Radar clutter trace point screening method and system using target short-time motion characteristics

Abstract

The invention belongs to the technical field of radars, and discloses a radar clutter trace point screening method using target short-time motion characteristics. The invention provides a radar clutter trace point screening method based on target motion characteristic parameter constraint and a short-time stability principle from trace point layer research on the basis that target motion generally has continuous and stable space-time relevance and clutter trace points appear randomly. According to the method, a set of clutter trace point screening method rules is provided based on target motion characteristic parameter constraints and short-term stability of target motion by only utilizing time and position basic information carried by trace points, clutter trace points can be effectively eliminated in a dense clutter background, target trace points can be effectively extracted, and the target trace points can be effectively extracted. And an effective technical support is provided for radar weak target detection and tracking under the clutter background.

Description

Technical Field

[0001] The invention belongs to the field of radar technology, and in particular relates to a radar clutter point trace screening method and system using target short-term motion characteristics. Background Art

[0002] When radar works in a ground or sea environment, it is inevitable that it will be affected by ground and sea clutter during target detection and tracking. Traditional radar clutter suppression algorithms are mainly concentrated in the field of signal processing. The most classic algorithm is to use Doppler processing to separate clutter and target echoes in the frequency domain. However, when the clutter spectrum is severely broadened and the target echo Doppler overlaps with the clutter Doppler spectrum, this classic Doppler processing method has little effect. In particular, modern radars generally adopt high-resolution system design to improve fine detection capabilities, which leads to obvious non-Gaussianity in the statistical characteristics of clutter. It is difficult to completely solve the problem by performing clutter suppression processing at the signal processing level.

[0003] The suppression of clutter should cover the whole process of radar signal processing and data processing as well as target reception, processing, detection and tracking. Among them, clutter suppression processing at the point level has important research value. The biggest advantage of clutter suppression based on point traces is its strong universality. The clutter suppression algorithm based solely on point traces can be separated from the individual application requirements of radar equipment such as radar system, signal waveform, radar signal processing and target detection method, and it is easy to apply in engineering implementation and has great promotion value. However, the biggest difficulty in clutter suppression based on the point trace level is that the available information is very limited, which is also the main reason for the lack of related research. Since the echo signal has been processed, threshold detected and point trace condensed, the information that can be used mainly includes the amplitude and position of the point trace. Some radars can also obtain the Doppler frequency shift information of the point trace.

[0004] The existing technology has the following main technical problems in industrial application: 1. The accuracy of clutter point removal is insufficient The existing technology has insufficient accuracy in screening out target points in complex environments (such as strong clutter interference or multi-target scenes). The traditional CFAR (Constant False Alarm Rate) detection algorithm is prone to false alarms in strong clutter backgrounds and cannot effectively distinguish target points from clutter points. In addition, since clutter usually has randomness and irregular motion characteristics, it is difficult for traditional methods to completely eliminate irregular clutter when processing clutter points, resulting in low accuracy and reliability of target detection.

[0005] 2. Failure to fully utilize the short-term motion characteristics of the target Most existing technologies focus on the detection and analysis of single frames or single points, but fail to make full use of the continuous motion characteristics of the target in a short period of time (such as speed, acceleration, steering angle, etc.), making it difficult to distinguish the motion patterns of the target and clutter. The lack of time domain analysis of the target's continuous trajectory can easily misjudge clutter in a short period of time as target points, thereby reducing the screening accuracy.

[0006] 3. Lack of real-time processing capabilities for dynamic parameters The radar system has limited computing resources for real-time processing, and the algorithms for selecting target points in existing technologies often have high complexity requirements, involving a large amount of data processing and multi-dimensional parameter analysis. When processing dynamic parameters (such as radial velocity and instantaneous steering angle), the traditional methods are not efficient enough, making it difficult to quickly complete point selection in radar scenarios with high real-time requirements, affecting the real-time performance and accuracy of target tracking.

[0007] 4. Poor adaptability to target types Existing technologies lack versatility when dealing with different types of targets. Some methods are optimized for specific target types (such as fixed-wing aircraft or ground targets), but cannot cope with complex scenarios with diverse target types (such as drones, missiles, etc.). Especially in the point trace recognition of small fast targets and low, slow and small targets, existing technologies are prone to missed detection or false detection, affecting the overall detection capability.

