Low-altitude moving target optical detection method and system

Abstract

The invention relates to the technical field of low-altitude moving target detection, in particular to a low-altitude moving target optical detection method and system. The system comprises a plurality of optical detection devices, a plurality of communication modules and a control center. The method has the advantages that the limitation that radar detection is poor in effect on targets such as floating objects which are low in moving speed and weak in radar wave reflection signal is avoided, the multiple optical detection devices are evenly distributed, large-range detection and intelligent recognition are achieved in combination with the embedded processing unit, the problems that the detection range is small and target recognition is difficult are solved, and in addition, the detection efficiency is improved. The control center carries out fusion processing on image signals of a plurality of optical detection devices, realizes adjustment of the visual angle and the orientation of the camera by using the rotating unit, realizes three-dimensional accurate positioning by using a triangulation positioning method, overcomes the challenge of difficult positioning, and finally realizes accurate positioning by using a relay tracking mechanism. It is ensured that the target can still be continuously tracked after leaving the detection range of a single device, and the problem that large-range tracking is difficult is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of low-altitude moving target detection, and particularly to an optical detection method and system for low-altitude moving targets. Background Art

[0002] With the increasing frequency of aviation activities, the low-altitude safety of important places such as airports has become the focus of attention. Low-altitude moving targets, such as birds, airborne objects, drones, etc., pose potential threats to aviation safety. At present, the main technical means for low-altitude moving target detection is the collaborative detection of radar and optics. Among them, radar detection is responsible for detecting targets, while optical detection is responsible for identifying targets. However, radar detection has limitations. Especially for targets with slow moving speeds and weak radar wave reflection signals such as airborne objects, the radar detection effect is not good.

[0003] As a supplementary means, optical detection technology has the advantages of being unaffected by electromagnetic interference and having high resolution, but it also faces many challenges in practical applications. First of all, the detection range of optical detection equipment is relatively small, and it is difficult to achieve large-scale coverage. Secondly, it is difficult to identify targets by optical detection, especially in complex backgrounds. In addition, optical detection equipment usually can only obtain the azimuth information of the target and it is difficult to achieve precise positioning. Finally, for large-scale tracking of targets, due to the limited detection range of optical detection equipment, it is difficult to achieve continuous tracking.

[0004] In summary, in the existing optical detection technology for low-altitude moving targets, radar detection has poor effects on targets with slow moving speeds and weak radar wave reflection signals such as airborne objects, while optical detection faces problems such as small detection range, difficult target identification, difficult positioning, and difficult large-scale tracking. Summary of the Invention

[0005] The purpose of the present invention is to provide an optical detection method and system for low-altitude moving targets, so as to solve the problems in the existing optical detection technology for low-altitude moving targets that radar detection has poor effects on targets with slow moving speeds and weak radar wave reflection signals such as airborne objects, while optical detection faces problems such as small detection range, difficult target identification, difficult positioning, and difficult large-scale tracking.

[0006] To achieve the above object, the present invention provides an optical detection system for low-altitude moving targets. The optical detection system for low-altitude moving targets includes a plurality of optical detection devices, a plurality of communication modules, and a control center. The plurality of optical detection devices are evenly distributed in the monitoring area and are used to collect image signals of low-altitude moving targets in real time. Each of the optical detection devices is provided with the communication module, and the communication module is used to realize data transmission between the optical detection device and the control center. The control center is used to receive the image signals and device status information of the plurality of optical detection devices, and perform signal fusion processing on the received information to realize three-dimensional positioning and tracking control of low-altitude moving targets; Each of the optical detection devices includes a visible light detection camera and an infrared detection camera. Each of the visible light detection cameras and each of the infrared detection cameras are provided with an embedded processing unit and a rotation unit. The embedded processing unit is used to autonomously detect and track moving targets, and perform real-time processing and analysis on the collected image signals to support intelligent recognition and classification of the targets. The rotation unit is used to realize horizontal and pitch rotation of the visible light detection camera and the infrared detection camera to adjust the viewing angle and orientation of the camera, ensure that the target always remains at the center of the field of view, and achieve wide-range coverage and precise tracking.

