66 results about "Aerosol extinction coefficient" patented technology

A method for determining parameter of atmospheric environment includes using laser radar determining system to receive backward scattering light of atmosphere, splitting received light to be various lights required by laser radar, carrying out analysis and treatment of data as per set program after photoelectric detection for realizing measurement on atmospheric environmental parameters such as temperature, steam density, airosol extinction coefficient, scattering coefficient, airosol optical thickness, visibility and depolarization ratio of non-spherical particle backward scattering light.

This invention is a detecting of Roman-Mie dispersion laser atmosphere signal and laser radar. It sets up the radar with the output of double-frequency 532nm and triple-frequency 355nm, launches the 532nm, 15% of the 35nm to the sky and 85% of the 355nm after diffusion, and the two optical paths parallel with the optical path of the receiving telescope, and simultaneously carry out the pitching motion with the receiving telescope; the receiving telescope backward dispersing light, the backward light gets into the telescope, then passes the glare tube, the adjusting field view stop and ocular glass, and the dichroic mirror process, and divides the 407nm, the 386nm and the 532nm scattered light into three beams, and the 532nm scattered light is divided into 15% and 85% beams, and the four beams are respectively received by the multiplier phototube, magnified by the magnifier and collect and process the data. It can detect the level visibility of the atmosphere, the aerosol of the whole troposphere and the vertical outline of winding cloud light eliminating system and the water and air mixture ratio from the ground to the lower part of the troposphere. The detecting error of the level visibility is 15%, the errors of the aerosol light eliminating modulus and the vertical outline of the water and air mixture are 20%.

This invention discloses dual field view dual-wavelength laser radar scattering meters structure and detection methods, including laser launch unit echo signal receiver modules, the follow-up optical modules, signal detection and acquisition module and control unit; The laser launch unit using Nd: YAG laser, launching 532 nm and 1064 nm wavelength of the laser pulse at the same time and received by the diameters of 400 mm and 200 mm telescope. Two receiving optical telescope module are follow-up optical module. Optical signal from the follow-up optical module are received by the detection and acquisition module and control unit. atmospheric aerosol extinction coefficient of the vertical profile and continuous distribution, and extinction coefficient level of continuous distribution, can be analyzed through the various atmospheric aerosol optical parameters.

The invention provides an inversion method for an extinction coefficient of an aerosol based on a Raman-Mie scattering laser radar, comprising the steps of: Step 1: obtaining an echo signal of a Ramanchannel in the Raman-Mie scattering laser radar, and determining an lidar ratio of the aerosol by Ansmann method, that is, obtaining the extinction coefficient and a backscattering coefficient of theaerosol by using Raman method; Step 2: obtaining an echo signal of a Mie channel in the Raman-Mie scattering laser radar, and inverting a distribution profile of the extinction coefficient of the aerosol based on Fernald method; and Step 3: correcting, based on an inversion result of the Raman method in step 1, key parameters required to invert the distribution profile of the extinction coefficient by using the Mie scattering method in step 2, that is, a boundary value of the extinction coefficient of the aerosol, thereby improving the inversion precision of the distribution profile of the extinction coefficient of the Mie scattering channel. According to the inversion method for the extinction coefficient of the aerosol based on the Raman-Mie scattering laser radar provided by the invention, high-precision detection of aerosols is achieved by combining the characteristics of Raman scattering and Mie scattering.

The invention provides a double-channel light cavity ring-down atmospheric aerosol extinction instrument and an extinction factor measuring method. According to the extinction instrument, utilizes a double-channel light cavity ring-down spectrum technology is applied to carry out in-situ real-time measurement on an extinction factor of atmospheric aerosol. The instrument comprises a light path system, a circuit system and a gas path system, wherein the light path system is internally provided with a first light cavity and a second light cavity, and the first light cavity and the second light cavity are utilized as double channels; and the gas path system respectively provides atmospheric gas and background atmospheric gas containing the aerosol for the first light cavity and the second light cavity, the circuit system can eliminate the transformation of the extinction factor of the aerosol caused by gas change in real time, and the extinction factor value of the atmospheric aerosol is accurately measured in a real time.

