A non-cooperative UAV ground station and operator search and positioning system and method

Abstract

The present invention belongs to the field of electronic information technology, and discloses a non-cooperative UAV ground station and operator search and positioning system and method, the system includes a ground control center, multiple air-based direction finding sites and at least one fixed direction finding site; the ground control center is composed of a control unit and a ground communication module; the air-based direction finding site is composed of a cooperative UAV and an airborne computing unit, a signal direction finding module, a visual perception module and an airborne communication module carried on the cooperative UAV; the fixed direction finding site is composed of a signal direction finding module and a wireless communication module fixed at a high point. The present invention can realize the signal direction finding of the non-cooperative UAV ground station and the rapid detection of the non-cooperative UAV operator, provide information guidance for capturing or striking targets, and effectively curb illegal behaviors such as "black flying" of UAVs from the source, which has important practical value for a safer and more orderly low-altitude order.

Description

Technical Field

[0001] The present invention belongs to the field of electronic information technology, and relates to a non-cooperative UAV ground station and operator search and positioning system and method. Background Art

[0002] With the development and commercialization of low-speed, slow, and small aircraft technologies represented by drones, the potential safety hazards they bring are also increasing. Drones frequently invade key areas such as oil depots, power stations, airports, and prisons. However, traditional drone countermeasures mainly focus on direct interference, interception, and destruction of the drone itself, including but not limited to interference blocking, navigation deception, and physical strikes. These methods only counter the drone itself, and can only temporarily and once damage the incoming target. They do not locate its ground station equipment, especially its operator, and cannot fundamentally eliminate the threat. Therefore, relying on traditional drone countermeasures to counter low-cost, high-efficiency, and cost-effective consumable commercial drones will inevitably fall into the dilemma of unbalanced scale confrontation and unequal value consumption. In response to the above problems, researchers proposed to detect and parse the broadcast information of drones or ground stations with specific known protocols through ground equipment to achieve the purpose of obtaining the location of their ground stations and their operators. Another type of method focuses on using specific behavioral characteristics of drones after the communication link is interrupted, such as the automatic return mechanism, and inferring the operator's location by analyzing the return path of the drone.

[0003] However, these solutions still face many key technical challenges. First, most ground detection equipment relies on static infrastructure, with limited coverage, single perception dimension, and lack of mobility. It is difficult to achieve full-area, real-time, and dynamic target detection for fast-moving non-cooperative UAV ground stations and operators. In addition, signal propagation is easily blocked by ground attachments such as buildings and trees, making it impossible to receive and detect signals from UAVs and their ground stations on the ground. Secondly, the communication modulation methods and communication protocols of UAVs of different manufacturers and models vary greatly. Most of the existing UAV communication protocols in the market are not public. In particular, self-made and modified UAVs mostly use custom protocols. It is extremely difficult to obtain the location of ground stations and operators through UAV signal analysis. In addition, using the return behavior of UAVs after abnormal communication links to counter UAVs also has great limitations. The primary problem is the uncertainty of the automatic return behavior itself. The return path of the UAV does not always directly point to the exact location of the operator, but depends on the preset return point, the navigation algorithm of the aircraft, and the surrounding terrain environment. Different models of UAVs may adopt completely different response strategies after communication interruption. This diversity and uncertainty makes the method of relying on passive behavior after communication interruption to infer the operator's location extremely unreliable. Summary of the invention

[0004] The purpose of the present invention is to provide a non-cooperative UAV ground station and operator search and positioning system and method to solve the problem that the existing UAV countermeasure technology only targets the UAV itself but not its control equipment and operators, thereby resulting in the UAV countermeasure only treating the symptoms but not the root cause.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] On the one hand, the present invention provides a non-cooperative UAV ground station and operator search and positioning system, including a ground control center, multiple air-based direction finding sites and at least one fixed direction finding site; wherein the ground control center is composed of a control unit and a ground communication module; the air-based direction finding site is composed of a cooperative UAV and an airborne computing unit, a signal direction finding module, a visual perception module and an airborne communication module carried on the cooperative UAV; the fixed direction finding site is composed of a signal direction finding module and a wireless communication module fixed at a high point; the air-based direction finding site and the fixed direction finding site are both used for detecting, identifying and direction finding signals of the non-cooperative UAV ground station, and the direction finding results are sent to the control unit of the ground control center through the airborne communication module, the wireless communication module and the ground communication module, and the air-based direction finding site is also used to search, detect and identify non-cooperative UAV operators by processing images obtained by the visual perception module; the ground control center is used to estimate the position of the non-cooperative UAV ground station, display the results and control the motion of the cooperative UAV according to the information sent by the air-based direction finding site and the fixed direction finding site.