[0007] Among them, the control center is provided with a signal fusion processing unit, an intelligent classification and recognition unit, a tracking control unit, a data storage unit, and a data display unit. The signal fusion processing unit is used to receive and fuse the image signals and device status information from the plurality of optical detection devices to realize three-dimensional positioning of low-altitude moving targets. The intelligent classification and recognition unit is used to perform intelligent classification and recognition on the fused target signals and output the recognition results and confidence levels. The tracking control unit is used to control the adjacent optical detection devices to perform target search, tracking, and three-dimensional precise positioning according to the target recognition results. The data storage unit is used to store all data generated during the detection process. The data display unit is used to intuitively display the information of the target's activity trajectory, recognition results, and device status on the human-computer interaction interface, facilitating the monitoring and management of operators.

[0008] The present invention also provides an optical detection method for low-altitude moving targets, which is applied to the optical detection system for low-altitude moving targets as described above, and includes the following steps: Detection mode: All of the optical detection devices default to work in the detection mode, and detect moving targets in real time to achieve wide-range monitoring coverage of the low-altitude monitoring area; Tracking mode: When the optical detection device discovers a target, it switches to the tracking mode, and uses the rotation unit to adjust the orientation and rotation speed of the turntable to keep the target at the center of the field of view; Target recognition and classification: The control center performs intelligent classification and recognition of the target based on the received information; Target search and three-dimensional precise positioning: When the control center discovers the target type of interest, it controls the adjacent optical detection devices to search and uses the triangulation method to locate the target; Relay tracking and large-scale activity trajectory generation: When the target continuously moves beyond the detection range of the current optical detection device, the control center controls the corresponding optical detection device for relay tracking; Tracking task termination condition and recovery mechanism: When the target leaves the detection range of all optical detection devices or the tracking is set to stop, all optical detection devices resume the detection mode.

[0009] Among them, in the step "detection mode", the detection mode is divided into two detection modes: watch detection and patrol detection; The watch mode specifically means that the optical detection device stares at the set detection area and the turntable does not rotate; The patrol mode specifically means that the optical detection device continuously rotates or cycles through several set preset positions.

[0010] Among them, in the step "tracking mode", during the tracking process, through the rotation unit, the turntable orientation and rotation speed are adjusted in real time to keep the target at the center of the field of view, and the focal length is continuously increased to obtain a higher-resolution target image. At the same time, the video and turntable azimuth angle collected by the optical detection device of the target are transmitted to the control center in real time. The control center continuously classifies and recognizes the target, outputs the recognition result and confidence level. When the recognition result of the moving target is a target type that is not of interest and the confidence level is higher than the set threshold, the tracking stops and the detection mode is resumed.

[0011] Among them, in the step "target search and three-dimensional precise positioning", when the recognition result of the moving target is a target type of interest and the confidence level is higher than the set threshold, the control center controls the adjacent optical detection devices to search with reference to the turntable orientation and target distance hypothesis of the current optical detection device. During the search process, the embedded processing unit uses the moving target detection algorithm to detect the moving target in real time.

[0012] Among them, in the step "target search and three-dimensional precise positioning", the specific content of using the moving target detection algorithm to detect the moving target in real time is: During the search process, it is assumed that the target is located at (x, y, z), and this position continuously changes with time t and satisfies the following conditions: ; wherein, are respectively the pitch angle and the horizontal angle of the target detected by the current optical detection device, and are updated in real time according to the detection results during the movement of the target, is the estimated target distance, which continuously changes with time during the search process; The specific calculation formula of is: wherein, minD and maxD are respectively the minimum and maximum detection distances, a is the search speed coefficient, t = 0 at the start of the search, and during the search process, the adjacent optical detection devices are directed towards the assumed target location, and at the same time, the embedded processing unit uses a moving target detection algorithm to detect moving targets in real time.

