Patents
Literature
Patsnap Eureka AI that helps you search prior art, draft patents, and assess FTO risks, powered by patent and scientific literature data.

62 results about "Differential absorption" patented technology

Laser radar multi-gas identification method and system based on deep learning

The invention discloses a laser radar multi-gas identification method and system based on deep learning, and relates to the technical field of laser radars, and the method comprises the steps: employing a differential absorption laser radar to emit lasers with different wavelengths, receiving echo signals after gas absorption, extracting multi-domain features, and employing multi-target optimization in combination with feature importance evaluation to screen key features; generating a gas portrait of the potential gas according to the key features, and obtaining the type of the interested gas; constructing a graph structure according to the gas portrait and the gas feature similarity, performing representation learning on the graph structure by using a graph convolutional network, enhancing the graph convolutional network by using an interested gas category, constructing a gas category branch, and outputting a gas category; gas concentration branches are built by adopting a multi-layer sensor, final node representation output by the graph convolutional network is used as input, and each gas concentration is output by using linear regression. According to the invention, the distinguishing capability of small difference gases is improved, and high-precision identification and concentration inversion of multi-component gases are realized.
Owner:SUZHOU CITY UNIV

Dual-wavelength-based adaptive methane detection method and system

The invention relates to the technical field of gas detection, in particular to a dual-wavelength-based adaptive methane detection method and system, and the method comprises the following steps: collecting environmental interference characteristics of a to-be-detected gas environment in real time; synchronously emitting a first laser beam and a second laser beam to a to-be-detected gas environment according to the tunable laser source; receiving optical signals of the first laser beam and the second laser beam and converting the optical signals into electric signals; calculating a light intensity difference value of the first laser beam and the second laser beam based on the electric signal to generate a differential absorption signal; performing optical differential compensation on the differential absorption signal, outputting a methane concentration value, and performing environmental drift compensation on the methane concentration value based on environmental interference characteristics; and performing real-time threshold value judgment on the methane concentration value, and if the methane concentration value exceeds a preset threshold value, triggering a local early warning signal. According to the invention, the problem that the detection precision is reduced due to the fact that methane absorption signal common-mode noise and absorption coefficient drift cannot be synchronously inhibited due to dust concentration and temperature and humidity interference in a dynamic complex environment under a mine is effectively solved.
Owner:JIANGSU SHINE TECH

Water vapor concentration online detection method and system based on multi-wavelength infrared absorption spectrum

The invention relates to the technical field of water vapor concentration detection, and discloses a water vapor concentration online detection method and system based on a multi-wavelength infrared absorption spectrum, and the method comprises the steps: controlling an infrared light source module to emit pre-modulated light, enabling the pre-modulated light to pass through a gas chamber module, inputting the pre-modulated light into a photoelectric detection module, and converting the pre-modulated light into a sample electric signal; acquiring temperature data and pressure data at a preset position of the air chamber module in real time; calculating to obtain an initial differential absorption signal by using the sample electric signal and combining a Lambert-Beer law; based on the temperature data and the pressure data, performing temperature and pressure dynamic compensation on the initial differential absorption signal by using a pre-stored compensation database to obtain a target differential absorption signal; and determining the water vapor concentration according to the target differential absorption signal. According to the invention, the effects of improving the measurement precision and the measurement stability of the water vapor concentration and measuring the water vapor concentration online in real time can be achieved.
Owner:GBPI PACKAGING TEST INSTR

Respiratory inflammation marker detection system based on differential absorption spectrum

