Unmanned aerial vehicle (UAV)-borne natural light fog visibility profiler

Abstract

This invention discloses an unmanned aerial vehicle (UAV)-borne natural light fog visibility profile detector, belonging to the technical field of atmospheric monitoring equipment. The detector includes an airborne unit, which comprises an upper-level computer fixed above the UAV and a lower-level computer fixed below the UAV, connected by a cable to transmit power and signals. The upper-level computer includes an optical lens, a GPS module, a gyroscope attitude sensor, and the optical lens includes a fluorinated glass cosine scatterer, a filter, a light-collecting element, and a light signal acquisition circuit. The lower-level computer includes a temperature, humidity, and pressure sensor, a meteorological parameter conversion circuit, a data communication module, and a power supply. The airborne unit passively receives natural light radiation to invert the horizontal visibility, vertical visibility, and visible height of the fog, and combines this with the meteorological parameters collected by the temperature, humidity, and pressure sensor to achieve vertical fog structure measurement.

Description

Technical Field

[0001] This invention belongs to the technical field of atmospheric monitoring equipment, specifically relating to an unmanned aerial vehicle (UAV)-borne natural light fog visibility profile detector. Background Technology

[0002] Fog, an aerosol system composed of tiny water droplets or ice crystals in the near-surface air, is a significant natural disaster affecting traffic safety and outdoor work safety. The vertical structure of fog (such as vertical visibility, visibility height, and fog thickness distribution) is a core parameter for studying fog formation mechanisms, evolution patterns, and early warning and prevention. While traditional ground-based visibility monitoring equipment can meet basic monitoring needs, it can only acquire visibility data in the horizontal direction at a single point, failing to reflect the vertical distribution characteristics of the fog layer, the concentration differences at different heights, and the vertical attenuation characteristics, leading to insufficient understanding of the overall fog distribution.

[0003] Currently, there are significant technological gaps in our understanding of the vertical structure of fog, primarily due to the lack of effective three-dimensional observation methods. Conventional meteorological radiosondes, limited by sampling frequency and spatial resolution, struggle to capture the fine structure of fog layers; while satellite remote sensing technology has blind spots in near-surface observations, failing to obtain accurate information on low-altitude fog layers. These technological limitations prevent meteorologists from fully grasping the mechanisms of fog formation and development, hindering the advancement of fog disaster early warning and prevention technologies.

[0004] While some existing detection devices can achieve aerial profile detection, they still suffer from numerous technical shortcomings in practical applications: they rely on weather balloons to carry airborne aircraft, and the balloon's ascent speed is determined by its volume and is uncontrollable, making it impossible to obtain high-resolution vertical data by adjusting the ascent and descent speeds; they lack specificity regarding fog droplet scattering characteristics, making it impossible to accurately invert fog visibility parameters; and the problem of optical element errors remains unresolved. These issues severely limit the accuracy and reliability of fog vertical structure measurement. Therefore, existing technologies urgently need improvement to address these problems.

[0005] Therefore, there is an urgent need for a dedicated detector optimized for fog characteristics and adapted for use on drones. Summary of the Invention

[0006] This invention provides an unmanned aerial vehicle (UAV)-borne natural light fog visibility profile detector, which has the advantages of realizing vertical fog structure measurement and improving measurement accuracy and reliability.

[0007] The present invention provides an unmanned aerial vehicle (UAV)-borne natural light fog visibility profile detector, including an airborne unit mounted on the UAV. The airborne unit includes an upper computer fixed above the UAV and a lower computer fixed below the UAV. The two are connected by a connecting cable to transmit power and signals. The host computer includes an optical lens, a GPS module, and an attitude sensor. The optical lens includes a fluorinated glass cosine scatterer, a filter and a light-collecting element, and a light signal acquisition circuit. The fluorinated glass cosine scatterer is used to receive natural light, and the light signal acquisition circuit is used to convert the light signal into an electrical signal. The lower-level machine includes a temperature, humidity and pressure sensor, a meteorological parameter conversion circuit, a data communication module, and a power supply. The temperature, humidity and pressure sensor is used to collect temperature, humidity and air pressure parameters. The meteorological parameter conversion circuit is used to convert meteorological parameters into electrical signals. The data communication module transmits the data collected by the airborne machine to the ground system host through a horizontal data communication antenna. The power supply provides power to the upper-level machine and the lower-level machine. The aerial vehicle retrieves the horizontal visibility, vertical visibility, and visibility height of the fog by passively receiving natural light radiation, and combines this with meteorological parameters collected by temperature, humidity, and pressure sensors to achieve vertical structure measurement of the fog.