[0007] Furthermore, the ground control center specifically implements the following three processes: ① Using the ground communication module to receive information transmitted by the air-based direction finding site and the ground direction finding site, including the signal detection and direction finding results of the non-cooperative UAV ground station of the air-based direction finding site and the ground direction finding site, the current position of the air-based direction finding site, and the visual detection results of the air-based direction finding site; the control unit calculates the position of the non-cooperative UAV ground station and the state of the air-based direction finding site according to the above information, performs task progress analysis in real time, and controls the motion trajectory of the cooperative UAV; ② The control unit provides an information interaction interface between the system of the present invention and the operator, so as to facilitate the reception of task instructions issued by the operator to the cooperative UAV; ③ The control unit sends the received task instructions to the air-based direction finding site through the ground communication module, so as to facilitate the cooperative UAV as the carrier of the air-based direction finding site to control itself according to the task instructions.

[0008] Furthermore, the control unit is implemented by a portable meter, and the ground communication module is implemented by a shortwave radio station.

[0009] Furthermore, the signal direction finding module includes an array antenna, a single-pole multi-throw radio frequency switch, a combiner, a low-noise amplifier, a mixer, a low-pass filter, an analog-to-digital converter and a control module; wherein each antenna unit of the array antenna is connected to the single-pole multi-throw radio frequency switch, the single-pole multi-throw radio frequency switch is connected to the combiner, the combiner, the low-noise amplifier, the mixer, the low-pass filter, the analog-to-digital converter and the control module are connected in sequence, and the control module is connected to the single-pole multi-throw radio frequency switch.

[0010] Furthermore, the working process of the signal direction finding module is as follows:

[0011] Step 1, each antenna unit in the array antenna receives a ground station signal, and the ground station signal collected by the antenna unit enters a single-pole multi-throw radio frequency switch respectively;

[0012] Step 2, the control module controls the single-pole multi-throw radio frequency switch to periodically select each unit antenna to receive the ground station signal according to a preset time sequence;

[0013] Step 3: The ground station signals received by each unit antenna are sequentially sent to a single radio frequency channel to achieve time serialization of spatial information;

[0014] Step 4, the ground station signal after time serialization enters the low noise amplifier through the combiner to enhance the signal strength and improve the signal-to-noise ratio; then it is mixed with the local oscillator signal through the mixer and converted to the intermediate frequency band; then it is sampled by the analog-to-digital converter after filtering out high-frequency clutter through a low-pass filter and converted into an intermediate frequency digital signal, and then the control module extracts the characteristics of each harmonic component from the intermediate frequency digital signal through spectrum analysis;

[0015] Step 5: The control module performs correlation matching on the characteristics of each harmonic component with the pre-calibrated harmonic characteristic library, and calculates the direction of the current ground station signal.

[0016] On the other hand, the present invention provides a non-cooperative UAV ground station and operator search and positioning method, characterized in that the non-cooperative UAV ground station and operator search and positioning system according to the present invention specifically includes the following steps:

[0017] Step 1: After the system is initialized, it enters the standby state, the air-based direction finding station is dormant, and the signal direction finding module of the fixed direction finding station detects the signal of the non-cooperative UAV ground station until the fixed direction finding station detects the signal of the non-cooperative UAV ground station or the ground control center receives the non-cooperative UAV intrusion alarm input from the outside of the system;

[0018] Step 2: The ground control center notifies all fixed direction finding stations to start signal detection based on the direction finding information received from the fixed direction finding stations or the intrusion information of the intruding non-cooperative UAV, preliminarily determines the position of the non-cooperative UAV ground station, and sends instructions through the ground communication module to notify the air-based direction finding station to take off and move to the position of the non-cooperative UAV ground station;

[0019] Step 3: After the airborne direction finding station is launched, it forms a direction finding network with the fixed direction finding station. The signal direction finding modules of the fixed direction finding station and the airborne direction finding station respectively find the direction of the non-cooperative UAV ground station signal and transmit the direction finding results to the ground control center.

