Method and device for obtaining extinction coefficients of aerosol

Abstract

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.

Description

technical field [0001] The present application relates to the technical field of lidar, and in particular to a method and device for obtaining an aerosol extinction coefficient. Background technique [0002] With the aggravation of industrial pollution, smog weather occurs frequently, and air pollution has seriously affected human health. Therefore, the detection of air quality has become particularly important, and the monitoring, analysis and research of particulate matter in the air has become the focus of current environmental protection work. [0003] According to the aerodynamic diameter, atmospheric particulate matter can be divided into: (1) total suspended particulate matter (TSP for short) with a diameter of less than 100 microns; (2) inhalable particulate matter with a diameter of less than 10 microns; fine particles. Among them, fine particulate matter PM2.5 can be suspended in the atmosphere for a long time, which has an important impact on air quality and vis...

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Problems solved by technology

[0007] 1) The slope method assumes that the atmosphere is a uniform atmosphere as a condition, but this kind of weather is difficult to occur in actual situations, so this method is difficult to achieve high accuracy, and can only be used in the horizontal direction

[0008] 2) The Klett method only considers a single component, that is, it can only be used when the aerosol concentration is large, and it is assumed that the relationship between the reflection and extinction coefficients satisfies β=B·α k , so this method can only be used in high-concentration weather, which has great limitations

[0009] 3) The Fernald method assumes that the scattering coefficient and extinction coefficient of particles at a certain height (about 5KM) are close to a fixed value, and that the ratio of the atmospheric extinction coefficient to the backscattering coefficient is 8π / 3, but the actual situation may not meet the above conditions, and this method can only be used in the vertical direction

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