[0008] Preferably, the system also includes a ground unit and a system host. The ground unit has the same structure as the air unit and is used to synchronously detect changes in ground-to-air illumination conditions and ground meteorological parameters. The system host is used to realize system control, observation process display, data reception and storage.

[0009] Preferably, the host computer further includes a signal amplification circuit, a data acquisition and AD circuit, and a data and power interface A, wherein the data and power interface A is used to connect to a power source and transmit the acquired data.

[0010] Preferably, the lower-level machine also includes a mounting platform, a chassis, and a data and power interface B. The chassis is used to integrate other components of the lower-level machine. The chassis is fixed below the drone by the mounting platform. The data and power interface B is used to connect to the power supply and transmit the collected data.

[0011] Preferably, the chassis is made of carbon fiber, and the interior of the chassis is provided with a foam insulation layer and a felt insulation layer in sequence to increase the strength of the chassis and maintain the stability of the internal temperature of the instrument, so as to ensure that the change in the internal temperature of the instrument during the observation meets the measurement accuracy requirements.

[0012] Preferably, the working spectrum of the filter and the light-collecting element is 430nm, 477nm, 547nm, 617nm and 687nm, which are used to reflect the scattering characteristics of different particulate droplets.

[0013] Preferably, the host computer also includes an electromagnetic interference suppression circuit, which is integrated into the signal amplification circuit to eliminate high-frequency pulse interference and achieve high-precision data acquisition.

[0014] Preferably, a time synchronization unit is also included, which employs quartz oscillator sampling control technology and a digital clock verification algorithm; the quartz oscillator sampling control technology is used to achieve time synchronization between the airborne aircraft and the ground aircraft, and the digital clock verification algorithm is used to correct the cumulative deviation between the quartz oscillators and restore the actual sampling time.

[0015] Preferably, a silicone ring is provided between the filter and the light-collecting element and the optical signal acquisition circuit to form an optical soft-seal structure; the optical soft-seal structure is used to reduce the impact of UAV vibration on the optical signal acquisition circuit, so that the optical signal is not affected by UAV vibration.

[0016] Preferably, the fluorinated glass cosine scatterer employs a transmission light correction algorithm to correct the optical signal error introduced by the fluorinated glass cosine scatterer. The transmission light correction algorithm treats the fluorinated glass cosine scatterer as a partially transparent medium, calculates the total incident light flux reaching the optical signal acquisition circuit through integration, and determines the correction coefficient δ using the following formula:

[0017] Among them, E r0 E represents the light flux when the cosine scatterer of the fluorinated glass is the same diameter as the aperture, obtained through synchronous measurement. R The total light flux reaching the aperture is calculated by integrating the light radiation from the upper surface of the fluorinated glass; and the voltage signal V output by the optical signal acquisition circuit is calculated based on the correction coefficient δ. r Corrected to v r ,Right now This is to eliminate the influence of the thickness of the fluorinated glass on the optical signal.

[0018] The beneficial effects of this invention are: (1) Achieve accurate detection of vertical fog structures and more comprehensive measurement parameters: This invention selects five atmospheric water vapor window bands of 430nm, 477nm, 547nm, 617nm and 687nm to accurately match the scattering characteristics of fog droplets. Compared with traditional wide-spectrum sensors, the fog visibility inversion error is reduced. It can simultaneously output three core parameters: horizontal visibility, vertical visibility and visibility height, filling the gap in existing technologies that cannot accurately measure vertical visibility.

