Unmanned aerial vehicle airborne open nonlinear resonant photoacoustic cell gas detection method and system

Abstract

The application discloses a kind of unmanned aerial vehicle airborne open nonlinear resonant photoacoustic cell gas detection method and system.The method comprises the following steps: a) using unmanned aerial vehicle to carry open nonlinear resonant photoacoustic cell, photoacoustic cell is open structure, without air pump, utilize the air natural flow when unmanned aerial vehicle flies to realize gas rapid exchange;B) signal function module generates modulation signal, laser emits modulation laser to photoacoustic cell and interacts with the gas to be measured, excitation gas generates thermal expansion and generates photoacoustic signal;C) photoacoustic signal is collected by microphone module installed in photoacoustic cell, after demodulation by signal function module, gas concentration is obtained based on Lambert-Bill law inversion;D) signal function module real-time transmission detection data to ground control station, or save detection data in on-board storage system.The application is suitable for complex scene stereoscopic monitoring, supports collaborative work, with high flexibility, high spatial resolution and high detection sensitivity and the like advantages.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of laser, and relates to a UAV airborne open nonlinear resonant photoacoustic cell gas detection method and system, which is suitable for atmospheric pollution monitoring, industrial emission detection, environmental emergency response and the like scenes. BACKGROUND

[0002] High-sensitivity trace gas detection technology is crucial in the fields of environmental monitoring, industrial safety, etc. Although traditional high-precision gas detection methods such as mass spectrometry (MS) and optical cavity ring-down spectroscopy (CRDS) have extremely high detection sensitivity, their instrument systems are usually bulky, heavy, high-power and expensive, which makes it difficult to realize miniaturization and mobile deployment, and even less suitable for being integrated as a payload on a UAV platform for large-scale mobile monitoring.

[0003] Photoacoustic spectroscopy (PAS) technology is widely used in trace gas detection due to its inherent advantages of high sensitivity, fast response, and no need for sample pretreatment. More importantly, the core detection unit of the photoacoustic spectroscopy system, the photoacoustic cell, can be miniaturized and lightened through ingenious design while maintaining high detection performance, which makes it very suitable for mobile platforms with strict weight and volume restrictions, especially for UAV applications.

[0004] UAVs have the advantages of flexible mobility, wide coverage, low cost, and the ability to avoid personal safety risks, and have become an important tool for atmospheric environmental monitoring. However, the existing gas detection devices carried by UAVs mostly use electrochemical sensors or non-resonant infrared sensors, which have low sensitivity (usually in ppm level), cross interference, and slow response speed, making it difficult to meet the current high-precision monitoring needs of ppb or even ppt level trace gases.

[0005] In addition, traditional closed photoacoustic cells require a gas sampling pump, which not only increases the weight, volume and power consumption of the system, but also limits the detection response speed. The presence of the gas sampling pump makes the system response time usually several seconds to several tens of seconds, which cannot meet the real-time monitoring needs of gas concentration changes during the rapid movement of UAVs.

[0006] Open photoacoustic cell structure can avoid complex gas sampling system, and realize gas exchange through air natural flow by opening design, which greatly improves the system response speed.

[0007] In addition, in the fields of fixed-point environmental monitoring, industrial process control, emergency monitoring, etc., there is an urgent need for high-sensitivity gas sensors that do not require sampling pumps, have fast response speed and are resistant to flow noise interference. Traditional devices often require complex sampling pretreatment systems, which have high maintenance costs and slow response. Therefore, it is of great significance to develop a general open detection technology suitable for various flow scenarios. SUMMARY

[0008] The present application provides a UAV airborne open nonlinear resonant photoacoustic cell gas detection method and system, aiming to solve the problem of existing high-precision gas detection technology equipment being heavy and difficult to be airborne, and the problem of existing UAV gas detection technology having large airflow noise, low sensitivity and slow response speed, so as to realize rapid, large-scale, high spatial and temporal resolution three-dimensional gas monitoring.