[0008] 5. Insufficient adaptability to highly dynamic environments In radar observation scenarios, high-dynamic environments (such as strong wind interference, platform shaking, target mutations, etc.) have a significant impact on the continuity and stability of point traces, and existing technologies perform poorly in such environments. It is difficult for point trace recognition algorithms in high-dynamic environments to quickly adjust parameters or adapt to environmental changes, resulting in an increase in the misjudgment rate.

[0009] 6. Lack of ability to integrate multi-source information Most existing technologies rely on single radar echo information for point screening, ignoring the fusion of other sensors (such as photoelectric, infrared) or multi-radar information. The defects of a single information source can easily lead to a decrease in detection accuracy, especially in the case of complex clutter background, the ability to accurately identify the target is severely limited.

[0010] The above technical problems show that the existing technology has limited effect on filtering out clutter points in industrial applications, especially in complex environments, with high real-time requirements, and multi-target scenes. In response to these problems, the present invention significantly improves the accuracy and robustness of point screening by introducing target short-term motion characteristics and multi-layer screening constraints, and has broader application prospects in complex environments. Summary of the invention

[0011] In view of the problems existing in the prior art, the present invention provides a radar clutter point trace screening method using the short-term motion characteristics of the target.

[0012] The present invention is achieved in that a radar clutter point trace screening method utilizing the short-term motion characteristics of a target comprises: Step 1, through a low threshold pre-detector, CFAR detection and agglomeration processing to obtain the original point trace data set; The original point trace data set obtained by radar observation in the nth frame is: (1) in, Indicates the nth frame A dot trace, Respectively represent the amplitude, time, slant range, azimuth, pitch and Doppler information corresponding to the point trace, The total number of original points observed by the radar in this frame; Step 2, coordinate transformation; find and satisfy the velocity and acceleration constraints for three consecutive frames; Step 3, radial velocity screening; Step 4, instantaneous steering angle constraint; Step 5, motion characteristic stability.

[0013] Further, the coordinate conversion: Considering the point screening problem in the Cartesian coordinate system, we first convert the point coordinates from polar coordinates to plane rectangular coordinates. (2).

[0014] Furthermore, the three consecutive frames find and satisfy the velocity and acceleration constraints: For three consecutive frames of traces ,in , , , calculate the speed and acceleration of the short track composed of the point track pair, and it is required to satisfy (5) in, are the front speed, rear speed and acceleration of the point pair respectively; assuming that the target satisfies the uniform acceleration (CA) assumption in a short period of time, the speed and acceleration of the point pair can be calculated using the following formula (6) (7) (8) in, , , .

[0015] Further, the radial velocity screening: For the current point to be filtered , according to the classical theoretical formula , calculate the corresponding Doppler velocity ; Estimate the time interval weighted average velocity vector of the point track (9) Calculate radial velocity (10) In the formula, For dot trace The position vector of It means to find the inner product; Compliance judgment like , then the judgment is the clutter point trace, and the point trace is be eliminated, among which Filter threshold for radial velocity.

[0016] Furthermore, the instantaneous steering angle constraint condition is: For the point trace pairs that pass the speed, acceleration and Doppler conformity screening, the maximum allowable steering angle constraint is set according to the short-term stability principle of the target motion characteristics to further screen the clutter point traces. (11) in represents the inner product, is the maximum permissible target short-term steering angle.

[0017] Furthermore, the motion characteristic stability: After the above screening, for the points after screening , connected with it and More than one; for the same or , there are also multiple To ensure the uniqueness of the point trace pair, the optimal selection is made based on the minimum criterion of relative velocity fluctuation. The specific optimization method is described as follows: (12) Result Output Output the filtered traces to the radar data processor. The new traces are vector traces, which contain the average time, average position, average speed, estimated acceleration and quality index value corresponding to the filtered traces after fitting. The appearance time and fitting position of the new traces can be calculated according to the following formulas: (13) (14) The average velocity and estimated acceleration are given by equation (9) and equation (8).

[0018] Another object of the present invention is to provide a radar clutter point trace screening system using target short-term motion characteristics, comprising: The data set acquisition module is used to obtain the original point trace data set through a low threshold pre-detector, CFAR detection and agglomeration processing; Transformation module, used for coordinate transformation; Screening module, which finds and satisfies velocity and acceleration constraints in three consecutive frames; used for radial velocity screening; Constraint module, used for instantaneous steering angle constraints; Stabilization module, used for motion characteristic stability.