[0019] The lower-level machine of this invention is equipped with a temperature, humidity and pressure sensor with an elliptical frame. Combined with a meteorological parameter conversion circuit, it can simultaneously acquire key environmental parameters (temperature, humidity and air pressure) for fog formation, providing data support for research on the causes of fog and analysis of its climate effects. Traditional lidar or ground instruments cannot simultaneously achieve vertical profile linkage observation of "visibility + meteorological parameters".

[0020] (2) Adapting to the characteristics of UAVs, flight and observation stability are significantly improved: The present invention features an airborne aircraft with a host and slave configuration. Signals and power are transmitted via connecting cables, and the overall center of gravity is controlled near the rotor plane of the UAV. Combined with the silicone ring optical soft sealing structure between the optical lens and the acquisition circuit, it can reduce more than 90% of the UAV vibration interference, ensuring that the light signal acquisition is not affected by the body shaking and that the flight attitude is stable.

[0021] By embedding an anti-electromagnetic interference circuit in the host computer signal amplification circuit and integrating resistors and capacitors into the interference shielding path, the influence of high-frequency electromagnetic pulses from the UAV engine on analog signal acquisition can be eliminated. After testing on multiple UAV models, the data anomaly rate is low, which is far superior to equipment without anti-interference design.

[0022] (3) High measurement accuracy and strong data reliability This invention employs a fluorinated glass correction algorithm to correct optical signal errors caused by the fluorinated glass cosine scatterer. Addressing the luminous flux error due to the thickness of the fluorinated glass cosine scatterer, the total incident luminous flux is calculated by integration, and a correction coefficient δ is introduced to control the relative deviation of the optical signal measurement within 1.5%. The lower-level computer chassis uses a carbon fiber structure, with internal foam insulation layers and felt insulation layers arranged sequentially. This minimizes internal temperature changes during observation, preventing component parameter drift in low-temperature environments and ensuring the stability of temperature, humidity, pressure, and optical signal data. Attached Figure Description

[0023] For ease of explanation, the present invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the host computer structure of the present invention; Figure 2 This is a schematic diagram of the lower-level machine structure of the present invention. In the picture: 100 - Host computer; 110 - Fluoride glass cosine diffuser; 120 - Filter and light-collecting element; 130 - Optical signal acquisition circuit; 140 - GPS module; 150 - Attitude sensor; 160 - Signal amplification circuit; 170 - Data acquisition and AD circuit; 180 - Data and power interface A; 200 - Lower-level machine; 210 - Temperature, humidity and pressure sensor; 220 - Meteorological parameter conversion circuit; 230 - Data communication module; 240 - Power supply; 250 - Horizontal data communication antenna; 260 - Mounting platform; 270 - Chassis; 280 - Data and power interface B. Detailed Implementation

[0025] The following are specific embodiments of the present invention described in conjunction with the accompanying drawings, further illustrating the technical solutions of the present invention. However, the present invention is not limited to these embodiments. Specific details, such as particular configurations and components, are provided in the following description merely to aid in a comprehensive understanding of the embodiments of the present invention. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Furthermore, for clarity and brevity, descriptions of known functions and structures have been omitted.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.

[0027] like Figures 1-2 As shown, the UAV-borne natural light fog visibility profile detector provided in this embodiment includes an airborne unit mounted on a UAV. The airborne unit includes a host computer 100 fixed above the UAV and a slave computer 200 fixed below the UAV. The two are connected by a connecting cable to transmit power and signals. The host computer 100 includes an optical lens, a GPS module 140, and an attitude sensor 150. The optical lens includes a fluorinated glass cosine diffuser 110, a filter and a light-collecting element 120, and a light signal acquisition circuit 130. The fluorinated glass cosine diffuser 110 is used to receive natural light, and the light signal acquisition circuit 130 is used to convert the light signal into an electrical signal. The slave computer 200... The system includes a temperature, humidity, and pressure sensor 210, a meteorological parameter conversion circuit 220, a data communication module 230, and a power supply 240. The temperature, humidity, and pressure sensor 210 is used to collect temperature, humidity, and air pressure parameters. The meteorological parameter conversion circuit 220 is used to convert meteorological parameters into electrical signals. The data communication module 230 transmits the data collected by the aircraft in the air to the system host on the ground through a horizontal data communication antenna 250. The power supply 240 supplies power to the host computer 100 and the slave computer 200. The aircraft in the air retrieves the horizontal visibility, vertical visibility, and visibility height of the fog by passively receiving natural light radiation, and combines this with the meteorological parameters collected by the temperature, humidity, and pressure sensor 210 to realize the vertical structure measurement of the fog.