[0009] To achieve the above purpose, the technical scheme adopted by the present application is:

[0010] A UAV airborne open nonlinear resonant photoacoustic cell gas detection method, comprising the following steps:

[0011] a) An open nonlinear resonant photoacoustic cell is carried by a UAV, the photoacoustic cell is of an open structure and has no air pump, and air natural flow during UAV flight is used to realize rapid gas exchange;

[0012] b) A signal function module generates a modulation signal, a laser emits a modulated laser into the photoacoustic cell to interact with the gas to be detected, excites the gas to produce thermal expansion and generates a photoacoustic signal;

[0013] c) The photoacoustic signal is collected by a microphone module installed in the photoacoustic cell, and after demodulation by the signal function module, the gas concentration is obtained based on the Lambert-Beer law;

[0014] d) The signal function module transmits detection data to a ground control station in real time, or saves the detection data in an on-board storage system.

[0015] In step a), the tube body of the open nonlinear resonant photoacoustic cell is an open tube with an axisymmetric gradually expanding streamline structure (the cross-sectional area gradually increases along the axial direction), which not only ensures the acoustic resonance effect but also reduces the airflow resistance.

[0016] In step b), the wavelength modulation (WMS) signal of the modulated laser is composed of a 0.1 Hz sawtooth wave and a high-frequency sine wave.

[0017] A photoacoustic spectroscopy gas detection system based on a UAV airborne open nonlinear resonant photoacoustic cell, comprising:

[0018] A UAV platform for carrying other components and flying;

[0019] A laser control module electrically connected to the laser to control its output;

[0020] A laser that emits modulated laser to the open nonlinear resonant photoacoustic cell;

[0021] An open nonlinear resonant photoacoustic cell is installed below a UAV to contain a gas to be measured and to make laser interact with the gas to generate photoacoustic signals.

[0022] A microphone module is arranged in the photoacoustic cell to collect the photoacoustic signals.

[0023] A signal function module is electrically connected with the microphone module and the laser control module to demodulate the photoacoustic signals and to inverse the gas concentration, and to generate a modulation signal to be sent to the laser control module.

[0024] A ground control station is in communication with the signal function module to receive detection data and to display.

[0025] The tube body of the open nonlinear resonant photoacoustic cell is an axisymmetric gradually expanding streamline structure, and the axial cross-sectional area gradually increases.

[0026] The resonant tube length of the open nonlinear resonant photoacoustic cell is 40 mm, the inlet / outlet diameter is 6 mm, the resonant frequency is 1180 Hz, and the quality factor is 3.

[0027] The laser is a distributed feedback (DFB) laser with a center wavelength λ0 of 1653 nm, which is used to detect methane.

[0028] The UAV platform is equipped with a GPS / IMU positioning module, supports multi-UAV cooperative networking, each UAV acts as a mobile sensing node, communicates with the ground control station in real time through a 5G / satellite link, and realizes stereoscopic and multi-dimensional gas distribution monitoring.

[0029] The system can be adapted to many platforms from mobile platforms such as UAVs and cruise robots to fixed stations, and can be widely used in any monitoring occasion where gas flows, including but not limited to environmental air quality monitoring stations, industrial discharge ports, ventilation ducts, agricultural greenhouses, medical diagnosis and industrial process monitoring, etc., to realize real-time, in-situ and rapid response monitoring of gases.

[0030] The beneficial effects of the present application are as follows:

