Dual-frequency laser coaxial modulation based covert video monitoring interference system and method

Abstract

This invention discloses a covert video surveillance jamming system and method based on dual-frequency laser coaxial modulation, comprising: a dual-frequency laser module for generating lasers in visible light and infrared light modes; a fully coaxial optical path module for receiving and transmitting the lasers generated by the dual-frequency laser module, and adjusting the laser emission direction by deflecting its internal reflector group; and a data processing and control module electrically connected to both the dual-frequency laser module and the fully coaxial optical path module. The data processing and control module is used to identify the target camera, calculate the offset between the target camera and the laser optical axis, control the operating mode of the dual-frequency laser module, and control the deflection of the reflector group in the fully coaxial optical path module. This invention, through the organic combination of a dual-frequency laser source, a fully coaxial optical path, and visual feedback control, significantly reduces the system's size and complexity, achieving high concealment and environmentally adaptive jamming effects.

Description

Technical Field

[0001] This invention relates to the field of laser jamming technology, and in particular to a covert video surveillance jamming system and method based on dual-frequency laser coaxial modulation. Background Technology

[0002] Laser jamming technology, as an important technical means in the fields of privacy protection and security countermeasures, achieves countermeasures by emitting laser beams of specific wavelengths or modulation modes to saturate or create artifacts in the imaging devices of surveillance cameras. In recent years, with the widespread deployment of surveillance equipment, the demand for laser jamming technology in public safety, personal privacy protection, and anti-espionage scenarios has become increasingly urgent.

[0003] In the prior art, prior patent CN113794843A discloses a laser interference scheme based on a coaxial optical path. This scheme uses a dichroic mirror to achieve a coaxial design between the laser optical path and the visible light aiming optical path, and combines this with a mechanical adjustment method involving the overall rotation of the laser to adjust the interference direction. However, this technology relies on external mechanical adjustment, requiring the overall rotation of the laser or galvanometer scanning to achieve beam pointing, resulting in a bulky device. Furthermore, the moving parts of this scheme easily expose the interference intent, lacking concealment. In addition, the beam splitting characteristics and mechanical rotation errors of the dichroic mirror easily cause optical path deviation, limiting its calibration accuracy and requiring frequent manual calibration, making it difficult to adapt to dynamic scenarios. Another prior patent, CN113794826A, proposes a technical solution based on light intensity modulation interference, which uses a ranging module to obtain the target distance and drives a zoom optical system to adjust the spot size. However, this solution has high system complexity, requiring the integration of an independent ranging module and zoom mechanism, increasing equipment cost and power consumption, and the ranging process is easily detected. Because it does not take into account the light source switching requirements of day and night scenes, it has poor environmental adaptability and requires manual replacement of laser modules or adjustment of parameters, making it difficult to cope with sudden covert missions.

[0004] Analysis of the existing technologies reveals the following problems with current laser jamming systems: 1. Insufficient concealment: To achieve precise jamming, current laser jamming systems often employ ranging modules, mechanical turntables, or multi-optical-path designs, resulting in bulky equipment with obvious movement characteristics, making them easy to detect. 2. Insufficient environmental adaptability: Current laser jamming systems use single-wavelength or fixed-modulation laser sources, failing to account for day and night lighting differences, requiring manual intervention to switch light sources, thus limiting all-weather operational capabilities. 3. Accumulated calibration errors: Current laser jamming systems have independently arranged cameras, lasers, and rangefinders, with non-strictly coaxial optical axes, introducing angular deviations. Although this solution mentions closed-loop feedback, it only relies on secondary shooting verification and does not address the initial optical path calibration error problem. Summary of the Invention

[0005] The purpose of this invention is to provide a covert video surveillance jamming system and method based on dual-frequency laser coaxial modulation. This invention significantly reduces the system's size and complexity by organically combining a dual-frequency laser source, a fully coaxial optical path, and visual feedback control, achieving high concealment and environmentally adaptive jamming effects.

[0006] The technical solution of this invention: a covert video surveillance jamming system based on dual-frequency laser coaxial modulation, comprising:

[0007] Dual-frequency laser module, used to generate lasers in visible light and infrared light modes;

[0008] The fully coaxial optical path module has its incident end connected to the laser output end of the dual-frequency laser module. It is used to receive and transmit the laser generated by the dual-frequency laser module, and adjust the laser output direction by deflecting its internal reflector group.