The invention provides an aerosol foundation data-based AOD (Aerosol Optical Depth) vertical correction effect evaluation method and system. The method comprises the steps of estimating a near-surface aerosol extinction coefficient and inverting the near-surface aerosol extinction coefficient based on observation data of a foundation visibility meter; inverting AOD based on observation data of a foundation sum photometer; inverting the near-surface aerosol extinction coefficient based on the visibility meter; performing vertical correction on the AOD based on a laser radar observation method or an atmospheric chemistry mode simulation method, and estimating the near-surface aerosol extinction coefficient according to a vertical correction result; and evaluating the effect and applicability of an AOD vertical correction method by comparing the difference between the estimated near-surface aerosol extinction coefficient with the inverted near-surface aerosol extinction coefficient. According to the method and the system, the errors caused by direct use of a satellite for AOD inversion and the evaluation uncertainty caused by a scale effect and the like can be avoided, so that the difficult problems in effect evaluation and applicability selection among various AOD vertical correction methods and various data sources are solved.

The invention discloses a micro pulse lidar system constant calibration method, which utilizes a solar radiation meter to measure and invert so as to obtain whole layer of atmospheric aerosol optical thicknesses of multiple wavelengths. Under the assumed condition that atmospheric aerosol particle-size spectra distribution meets the requirement of Junge size distribution, interpolation is carried out to obtain a whole layer of atmospheric aerosol optical thickness corresponding to a lidar measurement wavelength. Simultaneously, a Fernald method is utilized to solve echo data measured by a lidar along a same path so as to obtain height distribution of aerosol extinction coefficients. On a clear day, atmospheric aerosol can be assumed to be concentrated under the height lower than 6km, integration is performed on the 6km height by the height distribution of aerosol extinction coefficients, and the obtained numerical value can be regarded as the whole layer of atmospheric aerosol optical thickness. Through comparison, calibration coefficients can be obtained.

The invention relates to a novel method for measuring the extinction coefficient of atmospheric aerosol. According to the method, a film plated glass pipe, a laser light source, an optical system and a data collection system are included, wherein light has long transmission light path and low loss in the film plated glass pipe, light of a certain wavelength makes long-distance transmission with a certain angle between pipe walls in the glass pipe filled with aerosol, the attenuation information of light by aerosol can be measured through probes at two ends of the glass pipe, and multiple reflections of light in the glass pipe greatly improves the extinction sensitivity of aerosol. The invention sets up the measurement formula of the extinction coefficient of a wave of multi-wavelength, and the relative calculation method based on the ratio avoids the measurement error caused by light intensity fluctuation during photoelectric conversion; and the novel method has the characteristics of simple principle, convenience in operation and fastness in detection speed.

The invention provides a device and method for measuring the extinction coefficient of black carbon aerosol. The device is a two-channel transmission-type atmospheric aerosol measuring device which has high long term reliability and can accurately measure the extinction coefficient of the atmospheric aerosol. The method is characterized by adopting the two-channel photoelectric detection technology and using the ratio of the transmissivity of the filtered gas to the transmissivity of the unfiltered aerosol gas to be detected to show the extinction coefficient of the aerosol and has the advantage of accurate measuring result. The method comprises the following steps: a laser diode (LD) is adopted to transmit a light pulse sequence, the light pulse sequence becomes parallel light after being collimated and is sent out and the light beam is split into two light beams with approximately equal strength with a beam splitter; after respectively passing through a measurement cell channel and a reference cell channel, the two light beams are respectively received by receiving units; the signal received by each channel is processed by a photoelectric signal processing unit and then is sent to a computer control unit by a data acquisition unit; and the computer control unit is used for computing the ratio of the light power detected by the two channels and carrying out logarithmic operation to obtain the extinction coefficient of the aerosol.

The invention discloses a PM2.5 three-dimensional transport flux calculation method and apparatus, and belongs to the field of atmospheric remote sensing and monitoring and numerical simulation. The PM2.5 three-dimensional transport flux calculation method comprises the steps of obtaining an aerosol extinction coefficient height profile of a target region obtained through inversion operation by a laser radar system from the ground; obtaining PM2.5 mass concentration, detected by a ground particulate matter detector, of the ground of the target region; performing calculation according to the aerosol extinction coefficient height profile of the target region from the ground and the PM2.5 mass concentration to obtain a PM2.5 mass concentration height profile of the target region from the ground; performing final calculation according to horizontal and vertical meteorological fields, simulated according to a WRF mode, of the target region and the PM2.5 mass concentration height profile to obtain a PM2.5 total transport flux of the target region; and calculating PM2.5 horizontal and vertical net transport fluxes in a boundary of the target region. According to the method and the apparatus, the calculation is easy and the PM2.5 three-dimensional transport fluxes dynamically changed in different directions and different boundaries can be quantitatively calculated.

