076] With target 1 as the center of the field of view, the target information and corresponding wavelet numbers after the search is completed without fusion are shown in the table below:

[0077]

[0078] As can be seen from the table, Target 1, Target 2, and Target 3 appeared multiple times at different wave positions.

[0079] Target 1 was found using wave position 1. ( middle, Indicates the target sequence number. (Indicates the wavelet index), which is then stored in the target cache pool. At this point, the target cache pool contains only target one. After retrieving it as the reference target, the target cache pool becomes empty. Therefore, the target is saved to the fusion target pool. End the fusion process and move the results from the target pool to the target cache pool. .

[0080] Wave position 2 search found target three Store it in the target cache pool. Retrieve the first target from the target cache pool as the reference target. At this time, in the target cache pool .

[0081] Retrieve the target from the target cache pool for comparison. At this time, the neighboring positions of the reference target are [1,3,7,8,9,19]. The target sel used for comparison is at position 1, which is the neighboring position of the reference target, so the fusion condition decision is made.

[0082] Since abs(ref.azi-sel.azi)=|1.579-(-0.006)|=1.585°>ANGLE_THRESHOLD=0.8°, the fusion condition is not met.

[0083] At this point, the target cache pool traversal is complete, and the reference target is saved to the fusion target pool. .

[0084] At this time, the target cache pool only contains target one. If the target cache pool is empty after retrieving it as a reference target, then the target is saved to the fusion target pool. End the fusion process and move the results from the target pool to the target cache pool. .

[0085] Wave position 3 found target one again Store it in the target cache pool. Retrieve the first target from the target cache pool as the reference target. At this time, the target cache pool .

[0086] Retrieve the target from the target cache pool for comparison. At this time, the neighboring positions of the reference target are [1, 2, 4, 9, 10, 11]. The target sel used for comparison is at position 2, which is the neighboring position of the reference target. Then, the fusion condition decision is made.

[0087] Since abs(ref.azi-sel.azi) = |0.234-1.579| = 1.345° > ANGLE_THRESHOLD = 0.8°, the fusion condition is not met.

[0088] Retrieve the target from the target cache pool for comparison. If the target sel used for comparison is at wave position 1, which is a neighboring wave position of the reference target, then a fusion condition decision is made.

[0089] Since abs(ref.dist-sel.dist)=0≤DIST_THRESHOLD, abs(ref.azi-sel.azi)=|0.234-(-0.006)|=0.24°≤ANGLE_THRESHOLD=0.8°, and abs(ref.ele-sel.ele)= |-0.04-(-0.003)|=0.037°≤ANGLE_THRESHOLD=0.8° satisfy the fusion conditions, and the target amplitude used for comparison (79.83dBm) is greater than the reference target amplitude (70.70dBm), the comparison target is used instead of the reference target. Remove the target from the target cache pool. .

[0090] After the reference target changes, the process is re-traversed according to the above logic, and the final target cache pool is updated. .

[0091] Each wavelet is processed as described above. When all wavelets are completed, the target pool is merged. .

[0092] The target information and corresponding wavelet numbers after fusion are shown below:

[0093]

[0094] As can be seen, after target fusion, the same target in different wave positions is merged together, and the final fused target pool contains only three different targets.

[0095] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A target fusion method for an airborne phased array radar, characterized in that... include: The parameter information of each wave position when the target is detected is stored in the target cache pool; Take a target from the target cache pool and set it as a reference target for comparison with other targets in the target cache pool; Based on the comparison of the relative distance, azimuth, pitch angle, and amplitude information between the target and the reference target, it is determined whether the target meets the fusion conditions; All targets that meet the fusion criteria are retained in the fusion target pool, and the other targets are removed from the target cache pool.

2. The target fusion method for an airborne phased array radar according to claim 1, characterized in that: Once the reference target is retrieved from the target cache pool, it will not be returned to the target cache pool.

3. The target fusion method for an airborne phased array radar according to claim 2, characterized in that: If the target cache pool is empty after the reference target is retrieved, the reference target is then placed into the fusion target pool.

4. The target fusion method for an airborne phased array radar according to claim 2, characterized in that: All targets in the target cache pool are compared with the reference target in turn. If none of them meet the fusion conditions, the reference target is put into the fusion target pool.

5. The target fusion method for an airborne phased array radar according to claim 1, characterized in that: When comparing a target in the cache pool with a reference target, determine whether the target is located in a neighboring position of the reference target: When the target is not in a neighboring position of the reference target, the next target in the buffer pool is automatically switched for comparison with the reference target; When the target is in a neighboring position of the reference target, the absolute value of the difference between the target parameters and the reference target parameters is taken. If the absolute value is not greater than the set threshold value, it is determined that the fusion condition is met.

6. The target fusion method for an airborne phased array radar according to claim 5, characterized in that... The fusion conditions include: The absolute value of the difference between the measured distances of the target and the reference target is not greater than a set threshold value. The absolute value of the difference between the measured azimuth angles of the target and the reference target is not greater than the set threshold value. The absolute value of the difference between the measured pitch angles of the target and the reference target is not greater than the set threshold value.

7. The target fusion method for an airborne phased array radar according to claim 5, characterized in that: When a target is not in the vicinity of the reference target, it is determined that the target is an independent target and is retained in the target cache pool. When a target meets the fusion conditions, it is removed from the target cache pool and used for fusion with the reference target.

8. A target fusion method for an airborne phased array radar according to claim 5, characterized in that... When the target meets the fusion conditions: If the magnitude of the target is not greater than the magnitude of the reference target, remove the target from the target cache pool; If the magnitude of the target is greater than that of the reference target, remove the target from the target cache pool and replace it with the reference target.

9. A target fusion method for an airborne phased array radar according to claim 1, characterized in that... During the fusion process of a wave position, when the target buffer pool is detected to be empty, the result in the fusion target pool is moved to the target buffer pool, and the detection of the next wave position begins.

10. A target fusion method for an airborne phased array radar according to claim 9, characterized in that: After all wave positions have been detected, the final fusion result is displayed in the fusion target pool.

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