The invention relates to the technical field of chemical or physical testing, in particular to a differential absorption spectrum-based respiratory inflammation marker detection system, which comprises the following steps of: determining an effective spectrum interval of an original spectrum curve by using a marker wave band of a marker to be detected; splitting the effective spectral interval by using a wavelet basis to obtain a plurality of spectral decomposition hierarchies; determining the separation effectiveness of the spectral decomposition hierarchy waveform by using the difference of adjacent data points in the spectral decomposition hierarchy waveform and the difference of frequency peak values of adjacent spectral decomposition hierarchies; determining an effective hierarchy in the spectral decomposition hierarchy by using a differential value of the separation effectiveness sequence; and determining a target filtering frequency threshold value by utilizing respective separation effectiveness of the effective hierarchy and the current spectral decomposition hierarchy corresponding to the effective hierarchy, and further filtering the spectral decomposition hierarchy to obtain the content of the to-be-detected marker. According to the technical scheme, the accuracy of detecting multiple gas markers caused by inflammation of the respiratory tract is improved.
Owner:LUOYANG CENT HOSPITAL

Active and passive combined microwave remote sensing detection method for earth surface air pressure and air pressure profile

The invention provides an active and passive combined microwave remote sensing detection method for earth surface air pressure and air pressure profile, which comprises the following steps: by combining a satellite-borne / airborne millimeter wave differential absorption radar and a satellite-borne / airborne microwave radiometer and utilizing oxygen differential absorption measurement, obtaining accurate land / ocean surface air pressure data; and the air pressure profile is further obtained by combining temperature and humidity profile data measured by a satellite-borne / airborne microwave radiometer. Compared with the prior art, the method has the advantages that active and passive microwaves are adopted for combined detection, detection information obtained by a microwave radiometer is complemented, calculation of the surface pressure is enhanced, and the surface pressure inversion precision is improved; according to the method, the surface pressure value can be obtained, and the atmospheric pressure profile can also be obtained. According to the method, accurate surface pressure detection can be realized, and the atmospheric pressure profile can be further deduced by combining the temperature profile and the humidity profile observed by the microwave radiometer.
Owner:NAT SPACE SCI CENT CAS

LiDAR system for measuring atmospheric methane column concentration and water vapor profile

A lidar system for simultaneously measuring the column concentration of methane and the profile concentration of water vapor in the atmosphere is disclosed. The device includes a laser emission module: a 1645nm monoline seed laser, a 1645nm offline1 seed laser, a 1645nm offline2 seed laser, a 1064nm pump laser, a laser frequency-locking module, an optical parametric oscillator, a frequency doubling module, and emitting optical components; an echo receiving module: an integrating sphere module, an optical receiving telescope assembly, a beam splitter, filter assembly 1, filter assembly 2, photodetector 1, and photodetector 2; and a data acquisition and processing module. This invention utilizes the frequency doubling relationship between the absorption lines of methane and water vapor to simplify the complex structure of a dual-band, multi-wavelength laser. It employs seed-injected optical parametric oscillator technology to obtain a high-frequency stable 1645nm fundamental frequency light, which is then frequency-doubled to obtain an 822nm laser. The profile concentration of water vapor and the column concentration of methane in the atmosphere can be measured using differential absorption lidar (DIAL) and integral path differential absorption (IPDA) technologies, respectively.
Owner:SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI

All-solid-state troposphere and stratosphere ozone detection laser radar system

The invention relates to the technical field of laser radars, and discloses an all-solid-state troposphere and stratosphere ozone detection laser radar system, which comprises a pump light generation module used for generating an ultraviolet laser beam; the solid-state ultraviolet laser module is used for dividing the ultraviolet laser beam into four paths of detection laser to respectively form a differential absorption wavelength pair for detecting the ozone in the stratosphere and a differential absorption wavelength pair for detecting the ozone in the troposphere; the wavelength real-time monitoring module monitors the frequency of the four paths of detection laser in real time; the echo optical signal receiving module is used for receiving back scattering echo optical signals of the detection laser at different heights and converting the back scattering echo optical signals into electric signals; and the signal acquisition and storage module acquires the electric signal and stores the electric signal as a digital signal. According to the invention, four narrow-band laser ozone detection wavelengths are generated through an optical parametric oscillation technology, and meanwhile, the all-solid-state design of the system is realized, so that the ozone concentration of the stratosphere and the troposphere can be detected at the same time, and continuous observation in the daytime and at night can be realized.
Owner:UNIV OF SCI & TECH OF CHINA