[0019] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the radar clutter point trace screening method using the short-term motion characteristics of the target.

[0020] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to perform the steps of the radar clutter point trace screening method using the short-term motion characteristics of the target.

[0021] Another object of the present invention is to provide an information data processing terminal, which is used to implement the radar clutter point trace screening system using the short-term motion characteristics of the target.

[0022] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows: First, traditional clutter suppression processing is mainly concentrated in the radar signal processing link, and clutter is suppressed at the signal level and the target signal is enhanced through technologies such as moving target processing and multi-dimensional feature processing. This type of technology can effectively utilize the rich information carried by the echo signal to achieve a better clutter suppression effect, but it has the disadvantages of high requirements for computing resources, difficulty in engineering implementation and difficulty in application and promotion. Clutter suppression is carried out at the point trace level, mainly by screening the original point traces that pass the threshold. Due to the point trace link, a lot of information related to the target clutter has been lost, and it is very difficult to identify clutter or target point traces. This is also the main reason why the clutter suppression technology at the point trace level has not been fully developed in the past. The present invention is based on the fact that the target motion has a continuous and stable motion characteristic in a continuous short time period, while the false short track formed by the clutter point trace presents a significant random jump. From the point trace level, a radar clutter point trace screening method based on the constraint of target motion characteristic parameters and its short-term stability principle is proposed. Using only the basic information of time and position carried by the traces, a set of clutter point removal method rules was proposed based on the constraints of target motion characteristic parameters and the short-term stability of target motion. The clutter points can be effectively removed and the target traces can be extracted under dense clutter background, providing effective technical support for radar weak target detection and tracking under clutter background.

[0023] Second, the expected benefits and commercial value of the technical solution of the present invention after transformation are as follows: Through the application of the present invention in the radar data processing link, the radar's weak target detection and tracking capabilities in dense clutter can be significantly improved, which is conducive to the improvement of target detection effects in complex land and sea clutter environments, making radar systems and radar equipment more adaptable to complex environments. Since this technology performs clutter suppression at the point level and does not rely on specific radar systems and equipment models, it is easy to implement in engineering and has great potential for technology promotion.

[0024] The technical solution of the present invention overcomes technical prejudice: The present invention overcomes the traditional technical prejudice that the point trace level cannot effectively identify clutter / target point trace features, and successfully opens up a new technical path for filtering clutter points using only basic point trace information such as position and time, providing a new idea and method for promoting clutter suppression processing at the point trace level at home and abroad. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention provides a flow chart of a radar clutter point removal method using target short-term motion characteristics.

[0026] Figure 2 The present invention provides a block diagram of a radar clutter point removal system using short-term target motion characteristics.

[0027] Figure 3 It is a schematic diagram of the pre-detection and point trace screening structure provided by an embodiment of the present invention.

[0028] Figure 4 It is a schematic diagram of target point track and clutter point track provided by an embodiment of the present invention.

[0029] Figure 5 It is a basic flow chart of the algorithm provided by the embodiment of the present invention.

[0030] Figure 6 This is a diagram verifying the effect of the algorithm provided by the embodiment of the present invention using actual measured data. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] like Figure 1 As shown, a radar clutter point trace screening method using the short-term motion characteristics of a target provided by an embodiment of the present invention comprises the following steps: S101, through a low threshold pre-detector, CFAR detection and agglomeration processing to obtain the original point trace data set; The original point trace data set obtained by radar observation in the nth frame is: (1) in, Indicates the nth frame A dot trace, Respectively represent the amplitude, time, slant range, azimuth, pitch and Doppler information corresponding to the point trace, is the total number of original traces observed by the radar in the nth frame; S102, coordinate conversion; S103 Find and satisfy the velocity and acceleration constraints for three consecutive frames; S104, radial velocity screening; S105, instantaneous steering angle constraint condition; S106, motion characteristic stability.

[0033] 1. Obtaining the original point data set (step S101) The method of the present invention performs preliminary detection on radar echo data through a low threshold pre-detector, detects echo signals in background clutter using a constant false alarm rate (CFAR) algorithm, and forms a point trace set by agglomeration of the detected point trace data. Each point trace contains its amplitude, time, slant range, azimuth, pitch angle, and Doppler information. The purpose of the preliminary detection is to retain the point traces of all potential targets as much as possible while suppressing excessive clutter interference, so as to provide a complete data basis for subsequent screening steps.