[0009] The data processing and control module is electrically connected to the dual-frequency laser module and the coaxial optical path module, respectively. The data processing and control module is used to identify the target camera, calculate the offset between the target camera and the laser optical axis, control the working mode of the dual-frequency laser module, and control the deflection of the mirror group in the coaxial optical path module.

[0010] The aforementioned covert video surveillance jamming system based on dual-frequency laser coaxial modulation includes a dual-frequency laser module comprising:

[0011] Visible lasers and infrared lasers can work independently or in combination;

[0012] An ambient light sensor is used to monitor ambient light intensity in real time.

[0013] The laser control unit is configured to automatically activate the visible light laser when the ambient light intensity is higher than a preset threshold, and automatically activate the infrared laser when the ambient light intensity is lower than a preset threshold.

[0014] In the aforementioned covert video surveillance jamming system based on dual-frequency laser coaxial modulation, the laser emitting end of the visible light laser is equipped with a visible light collimating lens; and the laser emitting end of the infrared laser is equipped with an infrared collimating lens.

[0015] The aforementioned covert video surveillance jamming system based on dual-frequency laser coaxial modulation includes a fully coaxial optical path module comprising:

[0016] A dichroic mirror, whose beam-splitting wavelength matches the laser wavelength of the dual-frequency laser module, is used to achieve coaxial beam combining of visible and infrared light.

[0017] Multiple mirrors form the laser transmission optical path;

[0018] An internal rotating mechanism, driven by a stepper motor, is used to adjust the deflection angle of a specified reflector, thereby changing the final emission direction of the laser beam.

[0019] The aforementioned covert video surveillance jamming system based on dual-frequency laser coaxial modulation includes a data processing and control module comprising:

[0020] The visual positioning unit integrates a camera to capture environmental images and identify the features of the target camera through image processing algorithms;

[0021] An angle deviation calculation unit is configured to calculate the offset angle of the target relative to the laser optical axis based on the target position identified by the visual positioning unit;

[0022] The closed-loop control unit is configured to verify again through the visual positioning unit whether the laser spot covers the target after the laser is emitted, and dynamically adjust the deflection angle of the reflector group according to the verification result.

[0023] The aforementioned covert video surveillance jamming system based on dual-frequency laser coaxial modulation also includes a closed housing for encapsulating the dual-frequency laser module, the fully coaxial optical path module, and the data processing and control module.

[0024] The aforementioned concealed video surveillance jamming system based on dual-frequency laser coaxial modulation has a light window on its enclosed shell for laser emission and external scene light to enter, and the inner wall of the enclosed shell is provided with light-absorbing material to prevent internal light leakage.

[0025] The aforementioned interference method for a covert video surveillance jamming system based on dual-frequency laser coaxial modulation includes the following steps:

[0026] Step S1: After the system starts up, it performs a self-test, then scans the environment and identifies the target camera;

[0027] Step S2: The data processing and control module calculates the offset between the target camera and the laser optical axis, and drives the reflector group in the coaxial optical path module to rotate by the corresponding angle so that the laser optical axis is aligned with the target, and performs secondary verification and calibration.

[0028] Step S3: Select and enable visible light mode and / or infrared light mode based on ambient light intensity;

[0029] Step S4: The dual-frequency laser module emits a laser, which is then emitted to the target camera through the coaxial optical path module to interfere with it. During the interference process, the position of the target camera is continuously monitored, and the optical path is dynamically adjusted to ensure that the laser spot continuously covers the target camera.

[0030] In the aforementioned interference method, the offset is the offset angle between the target camera and the laser optical axis, and the calculation formula is as follows:

[0031]

[0032] In the formula, and These are the pixel offsets of the target camera relative to the laser optical axis reference point in the horizontal and vertical directions, respectively. This is the offset angle.

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

[0034] 1. No ranging required, simplifying system structure: This invention does not rely on an additional ranging module. Traditional laser jamming systems often require ranging equipment to determine the target distance and then adjust laser parameters. This not only increases the complexity and cost of the system but may also affect the jamming effect due to ranging errors. In contrast, this invention captures the target image in real time through visual positioning and directly calculates the target offset, achieving stable jamming without ranging. This simplifies the system structure, reduces costs, and improves the stability and reliability of the system.

[0035] 2. High concealment and adaptability to complex environments: This invention employs a fully enclosed shell design, with the inner wall of the shell made of light-absorbing material, effectively avoiding the risk of laser scattering and leakage. Simultaneously, the laser emission angle is dynamically adjusted by rotating an internal reflector, with no external moving mechanical parts, thus achieving extremely high concealment. This design allows the system to effectively blend into the environment and remain difficult to detect when performing jamming missions, making it particularly suitable for scenarios with extremely high concealment requirements, such as military reconnaissance and counter-terrorism operations.