LNG (Liquefied Natural Gas) dual-fuel ship exhaust gas monitoring device and cross interference correction method thereof

The invention relates to the technical field of gas detection, and provides an LNG (Liquefied Natural Gas) dual-fuel ship exhaust gas monitoring device and a cross interference correction method thereof, synchronous detection of SO2 (0-1500ppm), CO2 (0-30%), CH4 (0-1500ppm) and NO (0-1500ppm) is realized by adopting optical detection principles such as ultraviolet differential absorption, non-dispersive infrared absorption and tunable semiconductor laser absorption spectroscopy, the error is controlled within + / -2% FS, and the detection accuracy is high. And the response time does not exceed 30s. The device realizes simultaneous accurate detection of LNG dual-fuel characteristic gas, and has the advantages of high detection precision, fast response speed, simple operation and maintenance, relatively low cost and strong cross interference resistance of gas under complex working conditions.
Owner:THE 718TH RES INST OF CHINA STATE SHIPBUILDING CORP

Atmosphere multi-element integrated multi-wavelength coherent differential absorption laser radar system

The invention belongs to the technical field of atmosphere detection remote sensing, and discloses an atmosphere multi-element integrated multi-wavelength coherent differential absorption laser radar system. Lambda on1 wavelength laser generated by the first frequency stabilization seed laser, lambda on2 wavelength laser generated by the second frequency stabilization seed laser and lambda off wavelength laser generated by the third frequency stabilization seed laser are transmitted to the switching module for time domain modulation to obtain an output signal, and the output signal is decomposed into local oscillation light and a main signal by the first coupler. A main signal is modulated by the pulse modulator, amplified by the amplification module and then transmitted to the optical transceiver module, backward scattered light scattered by the atmosphere is transmitted to the second coupler and is subjected to coherent coupling and equalization with local oscillation light, and coherent electric signals are transmitted to the data analysis module through the balance detector to be analyzed. The water vapor concentration, the wind speed and the atmospheric temperature in the propagation path are obtained. Through the coherent detection technology, the signal-to-noise ratio of signals is remarkably improved, and high-precision atmospheric humidity and wind field detection is achieved.
Owner:SOUTH WEST INST OF TECHN PHYSICS

LNG dual-fuel ship exhaust monitoring device

The utility model relates to gas detection technical field, the utility model provides a kind of LNG dual-fuel ship exhaust monitoring device, using ultraviolet differential absorption, non-dispersed infrared absorption and tunable semiconductor laser absorption spectroscopy etc. Optical detection principle realizes the synchronous detection of four kinds of gases SO2 (0~1500ppm), CO2 (0~30%), CH4 (0~1500ppm) and NO (0~1500ppm), error is controlled within ±2%FS, response time is not more than 30s. Realize LNG dual-fuel characteristic gas accurate detection simultaneously, with the advantages of high detection precision, fast response speed, simple operation, relatively low cost and strong gas cross-interference resistance ability under complex working conditions.
Owner:THE 718TH RES INST OF CHINA STATE SHIPBUILDING CORP

Ozone precursor monitoring method and system based on two-channel differential absorption spectrum and nonlinear inversion, terminal and storage medium