[0034] 2. Coordinate transformation and short-term motion constraints (steps S102-S103) In the radar observation process, the original point traces are usually expressed in the form of radar polar coordinates. In order to facilitate the analysis of target motion characteristics, the original point traces are converted from polar coordinates (slant range, azimuth, pitch) to position coordinates (x, y, z) in the Cartesian rectangular coordinate system. After completing the coordinate conversion, the point traces are preliminarily screened based on the velocity and acceleration constraints of the point traces in the time series through three consecutive frames of data detection. Specifically, by detecting the short-term continuity of the target motion trajectory, the point traces that do not conform to the radar working scene are excluded, and the point traces that conform to the actual target motion characteristics are retained.

[0035] 3. Radial velocity screening (step S104) The radial velocity information of the trace is directly obtained from the Doppler frequency shift. According to the target motion characteristics, a reasonable velocity threshold range is set to filter the radial velocity in the trace. For stationary or slowly moving clutter traces (such as ground clutter), the radial velocity is close to zero or exceeds the set range. Such traces are excluded through velocity screening. For high-speed moving traces, further verification is performed to see whether they meet reasonable acceleration and instantaneous steering characteristics. This step effectively eliminates static clutter and improves the accuracy of trace screening.

[0036] 4. Instantaneous steering angle and motion characteristics stability (steps S105-S106) Combined with the position information of the traces in the three frames of data, the trend of its instantaneous steering angle change is calculated, and the traces that meet the real motion characteristics of the target are screened. For example, for high-speed flying targets, the steering angle change should be smooth, while the instantaneous steering angle of clutter usually shows drastic changes or discontinuities. Finally, by calculating the stability of the motion characteristics, the time series volatility of the velocity, acceleration, steering angle and other parameters of the traces is comprehensively evaluated to screen out the traces that do not meet the motion stability. This process ensures that the remaining traces can truly reflect the motion laws of the target, and finally forms a highly reliable target trace set.

[0037] Through the above steps, the method of the present invention effectively utilizes the short-term motion characteristics of the target, separates the clutter point traces from the target point traces, and improves the target detection and tracking performance of the radar system in complex environments.

[0038] Coordinate conversion provided by the embodiment of the present invention: Considering the point screening problem in the Cartesian coordinate system, we first convert the point coordinates from polar coordinates to plane rectangular coordinates. , (2).

[0039] The embodiment of the present invention provides three consecutive frames to find and satisfy the speed and acceleration constraints: For three consecutive frames of traces ,in , , , calculate the speed and acceleration of the short track composed of the point track pair, and it is required to satisfy (5) in, are the front speed, rear speed and acceleration of the point pair respectively; assuming that the target satisfies the uniform acceleration (CA) assumption in a short period of time, the speed and acceleration of the point pair can be calculated using the following formula (6) (7) (8) in, , , .

[0040] Radial velocity screening provided by the embodiment of the present invention: For the current point to be filtered , according to the classical theoretical formula , calculate the corresponding Doppler velocity ; Estimate the time interval weighted average velocity vector of the point track (9) Calculate radial velocity (10) In the formula, For dot trace The position vector of It means to find the inner product; Compliance judgment like , then the judgment is the clutter point trace, and the point trace is be eliminated, among which Filter threshold for radial velocity.

[0041] The instantaneous steering angle constraint conditions provided by the embodiment of the present invention are: For the point trace pairs that pass the speed, acceleration and Doppler conformity screening, the maximum allowable steering angle constraint is set according to the short-term stability principle of the target motion characteristics to further screen the clutter point traces. (11) in represents the inner product, is the maximum permissible target short-term steering angle.

[0042] The stability of the motion characteristics provided by the embodiment of the present invention is: After the above screening, for the points after screening , connected with it and More than one; for the same or , there are also multiple To ensure the uniqueness of the point trace pair, the optimal selection is made based on the minimum criterion of relative velocity fluctuation. The specific optimization method is described as follows: (12) Result Output Output the filtered traces to the radar data processor. The new traces are vector traces, which contain the average time, average position, average speed, estimated acceleration and quality index value corresponding to the filtered traces after fitting. The appearance time and fitting position of the new traces can be calculated according to the following formulas: (13) (14) The average velocity and estimated acceleration are given by equation (9) and equation (8).