[0036] 3. Dual-frequency adaptive design, supporting automatic switching between day and night environments: This invention supports adaptive switching between visible light and infrared laser frequencies, selecting the most suitable laser mode for interference based on ambient light intensity. During the day or in well-lit environments, the system automatically switches to visible light mode, utilizing a high-brightness laser beam for interference; while at night or in low-light environments, it switches to infrared mode, leveraging the stealth properties of infrared lasers for interference. This dual-frequency adaptive laser design supports automatic switching between day and night environments, adapting to various complex environments and greatly improving the system's practicality and flexibility.

[0037] 4. High precision and enhanced interference effect: This invention employs a fully coaxial optical path design. Through the precise coordination of dichroic mirrors and reflector groups, the coaxiality and transmission efficiency of the laser optical path are ensured. Simultaneously, combined with a visual positioning unit and an angle deviation algorithm, the system can calculate the target offset in real time and precisely adjust the angle of the reflector, ensuring the laser spot accurately covers the target camera. This design improves the accuracy and effectiveness of the interference, rendering the target camera ineffective within a short period.

[0038] 5. Compact structure, easy to deploy and carry: This invention integrates multiple optical elements into a single, compact design using a reflector assembly, significantly reducing the overall system size compared to traditional solutions. This structural design not only facilitates system deployment and installation but also makes the system lighter, easier to carry and transport, making it particularly suitable for scenarios requiring rapid response and flexible deployment, such as mobile reconnaissance and emergency response. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the system structure of Embodiment 1 of the present invention;

[0040] Figure 2 This is a schematic diagram of the method flow of Embodiment 2 of the present invention.

[0041] The labels in the attached diagram are as follows: 101, visible light laser; 102, infrared laser; 201, visible light collimating lens; 202, infrared collimating lens; 301, first reflecting mirror; 302, second reflecting mirror; 303, third reflecting mirror; 304, fourth reflecting mirror; 401, dichroic mirror; 501, camera; 601, housing. Detailed Implementation

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0043] Example 1: A covert video surveillance jamming system based on dual-frequency laser coaxial modulation, comprising:

[0044] Dual-frequency laser module, used to generate lasers in visible light and infrared light modes;

[0045] The fully coaxial optical path module has its incident end connected to the laser output end of the dual-frequency laser module. It is used to receive and transmit the laser generated by the dual-frequency laser module, and adjust the laser output direction by deflecting its internal reflector group.

[0046] The data processing and control module is electrically connected to the dual-frequency laser module and the coaxial optical path module, respectively. The data processing and control module is used to identify the target camera, calculate the offset between the target camera and the laser optical axis, control the working mode of the dual-frequency laser module, and control the deflection of the mirror group in the coaxial optical path module.

[0047] In this embodiment, as Figure 1 As shown, the dual-frequency laser module includes:

[0048] A visible light laser 101 and an infrared laser 102 can operate independently or in conjunction. The visible light laser 101 has an output wavelength of 532 nm, and the infrared laser 102 has an output wavelength of 808 nm. A visible light collimating lens 201 is provided at the laser emission end of the visible light laser 101, and an infrared collimating lens 202 is provided at the laser emission end of the infrared laser 102. Collimation of visible light and infrared light is achieved by the visible light collimating lens 201 and the infrared collimating lens 202, respectively.

[0049] An ambient light sensor is used to monitor ambient light intensity in real time. The ambient light sensor converts light signals in the environment into electrical signals through photosensitive elements (such as photoresistors, photodiodes, CMOS image sensors, etc.), and then converts the electrical signals into digital quantities that the system can recognize through internal signal processing circuits (such as amplification, filtering, and AD conversion), so as to achieve continuous and high-precision monitoring of ambient light intensity (the unit is usually lux).

[0050] The laser control unit is configured to automatically activate the visible light laser 101 when the ambient light intensity is higher than a preset threshold (e.g., ≥500 lux, suitable for daytime and strong light scenarios); and automatically activate the infrared laser 102 when the ambient light intensity is lower than a preset threshold (e.g., <50 lux, suitable for nighttime and low light scenarios). In addition to mode switching, the core parameters of the laser, such as laser output power (to avoid overheating due to excessive power or affecting the interference effect due to insufficient power) and laser modulation frequency (to adapt to the imaging characteristics of different types of target cameras and improve the interference success rate), can be fine-tuned according to instructions from the data processing and control module, ensuring precise matching between the laser output state and interference requirements.

