A method for identifying meteorological targets using bird-detecting radar

Abstract

This invention discloses a method for meteorological target identification using bird detection radar, belonging to the field of radar data processing technology. The method includes: spatial cell division; spatial cell identification; spatial cell processing; and track category updating. This invention comprehensively utilizes track spatial distribution characteristics and image processing techniques to effectively identify interfering meteorological targets in bird surveillance work. Verification has shown good engineering results, improving the meteorological target removal capability and statistical data accuracy of bird detection radar. Furthermore, this invention has low logical complexity, is easy to implement in engineering, and can quickly identify meteorological targets, ensuring identification efficiency. It is also highly versatile, applicable to various bird detection radar systems, including low-resolution radars, and can be extended to dynamic clutter identification in surveillance radars.

Description

Technical Field

[0001] This invention relates to a bird-detecting radar method for meteorological target identification, belonging to the field of radar data processing technology. Background Technology

[0002] Bird strikes are a major problem plaguing the global aviation industry. In recent years, with the rapid development of the aviation industry and improvements in the ecological environment, bird strike incidents have become increasingly frequent. Bird detection radar, as a crucial sensor for airport bird strike prevention, can achieve all-weather, 24 / 7 bird surveillance, providing vital data support for flight avoidance and bird control efforts. It has been gradually deployed and applied in military and civilian airports across China.

[0003] Birds are considered "small, maneuverable, and low-altitude" targets. In complex urban environments, achieving stable bird detection and tracking with radar presents significant technical challenges. These challenges stem from several factors: weak echo signals, high target maneuverability, complex low-altitude ground clutter and obstruction, and the negative impacts of ground personnel, vehicles, and aerial meteorological targets on bird detection probability and tracking stability. Among these factors, meteorological targets, such as clouds and rainfall, have a substantial impact. Removing meteorological targets is particularly difficult because their RCS, altitude, and speed distributions highly overlap with those of birds, making it difficult to distinguish them based on echo intensity, altitude, speed, and probability density. Furthermore, meteorological targets typically occupy a large area, resulting in dense, clustered tracks on radar screens. This can negatively impact airport assessments of real-time bird activity and flight schedules, and also lead to inaccurate bird statistics due to the inclusion of meteorological targets.

[0004] In radar engineering, the current bird-detecting radar in China has a less than satisfactory effect in identifying meteorological targets. Although target recognition methods based on artificial intelligence technologies are frequently published, intelligent radar technology is still under development and it is difficult to provide intelligent recognition technology that is easy to implement in engineering for current low-resolution radar. Summary of the Invention

[0005] To improve the ability of bird-detecting radar to identify meteorological targets, this invention provides a method for meteorological target identification using bird-detecting radar, comprising:

[0006] Step 1: In a Cartesian coordinate system, divide the space U detected by the bird-detecting radar into equal parts on the X, Y, and Z axes;

[0007] Step 2: Based on the total number of initial tracks within the unit space, identify the unit spaces containing meteorological targets in space U;

[0008] Step 3: Use connected component analysis to obtain the spatial region of meteorological targets;

[0009] Step 4: Based on the spatial area of ​​the meteorological target, determine whether the flight path belongs to the meteorological target.

[0010] Optionally, step two includes:

[0011] Set a threshold ThdC for the number of tracks, and count the number of tracks M generated by each initial space unit. If M≥ThdC, the space unit is considered to be a space unit with meteorological targets.

[0012] Optionally, step three includes:

[0013] Step 31: Mark the spatial units with meteorological targets as 1 and the other spatial units as 0 to obtain the three-dimensional matrix P;

[0014] Step 32: Analyze the connected components in the three-dimensional matrix P;

[0015] Step 33: Calculate the number of spatial units Q contained in each connected component;

[0016] Step 34: Set a spatial unit number threshold ThdD, remove connected components with Q < ThdD, and regard the remaining connected components as the meteorological target spatial region.