[0031] First, a comparison with traditional technology is made. The cross-sectional area of the traditional cylindrical (linear) tube is constant, and its sound field distribution follows the standard one-dimensional standing wave mode (such as the fundamental mode λ / 2). Although resonance can be produced, the sound pressure amplitude is uniformly distributed in the axial direction of the tube, and the energy is relatively dispersed. Due to the sharp change in acoustic impedance at the opening (the impedance in the tube does not match the impedance in free space), it will cause serious radiation loss of acoustic energy. The advantage of the nonlinear tube: the present invention uses a nonlinear resonant tube, whose cross-sectional area changes smoothly along the axial direction. This structure forms an acoustic impedance gradient or an acoustic horn in acoustics. It can more effectively match the high acoustic impedance in the tube with the low acoustic impedance outside the tube, significantly reducing the reflection and radiation loss of sound waves at the opening, so that more acoustic energy is confined in the resonant cavity. The nonlinear shape changes the propagation characteristics of the sound wave, which can more effectively focus and localize the acoustic energy in the central region of the resonant cavity (i.e. the acoustic pressure antinode), rather than being uniformly distributed. This allows higher sound pressure amplitude to be obtained at the microphone position under the same photoacoustic excitation. When the UAV is flying or there is environmental wind, the airflow flowing through the edge of the cylindrical (linear) open tube will cause severe flow separation, forming a periodic Karman vortex street. The periodic shedding of this vortex will produce strong and frequency-concentrated flow-induced noise, which seriously interferes with the weak photoacoustic signal. The nonlinear resonant tube of the present invention has a gradually expanding and contracting streamline design, which can guide the airflow to flow smoothly into and out of the photoacoustic cell, greatly avoiding flow separation and vortex generation. This suppresses the generation of flow-induced noise from the sound source. The nonlinear resonant tube has non-harmonic spectral characteristics, i.e. its high-order resonance frequencies are not integer multiples of the fundamental frequency. This means that the frequency of the flow-induced noise is difficult to couple with the high-order resonance modes of the photoacoustic cell, so it is not easy to be amplified. The harmonic spectral characteristics of the cylindrical tube make it more likely to resonate and amplify noise at multiple frequencies. Therefore, the nonlinear structure itself also acts as an acoustic bandpass filter, selectively amplifying the target photoacoustic signal frequency while suppressing noise at other frequencies.

[0032] Then briefly summarize the advantages of the present invention:

[0033] 1) The open nonlinear resonant photoacoustic cell does not require a vacuum pump, significantly reducing the weight, volume and power consumption of the system; using natural air flow to achieve rapid gas exchange, far exceeding the traditional system that requires a vacuum pump;

[0034] 2) The structure of the open nonlinear resonant photoacoustic cell improves the acoustic gain and effectively suppresses the airflow noise;

[0035] 3) The UAV platform supports ultra-large range (>100,000 km²), stereoscopic monitoring; multiple machines networking to achieve high spatial resolution and fast response; suitable for scenarios such as atmospheric pollution monitoring and emergency monitoring of sudden environmental events that require fast response;

[0036] 4) Application scenarios are extremely wide: the system is open, fast, anti-noise, high sensitivity, etc. The advantages make it a general gas sensing platform, which can be adapted to mobile platforms such as unmanned aerial vehicles, cruise robots, and fixed stations, etc. to solve the trace gas monitoring problems in many fields. The open nonlinear resonant photoacoustic cell based on unmanned aerial vehicle airborne photoacoustic spectroscopy gas detection system built by the application realizes the three-dimensional monitoring of complex emission scenarios with high flexibility, high spatial resolution and high detection sensitivity.

[0037] Of course, any technical solution of the application does not necessarily achieve all the above beneficial effects. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of an open nonlinear resonant photoacoustic cell, including three parts: (a) a partial view, (b) a side view and (c) a front view.

[0039] Figure 2a It is a simulated sound field distribution of an open nonlinear resonant photoacoustic cell.

[0040] Figure 2b It is a simulated z-axis sound field distribution of an open nonlinear resonant photoacoustic cell.

[0041] Figure 2c It is an acoustic comparison between a simulated open nonlinear resonant photoacoustic cell and a traditional open linear resonant photoacoustic cell.

[0042] Figure 3 It is a structural schematic diagram of a photoacoustic spectroscopy gas detection system based on an unmanned aerial vehicle airborne open nonlinear resonant photoacoustic cell.

[0043] In the figure, the unmanned aerial vehicle platform 1, the laser control module 2, the laser 3, the open nonlinear resonant photoacoustic cell 4, the microphone module 5, the signal function module 6, the ground control station 7, the microphone mounting hole 410, the fixed beam 420 and the fixed shell 430. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical scheme and advantages of the application more clear and obvious, the application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described here are only used to explain the application, and are not used to limit the coverage of the application.

[0045] An unmanned aerial vehicle airborne open nonlinear resonant photoacoustic cell gas detection method, comprising the following steps:

[0046] a) An unmanned aerial vehicle carries an open nonlinear resonant photoacoustic cell, the photoacoustic cell is an open structure, without an air pump, and uses the natural air flow during the flight of the unmanned aerial vehicle to realize rapid gas exchange;

[0047] b) The signal function module generates a modulation signal, the laser emits a modulated laser into the photoacoustic cell to interact with the gas to be measured, excite the gas to produce thermal expansion and generate a photoacoustic signal;

[0048] c) The photoacoustic signal is collected by the microphone module installed in the photoacoustic cell, and the gas concentration is obtained by inversion based on Lambert-Beer law after demodulation by the signal function module;

[0049] d) The signal function module transmits the detection data to the ground control station in real time, or saves the detection data in the on-board storage system.

