Device and method for automatic measurement of natural atmospheric aerosol Mueller matrix

Abstract

The invention discloses a device and method for automatic measurement of a natural atmospheric aerosol Mueller matrix.The device is mainly composed of a gas pretreatment unit, a light source unit, a light scattering unit, a scattered light acquiring and measuring unit, a data acquiring and controlling unit and a data processing unit.Mechanical servo control is adopted only for scattering angle measurement, electric control is adopted for all the other element parameters, measurement speed is remarkably increased, all optical components are cured, the number of components does not need to be changed during measurement, measurement processes are greatly simplified, accurate natural atmospheric aerosol scattering parameters can be provided for radiative transmission simulation, and accurate basic experiment data are provided for atmosphere ocean remote sensing and climatology study.

Description

technical field [0001] The invention belongs to the field of meteorological observation, and relates to a natural atmospheric aerosol Muller matrix automatic measurement device and method. Background technique [0002] The light scattering properties of aerosols are an important factor affecting the radiative transfer process. On the one hand, changes in aerosol scattering properties can change the planetary albedo of the Earth's atmosphere system, which is an important factor affecting the energy budget of the Earth-atmosphere system. The key to this is the important physical basis for the implementation of atmospheric and oceanic remote sensing. The Mueller scattering matrix is ​​an important parameter to describe the scattering characteristics of aerosols. It not only characterizes the spatial distribution characteristics of the scattered energy, but also establishes the conversion relationship between the incident light Stokes vector and the scattered light Stokes vecto...

AI Technical Summary

Problems solved by technology

The currently developed technical system includes two types: one is to set polarizers and 1 / 4 or 1 / 2 wave plates and other components at the incident light source and scattered light receiving end, and change the polarization state of light through mechanical rotation of these optical components , and then modulate different Mueller matrix elements to the scattered light intensity signal for measurement. Under this system, the measurement of the Mueller scattering matrix for a scattering angle involves multiple combinations of mechanical rotations of optical components, so the entire process takes a relatively long time. It is too long to monitor the rapid change of aerosol scattering characteristics, and the measurement accuracy is relatively low due to more mechanical control; another type of system uses photoelectric phase modulation technology, after the incident light passes through the polarizer, it uses photoelectric phase modulation The high-frequency phase modulation is performed on it, and different Mueller matrix elements are modulated to different frequency harmonic signals. At the scattered light measurement end, different Screen the elements of the matrix, and then realize the measurement of the elements of the Mueller matrix through lock-in amplification technology. This system partially overcomes the mechanical rotation of the optical components, but in order to realize the measurement of the 16 elements of the Mueller scattering matrix, it is necessary to perform some optical Devices are manually added or removed, the degree of automation is insufficient, and the measurement cycle is too long. At the same time, the system measurement device is mainly used for the observation of experimental sample aerosols, and the measurement of the natural aerosol Muller scattering matrix has not yet been realized.

Generally speaking, the Muller scattering matrix measuring instrument is still in the stage of experimental prototype, which has the disadvantages of insufficient automation and long measurement time. At the same time, the measurement objects are mainly for laboratory particles, and there are very few experimental instruments for the observation of natural atmospheric aerosols, which cannot meet the requirements. High-precision radiative transfer simulation and climatological research needs, therefore, if a fully automatic Mueller scattering matrix measurement device can be constructed and developed to achieve rapid and accurate measurement of aerosol Mueller scattering matrix under natural atmospheric conditions, whether it is for the atmosphere Environmental monitoring, atmospheric radiative transfer simulation and research in other fields have application value

Images