[0017] Optionally, the criteria for determining the meteorological target in step four include:

[0018] (1) The starting point A of the target track is within the space area of ​​the meteorological target;

[0019] (2) The number of historical associations of the target trajectory N is less than the preset association number threshold ThdN;

[0020] (3) The spatial distance R between the starting position A of the target track and the current real-time position B is less than the spatial distance threshold ThdR.

[0021] Optionally, step two further includes: dividing the space U into three types of unit spaces: unit spaces without targets, unit spaces with meteorological targets, and unit spaces with other targets.

[0022] Optionally, step three further includes performing connected body morphology operations on the meteorological target spatial region obtained in step 34.

[0023] The second objective of this invention is to provide a meteorological target identification system, comprising: a bird-detecting radar and an identification processing unit; the bird-detecting radar sends the collected target data to the identification processor, and the identification processing unit identifies meteorological targets using any of the meteorological target identification methods described above.

[0024] The third objective of this invention is to provide a bird detection method, comprising: identifying meteorological targets among the targets detected by bird detection radar using any of the meteorological target identification methods described above, and then eliminating them.

[0025] The beneficial effects of this invention are:

[0026] (1) The bird-finding radar meteorological target identification method of the present invention comprehensively utilizes the spatial distribution characteristics of flight tracks and image processing related technologies, which can effectively identify meteorological targets that cause interference in bird situation statistics. It has been verified to have good engineering results, and has improved the meteorological target elimination capability and statistical data accuracy of bird-finding radar.

[0027] (2) The analysis process of the method of the present invention is fully based on reality, with low technical logic complexity, easy to implement in engineering, and can quickly identify meteorological targets, thus ensuring identification efficiency.

[0028] (3) The technology of the present invention is highly versatile and can be applied to various bird detection radar systems, including low-resolution radar. It can also be extended to the dynamic clutter identification of surveillance radar. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a flowchart of the bird-detecting radar meteorological target identification method of the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0032] Example 1:

[0033] This embodiment provides a method for identifying meteorological targets using bird-detecting radar, such as... Figure 1 As shown, it includes:

[0034] Step 1: In a Cartesian coordinate system, divide the space U detected by the bird-detecting radar into equal parts on the X, Y, and Z axes;

[0035] Step 2: Based on the total number of initial tracks within the unit space, identify the unit spaces containing meteorological targets in space U;

[0036] Step 3: Use connected component analysis to obtain the spatial region of meteorological targets;

[0037] Step 4: Based on the spatial area of ​​the meteorological target, determine whether the flight path belongs to the meteorological target.

[0038] Example 2:

[0039] This embodiment provides a method for identifying meteorological targets using bird-detecting radar. (See also...) Figure 1 The method includes:

[0040] (I) Spatial Unit Division

[0041] In a Cartesian coordinate system, the space U detected by the radar is divided equally along the X, Y, and Z axes. The interval between the three divisions can be set manually. In this embodiment, the interval between the three divisions is set to 100m.

[0042] (II) Spatial Unit Identification

[0043] Space U has three types of unit spaces: 1) unit spaces without targets; 2) unit spaces with meteorological targets; 3) unit spaces with other targets. This step requires identifying the "spatial units with meteorological targets".

[0044] Meteorological targets typically appear in relatively fixed areas over a certain time span. Therefore, the total number of starting tracks within a spatial area within a time window can be used as a feature for identification.

[0045] The radar scans a 360° range. If the starting point A of a certain track is located in a certain spatial cell, the spatial cell is called the "starting spatial cell" of the track. A quantity threshold ThdC is set, and the number of tracks M generated by each starting spatial cell is counted. When M≥ThdC, the spatial cell is considered to be a "spatial cell with meteorological targets".

[0046] In this embodiment, a quantity threshold ThdC = 3 is set, and the number of tracks M generated by each initial space unit is counted. When M ≥ ThdC, the space unit is considered to be a "space unit with meteorological targets".

[0047] (III) Spatial Unit Processing

[0048] The spatial unit processing steps include:

[0049] 1) Binary transformation. Mark "spatial units with meteorological targets" as 1 and other spatial units as 0 to obtain a three-dimensional matrix P.

[0050] 2) Analyze the connected components in the three-dimensional matrix P. There are 15 connected components in total.