[0020] Step 4: The ground control center calculates the position of the non-cooperative UAV ground station based on the direction finding results of the airborne direction finding station and the fixed direction finding station, and sends it to each direction finding station;

[0021] Step 5: The airborne computing unit of the airborne direction finding station uses the direction finding result of the signal direction finding module to perform target detection;

[0022] Step 6: The airborne direction finding station moves from different directions to the estimated position of the non-cooperative UAV ground station; the visual perception module carried by the airborne direction finding station continues to search for the non-cooperative UAV ground station operator until the target is found;

[0023] Step 7, the air-based direction finding site that has found the ground station operator sends the target location information to the ground control center, and the control center sends the location information to other air-based direction finding sites, and each air-based direction finding site performs encirclement and tracking movements toward the target until the system user of the present invention inputs an instruction to terminate the task.

[0024] Furthermore, the specific process of step 5 is as follows:

[0025] Step 1: The airborne computing unit obtains the signal direction finding information of the non-cooperative UAV ground station and the cooperative UAV's own gimbal sensor information from the signal direction finding module;

[0026] Step 2: The onboard computing unit uses the perspective projection model of the object imaged by the optical lens to adjust the shooting direction of the visual perception module in real time according to the signal direction finding information of the ground station and the information of the gimbal sensor of the cooperative UAV. The onboard computing unit uses the target detection algorithm to perform target detection on the captured image.

[0027] Furthermore, in step 2, the onboard computing unit uses the perspective projection model of the object imaged in the optical lens, based on the signal direction finding information of the ground station and the gimbal sensor information of the cooperative UAV itself, to estimate the size range of the target image projected by the non-cooperative UAV operator on the visual perception module, and narrows the target search range in the image obtained from the visual perception module according to the size range of the target image, simplifies the upsampling process in the feature pyramid network of the model in the target detection algorithm, and deletes the feature fusion module with low contribution to the detection of targets of a specific scale, and performs target detection on the captured image.

[0028] Compared with the prior art, the present invention fills the gap in the previous UAV countermeasure method of directly automatically searching, detecting and locating non-cooperative UAV ground stations and operators. This method has the following advantages:

[0029] (1) New countermeasure model

[0030] Different from the traditional "ground-to-air" and "air-to-air" drone countermeasures, the present invention adopts the "air-ground joint" method of cooperative drone-mounted and tower-fixed signal processing payloads to collaboratively achieve the azimuth determination of non-cooperative drone ground stations, and then use the visual payload carried by the cooperative drone to complete the search and positioning of non-cooperative drone operators. This countermeasure system and method not only takes advantage of the pre-installation of fixed sites and fast target detection, but also can use mobile sites with cooperative drones as carriers to continuously move according to the target azimuth, optimize site layout, and improve the accuracy of ground station position estimation. The present invention can provide effective support for combating or capturing "illegal" drone remote control equipment and criminals.

[0031] (2) New technical route

[0032] The non-cooperative UAV ground station signal direction finding adopted by the invention adopts time modulation array antenna technology and ground station operator detection technology, which are different from the existing traditional methods. They can effectively overcome the prominent problems of signal direction finding methods such as complex hardware, high power consumption, and slow processing speed, and can realize the miniaturization, lightweight, and low-cost design of UAV ground stations and operator detection payloads. The present invention integrates the signal direction finding information with the UAV's own flight altitude, gimbal shooting angle and other information, estimates the imaging size of the non-cooperative UAV operator through a perspective projection model, and then selects an optimized target detection model suitable for detecting targets of this size according to the size information to perform the detection task. The optimized target detection model reduces the multiple detection heads originally used to detect targets of different sizes, simplifies the number of layers and channels of the feature extraction network, achieves approximate detection accuracy through a lower number of parameters and calculations, and greatly improves the detection speed, effectively improving the detection speed of the UAV platform.