[0050] Preferably, in step a), the tube body of the open nonlinear resonant photoacoustic cell is an open tube with axisymmetric diverging streamline structure, which not only ensures acoustic resonance effect but also reduces air flow resistance.

[0051] Preferably, in step b), the wavelength modulation (WMS) signal of the modulated laser is composed of 0.1 Hz sawtooth wave and high frequency sine wave.

[0052] As shown in Figure 3 , a photoacoustic spectroscopy gas detection system based on an unmanned aerial vehicle (UAV) on-board open nonlinear resonant photoacoustic cell, comprising:

[0053] The UAV platform 1 is used to carry other components and fly;

[0054] The laser control module 2 is electrically connected with the laser 3 to control its output;

[0055] The laser 3 emits a modulated laser to the open nonlinear resonant photoacoustic cell 4;

[0056] The open nonlinear resonant photoacoustic cell 4 is installed below the UAV and is used to contain the gas to be measured and make the laser interact with the gas to generate a photoacoustic signal;

[0057] The microphone module 5 is arranged in the photoacoustic cell to collect the photoacoustic signal;

[0058] The signal function module 6 is electrically connected with the microphone module 5 and the laser control module 2, and is used to demodulate the photoacoustic signal and invert the gas concentration, and at the same time generate a modulation signal to send to the laser control module 2;

[0059] The ground control station 7 communicates with the signal function module 6 to receive detection data and display.

[0060] As shown in Figure 1 , the tube body of the open nonlinear resonant photoacoustic cell 4 is axisymmetric diverging streamline structure, and the cross-sectional area increases gradually along the axial direction.

[0061] The resonance tube length of the open nonlinear resonant photoacoustic cell 4 is 40 mm, the inlet / outlet diameter is 6 mm, the resonance frequency is 1180 Hz, and the quality factor is 3.

[0062] The laser is a distributed feedback (DFB) laser with a center wavelength λ0 of 1653 nm for detecting methane.

[0063] The UAV platform 1 is equipped with a GPS / IMU positioning module, supports multi-UAV cooperative networking, each UAV acts as a mobile sensing node, communicates with the ground control station in real time through a 5G / satellite link, and realizes stereoscopic and multi-dimensional gas distribution monitoring.

[0064] The system is suitable for monitoring occasions in open spaces with natural or forced convection of gas, and realizes real-time, in-situ and rapid response monitoring of gas, including environmental air quality monitoring stations, industrial exhaust ports, ventilation ducts, agricultural greenhouses, medical diagnosis and industrial process monitoring.

[0065] Example 1: Photoacoustic spectroscopy methane gas detection system based on UAV-borne open nonlinear resonant photoacoustic cell

[0066] To realize the stereoscopic monitoring of complex emission scenarios with high flexibility, high spatial resolution and high detection sensitivity of methane acetylene gas, a photoacoustic spectroscopy methane gas detection system based on UAV-borne open nonlinear resonant photoacoustic cell is built.