[0051] For the analysis of connected components in space, this embodiment can employ methods such as the Two-Pass method and the Seed-Filling method.

[0052] 3) Calculate the number of spatial units Q contained in each connected component.

[0053] 4) Eliminate smaller connected components. Each connected component represents a spatial region where a meteorological target appears. Based on the characteristic that "meteorological targets typically occupy a large spatial region," this embodiment sets a quantity threshold ThdD = 4. When Q < ThdD, the connected component needs to be eliminated. There are 5 remaining larger connected components, which are considered as the spatial regions of meteorological targets.

[0054] 5) Connected-body morphological operations. A dilation operation is performed on connected bodies, using a 2×2 structuring element.

[0055] Through the above steps, five spatial regions (connected bodies) of meteorological targets were obtained.

[0056] (iv) Track Category Update

[0057] To determine whether a flight path is classified as a meteorological target, the following three conditions must be met:

[0058] 1) The starting point A of the flight path is within the spatial area of ​​the meteorological target;

[0059] 2) The number of historical trajectory associations N is less than the threshold ThdN = 10;

[0060] 3) The spatial distance R between the starting position A of the flight path and the current real-time position B is less than the threshold ThdR = 500m.

[0061] A bird-detecting radar used at an airport, during a rainy day, identified 93% of flight paths as meteorological targets within a 1-minute time window. This was confirmed by radar-guided high-definition optoelectronic equipment. After sampling verification, the identification of meteorological targets was deemed effective, and bird targets were not misidentified as meteorological targets.

[0062] Some steps in the embodiments of the present invention can be implemented using software, and the corresponding software program can be stored in a readable storage medium, such as an optical disc or a hard disk.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for identifying meteorological targets using bird-detecting radar, characterized in that, The method includes: Step 1: In a Cartesian coordinate system, divide the space U detected by the bird-detecting radar into equal parts on the X, Y, and Z axes; Step 2: Based on the total number of initial tracks within the unit space, identify the unit spaces containing meteorological targets in space U; Step 3: Obtain the spatial region of meteorological targets using connected component analysis, including: Step 31: Mark the spatial units with meteorological targets as 1 and the other spatial units as 0 to obtain the three-dimensional matrix P; Step 32: Analyze the connected components in the three-dimensional matrix P; Step 33: Calculate the number of spatial units Q contained in each connected component; Step 34: Set a spatial unit number threshold ThdD, remove connected components with Q < ThdD, and consider the remaining connected components as the meteorological target spatial region; Step 4: Based on the spatial area of ​​the meteorological target, determine whether the flight path belongs to the meteorological target. The criteria for determining the meteorological target include: (1) The starting point A of the target track is within the space area of ​​the meteorological target; (2) The number of historical associations of the target track, N, is less than the preset association number threshold, ThdN; (3) The spatial distance R between the starting position A of the target track and the current real-time position B is less than the spatial distance threshold ThdR.

2. The bird-detecting radar meteorological target identification method according to claim 1, characterized in that, Step two includes: Set a threshold ThdC for the number of tracks, and count the number of tracks M generated by each initial space unit. If M≥ThdC, the space unit is considered to be a space unit with meteorological targets.

3. The bird-detecting radar meteorological target identification method according to claim 2, characterized in that, Step two further includes: dividing the space U into three types of unit spaces: unit spaces without targets, unit spaces with meteorological targets, and unit spaces with other targets.

4. The bird-detecting radar meteorological target identification method according to claim 2, characterized in that, Step 3 also includes performing connected body morphology operations on the meteorological target spatial region obtained in step 34.

5. A meteorological target identification system, characterized in that, The system includes: a bird-detecting radar and an identification processing unit; the bird-detecting radar sends the collected target data to the identification processor, and the identification processing unit identifies meteorological targets using the meteorological target identification method according to any one of claims 1-4.

6. A method for detecting birds in flight, characterized in that, The method includes: identifying meteorological targets among the targets detected by bird-hunting radar using the meteorological target identification method according to any one of claims 1-4, and then eliminating them.

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