[0033] (3) High countermeasure effectiveness

[0034] Compared with directly countering drones, the technology proposed in the present invention provides the possibility of interrupting drone control in a non-destructive way, which can effectively reduce the probability of accidental injury. At the same time, it can provide strong support for capturing enemy personnel to obtain intelligence or direct fire strikes and completely destroying enemy drone combat units, and the countermeasure effectiveness is significantly enhanced.

[0035] In summary, the present invention can realize non-cooperative UAV ground station signal direction finding and non-cooperative UAV operator rapid detection, provide information guidance for capturing or attacking targets, and effectively curb illegal behaviors such as UAV "black flying" from the source, which has important practical value for a safer and more orderly low-altitude order. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the system composition of the present invention;

[0037] Figure 2 This is the schematic diagram of the signal direction finding module;

[0038] Figure 3 It is a schematic diagram of the principle of multi-site joint non-cooperative UAV ground station signal direction finding;

[0039] Figure 4 Schematic diagram of the visual search and detection principle of a non-cooperative UAV ground station and operator.

[0040] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. DETAILED DESCRIPTION

[0041] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] like Figure 1As shown, the non-cooperative UAV ground station and operator search and positioning system provided by the present invention includes a ground control center, multiple air-based direction finding sites and at least one fixed direction finding site. Among them, the ground control center is composed of a control unit and a ground communication module; the air-based direction finding site is composed of a cooperative UAV and an airborne computing unit, a signal direction finding module, a visual perception module and an airborne communication module carried on the cooperative UAV; the fixed direction finding site is composed of a signal direction finding module and a wireless communication module fixed at high points such as towers and buildings. The air-based direction finding site and the fixed direction finding site are both used for the detection, identification and direction finding of the signals of the non-cooperative UAV ground station, and the direction finding results are sent to the control unit of the ground control center through the airborne communication module and the wireless communication module via the ground communication module, and the air-based direction finding site is also used to search, detect and identify the non-cooperative UAV operator by processing the image obtained by the visual perception module; the ground control center is used to estimate the position of the non-cooperative UAV ground station, display the results and control the motion of the cooperative UAV according to the information sent by the air-based direction finding site and the fixed direction finding site.

[0043] The system of the present invention can fully and autonomously complete the detection and identification of target signals, direction measurement, position estimation, and visual detection and positioning.

[0044] (1) Ground control center. It is used to implement the following three processes: ① Using the ground communication module to receive information transmitted by the air-based direction finding station and the ground direction finding station, including the signal detection and direction finding results of the non-cooperative UAV ground station of the air-based direction finding station and the ground direction finding station, the current position of the air-based direction finding station, and the visual detection results of the air-based direction finding station; the control unit calculates the position of the non-cooperative UAV ground station and the status of the air-based direction finding station based on the above information, performs task progress analysis in real time, and controls the motion trajectory of the cooperative UAV; ② The control unit provides an information interaction interface (such as an interface, a keyboard, etc.) between the system of the present invention and the operator, so as to facilitate the reception of task instructions issued by the operator to the cooperative UAV (the operator can dynamically adjust the task execution strategy based on the information output by the control unit, and input control instructions to the control unit); ③ The control unit sends the received task instructions to the air-based direction finding station through the ground communication module, so that the cooperative UAV as the carrier of the air-based direction finding station can control itself according to the task instructions.

[0045] The control unit can be implemented using a portable computer, and the ground communication module can be implemented using a shortwave radio. The ground control center builds a real-time information link between the ground-end equipment and the air-based direction-finding site and the fixed direction-finding site through the ground communication module, thereby ensuring the tight coupling and seamless coordination of the perception-decision-execution links. The control unit is the core of the system. By collecting, processing and responding to the state of the direction-finding site and the signal direction measurement and image detection results, it commands each direction-finding site to fully autonomously complete the search and positioning of the non-cooperative UAV ground station and operator.