The invention relates to the technical field of differential absorption spectrum inversion, and discloses an ozone precursor monitoring method and system based on a two-channel differential absorption spectrum and nonlinear inversion, a terminal and a storage medium, the method comprises the following steps: synchronously obtaining a target spectrum and a reference spectrum of a target area to calculate a multiband atmospheric differential optical thickness; building a combination model based on the difference optical thickness of each wave band, dividing a fitting window, and obtaining the difference inclined column concentration through multi-angle fitting; and inverting a vertical concentration distribution profile of the ozone precursor by using different sensitivities in combination with a radiation transmission model and a logarithmic space iterative inversion algorithm. According to the invention, through a high-performance dual-channel spectrometer observation system and a high-precision nonlinear inversion algorithm, high-spectral-resolution measurement of ultraviolet-visible light full wavebands is realized, logarithmic space processing is introduced in inversion, the inherent problems of strong nonlinearity and large dynamic range of a vertical profile of aerosol and trace gas are effectively solved, and the measurement accuracy is improved. And the measurement precision and stability are improved.
Owner:SOUTHERN UNIVERSITY OF SCIENCE AND TECHNOLOGY

A method for inverting remote sensing data with overlapping strong and weak greenhouse gas absorption lines

This invention relates to a method for inverting remote sensing data from overlapping strong and weak absorption lines of greenhouse gases, belonging to the field of satellite remote sensing technology. Specifically, it includes the following steps: Step 1: Constructing an optical system, including a satellite platform, camera 1, and camera 2; camera 1 and camera 2 are mounted at the bottom of the satellite platform; camera 1 and camera 2 are mirrored; the imaging spectral band of camera 1 moves from the weak absorption spectral band to the strong absorption spectral band along the positive push-broom direction to the negative push-broom direction; the imaging spectral band of camera 2 is in the opposite direction; the optical system moves horizontally from left to right to achieve horizontal push-brooming of greenhouse gases on the ground, obtaining a dual-camera fused image; the dual-camera differential absorption spectroscopy algorithm is used to invert the dual-camera fused image to obtain the greenhouse gas column concentration; this invention, based on the spectral characteristics of strong and weak absorption lines of greenhouse gases, adopts a detector focal plane segmentation method, and the dual cameras achieve differential absorption and inversion in the same region, which can guide the design of greenhouse gas detection micro / nano satellite payloads.
Owner:AEROSPACE DONGFANGHONG SATELLITE

An apparatus and method for in-situ detection of internal products of combustion in a porous medium

The application discloses a kind of porous medium combustion internal product in-situ detection device and method, including porous medium combustor, is equipped with combustion chamber, the combustion chamber is filled with ordered structure porous medium material, the two side walls of the combustion chamber are equipped with first penetration layer and second penetration layer, the two outer sides of the first penetration layer and second penetration layer are respectively equipped with first collimating lens and second collimating lens, first lens group between the first collimating lens and first penetration layer is arranged to make that light beam converges into the light beam of extremely small diameter and passes through first penetration layer, second lens group between the second collimating lens and second penetration layer is arranged to make that light beam converges into the light beam of extremely small diameter and is shot into first collimating lens;Light source;Spectrometer, computer.By adjusting the structure design of porous medium, in-situ detection of internal components of porous medium is realized in combination with ultraviolet differential absorption spectrometry.Compared with traditional extraction type, it is faster, lower in cost and stronger in real-time performance.
Owner:FOSHAN XIANHU LAB +1

Device for detecting ammonia-nitrogen concentration difference absorption of water body based on microwave remote sensing

The application discloses a water body ammonia nitrogen concentration differential absorption detection device based on microwave remote sensing, relates to the technical field of water pollution detection, and comprises a floating platform for floating on a detection water body and a mounting plate arranged on the floating platform. A microwave emission module and a microwave receiving module for microwave remote sensing detection are mounted on the mounting plate. A signal processing and analysis module for information processing and a data storage and display module are arranged on the floating platform. In the detection process, through the cooperation of a swing assembly, a water body depth identification assembly, a lifting assembly and an adjusting assembly, the microwave signal emitted by the microwave emission module on the mounting plate can cover a larger area of the water surface, three-dimensional sampling of the water body can be realized, one-sidedness of single-point detection can be avoided, the detection state can be adaptively adjusted according to the depth of the detection water body during the detection, and flexible detection operation is facilitated.
Owner:ANHUI TECHN COLLEGE OF IND & ECONOMY +2