The invention discloses a computing method applied to atmospheric aerosol mass concentration horizontal route distribution and can effectively solve the obtaining problem of an aerosol mass concentration real-time distribution situation caused by quick city near-ground aerosol distribution time-space change, non-uniform city pollution source distribution and the like. Only the aerosol mass concentration of a limited position in a zone can be obtained through common fixed-point monitoring, and an aerosol pollution time-space distribution characteristic in a certain route cannot be expressed. In order to solve a distribution situation of aerosol and pollutants in a near-ground horizontal route, the invention provides the computing method for obtaining aerosol mass concentration distribution in routes within 0 to 6 kilometers in real time by comprehensively utilizing a micropulse laser radar and combining a particle counter, a visibility meter and a particle mass concentration measuring instrument. Parameters of aerosol extinction coefficient, particle distribution, mass concentration and the like are associated through theoretical and mathematic models. According to the computing method disclosed by the invention, an effective technical support is provided for research on pollution sources of city aerosol and monitoring on dynamic variation.

The present invention discloses a method for inverting the function relationship between the aerosol extinction coefficient moisture absorption increasing factor and the relative humidity by adopting the PM2.5 mass concentration as the constraint condition. According to the method, the determined aerosol extinction coefficient alpha dry at the relative humidity of no more than 40% and the PM2.5 mass concentration CPM2.5 are substituted into the formula defined in the specification to calculate the proportional coefficient K, the aerosol extinction coefficient alpha wet and the PM2.5 mass concentration CPM2.5 at the arbitrary relative humidity are determined at the same position, the proportional coefficient K and the PM2.5 mass concentration CPM2.5 at the arbitrary relative humidity are substituted into the formula alpha=K.CPM2.5 to calculate the dry aerosol extinction coefficient alpha dry at the arbitrary relative humidity, the determined alpha wet and the calculated alpha dry are substituted into the formula defined in the specification to calculate the aerosol extinction coefficient moisture absorption increasing factor f, the calculation process of the f is repeatedly performed at least 5 times, and the two groups of the data such as the relative humidity RH of atmosphere determined at the same position and the calculated aerosol extinction coefficient moisture absorption increasing factor f are subjected to fitting to obtain the function relationship. According to the present invention, with the method, the PM2.5 mass concentration in the height range of 0-30 km on the ground can be conveniently detected at any time in a low cost manner.

The invention discloses a multi-wavelength laser radar aerosol particle spectrum distribution inversion method and system. The method comprises the following steps: acquiring optical data and regularparameters, wherein the optical data comprises an aerosol extinction coefficient and an aerosol backscattering coefficient; determining a kernel matrix; calculating a weight coefficient according to the kernel matrix, optical data and regular parameters; calculating evaluation error according to the optical data, kernel matrix and weight coefficient; determining an evaluation set; and judging whether the evaluation error is within the evaluation set, and if not, adjusting the regular parameters and returning to the step of calculating the weight coefficient, and if yes, determining the spectral distribution of atmospheric aerosol particles based on the weight coefficient through inversion. Compared with the prior art, the method adopts an NCRE algorithm to select appropriate regular parameters to achieve accurate inversion of atmospheric aerosol particle spectrum distribution, and has simple calculation and wide application range.

The invention provides a laser radar transport flux computing method and a laser radar transport flux computing device. The laser radar transport flux computing method includes acquiring extinction coefficients of particulate pollutants collected by laser radar as well as reanalysis-mode meteorological data including wind-field data and humidity data; subjecting the extinction coefficients to humidity correction according to the humidity data in the reanalysis-mode meteorological data so as to obtain dry aerosol extinction coefficients; computing particulate pollutant vertical profiles according to the dry aerosol extinction coefficients and ground monitoring particulate pollutants; computing laser radar transport fluxes according to the particulate pollutant vertical profiles and the wind-field data of the reanalysis-mode meteorological data. The laser radar transport flux computing method has the advantages that the reanalysis-mode meteorological data are used for humidity correction of the extinction coefficients and laser radar transport flux computation, are acquired simply at a quite low cost and comprise the wind-field data and the humidity data which are both high in precision, and accordingly the whole laser radar transport flux computing method is low in cost and high in popularization degree.