[0046] (2) Airborne direction-finding station. The signal direction-finding module is used to find the direction of the non-cooperative UAV ground station signal, obtain the signal direction angle, and send the direction-finding information to the airborne computing unit. The airborne computing unit is the control core of the airborne direction-finding station, which is used to collect and process the sensor data of the signal direction-finding module and the visual sensing module, and the control instructions sent by the ground control center, send the control instructions to the cooperative UAV, adjust the shooting direction of the visual perception module according to the direction-finding information, and perform target detection on the image obtained by the visual perception module, and transmit the direction-finding information and target detection results to the ground control center through the airborne communication module.

[0047] As a preferred embodiment of the present invention, the signal direction finding module is implemented by using a direction finding method based on a time modulation array antenna, and its composition is as follows: Figure 2 As shown, it includes an array antenna, a single-pole multi-throw RF switch, a combiner, a low-noise amplifier, a mixer, a low-pass filter, an analog-to-digital converter and a control module. Among them, each antenna unit of the array antenna is connected to a single-pole multi-throw RF switch, the single-pole multi-throw RF switch is connected to the combiner, the combiner, the low-noise amplifier, the mixer, the low-pass filter, the analog-to-digital converter and the control module are connected in sequence, and the control module is connected to the single-pole multi-throw RF switch. Due to resource limitations such as hardware, it is also difficult for the UAV platform to carry a complex direction-finding system. Therefore, the signal direction-finding module converts the multi-channel reception problem into a single-channel reception problem through time series modulation, and can realize signal direction-finding with low hardware complexity, light weight and low power consumption on air-based platforms such as UAVs.

[0048] The working process of the signal direction finding module designed above is as follows:

[0049] Step 1, each antenna unit in the array antenna receives a ground station signal, and the ground station signal collected by the antenna unit enters a single-pole multi-throw radio frequency switch respectively;

[0050] Step 2, the control module controls the single-pole multi-throw radio frequency switch to periodically select each unit antenna to receive the ground station signal according to a preset time sequence;

[0051] Step 3: The ground station signals received by each unit antenna are sequentially sent to a single radio frequency channel to achieve time serialization of spatial information;

[0052] Step 4, the ground station signal after time serialization enters the low noise amplifier through the combiner to enhance the signal strength and improve the signal-to-noise ratio; then it is mixed with the local oscillator signal through the mixer and converted to the intermediate frequency band to facilitate subsequent signal acquisition and processing; then it is sampled by the analog-to-digital converter after filtering out high-frequency clutter through a low-pass filter and converted into an intermediate frequency digital signal, and then the control module uses digital signal processing technology in the intermediate frequency digital domain to extract the characteristics of each harmonic component from the intermediate frequency digital signal through spectrum analysis;

[0053] Step 5: Since the switch selection process of step 2 and step 3 modulates the ground station signal, the ground station signal with different incident directions will produce specific harmonic components in the spectrum. The amplitude and phase of these harmonics contain the spatial direction information of the ground station signal. The control module can accurately calculate the direction of the current ground station signal by matching the characteristics of each harmonic component extracted in step 4 with the pre-calibrated harmonic feature library.

[0054] As a preferred embodiment of the present invention, the visual perception module is implemented by a camera, and the airborne computing unit is implemented by an edge computing device equipped with a graphics processor. Considering that the cooperative UAV platform of the air-based direction-finding unit has strict resource constraints, and the approximate position of the non-cooperative UAV operator has been obtained through the ground station signal direction-finding unit, the target image size range is known. Existing image target detection models based on neural networks are all capable of detecting operators, and the present invention can accelerate the detection process according to the target image size information. Specifically, by reducing the number of detection heads originally used to detect targets of different sizes and simplifying the feature extraction network, the number of layers and channels can be reduced, and only the most critical features for detecting targets of a specific size can be retained. The above-mentioned optimization measures can significantly reduce the complexity of the model, improve the efficiency of target detection, and make the model more suitable for operation in a resource-constrained environment.

[0055] (3) Fixed direction finding station: The signal direction finding module is used to find the direction of the non-cooperative UAV ground station signal to obtain direction finding information, and the direction finding information is transmitted to the ground control center through the wireless communication module.