Data processing method based on carbon dioxide column concentration from spaceborne lidar

This invention discloses a data processing method for carbon dioxide column concentration based on a spaceborne lidar, comprising: performing nonlinear correction on the spaceborne integral path differential absorption (IPDA) lidar detection signal; calculating the differential optical thickness based on the IPDA lidar signal; calculating the echo height above sea level and geographic coordinates based on the echo signal location; establishing an absorption cross-section lookup table using differential absorption cross-section data from the High Resolution Transmission Molecular Absorption (HITRAN) database; calculating the pressure at the echo location using the European Centre for Medium-Range Weather Forecasts Reanalysis Dataset (ERA5) and the echo signal height above sea level; calculating the Doppler frequency shift; calculating a weighting function based on pressure profiles, humidity profiles, temperature profiles, and Doppler frequency shift data; and calculating the carbon dioxide column concentration. The key features of this invention are the nonlinear correction of the spaceborne IPDA lidar echo signal, the establishment of a differential absorption cross-section lookup table for carbon dioxide molecules, and the accurate and efficient calculation of the carbon dioxide column concentration using spaceborne IPDA lidar detection data and ERA5 meteorological dataset data.
Owner:SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI

Differential absorption detection device for ammonia nitrogen concentration of water body based on microwave remote sensing

The invention discloses a microwave remote sensing-based water ammonia nitrogen concentration differential absorption detection device, and relates to the technical field of water pollution detection, the microwave remote sensing-based water ammonia nitrogen concentration differential absorption detection device comprises a floating platform used for floating on a detected water body and a mounting plate arranged on the floating platform, and the mounting plate is provided with a microwave transmitting module and a microwave receiving module which are used for microwave remote sensing detection; the floating platform is provided with a signal processing and analyzing module used for information processing and a data storage and display module. In the detection process, through mutual cooperation of the swing assembly, the water body depth recognition assembly, the lifting assembly and the adjusting assembly, microwave signals emitted by the microwave emission module on the mounting plate can cover the water surface with a larger area, three-dimensional sampling of the water body is achieved, and the one-sidedness of single-point detection is avoided; the detection state can be adaptively adjusted according to the depth of the detected water body in the detection process, and flexible detection operation is facilitated.
Owner:ANHUI TECHN COLLEGE OF IND & ECONOMY +2

Method and equipment for simultaneously detecting at least two target gases in exhaled gases

The invention provides a method and equipment for simultaneously detecting at least two target gases in exhaled gases, and relates to the technical field of gas detection. The method comprises the following steps: constructing a first characteristic space according to a differential absorption spectrum of a first target gas in a standard state, and constructing a second characteristic space according to a differential absorption spectrum of a second target gas in the standard state; obtaining a differential absorption spectrum of the exhaled gas sample; respectively projecting the differential absorption spectrum of the exhaled gas sample to the first characteristic space and the second characteristic space to carry out spectrum decoupling so as to obtain a first differential absorption spectrum and a second differential absorption spectrum; and inputting the first differential absorption spectrum into a first multi-scale convolutional network, inputting the second differential absorption spectrum into a second multi-scale convolutional network, and respectively obtaining the concentration of the first target gas and the concentration of the second target gas in the exhaled gas sample. The problem of spectrum overlapping caused by high noise interference and complex components when multiple target gases in exhaled gases are detected at the same time is solved.
Owner:YANSHAN UNIV

Differential absorption laser radar correction method and device, equipment and storage medium

The invention discloses a differential absorption laser radar correction method and device, equipment and a storage medium, and relates to the technical field of laser radars. The method comprises the following steps: acquiring echo signal intensity curves and first beam divergence diagrams of a plurality of angle intervals of a to-be-processed laser radar; the plurality of angle intervals comprise a first angle interval and a plurality of second angle intervals, and the echo signal intensity curve comprises echo signal intensity curves of emitted light beams with a plurality of wavelengths; executing the following operations on the emitted light beam of each wavelength: determining a first height corresponding to an echo signal intensity curve of a first angle interval and a second height corresponding to an echo signal intensity curve of each second angle interval; based on the first height and the angle interval corresponding to the first height, and each second height and the angle interval corresponding to each second height, generating a second beam divergence graph by using a preset generation algorithm; and performing correction processing on the laser radar based on the first beam divergence graph and the second beam divergence graph.
Owner:北京华云东方探测技术有限公司