[0028] The attitude sensor 150 is a gyroscope attitude sensor. The fluorinated glass cosine scatterer 110 is an optical element with a specific refractive index, whose surface is treated with cosine characteristics to uniformly receive natural light radiation from different incident angles, thus eliminating the influence of changes in light angle on light signal acquisition. The filter and light-collecting element 120 is a composite optical component composed of a multi-layer coated filter and a focusing lens, used to separate the scattering spectral signals of fog droplets of different sizes. The light signal acquisition circuit 130 is an electronic module that converts light signals into voltage signals, used to quantify the attenuation of natural light in fog. The temperature, humidity, and pressure sensor 210 is a miniature sensor integrating temperature, humidity, and air pressure measurements, used to synchronously acquire atmospheric environmental parameters to correct visibility inversion errors. The data communication module 230 is a wireless data transmission unit used to stably transmit data to the ground system during UAV flight.

[0029] Specifically, after the optical lens receives natural light radiation, the fluorinated glass cosine scatterer 110 homogenizes the incident light at different angles, the filter 120 filters light signals of specific wavelengths, and the light-collecting element 120 focuses the light signal onto the light signal acquisition circuit 130, which converts it into an electrical signal. The GPS module 140 and the gyroscope attitude sensor 150 record the spatial position and attitude data of the UAV, which are used to correct spatial attitude deviations during light signal acquisition. The temperature, humidity, and pressure sensor 210 in the lower-level computer 200 collects atmospheric environmental parameters in real time. After being processed into digital signals by the meteorological parameter conversion circuit 220, the data is transmitted to the data communication module 230 via a connecting cable along with the light signal data from the upper-level computer 100, and finally sent to the ground system. The ground system calculates the visibility distribution and visibility height at different heights of the fog layer by fusing light attenuation data and meteorological parameters, and generates a vertical structure profile of the fog by combining the UAV's ascent and descent trajectory.

[0030] Through the above technical solution, this application can simultaneously acquire horizontal and vertical visibility data of fog layers, and analyze the vertical distribution characteristics of fog by combining temperature, humidity, and air pressure parameters, providing multi-dimensional observation data for meteorological research. The separate arrangement of the optical module and meteorological module avoids signal interference, and the horizontal antenna 250 and lightweight structure ensure the flight stability of the UAV, making it suitable for fog layer detection missions in complex environments.

[0031] This application further proposes that the detector also includes a ground unit and a system host. The ground unit refers to a detection device with the same structure as the airborne unit, specifically employing the same optical lens, temperature, humidity, and pressure sensor 210, and communication module 230 as the airborne unit. It is used to synchronously collect illumination conditions and meteorological parameters on the ground, eliminating interference from changes in environmental factors on the airborne detection data. The system host refers to the data processing and control terminal, used to integrate the data from the ground unit and the airborne unit. By displaying the observation process in real time and storing multi-source data, it ensures the controllability and integrity of the measurement process.

[0032] This application further proposes that the host computer 100 also includes a signal amplification circuit 160, a data acquisition and AD circuit 170, and a data and power interface A180. The signal amplification circuit 160 is a circuit module that amplifies the weak electrical signal output from the optical signal acquisition circuit 130, its function being to enhance signal strength and improve the signal-to-noise ratio of subsequent processing stages. The data acquisition and AD circuit 170 is a circuit module that converts analog electrical signals into digital signals, its function being to convert the amplified analog signals into digital signals for transmission and storage. The data and power interface A180 is a physical interface used to connect the power line and the data transmission line, its function being to provide a stable power input to the host computer 100 and establish a data communication link with the slave computer 200.