[0056] The non-cooperative UAV ground station and operator search and positioning method of the present invention specifically includes the following steps:

[0057] Step 1: After the system is initialized, it enters the standby state, the air-based direction finding station is dormant, and the signal direction finding module of the fixed direction finding station detects the signal of the non-cooperative UAV ground station until the fixed direction finding station detects the signal of the non-cooperative UAV ground station or the ground control center receives the non-cooperative UAV intrusion alarm input from the outside of the system;

[0058] Step 2: The ground control center notifies all fixed direction finding stations to start signal detection based on the direction finding information received from the fixed direction finding stations or the intrusion information of the intruding non-cooperative UAV, preliminarily determines the position of the non-cooperative UAV ground station, and sends instructions through the ground communication module to notify the air-based direction finding station to take off and move to the position of the non-cooperative UAV ground station;

[0059] Step 3: After the airborne direction finding station is launched, it forms a direction finding network with the fixed direction finding stations (see Figure 3). Figure 3), the signal direction finding modules of the fixed direction finding station and the airborne direction finding station respectively find the direction of the non-cooperative UAV ground station signal and transmit the direction finding results to the ground control center;

[0060] Step 4: The ground control center calculates the position of the non-cooperative UAV ground station based on the direction finding results of the airborne direction finding station and the fixed direction finding station, and sends it to each direction finding station;

[0061] Step 5: The airborne computing unit of the airborne direction finding station uses the direction finding results of the signal direction finding module to detect the target. The specific process is as follows. Figure 4 shown.

[0062] Step 1, the airborne computing unit obtains the signal direction finding information of the non-cooperative UAV ground station and the cooperative UAV's own gimbal sensor information (including but not limited to the UAV flight altitude, UAV three-dimensional coordinates, gimbal pitch angle and azimuth) from the signal direction finding module;

[0063] Step 2: The onboard computing unit uses the perspective projection model of the object imaged by the optical lens to adjust the shooting direction of the visual perception module in real time according to the signal direction finding information of the ground station and the gimbal sensor information of the cooperative UAV. The onboard computing unit uses the loaded common target detection algorithm to perform target detection on the captured image.

[0064] Preferably, in step 2, the onboard computing unit uses the perspective projection model of the object imaged in the optical lens, based on the signal direction finding information of the ground station and the pan / tilt sensor information of the cooperative UAV itself, to estimate the size range of the target image projected by the non-cooperative UAV operator on the visual perception module, and according to the size range of the target image, narrows the target search range in the image obtained from the visual perception module, reduces the computational overhead of the feature map by simplifying the upsampling process in the feature pyramid network, deletes the feature fusion module with a low contribution to the detection of targets of a specific scale, reduces the number of detection heads used by the target detection model to detect targets of different sizes, simplifies the feature extraction network, and reduces the number of layers and channels, thereby speeding up the target detection speed.

[0065] Step 6: The airborne direction finding station moves from different directions to the estimated position of the non-cooperative UAV ground station. The main goal of the movement is to increase the geometric precision factor of the direction measurement, so as to obtain a higher signal-to-noise ratio of the non-cooperative UAV ground station signal and a clearer image of the operator's area. The visual perception module carried by the airborne direction finding station continues to search for the non-cooperative UAV ground station operator until the target is found;

[0066] Step 7, the air-based direction finding site that has found the ground station operator sends the target location information to the ground control center, and the control center sends the location information to other air-based direction finding sites, and each air-based direction finding site performs encirclement and tracking movements toward the target until the system user of the present invention inputs an instruction to terminate the task.

[0067] In summary, the present invention proposes a non-cooperative UAV ground station and operator search and positioning system and method in order to fundamentally achieve high-efficiency, high-precision, and low-cost countermeasures against illegal UAVs. After confirming the existence of illegal behaviors such as "illegal flying" of UAVs, the ground control center controls the fixed and air-based direction-finding stations to start search and positioning, and uses a time-modulated array antenna signal direction-finding method to preliminarily determine the approximate position of the non-cooperative UAV ground station; then, the air-based direction-finding station completes the rapid search, detection, and final positioning of the target through the visual perception module with the assistance of direction-finding information, further locks the non-cooperative UAV ground station and operator, provides target guidance for capturing or attacking non-cooperative UAV operators, and provides technical and means support for eradicating the threat of "illegal flying" UAVs.