[0043] like Figure 2 As shown, a radar clutter point trace screening system using target short-term motion characteristics provided by an embodiment of the present invention includes: The data set acquisition module is used to obtain the original point trace data set through a low threshold pre-detector, CFAR detection and agglomeration processing; Transformation module, used for coordinate transformation; Screening module, which finds and satisfies velocity and acceleration constraints in three consecutive frames; used for radial velocity screening; Constraint module, used for instantaneous steering angle constraints; Stabilization module, used for motion characteristic stability.

[0044] 1. Working principle of dataset acquisition and processing module The data set acquisition module performs preliminary detection through a low threshold pre-detector, and processes the radar echo data in combination with the constant false alarm rate (CFAR) algorithm to extract the original point data containing the target. Subsequently, the discrete point data are merged using the condensation processing technology to form a point data set with higher reliability and integrity. Each point includes information such as amplitude, time, slant range, azimuth, pitch and Doppler, providing a data basis for subsequent coordinate conversion and feature screening.

[0045] 2. Working principle of coordinate transformation module The coordinate conversion module converts the original point trace from polar coordinates (slant range, azimuth, pitch) to position coordinates (x, y, z) in the Cartesian rectangular coordinate system. This conversion facilitates the analysis of the target's motion trajectory characteristics, while supporting further geometric calculations and feature screening. Through this module, the representation of point trace data is expanded from single-frame static information to three-dimensional spatiotemporal features, providing a dynamic analysis basis for the screening module.

[0046] 3. Working principle of the screening and constraint module The screening module analyzes the motion characteristics of three consecutive frames of point trace data, and screens out points that do not conform to the target motion law based on the constraints of speed and acceleration. For points that meet the constraints, the constraint module further performs constraint analysis by calculating their instantaneous steering angle change trend. The steering angle change should be smooth. If a drastic change or discontinuous point trace is detected, it is determined to be clutter and removed. Through multi-level constraints, the screening module can accurately distinguish target points from environmental clutter.

[0047] 4. Working principle of the motion characteristic stabilization module The motion characteristic stabilization module comprehensively evaluates the volatility of motion parameters such as velocity, acceleration, steering angle, etc. of the point traces in the time series, and selects the point traces with stable motion characteristics. Based on the statistical characteristics of the motion parameters, this module removes the points with large randomness, while retaining the points that conform to the motion law of the real target. The core of the stabilization module is to verify the consistency of the motion characteristics, so as to finally generate a high-reliability target point trace set, providing strong support for radar target detection and tracking.

[0048] Through the collaborative work of the above modules, the method of the present invention can effectively utilize the short-term motion characteristics of the target, extract the real target point traces from the complex clutter, and enhance the target recognition and tracking capabilities of the radar system in a dynamic environment. This working principle ensures the efficiency and accuracy of the present invention.

[0049] The present invention is specifically implemented: Assuming that the Figure 3 The detector structure shown in the figure, after the radar received signal is processed, it first passes through a low threshold pre-detector, and then undergoes CFAR detection and condensation processing to obtain the original point trace data set. The original point trace data set obtained by the radar n-th frame observation is denoted as (1) in, Indicates the nth frame A dot trace, Respectively represent the amplitude, time, slant range, azimuth, pitch and Doppler information corresponding to the point trace, is the total number of original traces observed by the radar in this frame. To ensure that low observable targets can be detected smoothly, the CFAR detection threshold of the pre-detector should be low enough to ensure that the weak targets to be detected can pass the pre-detection with a high probability of discovery. As a result, it is inevitable that there will be a large number of false traces caused by clutter in the original trace data set.

[0050] like Figure 4 The figure shows a schematic diagram of a target track. It can be seen from the figure that the target meets specific regularity constraints in time and space. First, due to the use of a lower primary detection threshold, the target point track is more able to meet the multi-frame continuous detection conditions than the clutter point track; second, whether it is an aerial target, a sea target, or a ground target, there are specific kinematic parameter constraints, such as the maximum expected velocity, the maximum expected acceleration, etc., and for a radar with Doppler measurement capability, there is a corresponding relationship between the target Doppler obtained by instantaneous measurement and the radial distance change rate; third, depending on the specific target type and radar data rate, there are certain constraints on the target's instantaneous turning angle; fourth, the long-term track of the target is localized, and within a shorter observation time, it can be assumed that the target's motion characteristics are stable.