A method and system for analyzing emission pollution sources based on lidar

The application discloses a kind of based on laser radar's discharge pollution source analysis method and system, the method includes: according to first pollutant concentration information and second pollutant concentration information, respectively to the various pollutant gases directly obtained from ground monitoring station or satellite and the single pollutant gas monitored by differential absorption module, and the various particulates directly obtained from ground monitoring station or satellite and the multiple particulates monitored by differential absorption module are carried out correlation analysis, and correlation analysis result is obtained;Based on correlation analysis result, identify the composition of discharge pollution source in the discharge area to be measured.The application can carry out high spatial resolution and accurate discharge analysis to discharge pollution source.
Owner:NANJING UNIV OF INFORMATION SCI & TECH

Sulfur hexafluoride concentration detection method based on dual-band TDLAS

The invention belongs to the technical field of gas detection, and particularly relates to a sulfur hexafluoride (SF) concentration detection method and device based on a dual-band tunable diode laser absorption spectrum (TDLAS) and electronic equipment. In order to solve the problems that in an existing SFdetection technology, quantification and positioning functions are separated, the anti-interference capability is poor, and high sensitivity and rapid imaging cannot be synchronously achieved, the invention provides a method combining dual-band differential absorption and TDLAS. According to the scheme, a detection device in which an open type backward reflection path is combined with a built-in White cell (a multi-reflection cell) is adopted, 10.55 microns are selected as a measurement wave band, and 9 microns are selected as a reference wave band; through synchronous or alternate acquisition of dual-band signals, wavelet denoising preprocessing, differential absorption concentration inversion, Kalman filtering gas cloud tracking and Gaussian plume model leakage source inversion, rapid imaging positioning and accurate concentration quantification of an SFleakage point are realized. The system has the advantages of high detection sensitivity, strong anti-interference capability and integrated quantitative positioning function, and is suitable for efficient inspection and accurate diagnosis of the SFleakage of the power equipment.
Owner:GUANGXI UNIV

Laser radar system for measuring carbon dioxide column concentration of carbon 12 and carbon 13 in atmosphere

The invention discloses a laser radar system for synchronously measuring the concentration of C12 and C13 carbon dioxide columns in the atmosphere. The laser radar system comprises a laser emission module, an echo receiving module and a data acquisition and processing module. The laser transmitting module adopts a main oscillation power amplification technology and is integrated with three 2051nm seed lasers, the wavelengths of the seed lasers are respectively locked at a C12 absorption peak, a C13 absorption peak and absorption valleys of the C12 absorption peak and the C13 absorption peak, and high-energy detection pulses are generated by using time division multiplexing and two-stage amplification. The echo receiving module collects back scattering signals through a telescope, and the back scattering signals are received by a detector after being filtered. The system monitors emission energy through an integrating sphere, a data acquisition module synchronously acquires emission and echo signals of each wavelength, and respective column concentrations of two isotopes are obtained through inversion according to a differential absorption algorithm. According to the invention, active, synchronous and high-precision column concentration remote sensing measurement of C12 and C13 carbon dioxide is realized, excellent daytime detection capability of the system is ensured, and real all-day continuous observation is realized.
Owner:SHANGHAI INST OF OPTICS & FINE MECHANICS CHINESE ACAD OF SCI