Claims

1. A non-cooperative UAV ground station and operator search and positioning system, characterized in that: It includes a ground control center, multiple air-based direction-finding sites and at least one fixed direction-finding site; wherein the ground control center is composed of a control unit and a ground communication module; the air-based direction-finding site is composed of a cooperative UAV and an airborne computing unit, a signal direction-finding module, a visual perception module and an airborne communication module carried by the cooperative UAV; the fixed direction-finding site is composed of a signal direction-finding module and a wireless communication module fixed at a high point; the air-based direction-finding site and the fixed direction-finding site are both used for detecting, identifying and direction-finding signals from ground stations of non-cooperative UAVs, and the direction-finding results are sent to the control unit of the ground control center through the airborne communication module and the wireless communication module via the ground communication module, and the air-based direction-finding site is also used for searching, detecting and identifying non-cooperative UAV operators by processing images obtained by the visual perception module. The specific process is as follows: Step 1, the airborne computing unit obtains the signal direction-finding information of the ground station of the non-cooperative UAV and the pan-tilt sensor information of the cooperative UAV from the signal direction-finding module; Step 2, the airborne computing unit uses the object in The perspective projection model of optical lens imaging adjusts the shooting direction of the visual perception module in real time according to the signal direction finding information of the ground station and the pan-tilt sensor information of the cooperative UAV itself; the airborne computing unit uses the target detection algorithm to perform target detection on the captured image; wherein, the airborne computing unit uses the perspective projection model of the object in the optical lens imaging, according to the signal direction finding information of the ground station and the pan-tilt sensor information of the cooperative UAV itself, to estimate the size range of the target image projected by the non-cooperative UAV operator on the visual perception module, and narrows the target search range in the image obtained from the visual perception module according to the size range of the target image, simplifies the upsampling process in the feature pyramid network of the model in the target detection algorithm, and deletes the feature fusion module with low contribution to the detection of specific scale targets, and performs target detection on the captured image; the ground control center is used to estimate the position of the non-cooperative UAV ground station, display the results and control the motion of the cooperative UAV according to the information sent by the air-based direction finding station and the fixed direction finding station; The ground control center specifically implements the following three processes: ① Using the ground communication module to receive information transmitted by the air-based direction finding site and the fixed direction finding site, including the signal detection and direction finding results of the non-cooperative UAV ground station of the air-based direction finding site and the fixed direction finding site, the current position of the air-based direction finding site, and the visual detection results of the air-based direction finding site; the control unit calculates the position of the non-cooperative UAV ground station and the state of the air-based direction finding site based on the above information, performs task progress analysis in real time, and controls the motion trajectory of the cooperative UAV; ② The control unit provides the non-cooperative UAV ground station and the operator search and positioning system with the operator to facilitate the reception of the task instructions issued by the operator to the cooperative UAV; ③ The control unit sends the received task instructions to the air-based direction finding site through the ground communication module, so that the cooperative UAV as the carrier of the air-based direction finding site can control itself according to the task instructions; The signal direction finding module comprises an array antenna, a single-pole multi-throw radio frequency switch, a combiner, a low-noise amplifier, a mixer, a low-pass filter, an analog-to-digital converter and a control module; wherein each antenna unit of the array antenna is connected to the single-pole multi-throw radio frequency switch, the single-pole multi-throw radio frequency switch is connected to the combiner, the combiner, the low-noise amplifier, the mixer, the low-pass filter, the analog-to-digital converter and the control module are connected in sequence, and the control module is connected to the single-pole multi-throw radio frequency switch; The working process of the signal direction finding module is as follows: Step 1, each antenna unit in the array antenna receives a ground station signal, and the ground station signal collected by the antenna unit enters a single-pole multi-throw radio frequency switch respectively; Step 2, the control module controls the single-pole multi-throw radio frequency switch to periodically select each unit antenna to receive the ground station signal according to a preset time sequence; Step 3: The ground station signals received by each unit antenna are sequentially sent to a single radio frequency channel to achieve time serialization of spatial information; Step 4, the ground station signal after time serialization enters the low noise amplifier through the combiner to enhance the signal strength and improve the signal-to-noise ratio; then it is mixed with the local oscillator signal through the mixer and converted to the intermediate frequency band; then it is sampled by the analog-to-digital converter after filtering out high-frequency clutter through a low-pass filter and converted into an intermediate frequency digital signal, and then the control module extracts the characteristics of each harmonic component from the intermediate frequency digital signal through spectrum analysis; Step 5: The control module performs correlation matching on the characteristics of each harmonic component with the pre-calibrated harmonic characteristic library, and calculates the direction of the current ground station signal.