The invention provides a method and device for obtaining extinction coefficients of aerosol. The method includes the steps that a laser pulse is emitted into the atmosphere through a lidar, and the power of backscattered light after the laser pulse is scattered by the atmosphere is obtained after receiving and measuring; atmospheric correction parameters at one or more preset positions are obtained through an atmospheric integrating nephelometer; a relational expression between the extinction coefficients of the aerosol and backscattering coefficients is obtained according to the atmospheric correction parameters; and the power of the backscattered light and the relational expression between the extinction coefficients of the aerosol and the backscattering coefficients are substituted intoa lidar equation, and the extinction coefficients of the aerosol at the preset positions are calculated. According to the method and device for obtaining the extinction coefficients of the aerosol, the extinction coefficients of the aerosol can be calculated accurately.

The invention discloses an optical cavity, which comprises a cavity body, the cavity body is in the shape of a cylinder, both ends of the cavity body are sealed with high-reflection cavity mirrors, and one side of the high-reflection cavity mirror is a curved surface. The high reverse surface, and the high reverse surfaces are all facing the cavity, and the reflectivity of the high negative surface is greater than 99.95%; the cavity is connected with the first protective gas nozzle, the second protective gas nozzle, the sampling gas nozzle and the exhaust gas The first protective gas nozzle and the second protective gas nozzle are separated at both ends of the cavity, the sampling gas nozzle and the exhaust nozzle are also separated at both ends of the cavity, and the first protective gas nozzle The gas nozzle and the second protective gas nozzle are relatively closer to the two ends of the cavity. Simultaneously, the invention also discloses a wide-band cavity-enhanced aerosol extinction instrument with the optical cavity, and a measurement method of the aerosol extinction spectrum realized by the aerosol extinction instrument. The measurement result of the invention has high accuracy.

The invention discloses an aerosol extinction coefficient inversion method base on a feedback type RBF neural network. The method includes the following steps: 1) training the RBF neural network by using input and expected output, wherein the power of historical echo signals is used as the input of the RBF neural network and aerosol extinction coefficients obtained from the historical echo signalsare used as the expected output of the RBF neural network; and 2) inverting the aerosol extinction coefficients based on the feedback type RBF neural network. The method uses the feedback type RBF neural network to invert the aerosol extinction coefficients and stores internal mechanisms between information in a network through the learning of sample patterns, which effectively avoids the uncertainty caused by a plurality of assumptions. The method has fast response speed and good robustness.

The invention discloses a measurement method and apparatus for a laser radar ratio of an aerosol. The measurement apparatus a laser beam source, a spectroscope, an aerosol accommodation space, and a detector. The method comprises the following steps: measuring and obtaining a light energy value E0 of laser before aerosol scattering, a light energy value E of laser after aerosol scattering, and a light energy value Eback of backward scattering light during aerosol scattering of the laser; and the carrying out calculation to obtain aerosol laser radar ratio S according to a formula: S=(E0-E)/Eback. According to the previous method, hypothesis of a laser radar ratio of an aerosol needs to be carried out and then inversion of an aerosol extinction coefficient and a backscattering coefficient of the laser radar can be carried out. However, with the provided method and apparatus, single-point sampling of the laser radar ratio of the aerosol can be realized; the parametric hypothesis during the laser radar aerosol profile measurement technology process can be reduced; and the accuracy, comparability, and representativeness of measurement data can be guaranteed.

The invention discloses an integrating sphere embedded photo-thermal interferential aerosol scattering and absorbing synchronous measurement device. The core is to depend on an optical path system and an air path system of the integrating sphere; the optical path system comprises a stimulating optical path and a detection optical path; some energy of the stimulating optical path is scattered by the aerosol particle and then a scattering signal is generated under the effect of integrating sphere; and meanwhile, the energy has a photothermal effect with the aerosol particle so as to generate an aerosol absorbing signal; the detection optical path is divided into an absorbing measuring part and a scattering measuring part; the scattering measurement adopts an integral optical detector for realizing the scattering coefficient measurement; an optical type Michelson vertical reflecting interference sensing structure is adopted for absorbing measurement; the photo-thermal interference principle is utilized to realize the absorbing coefficient measurement; the scattering and absorbing coefficient measurement of multiple wavelengths can be realized through the device; parameters, such as, aerosol extinction coefficient and single scattering reflection ratio can be acquired through simple treatment on the above basis; the research work for aerosol optical property can be further satisfied; the integrating sphere embedded photo-thermal interferential aerosol scattering and absorbing synchronous measurement device is suitable for the online detection for the atmospheric aerosol optical property.