[0051] Therefore, the present invention proposes to perform point trace screening in the original point trace data set based on criteria such as continuous 3-frame discovery, maximum expected speed and acceleration, Doppler speed conformity, maximum instantaneous steering angle, and minimum motion speed fluctuation, so as to eliminate clutter point traces and retain target point traces, thereby providing a better input point trace environment for the formation and maintenance of subsequent radar tracks.

[0052] 3 Algorithm Flow Assuming that the frame to be filtered is the nth frame, the original trace data of the current frame and the previous and next frames are comprehensively used for trace filtering. The specific algorithm flow is described as follows: Coordinate transformation Considering the point screening problem in the Cartesian coordinate system, we first convert the point coordinates from polar coordinates to plane rectangular coordinates. (2) (2) Find and satisfy the velocity and acceleration constraints for three consecutive frames.

[0053] For three consecutive frames of traces ,in , , , calculate the speed and acceleration of the short track composed of the point track pair, and it is required to satisfy (5) in, are the front speed, rear speed and acceleration of the point pair respectively. Assuming that the target satisfies the uniform acceleration (CA) assumption in a short period of time, the speed and acceleration of the point pair can be calculated using the following formula: (6) (7) (8) in, , , .

[0054] (3) Radial velocity screening For coherent radars with Doppler measurement capabilities, the Doppler frequency shift directly measured by the radar can be used to convert the radial velocity information corresponding to the current point track, and then compared with the distance change rate of the currently obtained point track pair to further suppress clutter point tracks. The specific method is: For the current point to be filtered , according to the classical theoretical formula , calculate the corresponding Doppler velocity ; Estimate the time interval weighted average velocity vector of the point track (9) Calculate radial velocity (10) In the formula, For dot trace The position vector of It means to find the inner product.

[0055] Compliance judgment like , then the judgment is the clutter point trace, and the point trace is be eliminated, among which Filter threshold for radial velocity.

[0056] (4) Instantaneous steering angle constraints For the point trace pairs that pass the speed, acceleration and Doppler conformity screening, the maximum allowable steering angle constraint is set according to the short-term stability principle of the target motion characteristics to further screen the clutter point traces. (11) in represents the inner product, is the maximum permissible target short-term steering angle.

[0057] (5) Stability of motion characteristics After the above screening, for the points after screening , connected with it and More than one; for the same or , there are also multiple To ensure the uniqueness of the point trace pair, the optimal selection is made based on the minimum relative velocity fluctuation criterion. The specific optimization method is described as follows: (12) Result Output Output the filtered traces to the radar data processor. The new traces are vector traces, which contain the average time, average position, average speed, estimated acceleration and quality index value corresponding to the filtered traces after fitting. The appearance time and fitting position of the new traces can be calculated according to the following formulas: (13) (14) The average velocity and estimated acceleration are given by equation (9) and equation (8).

[0058] Summarize the specific process of the point trace screening algorithm proposed in the present invention, as follows: Figure 5 shown.

[0059] 1. Specific application fields or related products of the present invention.

[0060] At present, the present invention has been successfully applied to shipborne navigation radar, Ku-band anti-UAV radar, ground wave over-the-horizon radar and other equipment, achieving significant clutter suppression effect.

[0061] 2. Relevant evidence of the technical effects obtained by the embodiments of the present invention.

[0062] The technical effect of the present invention is demonstrated by the measured data processing effect of a Ku-band anti-UAV radar. The radar adopts pulse Doppler and two-dimensional phase scanning system, which can measure the distance, azimuth, pitch and Doppler information of aerial UAV targets. According to the radar technical indicator parameters and the attribute parameters of the target to be detected, during the point screening process, the maximum expected speed is set to 100m / s, the minimum expected speed is set to 10m / s, the maximum allowable acceleration is set to 5m / s2, the Doppler compliance threshold is set to ±2m / s, and the instantaneous steering angle cosine value is required to be greater than 0.2. The measured data is processed according to the above algorithm, and the results are as follows: Figure 6 The test data consists of 240 frames. During the acquisition, the radar was fixed on the shore. The clutter environment was sea clutter. It contained 235,828 original traces after condensation processing, and the average single-frame trace density was 983 (as shown in Figure 2). Figure 6As shown in the left figure); after being processed by the point trace screening algorithm proposed in the present invention, 843 points are screened, and the average single-frame point trace density after screening is about 3.5 (as shown in the left figure); Figure 6 The filtered points are output to the subsequent track processor for processing. The results are shown in the figure below. Figure 6 As shown in the right figure, it can be seen that most of the target points are retained, and the remaining small amount of clutter points can be smoothly processed by the track initiation and track tracking algorithms without forming false track outputs, which verifies the correctness and effectiveness of the clutter point screening algorithm proposed in the present invention.