[0013] wherein, in the step of "target search and three-dimensional precise positioning", using the triangulation method to locate the target specifically means: after the adjacent optical detection devices detect a moving target, switch to the tracking mode, further determine that the moving target is the target type of interest, and after the confidence level is higher than the set threshold, use the triangulation method to locate the moving target in real time; Specifically, let the positions of the current optoelectronic detection device and the adjacent optoelectronic detection device be vectors P1=(P1x, P1y, P1z) and P2=(P2x, P2y, P2z) respectively, and the target positioning orientations be vectors V1=(V1x, V1y, V1z) and V2=(V2x, V2y, V2z) respectively; , , , , wherein, 、 are respectively the pitch angle and the horizontal angle of the target detected by the current optical detection device and the adjacent optical detection device, and according to the formula: Calculate the intermediate parameter t1 and the intermediate parameter t2, and calculate the target positioning P according to the formula; .

[0014] Among them, the specific content of the step "relay tracking and large-range activity trajectory generation" is as follows: After obtaining the positioning of the moving target, when the moving target enters the tracking range of any one of the optical detection devices, the control center controls the optical detection device to turn to the target and sets the focal length that enables the target to be clearly imaged. After the optical detection device detects the tracking target, it switches to the tracking mode for relay tracking, and at the same time uses the positioning method in the step "target search and three-dimensional precise positioning" to obtain the real-time positioning of the target, forming a continuous activity trajectory. Specifically, the focal length value that enables the target to be clearly imaged refers to obtaining the target size parameter according to the target classification and recognition result, obtaining the target distance according to the target positioning and the coordinates of the optical detection device, and then calculating the focal length value in combination with the optical system parameters, so that the size of the image is not less than 2 pixels and not higher than 20 pixels.

[0015] An optical detection method and system for low-altitude moving targets of the present invention includes a plurality of optical detection devices, a plurality of communication modules, and a control center. The plurality of optical detection devices are evenly distributed in the monitoring area. Each optical detection device includes a visible light detection camera and an infrared detection camera. Each visible light detection camera and each infrared detection camera are provided with an embedded processing unit and a rotation unit. By adopting pure optical detection technology, it circumvents the limitation of poor detection effect of radar detection on targets with slow moving speeds such as airborne objects and weak radar wave reflection signals. Secondly, through the even distribution of the plurality of optical detection devices and in combination with the embedded processing unit, large-range detection and intelligent recognition are realized, solving the problems of small detection range and difficult target recognition. Furthermore, the control center performs fusion processing on the image signals of the plurality of optical detection devices, and uses the rotation unit to adjust the camera view angle and azimuth, and realizes three-dimensional precise positioning through the triangulation method, overcoming the challenge of difficult positioning. Finally, through the relay tracking mechanism, it is ensured that the target can still be continuously tracked after leaving the detection range of a single device, solving the problem of difficult large-range tracking. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a principle block diagram of an optical detection system for low-altitude moving targets provided by the present invention.

[0018] Figure 2 It is a step flow chart of an optical detection method for low-altitude moving targets provided by the present invention.

[0019] 101 - Optical detection device, 102 - Communication module, 103 - Control center, 104 - Visible light detection camera, 105 - Infrared detection camera, 106 - Embedded processing unit, 107 - Rotating unit, 108 - Signal fusion processing unit, 109 - Intelligent classification and recognition unit, 110 - Tracking control unit, 111 - Data storage unit, 112 - Data display unit. Detailed implementation manners