A dual-wavelength adaptive methane detection method and system

The present application relates to the technical field of gas detection, and particularly relates to a dual-wavelength adaptive methane detection method and system, which comprises the following steps: collecting the environmental interference characteristics of a to-be-detected gas environment in real time; synchronously emitting a first laser beam and a second laser beam to the to-be-detected gas environment according to a tunable laser source; receiving the optical signals of the first laser beam and the second laser beam and converting them into electrical signals; calculating the light intensity difference value of the first laser beam and the second laser beam based on the electrical signals to generate a differential absorption signal; performing optical differential compensation on the differential absorption signal and outputting a methane concentration value, and performing environmental drift compensation on the methane concentration value based on the environmental interference characteristics; and performing real-time threshold judgment on the methane concentration value, and triggering a local warning signal if the methane concentration value exceeds a preset threshold. Through the present application, the problem of detection precision decline caused by the fact that the dust concentration and temperature and humidity interference cannot synchronously inhibit the common-mode noise of the methane absorption signal and the absorption coefficient drift in the dynamic and complex environment under the mine is effectively solved.
Owner:JIANGSU SHINE TECH

Differential absorption micro-pulse laser emission unit, control method and water vapor profile detection system

The invention provides a differential absorption micro-pulse laser emission unit, a temperature and current control method, a pulse control method and a water vapor profile detection system. The differential absorption micro-pulse laser emission unit adopts a laser emission module, the constant temperature design of the laser emission module is realized through a high-precision temperature and current control module, and accurate compensation under tiny temperature fluctuation is carried out through current adjustment, so that the laser emission module generates high-precision online wavelength laser and offline wavelength laser, and the high-precision online wavelength laser and the high-precision offline wavelength laser are integrated. According to the water vapor profile detection system adopting the differential absorption micro-pulse laser emission unit, the vertical distribution characteristics of the water vapor content are obtained by detecting the scattered signal intensity of the pulse laser by the atmosphere at different heights, and the water vapor profile detection system has higher time and space resolution and better environmental adaptability and daytime detection performance.
Owner:CHINA HUAYUN METEOROLOGICAL TECH GRP CORP

LIDAR system for differential absorption and background distance measurements

To provide a new LIDAR system attainable by an optical fiber that can execute IPDA (Integrated Path Differential Absorption) and can determine separation distance from an obstacle existing in the background of a measurement region.SOLUTION: A LIDAR system is configured so as to execute differential absorption measurement of a chemical compound between two separate optical frequencies (ν1, ν2) and measure separation distance from an obstacle existing in the background of a measurement region in which absorption occurs. Since the LIDAR system can implement an optical fiber technique while having sufficient light emitting power, a light emitting light power value is changed at a different time interval between radiation light emitting sequences. The LIDAR system can evaluate the amount of chemical compounds included in the measurement region, and separation distance from an obstacle positioned in the background of the measurement region.SELECTED DRAWING: Figure 1a
Owner:OFFICE NAT DETUDES & DE RECH AEROSPATIALES

Acetylene gas detection method, system, device and medium based on laser multiplexing

The present application belongs to the technical field of gas detection, and discloses an acetylene gas detection method, system, device and medium based on laser multiplexing, to solve the problems of low detection precision and poor real-time performance in the prior art. The method comprises: emitting two laser beams with different wavelengths; controlling the two laser beams to be emitted alternately in time sequence and transmitted through the same optical path; generating periodic pressure fluctuations through gas molecule absorption of laser energy to generate an acoustic signal; detecting the intensity and phase of the acoustic signal; converting the acoustic signal into an electric signal and performing low-noise amplification and band-pass filtering processing; performing second harmonic demodulation on the signal with improved signal-to-noise ratio to obtain the amplitude and phase information of the acoustic signal corresponding to the excitation laser beam and the detection laser beam respectively; using differential absorption algorithm analysis to separate the absorption contribution of acetylene gas and water vapor to the absorption signal; and calculating the acetylene concentration according to the separated acetylene net absorption signal by applying Beer-Lambert law.
Owner:ELECTRIC POWER RES INST OF STATE GRID ZHEJIANG ELECTRIC POWER COMAPNY