[0051] Furthermore, the all-coaxial optical path module includes:

[0052] Dichroic mirror 401, whose beam-splitting wavelength matches the laser wavelength of the dual-frequency laser module, is used to achieve coaxial beam combining of visible and infrared light. The beam-splitting wavelength range of dichroic mirror 401 is 650nm, achieving coaxial beam combining of 532nm visible light transmission and 808nm infrared light reflection. As the confluence point of the fully coaxial optical path, dichroic mirror 401 can precisely guide the two different wavelength lasers output from visible laser 101 and infrared laser 102 onto the same optical axis, forming a single coaxial laser beam. This function replaces the traditional multi-path parallel design, significantly reducing the size of the optical path module, while ensuring that the output directions of the two lasers are completely consistent, avoiding interference deviations caused by optical axis offset.

[0053] Multiple reflectors form the laser transmission optical path. In this embodiment, the reflectors include a first reflector 301, a second reflector 302, a third reflector 303, and a fourth reflector 304. The first reflector 301 is located after the infrared collimating lens 202, and the reflected laser light exits to the dichroic mirror 401. The second and third reflectors 302 and 303 are sequentially located on the beam combining optical path of the dichroic mirror 401, used to guide and fold the coaxial beam after beam combining. The fourth reflector 304 is located at the end of the optical path and is the last reflector before laser emission. The laser transmission optical path in this embodiment has a Z-shaped folding design, which can greatly shorten the physical size of the system while ensuring stable transmission of the optical path within the housing.

[0054] An internal rotating mechanism, driven by a stepper motor, is used to adjust the deflection angle of a specified reflector, thereby changing the final emission direction of the laser beam. In this embodiment, the internal rotating mechanism mainly consists of a stepper motor, a transmission assembly, and a reflector mounting base. The stepper motor, as the power source, is a high-precision stepper motor (such as a two-phase hybrid stepper motor). Its characteristic is that it can rotate in steps according to the input electrical pulse signal. The angle of each step (step angle, typically 0.9° / 1.8°, which can be further reduced to below 0.01° through microstepping) is fixed and controllable, providing stable and precise power for the reflector deflection and avoiding angle control errors caused by continuous rotation of ordinary motors. The transmission assembly uses gear transmission or direct coupling connection to transmit the rotational torque of the stepper motor to the reflector mounting base. The reflector mounting base is made of a high-strength, low-deformation metal material (such as aluminum alloy) and is used to securely fix the fourth reflector 304 in the fully coaxial optical path.

[0055] Furthermore, the data processing and control module includes:

[0056] The visual positioning unit integrates a camera 501 to capture environmental images and identify the features of the target camera using image processing algorithms. The integrated camera 501 typically employs a miniature high-definition CMOS camera (1920×1080 resolution) and is equipped with an optical lens adapted to the fully coaxial optical path (such as a fixed-focus lens with a focal length designed according to the system's interference distance), capable of capturing environmental images within a certain field of view (such as 60° horizontally and 45° vertically) in front of the system. The image processing algorithm first performs noise reduction and other preprocessing on the raw images captured by the camera to eliminate environmental interference factors and improve image quality to ensure subsequent recognition accuracy. Then, a lightweight CNN model of "feature extraction and classification recognition" is used to accurately select the target camera from the preprocessed image. Next, the position of the identified target camera in the image is marked with a rectangle and its center coordinates are determined. Finally, the correspondence between the image coordinate system and the laser optical axis coordinate system is established: by pre-calibration (such as placing a standard target at a known distance and recording the pixel coordinates of the target in the image and the physical angle between the target and the laser optical axis reference point), the conversion coefficient between "image pixel offset" and "actual angle offset" is determined (such as 10 pixels corresponding to 1° angle), ensuring that the pixel coordinates of the target camera can be converted into laser optical axis recognizable angle offset data in the subsequent process. Lightweight CNN models can utilize the mature MobileNet model, whose core is depthwise separable convolution (splitting standard convolution into depthwise convolution and pointwise convolution), combined with 1×1 convolution dimensionality reduction, ReLU6 activation, and global average pooling, making it a mature image processing model. Training methods include: 1. Data preprocessing: image normalization (e.g., to [-1,1]), random cropping, flipping, and other data augmentation to adapt to small sample training; 2. Optimizer: commonly using SGD (motivated) or Adam, with an initial learning rate of 0.001–0.01, adjusted through learning rate decay (e.g., StepLR); 3. Loss function: cross-entropy loss for classification tasks, combined with specific losses (e.g., SSD multi-task loss) for detection / segmentation tasks; 4. Regularization: adding L2 regularization and Dropout (or the sparsity inherent in depthwise separable convolution) to prevent overfitting; 5. Training strategy: supporting transfer learning (fine-tuning based on ImageNet pre-trained weights), adapting to specific task datasets, and reducing training costs.