[0020] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0021] Please refer to Figure 1 , the present invention provides a low - altitude moving target optical detection system. The low - altitude moving target optical detection system includes a plurality of optical detection devices 101, a plurality of communication modules 102, and a control center 103. The plurality of optical detection devices 101 are evenly distributed in the monitoring area and are used to collect image signals of low - altitude moving targets in real time. Each of the optical detection devices 101 is provided with the communication module 102. The communication module 102 is used to realize data transmission between the optical detection device 101 and the control center 103. The control center 103 is used to receive the image signals and device status information of the plurality of optical detection devices 101, and perform signal fusion processing on the received information to realize three - dimensional positioning and tracking control of low - altitude moving targets; Each of the optical detection devices 101 includes a visible light detection camera 104 and an infrared detection camera 105. Each of the visible light detection cameras 104 and each of the infrared detection cameras 105 are provided with an embedded processing unit 106 and a rotating unit 107. The embedded processing unit 106 is used to autonomously detect and track moving targets, and perform real - time processing and analysis on the collected image signals to support intelligent identification and classification of the targets. The rotating unit 107 is used to realize the horizontal and pitch rotation of the visible light detection camera 104 and the infrared detection camera 105, so as to adjust the viewing angle and azimuth of the cameras, ensure that the target always remains at the center of the field of view, and realize large - range coverage and precise tracking.

[0022] In this embodiment, a pure optical detection technology is adopted to avoid the limitations of radar detection, which has poor effects on targets with slow moving speeds such as airborne objects and weak radar wave reflection signals. Secondly, through the uniform distribution of multiple optical detection devices 101 and in combination with the embedded processing unit 106, large-range detection and intelligent recognition are achieved, solving the problems of small detection range and difficult target recognition. Furthermore, the control center 103 performs fusion processing on the image signals of multiple optical detection devices 101, and uses the rotation unit 107 to adjust the camera view angle and azimuth, and realizes three-dimensional precise positioning through the triangulation method, overcoming the challenge of difficult positioning. Finally, through the relay tracking mechanism, it is ensured that the target can still be continuously tracked after leaving the detection range of a single device, solving the problem of difficult large-range tracking.

[0023] Furthermore, the control center 103 is provided with a signal fusion processing unit 108, an intelligent classification and recognition unit 109, a tracking control unit 110, a data storage unit 111 and a data display unit 112. The signal fusion processing unit 108 is used to receive and fuse the image signals and device status information from multiple optical detection devices 101 to realize three-dimensional positioning of low-altitude moving targets. The intelligent classification and recognition unit 109 is used to perform intelligent classification and recognition on the fused target signals and output the recognition results and confidence levels. The tracking control unit 110 is used to control the adjacent optical detection devices 101 to perform target search, tracking and three-dimensional precise positioning according to the target recognition results. The data storage unit 111 is used to store all data generated during the detection process. The data display unit 112 is used to intuitively display the information of the target's activity trajectory, recognition results and device status on the human-computer interaction interface, facilitating the monitoring and management by operators.

[0024] Please refer to Figure 2 , the present invention also provides an optical detection method for low-altitude moving targets, which is applied to the optical detection system for low-altitude moving targets as described above, and includes the following steps: S1. Detection mode: All the optical detection devices 101 default to work in the detection mode, and continuously detect moving targets to achieve large-range monitoring coverage of the low-altitude monitoring area; S2. Tracking mode: When the optical detection device 101 discovers a target, it switches to the tracking mode, and uses the rotation unit 107 to adjust the turntable orientation and rotation speed to keep the target at the center of the field of view; S3. Target recognition and classification: The control center 103 performs intelligent classification and recognition on the target according to the received information; S4. Target search and three-dimensional precise positioning: When the control center 103 discovers the target type of concern, it controls the adjacent optical detection devices 101 to perform a search and uses the triangulation method to position the target; S5. Relay Tracking and Generation of Large-Scale Activity Trajectories: When the target continuously moves beyond the detection range of the current optical detection device 101, the control center 103 controls the corresponding optical detection device 101 to perform relay tracking; S6. Tracking Task Termination Conditions and Recovery Mechanism: When the target leaves the detection range of all optical detection devices 101, or after setting to stop tracking, all optical detection devices 101 resume the detection mode.