LIDAR system for differential absorption and background distance measurements

A LIDAR system is adapted for performing differential absorption measurements of a chemical compound between two distinct optical frequencies (ν1, ν2), and for measuring a separation distance from an obstacle which is present in a background of a measurement zone where the absorption occurs. An emission optical power value is varied between different time intervals during a radiation emission sequence, in order to allow that the LIDAR system implements an optical fiber technology while having sufficient emission power. The LIDAR system makes it possible to evaluate an amount of the chemical compound which is contained in the measurement zone, as well as a separation distance from an obstacle which is located in the background of the measurement zone.
Owner:OFFICE NAT DETUDES & DE RECH AEROSPATIALES

A composite optical detector based on ultraviolet differential absorption spectroscopy and microfluidic infrared technology

The present invention discloses a composite optical detector based on ultraviolet differential absorption spectroscopy and microflow infrared technology, comprising: a first measuring chamber, which is mainly used to contain measurement gas, and the structure of the first measuring chamber is a transparent structure; a spectrometer, which is arranged on the right side of the first measuring chamber; a sample gas chamber, which is installed at the front end of the first measuring chamber, and the structure of the sample gas chamber is a transparent structure; an air inlet and outlet, which are connected between the first measuring chamber and the sample gas chamber, and the air inlet and outlet are mainly used to charge and discharge sample gas into and out of the first measuring chamber and the sample gas chamber; a second light source, which is installed on the left side of the second measuring chamber, and the second light source is an infrared band light; a reference gas chamber, which is installed at the right end of the second measuring chamber. The composite optical detector based on ultraviolet differential absorption spectroscopy and microflow infrared technology can perform measurement and analysis on the sample gas in different bands, thereby improving the comprehensive measurement capability of the device.
Owner:STATE GRID HUBEI EXTRA HIGH VOLTAGE CO +1

Gas analyzer for detecting indole and 3-methylindole

The utility model discloses a gas analyzer for detecting indole and 3-methylindole. The gas analyzer comprises a preprocessor, an ultraviolet differential absorption spectrometry analyzer and a sampling control and data processing unit, the preprocessor comprises a particulate matter filter and a heater which are connected through a pipeline; the ultraviolet differential absorption spectrometry analyzer comprises a heating gas absorption cell connected with the heater, and the heating gas absorption cell is respectively connected with a spectrograph and an ultraviolet light source generation module through optical fibers. The problems of complicated operation steps and long time consumption of original gas chromatography, high performance liquid chromatography or liquid chromatography-mass spectrometry and the like can be solved, and the indole gas can be intuitively and qualitatively determined; one gas analyzer can be used for monitoring other indole derivative gases, so that the gas analyzer has multiple functions, the purchase cost of a user is reduced, social resources are saved, and convenience is brought to use of people.
Owner:QINGDAO BRAIN OPTICS TECH CO LTD

Lidar multi-gas recognition method and system based on deep learning

The application discloses a laser radar multi-gas identification method and system based on deep learning, and relates to the technical field of laser radar, and comprises the following steps: a differential absorption laser radar emits laser beams with different wavelengths, receives echo signals after gas absorption, extracts multi-domain features, and adopts multi-objective optimization combined with feature importance evaluation to screen key features; the key features are used to generate a gas image of potential gas, and a gas category of interest is obtained; a graph structure is constructed according to the gas image and gas feature similarity, representation learning of the graph structure is performed by using a graph convolution network, the graph convolution network is enhanced by using the gas category of interest, a gas category branch is constructed, and a gas category is output; a multi-layer perception mechanism is used to construct a gas concentration branch, the final node representation output by the graph convolution network is used as input, and linear regression is used to output the concentrations of various gases. The application improves the distinguishing ability of small difference gases, and realizes high-precision identification and concentration inversion of multi-component gases.
Owner:SUZHOU CITY UNIV