[0063] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0064] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A radar clutter point screening method using the short-term motion characteristics of a target, characterized in that: The following steps are involved: Step 1, through a low threshold pre-detector, CFAR detection and agglomeration processing to obtain the original point trace data set; The original point data set obtained by radar observation in the nth frame is: （1） in, Indicates the nth frame A dot trace, Respectively represent the amplitude, time, slant range, azimuth, pitch and Doppler information corresponding to the point trace, The total number of original points observed by the radar in this frame; Step 2, coordinate transformation; find and satisfy the velocity and acceleration constraints for three consecutive frames; Step 3, radial velocity screening; Step 4, instantaneous steering angle constraint; Step 5, motion characteristic stability.

2. The radar clutter point removal method using the short-term motion characteristics of the target as claimed in claim 1, characterized in that: The coordinate transformation: Considering the point screening problem in the Cartesian coordinate system, we first convert the point coordinates from polar coordinates to plane rectangular coordinates. （2）。 3. The radar clutter point removal method using the short-term motion characteristics of the target as claimed in claim 1, characterized in that: The three consecutive frames find and satisfy the velocity and acceleration constraints: For three consecutive frames of traces ,in , , , calculate the speed and acceleration of the short track composed of the point track pair, and it is required to satisfy （5） in, are the front speed, rear speed and acceleration of the point pair respectively; assuming that the target satisfies the uniform acceleration (CA) assumption in a short period of time, the speed and acceleration of the point pair can be calculated using the following formula （6） （7） （8） in, , , .

4. The radar clutter point removal method using the short-term motion characteristics of the target as claimed in claim 1, characterized in that: The radial velocity filter: For the current point to be filtered , according to the classical theoretical formula , calculate the corresponding Doppler velocity ; Estimate the time interval weighted average velocity vector of the point track （9） Calculate radial velocity (10) In the formula, For dot trace The position vector of It means to find the inner product; Compliance judgment like , then the judgment is the clutter point trace, and the point trace is be eliminated, among which Filter threshold for radial velocity.

5. The radar clutter point removal method using the short-term motion characteristics of the target as claimed in claim 1, characterized in that: The instantaneous steering angle constraint condition is: For the point trace pairs that pass the speed, acceleration and Doppler conformity screening, the maximum allowable steering angle constraint is set according to the short-term stability principle of the target motion characteristics to further screen the clutter point traces. （11） in represents the inner product, is the maximum permissible target short-term steering angle.

6. The radar clutter point removal method using the short-term motion characteristics of the target as claimed in claim 1, characterized in that: The stability of the motion characteristics: After the above screening, for the points after screening , connected with it and More than one; for the same or , there are also multiple To ensure the uniqueness of the point trace pair, the optimal selection is made based on the minimum criterion of relative velocity fluctuation. The specific optimization method is described as follows: （12） Result Output Output the filtered traces to the radar data processor. The new traces are vector traces, which contain the average time, average position, average speed, estimated acceleration and quality index value corresponding to the filtered traces after fitting. The appearance time and fitting position of the new traces can be calculated according to the following formulas: （13） （14） The average velocity and estimated acceleration are given by equation (9) and equation (8).

7. A radar clutter point trace screening system using target short-term motion characteristics, which implements the radar clutter point trace screening method using target short-term motion characteristics as claimed in any one of claims 1 to 6, characterized in that: The radar clutter point trace screening system using the short-term motion characteristics of the target includes: The data set acquisition module is used to obtain the original point trace data set through a low threshold pre-detector, CFAR detection and agglomeration processing; Conversion module, used for coordinate conversion; discover and satisfy velocity and acceleration constraints for three consecutive frames; Screening module for radial velocity screening; Constraint module, used for instantaneous steering angle constraints; Stabilization module, used for motion characteristic stability.

8. A computer device, characterized in that: The computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the radar clutter point trace screening method using the short-term motion characteristics of the target as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the radar clutter point removal method using the short-term motion characteristics of a target as claimed in any one of claims 1 to 6.

10. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the radar clutter point trace screening system using the short-term motion characteristics of the target as described in claim 7.

Images