[0025] In this embodiment, by default, all the optical detection devices 101 operate in the detection mode to achieve large-scale monitoring of the low-altitude monitoring area, effectively solving the problem of small detection range. When a target is detected, the optical detection device 101 switches to the tracking mode, and the rotation unit 107 is used to adjust the turntable orientation and rotation speed to ensure that the target always remains at the center of the field of view, achieving precise tracking. The control center 103 performs intelligent classification and recognition of the target based on the received information, improving the accuracy and efficiency of target recognition and solving the problem of difficult target recognition. When a target type of concern is detected, the control center 103 controls the adjacent optical detection device 101 to search and uses the triangulation method to locate the target, achieving three-dimensional precise positioning of the target and solving the problem of difficult positioning. When the target continuously moves beyond the detection range of the current optical detection device 101, the control center 103 controls the corresponding optical detection device 101 to perform relay tracking to ensure that the target is not lost, solving the problem of difficult large-scale tracking. And because the tracking task termination conditions and recovery mechanism are set, when the target leaves the detection range of all the optical detection devices 101 or after setting to stop tracking, all the optical detection devices 101 resume the detection mode, improving the flexibility and efficiency of the system.

[0026] Further, in the step "detection mode", the detection mode is divided into two detection modes: watch detection and patrol detection; The watch mode specifically means that the optical detection device 101 stares at the set detection area and the turntable does not rotate; The patrol mode specifically means that the optical detection device 101 rotates continuously or cycles through several set preset positions.

[0027] Further, in the "tracking mode" step, during the tracking process, the turntable orientation and rotation speed are adjusted in real time through the rotation unit 107 to keep the target at the center of the field of view, and the focal length is continuously increased to obtain a target image with higher resolution. At the same time, the video and the turntable azimuth angle collected by the optical detection device 101 of the target are transmitted to the control center 103 in real time. The control center 103 continuously classifies and identifies the target, outputs the recognition result and confidence level. When the recognition result of the moving target is a target type that is not of concern and the confidence level is higher than the set threshold, the tracking is stopped and the detection mode is restored.

[0028] Further, in the "target search and three-dimensional precise positioning" step, when the recognition result of the moving target is a target type of concern and the confidence level is higher than the set threshold, the control center 103 controls the adjacent optical detection device 101 to search with reference to the turntable orientation and target distance assumption of the current optical detection device 101. During the search process, the embedded processing unit 106 uses a moving target detection algorithm to detect the moving target in real time.

[0029] Further, in the "target search and three-dimensional precise positioning" step, the specific content of using a moving target detection algorithm to detect the moving target in real time is as follows: During the search process, it is assumed that the target is located at (x, y, z), and this position changes continuously with time t and satisfies the following conditions: ; Among them, are the pitch angle and horizontal angle detected by the current optical detection device 101 for the target respectively, and are updated in real time according to the detection results during the target movement. is the estimated target distance, which changes continuously with time during the search process; The specific calculation formula of is: Among them, minD and maxD are the minimum and maximum detection distances respectively, a is the search speed coefficient. At the beginning of the search, t = 0. During the search process, the adjacent optical detection device 101 is oriented towards the assumed target location, and at the same time, the embedded processing unit 106 uses a moving target detection algorithm to detect the moving target in real time.

[0030] Further, in the step of "target search and three-dimensional precise positioning", the use of the triangulation method to locate the target specifically means that after the adjacent optical detection device 101 discovers a moving target, it switches to the tracking mode, further determines that the moving target is the target type of concern, and after the confidence level is higher than the set threshold, the triangulation method is used to locate the moving target in real time; Specifically, let the positions of the current optoelectronic detection device and the adjacent optoelectronic detection device be vectors P1=(P1x, P1y, P1z) and P2=(P2x, P2y, P2z) respectively, and the target positioning orientations be vectors V1=(V1x, V1y, V1z) and V2=(V2x, V2y, V2z) respectively; , , , , Among them, 、 are respectively the elevation angle and the horizontal angle at which the current optical detection device 101 and the adjacent optical detection device 101 detect the target. According to the formula: Calculate the intermediate parameter t1 and the intermediate parameter t2, and calculate the target positioning P according to the formula; 。