[0033] Specifically, after the optical lens receives natural light, it converts it into an electrical signal via the optical signal acquisition circuit 130. The signal amplification circuit 160 amplifies the electrical signal, and the data acquisition and AD circuit 170 converts the amplified analog signal into a digital signal. Finally, the digital signal and power supply are transmitted synchronously to the lower-level computer 200 through the data and power interface A180. In this process, the coordinated operation of the signal amplification circuit 160 and the data acquisition and AD circuit 170 ensures that the optical signal can maintain stable transmission even under the vibration and electromagnetic interference environment of the UAV during flight, while the integrated design of the data and power interface A180 simplifies the complexity of the internal wiring of the aircraft.

[0034] This application further proposes that the lower-level machine 200 also includes a mounting platform 260, a chassis 270, and a data and power interface B280. The chassis 270 is used to centrally install the temperature, humidity and pressure sensor 210, the meteorological parameter conversion circuit 220, and the data communication module 230, reducing the interference of the external environment on the internal components. The chassis 270 is fixed under the UAV by the mounting platform 260 to prevent the components from shifting due to vibration during flight. The data and power interface B280 is a physical port that connects the power supply and data transmission channels, used to establish the connection between the lower-level machine 200 and the UAV power supply system, and at the same time transmit the collected meteorological data to the ground system through cables.

[0035] This application further proposes that the chassis 270 adopts a carbon fiber structure, whose bending strength can withstand the airflow impact during the flight of the UAV. The chassis 270 is provided with a foam insulation layer and a felt insulation layer in sequence to increase the strength of the chassis 270 and maintain the stability of the internal temperature of the instrument, so as to ensure that the internal temperature change of the instrument meets the measurement accuracy requirements during the observation period.

[0036] This application further proposes that the working spectral bands of the filter and light-collecting element 120 are 430nm, 477nm, 547nm, 617nm, and 687nm, to reflect the scattering characteristics of different droplet particles. Specifically, the five discrete spectral bands of 430nm, 477nm, 547nm, 617nm, and 687nm cover the typical response spectral characteristics of droplet scattering in the visible light range. When natural light passes through the fog layer, the degree of light intensity attenuation in each spectral band is functionally related to the scattering cross-section of the corresponding droplet size. By simultaneously acquiring light intensity data from five channels, a correlation model between particle size distribution and light attenuation can be established, thereby retrieving the vertical distribution characteristics of the droplets. This multi-spectral band collaborative working mechanism effectively solves the technical limitation that a single wavelength cannot distinguish between droplets of mixed particle sizes.

[0037] This application further proposes that the host computer 100 also includes an electromagnetic interference suppression circuit, which is integrated in the signal amplification circuit 160 to eliminate high-frequency pulse interference and achieve high-precision data acquisition; the processed electrical signal enters the data acquisition and AD circuit 170 for digital processing, thereby eliminating the influence of high-frequency interference on optical signal acquisition and ensuring the accuracy of optical signal to electrical signal conversion.

[0038] This application further proposes that the detector also includes a time synchronization unit, which adopts quartz oscillator sampling control technology and digital clock verification algorithm; the quartz oscillator sampling control technology is used to realize the time synchronization between the airborne aircraft and the ground aircraft, and the digital clock verification algorithm is used to correct the cumulative deviation between the quartz oscillators and restore the actual sampling time.

[0039] Specifically, during the vertical structure measurement of fog, the aerial and ground-based aircraft need to synchronously collect data on illumination conditions and meteorological parameters. Quartz oscillator sampling control technology generates precise synchronization trigger signals at the hardware level, enabling the aerial and ground-based aircraft to start data acquisition at the same time. The digital clock verification algorithm continuously monitors clock deviation at the software level. When the accumulated time error exceeds the set threshold, it automatically adjusts the timestamp data in the sampling time series to ensure that the data collected by different devices are strictly aligned in the time dimension.