[0057] An angle deviation calculation unit is configured to calculate the offset angle of the target relative to the laser optical axis based on the target position identified by the visual positioning unit; in this embodiment, the offset angle calculation formula is as follows:

[0058]

[0059] In the formula, and These are the pixel offsets of the target camera relative to the laser optical axis reference point in the horizontal and vertical directions, respectively. This is the offset angle.

[0060] The closed-loop control unit is configured to verify, again via the visual positioning unit, whether the laser spot covers the target after laser emission, and dynamically adjust the deflection angle of the reflector group based on the verification result. During the interference process, the visual positioning unit continuously monitors the positional changes of the target camera. If the target moves, the offset is immediately recalculated, and the angle of the reflector group is dynamically adjusted to ensure that the laser spot always covers the target camera. The system evaluates the interference effect by analyzing the spot coverage in the camera image and the response of the target camera. If the interference effect is insufficient (e.g., the target camera does not saturate or the image is abnormal), the system can automatically switch to a dual-frequency laser collaborative interference mode based on visual feedback, increasing the light intensity or introducing a modulation frequency to improve the interference success rate.

[0061] Furthermore, the system also includes a sealed housing 601 for enclosing the dual-frequency laser module, the fully coaxial optical path module, and the data processing and control module. The sealed housing has optical windows for laser emission and external scene light entry. The inner wall of the sealed housing is lined with light-absorbing material to effectively absorb scattered light that may be generated during laser transmission, preventing light leakage and further enhancing the system's stealth. The entire optical path system is enclosed within a fixed housing, and all optical path adjustments are completed through internal reflectors. There are no external moving parts, thus completely eliminating the risk of revealing interference intentions due to mechanical movement.

[0062] Example 2: This example provides an interference method based on the system in Example 1, such as... Figure 2 As shown, it includes the following steps:

[0063] Step S1: System Self-Check and Target Localization: Upon receiving the start command, the system first performs a self-check, verifying the operational status of each module, including the dual-frequency laser, reflector group, camera, stepper motor, and ambient light sensor, to ensure all components are functioning correctly. Simultaneously, it initializes the relevant parameters of the visual positioning unit and the angle deviation algorithm. Subsequently, the system activates the camera inside the casing to scan the environment, using feature recognition algorithms to search for features such as reflections and specific shapes from the target camera within the image.

[0064] Step S2: Dynamic Optical Path Calibration: The visual positioning unit continuously captures images from the target camera. Once the target camera is identified, the system immediately calculates the target's offset within the field of view, without relying on additional ranging equipment. This is achieved through the formula... The target angle deviation is calculated, and the control module drives the stepper motor to precisely adjust the rotation angle of the fourth reflector based on the calculation result of the angle deviation algorithm, so that the laser optical axis is accurately aligned with the target camera. After adjustment, the system performs a second shooting verification to check whether the laser spot accurately covers the target lens. If there is a deviation, the above calibration process is repeated until the preset accuracy requirement is met.

[0065] Step S3: Intelligent Laser Mode Switching: The ambient light sensor monitors the current ambient light intensity in real time to determine whether it is daytime or nighttime mode. Based on the ambient light detection results, the system automatically selects the most suitable laser mode. In daytime or well-lit environments, visible light mode is selected. In nighttime or low-light environments, infrared mode is selected. The system also supports manual selection of the laser mode or simultaneous operation of dual-frequency lasers according to user needs. The laser control module precisely modulates the laser based on the selected laser mode and preset interference parameters such as light intensity and frequency to generate the most suitable interference laser beam for the current scene.

[0066] Step S4: Adaptive Continuous Interference: The modulated laser beam is precisely projected onto the target camera through a fully coaxial optical path to interfere with its operation. During interference, the visual positioning unit continuously monitors changes in the target camera's position. If the target moves, the system immediately recalculates the offset and dynamically adjusts the angle of the reflector group to ensure the laser spot always covers the target camera. The system evaluates the interference effect by analyzing the spot coverage in the camera image and the target camera's response. If the interference effect is insufficient, the system can automatically switch to a dual-frequency laser collaborative interference mode or adjust the laser parameters to optimize the interference effect. All adjustments are completed inside the housing, with no external mechanical movement or exposed optical path, ensuring the system's stealth. Simultaneously, the system also features an anti-reflective coating and light-absorbing materials to further reduce the risk of light leakage.