[0031] Further, the specific content of the step of "relay tracking and large-range activity trajectory generation" is: after obtaining the positioning of the moving target, when the moving target enters the tracking range of any one of the optical detection devices 101, the control center 103 controls the optical detection device 101 to turn to the target and sets the focal length that enables the target to be clearly imaged. After the optical detection device 101 detects the tracking target, it switches to the tracking mode for relay tracking, and at the same time uses the positioning method in the step of "target search and three-dimensional precise positioning" to obtain the real-time positioning of the target, forming a continuous activity trajectory. Specifically, the focal length value that enables the target to be clearly imaged refers to obtaining the target size parameter according to the target classification and recognition result, obtaining the target distance according to the target positioning and the coordinates of the optical detection device 101, and then calculating the focal length value in combination with the optical system parameters, so that the size of the image is not less than 2 pixels and not higher than 20 pixels.

[0032] The above-disclosed is only a preferred embodiment of the present invention. Of course, the scope of the rights of the present invention cannot be limited by this. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. An optical detection system for low-altitude moving targets, characterized in that it includes multiple optical detection devices, multiple communication modules and a control center. The multiple optical detection devices are evenly distributed in the monitoring area and are used to collect image signals of low-altitude moving targets in real time. Each of the optical detection devices is provided with the communication module, and the communication module is used to realize data transmission between the optical detection device and the control center. The control center is used to receive the image signals and device status information of the multiple optical detection devices, and perform signal fusion processing on the received information to realize three-dimensional positioning and tracking control of low-altitude moving targets; each of the optical detection devices includes a visible light detection camera and an infrared detection camera. Each of the visible light detection cameras and each of the infrared detection cameras is provided with an embedded processing unit and a rotating unit. The embedded processing unit is used to autonomously detect and track moving targets, and perform real-time processing and analysis on the collected image signals to support intelligent identification and classification of targets. The rotating unit is used to realize horizontal and pitch rotation of the visible light detection camera and the infrared detection camera to adjust the viewing angle and orientation of the camera, ensure that the target always remains at the center of the field of view, and realize large-range coverage and precise tracking.

2. The optical detection system for low-altitude moving targets according to claim 1, characterized in that the control center is provided with a signal fusion processing unit, an intelligent classification and recognition unit, a tracking control unit, a data storage unit and a data display unit. The signal fusion processing unit is used to receive and fuse the image signals and device status information from the multiple optical detection devices to realize three-dimensional positioning of low-altitude moving targets. The intelligent classification and recognition unit is used to perform intelligent classification and recognition on the target signals after fusion processing, and output the recognition results and confidence levels. The tracking control unit is used to control the adjacent optical detection devices to perform target search, tracking and three-dimensional precise positioning according to the target recognition results. The data storage unit is used to store all data generated during the detection process. The data display unit is used to intuitively display the information of the target's activity trajectory, recognition results and device status on the man-machine interaction interface, facilitating operators to monitor and manage.

3. An optical detection method for low-altitude moving targets, which is applied to the low-altitude moving target optical detection system as described in claim 1, and is characterized in that, including the following steps: Detection mode: All of the optical detection devices default to work in the detection mode to detect moving targets in real time and realize large-range monitoring coverage of the low-altitude monitoring area; Tracking mode: When the optical detection device discovers a target, it switches to the tracking mode, and uses the rotating unit to adjust the turntable orientation and speed to keep the target at the center of the field of view; Target identification and classification: The control center performs intelligent classification and recognition on the target based on the received information; Target search and three-dimensional precise positioning: When the control center discovers the target type of concern, it controls the adjacent optical detection devices to search and uses the triangulation method to locate the target; Relay tracking and large-range activity trajectory generation: When the target continuously moves beyond the detection range of the current optical detection device, the control center controls the corresponding optical detection device to perform relay tracking; Tracking task termination condition and recovery mechanism: When the target leaves the detection range of all optical detection devices, or after setting to stop tracking, all optical detection devices resume the detection mode.