[0040] This application further proposes that a silicone ring be provided between the filter and the light-collecting element 120 and the optical signal acquisition circuit 130 to form an optical soft-seal structure. This optical soft-seal structure is used to reduce the impact of UAV vibration on the optical signal acquisition circuit 130, ensuring that the optical signal is not interfered with by UAV vibration. This technical solution effectively isolates the mechanical vibration generated during UAV flight, avoids signal distortion caused by optical path misalignment or component loosening, and ensures the stability and accuracy of the output data from the optical signal acquisition circuit 130.

[0041] This application further proposes using a transmission light correction algorithm to correct the optical signal error caused by the fluorinated glass cosine scatterer 110. The fluorinated glass cosine scatterer 110 has different light-gathering conditions: not only can the light energy directly above it enter the light-gathering aperture, but light from the rest of the fluorinated glass also enters the aperture, resulting in a significant increase in received energy; the additional energy is related to the thickness of the fluorinated glass. In physical optics, light is repeatedly scattered in fluorinated glass, eventually reaching its lower surface; the propagation process of light in fluorinated glass is complex. Here, we consider fluorinated glass as a special partially transparent material, and the complex process of light in fluorinated glass is equivalent to light attenuation; let the thickness of the fluorinated glass be h, the irradiance illuminating the upper surface of the glass be E0, the attenuation coefficient be k, and the attenuation distance be the distance l from the upper boundary of the fluorinated glass to a point above the light-gathering aperture. The irradiance reaching the bottom of the fluorinated glass sheet should be: Equation (1) The integral irradiance of light reaching a point p from the entire surface of the fluorinated glass is: Equation (2) Where r is the distance from any point on the fluorinated glass to the center point of the upper surface of the fluorinated glass, and R is the maximum distance to the center point of the fluorinated glass. Since: Equation (3) Then equation (2) becomes: Equation (4) When R approaches infinity, the theoretical solution to equation (4) can be obtained. Equation (5) Where K1 is a modified Bessel function of the second kind: Equation (6) Among them, I v The first-order modified Bessel function of order v is: Equation (7) In fact, when r equals 12 mm, the energy entering the aperture essentially no longer changes, and equation (5) already well reflects the additional energy entering the aperture through the fluorinated glass. The correction coefficient δ is obtained as: Equation (8) Among them, E r0 E represents the light flux when the cosine scatterer of the fluorinated glass is the same diameter as the aperture, obtained through synchronous measurement. R The total light flux reaching the aperture is given by equation (5); and the voltage signal V output by the optical signal acquisition circuit is calculated based on the correction coefficient δ. r Corrected to v r,Right now: Equation (9) To eliminate the influence of the thickness of fluorinated glass on the optical signal, actual verification shows that the correction effect obtained by equation (9) is very ideal, with a relative deviation of less than 1.5%.

[0042] In addition, the supporting drone selected in this application must meet the following basic requirements: (1) The upper part of the drone must have a flat space with a diameter of not less than 10cm for carrying optical instruments, and the center of the space must be roughly consistent with the center of gravity; (2) The lower part of the drone should have enough space to carry the data transmission system. If there is an altimeter for downward detection, it must be more than 7cm away from the center of gravity of the drone; (3) The drone must meet the requirement of a load capacity of 3kg and have the ability to fly at a height of 700m with a load.

[0043] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0044] In the description of this application, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

Claims

1. An unmanned aerial vehicle (UAV)-borne natural light fog visibility profile detector, characterized in that, The system includes an airborne unit mounted on a drone, which includes a host computer (100) fixed above the drone and a slave computer (200) fixed below the drone, which are connected by a connecting cable to transmit power and signals. The host computer (100) includes an optical lens, a GPS module (140), and an attitude sensor (150). The optical lens includes a fluorinated glass cosine scatterer (110), a filter and a light-collecting element (120), and a light signal acquisition circuit (130). The fluorinated glass cosine scatterer (110) is used to receive natural light, and the light signal acquisition circuit (130) is used to convert the light signal into an electrical signal. The lower-level machine (200) includes a temperature, humidity and pressure sensor (210), a meteorological parameter conversion circuit (220), a data communication module (230), and a power supply (240). The temperature, humidity and pressure sensor (210) is used to collect temperature, humidity and air pressure parameters. The meteorological parameter conversion circuit (220) is used to convert meteorological parameters into electrical signals. The data communication module (230) transmits the data collected by the aircraft in the air to the system host on the ground through a horizontal data communication antenna (250). The power supply (240) supplies power to the upper-level machine (100) and the lower-level machine (200). The aircraft in the air retrieves the horizontal visibility, vertical visibility, and visibility height of the fog by passively receiving natural light radiation, and combines this with meteorological parameters collected by the temperature, humidity, and pressure sensor (210) to achieve vertical structure measurement of the fog.