2. The non-cooperative UAV ground station and operator search and positioning system as claimed in claim 1, characterized in that: The control unit is implemented by a portable computer, and the ground communication module is implemented by a shortwave radio station.

3. A non-cooperative UAV ground station and operator search and positioning method, characterized in that: The non-cooperative UAV ground station and operator search and positioning system according to claim 1 or 2 specifically comprises the following steps: Step 1: After the system is initialized, it enters the standby state, the air-based direction finding station is dormant, and the signal direction finding module of the fixed direction finding station detects the signal of the non-cooperative UAV ground station until the fixed direction finding station detects the signal of the non-cooperative UAV ground station or the ground control center receives the non-cooperative UAV intrusion alarm input from the outside of the system; Step 2: The ground control center notifies all fixed direction finding stations to start signal detection based on the direction finding information received from the fixed direction finding stations or the intrusion information of the intruding non-cooperative UAV, preliminarily determines the position of the non-cooperative UAV ground station, and sends instructions through the ground communication module to notify the air-based direction finding station to take off and move to the position of the non-cooperative UAV ground station; Step 3: After the airborne direction finding station is launched, it forms a direction finding network with the fixed direction finding station. The signal direction finding modules of the fixed direction finding station and the airborne direction finding station respectively find the direction of the non-cooperative UAV ground station signal and transmit the direction finding results to the ground control center. Step 4: The ground control center calculates the position of the non-cooperative UAV ground station based on the direction finding results of the airborne direction finding station and the fixed direction finding station, and sends it to each direction finding station; Step 5: The airborne computing unit of the airborne direction finding station uses the direction finding result of the signal direction finding module to perform target detection. The specific process is as follows: Step 1: The airborne computing unit obtains the signal direction finding information of the non-cooperative UAV ground station and the cooperative UAV's own gimbal sensor information from the signal direction finding module; Step 2: The onboard computing unit uses the perspective projection model of the object imaged in the optical lens, and adjusts the shooting direction of the visual perception module in real time according to the signal direction finding information of the ground station and the information of the pan / tilt sensor of the cooperative UAV. The onboard computing unit uses the target detection algorithm to perform target detection on the captured image. Among them, the onboard computing unit uses the perspective projection model of the object imaged in the optical lens, based on the signal direction finding information of the ground station and the information of the pan / tilt sensor of the cooperative UAV, to estimate the size range of the target image projected by the non-cooperative UAV operator on the visual perception module, and narrows the target search range in the image obtained from the visual perception module according to the size range of the target image, simplifies the upsampling process in the feature pyramid network of the model in the target detection algorithm, and deletes the feature fusion module with low contribution to the detection of targets of a specific scale, so as to perform target detection on the captured image; Step 6: The airborne direction finding station moves from different directions to the estimated position of the non-cooperative UAV ground station; the visual perception module carried by the airborne direction finding station continues to search for the non-cooperative UAV ground station operator until the target is found; Step 7, the air-based direction finding site that has found the ground station operator sends the target location information to the ground control center, and the control center sends the location information to other air-based direction finding sites. Each air-based direction finding site performs encirclement and tracking movements toward the target until the non-cooperative UAV ground station and the operator search and positioning system user inputs an instruction to terminate the task.

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