4. The low-altitude moving target optical detection method according to claim 3, characterized in that In the step "detection mode", the detection mode is divided into two detection modes: watch detection and patrol detection; The watch mode specifically means that the optical detection device stares at the set detection area and the turntable does not rotate; The patrol mode specifically means that the optical detection device continuously rotates or cycles through several set preset positions.

5. The low-altitude moving target optical detection method according to claim 4, characterized in that In the step "tracking mode", during the tracking process, through the rotation unit, the orientation and rotation speed of the turntable are adjusted in real time to keep the target at the center of the field of view, and the focal length is continuously increased to obtain a higher-resolution target image. At the same time, the video and turntable azimuth angle collected by the optical detection device of the target are transmitted to the control center in real time. The control center continuously classifies and identifies the target, outputs the identification result and confidence level. When the identification result of the moving target is a target type that is not of concern and the confidence level is higher than the set threshold, the tracking is stopped and the detection mode is resumed.

6. The low-altitude moving target optical detection method according to claim 5, characterized in that In the step "target search and three-dimensional precise positioning", when the identification result of the moving target is a target type that is of concern and the confidence level is higher than the set threshold, the control center controls the adjacent optical detection devices to search with reference to the turntable orientation and target distance assumption of the current optical detection device. During the search process, the embedded processing unit uses a moving target detection algorithm to detect the moving target in real time.

7. The low-altitude moving target optical detection method according to claim 6, characterized in that In the step "target search and three-dimensional precise positioning", the specific content of using the moving target detection algorithm to detect the moving target in real time is: During the search process, assume that the target is located at (x, y, z), and this position changes continuously with time t and satisfies the following conditions: ； wherein, are respectively the pitch angle and the horizontal angle of the target detected by the current optical detection device, and are updated in real time according to the detection results during the movement of the target, is the estimated target distance, which continuously changes with time during the search; The specific calculation formula is as follows: where minD and maxD are the minimum and maximum detection distances respectively, a is the search speed coefficient. When the search starts, t = 0. During the search process, the adjacent optical detection devices are oriented towards the assumed target position, and at the same time, the embedded processing unit uses a moving target detection algorithm to detect the moving target in real time.

8. The low-altitude moving target optical detection method according to claim 7, characterized in that In the step "target search and three-dimensional precise positioning", the specific method of using triangulation to locate the target means that after the adjacent optical detection devices detect the moving target, they switch to the tracking mode. After further determining that the moving target is a target type that is of concern and the confidence level is higher than the set threshold, the triangulation method is used to locate the moving target in real time; Specifically, let the positions of the current optoelectronic detection device and the adjacent optoelectronic detection device be vectors P1 = (P1x, P1y, P1z) and P2 = (P2x, P2y, P2z) respectively, and the target positioning orientations be vectors V1 = (V1x, V1y, V1z) and V2 = (V2x, V2y, V2z) respectively; , , , , Among them, and are respectively the pitch angle and the horizontal angle of the target detected by the current optical detection device and the adjacent optical detection device. According to the formula: Calculate the intermediate parameter t1 and the intermediate parameter t2, and calculate the target positioning P according to the formula; 。 9. The low-altitude moving target optical detection method according to claim 8, characterized in that The specific content of the step "relay tracking and large-range activity trajectory generation" is: after obtaining the positioning of the moving target, when the moving target enters the tracking range of any one of the optical detection devices, the control center controls the optical detection device to turn to the target and sets the focal length that enables the target to be clearly imaged. After the optical detection device detects the tracking target, it switches to the tracking mode for relay tracking, and at the same time uses the positioning method in the step "target search and three-dimensional precise positioning" to obtain the real-time positioning of the target, forming a continuous activity trajectory. Specifically, the focal length value that enables the target to be clearly imaged refers to obtaining the target size parameter according to the target classification and recognition result, obtaining the target distance according to the target positioning and the coordinates of the optical detection device, and then calculating the focal length value in combination with the optical system parameters, so that the size of the image is not less than 2 pixels and not higher than 20 pixels.

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