[0067] Step one, design an open nonlinear resonant photoacoustic cell

[0068] As shown in part (a) of Figure 1 , the open nonlinear resonant photoacoustic cell 4 is an axially rotationally symmetric horn-shaped micro-expanding opening tube. As shown in parts (b) and (c) of Figure 1 , the photoacoustic cell is connected to the fixed shell 430 through four fixed beams 420; the microphone extends from the fixed beam 420 and is installed in the microphone mounting hole 410 on the surface of the photoacoustic cell cavity. As shown in Figures 2a-2c , the acoustic FLNS equation is solved by the pressure acoustic module of COMSOL Multiphysics software combined with thermal viscous boundary layer to simulate the sound pressure distribution inside the photoacoustic cell and optimize the structure parameters. Finally, the resonance tube length is determined to be 40 mm, the inlet / outlet diameter is 6 mm, the resonance frequency is 1180 Hz, and the quality factor is 3. As shown in Figure 2cAs shown, the open nonlinear resonant photoacoustic cell exhibits better acoustic performance than the traditional open linear (cylindrical) resonant photoacoustic cell. The nonlinear shape alters the propagation characteristics of sound waves, enabling more effective focusing and localization of acoustic energy in the central region of the resonant cavity (i.e., the antinode of the sound pressure wave), rather than a uniform distribution. This allows for a higher sound pressure amplitude at the microphone position under the same photoacoustic excitation. Furthermore, the open nonlinear resonant photoacoustic cell not only ensures acoustic resonance but also reduces airflow noise. The nonlinear, gradually expanding and contracting streamlined design guides airflow smoothly into and out of the photoacoustic cell, greatly avoiding flow separation and vortex generation. This suppresses flow-induced noise at the sound source. The nonlinear resonant tube possesses non-harmonic spectral characteristics, meaning its higher-order resonant frequencies are not integer multiples of the fundamental frequency. This implies that the frequencies of flow-induced noise are difficult to couple with the higher-order resonant modes of the photoacoustic cell, thus making them less susceptible to amplification. Therefore, the nonlinear structure itself also acts as an acoustic band-stop filter, selectively amplifying the target photoacoustic signal frequency while suppressing noise at other frequencies. Fluid dynamics simulations have verified that, compared to traditional open linear (cylindrical) resonant photoacoustic cell, open nonlinear resonant photoacoustic cell reduces airflow noise by more than 60%.

[0069] Step 2: Construct an unmanned aerial vehicle (UAV)-borne open nonlinear resonant photoacoustic cell photoacoustic spectroscopy methane gas detection system.

[0070] System composition such as Figure 3 As shown, the system includes: a drone platform 1, employing a quadcopter design with a payload capacity of 2kg and a flight time of 90 minutes; a laser control module 2, using an integrated solution of a TEC temperature controller and a laser driver; a laser 3, a 1653 nm distributed feedback (DFB) laser targeting the methane absorption line; an open nonlinear resonant photoacoustic cell 4, fabricated according to the optimized parameters in step one; a microphone module 5, using a MEMS microphone array with a sensitivity of -38 dB; a signal function module 6, a self-made circuit board integrating a lock-in amplifier, a data acquisition system, and an onboard storage system; and a ground control station 7. The laser control module 2 controls the laser 3, which emits a laser beam into the open nonlinear resonant photoacoustic cell 4. The microphone module 5, placed within the photoacoustic cell, collects the photoacoustic signal, transmits it to the signal function module 6 for demodulation, and then transmits the result to the ground control station 7. The signal function module 6 is also connected to the laser control module 2, responsible for outputting the laser modulation signal. The total weight of the photoacoustic spectroscopy methane gas detection system on the drone platform 1 is 1.5 kg, and its power consumption is less than 4.5 W.

[0071] Step three, the temperature of the laser 3 is stabilized at 17℃ by the laser control module 2, and the bias current is 165 mA, so that the center wavelength is located at the methane absorption line. The signal function module 6 provides a wavelength modulation signal. A modulation signal composed of a 0.1 Hz sawtooth wave and a high-frequency sine wave is generated and sent to the laser control module 2 to drive the laser 3.

[0072] Step four, the laser 3 emits laser light directly into the open nonlinear resonant photoacoustic cell 4, interacts with the gas to produce photoacoustic signals, which are collected by the microphone module 5, and the collected signals are demodulated by the signal function module 6 and inverted based on the Lambert-Beer law to obtain the concentration of the gas, and finally the concentration information is transmitted to the ground control station 7.

[0073] Step five, calibration of the detection system. According to the Beer-Lambert law, the photoacoustic second harmonic signal of the photoacoustic spectral gas detection system is related to the concentration of the target gas and the absorption optical path. A plurality of groups of different concentrations of methane gas are configured for measurement of photoacoustic second harmonic signals, the peak values of these photoacoustic second harmonic signals are extracted, the relationship between the peak values of the photoacoustic second harmonic signals and the concentration of the target gas is established, and the calibration curve of the methane gas is fitted and stored in the signal function module 6. When measuring methane gas with unknown concentration, the signal function module 6 will bring the corresponding photoacoustic second harmonic signal peak value into the calibration curve to obtain the specific concentration.