[0067] Through the implementation process described in detail above, the covert video surveillance jamming system and method based on dual-frequency laser coaxial modulation can achieve efficient, accurate, and covert laser jamming tasks, meeting the needs of various complex scenarios.

Claims

1. A covert video surveillance jamming system based on dual-frequency laser coaxial modulation, characterized in that: include: Dual-frequency laser module, used to generate lasers in visible light and infrared light modes; The fully coaxial optical path module has its incident end connected to the laser output end of the dual-frequency laser module. It is used to receive and transmit the laser generated by the dual-frequency laser module, and adjust the laser output direction by deflecting its internal reflector group. The data processing and control module is electrically connected to the dual-frequency laser module and the all-coaxial optical path module, respectively. The data processing and control module is used to identify the target camera, calculate the offset between the target camera and the laser optical axis, control the working mode of the dual-frequency laser module, and control the deflection of the mirror group in the all-coaxial optical path module. The dual-frequency laser module includes: Visible laser (101) and infrared laser (102) can work independently or in combination; An ambient light sensor is used to monitor ambient light intensity in real time. The laser control unit is configured to automatically activate the visible light laser (101) when the ambient light intensity is higher than a preset threshold, and automatically activate the infrared laser (102) when the ambient light intensity is lower than a preset threshold. The fully coaxial optical path module includes: The dichroic mirror (401) has a beam splitting wavelength that matches the laser wavelength of the dual-frequency laser module, and is used to achieve coaxial beam combining of visible light and infrared light. Multiple mirrors form the laser transmission optical path; An internal rotating mechanism, driven by a stepper motor, is used to adjust the deflection angle of a specified reflector, thereby changing the final emission direction of the laser beam.

2. The covert video surveillance jamming system based on dual-frequency laser coaxial modulation according to claim 1, characterized in that: The visible light laser (101) is provided with a visible light collimating lens (201) at its laser emission end; the infrared laser (102) is provided with an infrared collimating lens (202) at its laser emission end.

3. The covert video surveillance jamming system based on dual-frequency laser coaxial modulation according to claim 1, characterized in that: The data processing and control module includes: The visual positioning unit integrates a camera (501) for capturing environmental images and identifying the features of the target camera through image processing algorithms; An angle deviation calculation unit is configured to calculate the offset angle of the target relative to the laser optical axis based on the target position identified by the visual positioning unit; The closed-loop control unit is configured to verify again through the visual positioning unit whether the laser spot covers the target after the laser is emitted, and dynamically adjust the deflection angle of the reflector group according to the verification result.

4. The covert video surveillance jamming system based on dual-frequency laser coaxial modulation according to claim 1, characterized in that: It also includes a closed housing for encapsulating the dual-frequency laser module, the all-coaxial optical path module, and the data processing and control module.

5. The covert video surveillance jamming system based on dual-frequency laser coaxial modulation according to claim 4, characterized in that: The enclosed shell is equipped with a light window for laser emission and external scene light to enter, and the inner wall of the enclosed shell is equipped with light-absorbing material to prevent internal light leakage.

6. The interference method for a concealed video surveillance interference system based on dual-frequency laser coaxial modulation according to any one of claims 1-5, characterized in that: Includes the following steps: Step S1: After the system starts up, it performs a self-test, then scans the environment and identifies the target camera; Step S2: The data processing and control module calculates the offset between the target camera and the laser optical axis, and drives the reflector group in the coaxial optical path module to rotate by the corresponding angle so that the laser optical axis is aligned with the target, and performs secondary verification and calibration. Step S3: Select and enable visible light mode and / or infrared light mode based on ambient light intensity; Step S4: The dual-frequency laser module emits a laser, which is then emitted to the target camera through the coaxial optical path module to interfere with it. During the interference process, the position of the target camera is continuously monitored, and the optical path is dynamically adjusted to ensure that the laser spot continuously covers the target camera.

7. The interference method according to claim 6, characterized in that: The offset is the offset angle between the target camera and the laser optical axis, and the calculation formula is as follows: In the formula, and These are the pixel offsets of the target camera relative to the laser optical axis reference point in the horizontal and vertical directions, respectively. This is the offset angle.

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