2. The UAV-borne natural light fog visibility profiler according to claim 1, characterized in that, It also includes a ground unit and a system host. The ground unit has the same structure as the air unit and is used to synchronously detect changes in ground-to-air illumination conditions and ground meteorological parameters. The system host is used to realize system control, observation process display, data reception and storage.

3. The UAV-borne natural light fog visibility profiler according to claim 1, characterized in that, The host computer (100) also includes a signal amplification circuit (160), a data acquisition and AD circuit (170), and a data and power interface A (180), which is used to connect to the power supply and transmit the acquired data.

4. The UAV-borne natural light fog visibility profiler according to claim 1, characterized in that, The lower-level machine (200) also includes an installation platform (260), a chassis (270), and a data and power interface B (280). The chassis (270) is used to integrate other components of the lower-level machine (200). The chassis (270) is fixed to the bottom of the UAV through the installation platform (260). The data and power interface B (280) is used to connect to the power supply and transmit the collected data.

5. The UAV-borne natural light fog visibility profiler according to claim 4, characterized in that, The chassis (270) is made of carbon fiber and has a foam insulation layer and a felt insulation layer inside it in sequence. These are used to increase the strength of the chassis (270) and maintain the stability of the internal temperature of the instrument, so as to ensure that the change in the internal temperature of the instrument meets the measurement accuracy requirements during the observation period.

6. The UAV-borne natural light fog visibility profiler according to claim 1, characterized in that, The working spectrum of the filter and the light-collecting element (120) is 430nm, 477nm, 547nm, 617nm and 687nm, which are used to reflect the scattering characteristics of different particulate droplets.

7. The UAV-borne natural light fog visibility profiler according to claim 3, characterized in that, The host computer (100) also includes an electromagnetic interference suppression circuit, which is integrated in the signal amplification circuit (160) to eliminate high-frequency pulse interference and achieve high-precision data acquisition.

8. The UAV-borne natural light fog visibility profiler according to claim 2, characterized in that, It also includes a time synchronization unit, which employs quartz oscillator sampling control technology and a digital clock verification algorithm. The quartz oscillator sampling control technology is used to achieve time synchronization between the airborne aircraft and the ground aircraft, and the digital clock verification algorithm is used to correct the cumulative deviation between the quartz oscillators and restore the actual sampling time.

9. The UAV-borne natural light fog visibility profiler according to claim 1, characterized in that, A silicone ring is provided between the filter and the light-collecting element (120) and the optical signal acquisition circuit (130) to form an optical soft-seal structure; the optical soft-seal structure is used to reduce the impact of UAV vibration on the optical signal acquisition circuit (130) so that the optical signal is not affected by UAV vibration.

10. The UAV-borne natural light fog visibility profiler according to claim 1, characterized in that, The fluorinated glass cosine scatterer (110) employs a transmission light correction algorithm to correct the optical signal error caused by the fluorinated glass cosine scatterer. The transmission light correction algorithm treats the fluorinated glass cosine scatterer (110) as a partially transparent medium, calculates the total incident light flux reaching the optical signal acquisition circuit through integration, and determines the correction coefficient δ using the following formula: ； Among them, E r0 The light flux of the fluorinated glass cosine scatterer (110) when the aperture diameter is the same is obtained by synchronous measurement, E. R The total light flux reaching the aperture is calculated by integrating the light radiation from the upper surface of the fluorinated glass; and the voltage signal V output by the optical signal acquisition circuit (130) is calculated based on the correction coefficient δ. r Corrected to v r ,Right now This is to eliminate the influence of the thickness of the fluorinated glass on the optical signal.

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