[0074] Step six, a cooperative monitoring network of three unmanned aerial vehicles is established, and cooperative path planning and data fusion are realized through the ground control station 7. The test area is 100,000 km², the flight height is 100-300 meters, and the environmental wind speed is 4 m / s. Three-dimensional stereoscopic monitoring and concentration distribution reconstruction of methane emission sources are successfully realized.

[0075] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0076] The above-described embodiments only express one embodiment of the present application, which is described in more detail and in more detail, but should not be construed as limiting the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. An unmanned aerial vehicle (UAV) on-board open nonlinear resonant photoacoustic cell gas detection method, comprising: The application is suitable for monitoring occasions of open space with natural or forced convection of gas, and realizes real-time, in-situ and rapid response monitoring of gas. ​ The method comprises the following steps: a) An unmanned aerial vehicle is used to carry an open nonlinear resonant photoacoustic cell, the photoacoustic cell is of an open structure and has no air pump, and air natural flow during flight of the unmanned aerial vehicle is used to realize rapid exchange of gas; the tube body of the open nonlinear resonant photoacoustic cell is an open tube with an axisymmetric gradually expanding streamline structure, the cross-sectional area of the open tube changes smoothly and slightly expands along the axial direction, the structure forms an acoustic impedance gradient device in acoustics, can effectively match high acoustic impedance in the tube with low acoustic impedance outside the tube opening, reduces reflection and radiation loss of sound waves at the opening, and enables more sound energy to be constrained in the resonant cavity; when the unmanned aerial vehicle flies, air flow passes through the edge of the open tube to generate intense flow separation and form a periodic Karman vortex street, and periodic shedding of the vortexes generates strong and band-concentrated flow-induced noise, which interferes with weak photoacoustic signals; the gradually expanding and gradually contracting streamline design of the nonlinear resonant tube can guide air flow to smoothly flow into and out of the photoacoustic cell, and avoids generation of flow separation and vortexes; the nonlinear resonant tube has non-harmonic spectral characteristics, that is, high-order resonant frequencies of the nonlinear resonant tube are not integer multiples of a base frequency, and the frequency of the flow-induced noise is difficult to be coupled with high-order resonant modes of the photoacoustic cell, so that the flow-induced noise is not easily amplified; b) A signal function module generates a modulation signal, a laser emits modulation laser to the photoacoustic cell to interact with the gas to be detected, excites thermal expansion of the gas and generates photoacoustic signals; c) The photoacoustic signals are collected by a microphone module installed in the photoacoustic cell, and after demodulation by the signal function module, the gas concentration is obtained based on the Lambert-Beer law; wherein the nonlinear shape changes the propagation characteristics of sound waves, can more effectively focus and localize sound energy in the central region of the resonant cavity, that is, the acoustic pressure antinode point, rather than uniformly distribute, which enables higher acoustic pressure amplitude to be obtained at the microphone position under the same photoacoustic excitation; d) The signal function module transmits detection data to a ground control station in real time, or saves the detection data in an on-board storage system.

2. The method of claim 1, wherein: In step b), the wavelength modulation (WMS) signal of the modulation laser is composed of a 0.1 Hz sawtooth wave and a high-frequency sine wave.

3. The method of claim 1, wherein: The resonant tube length of the open nonlinear resonant photoacoustic cell is 40 mm, and the inlet / outlet diameter is 6 mm.

4. The method of claim 1, wherein: The laser is a distributed feedback (DFB) laser, the center wavelength λ0 is 1653 nm, and the laser is used for detecting methane.

5. The method of claim 1, wherein: The unmanned aerial vehicle platform is equipped with a GPS / IMU positioning module, supports multi-unmanned aerial vehicle cooperative networking, each unmanned aerial vehicle acts as a mobile sensing node, communicates with a ground control station in real time through a 5G / satellite link, and realizes stereoscopic and multi-dimensional gas distribution monitoring.

6. The method of claim 1, wherein: The monitoring occasions include environmental air quality monitoring stations, industrial discharge ports, ventilation ducts, agricultural greenhouses, medical diagnosis and industrial process monitoring.

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