Atmospheric Temperature And Aerosol Measurements Using A Pure Rotational Raman Lidar And Comparison With Edge Technique Doppler Lidar

The atmosphere is composed of a variety of gases and floating in some of the solid and liquid particulate matter. These particulate matter include dust, smoke, water droplets, ice crystals, pollen and so on. In atmospheric science, the atmosphere containing suspended solid, liquid particles is usually known as the atmospheric aerosol, while these particles are called atmospheric aerosol particles. Atmospheric aerosol is the condensation nuclei of clouds, rain, fog, snow, which significantly influence the magnitude of radiative fluxes on the earth’s surface and within the atmosphere through the scattering and absorption of incoming solar and outgoing thermal radiation. Accordingly, aerosol have an important impact on local, regional and even global climate.It has been proved to be a high precision method to use pure rotational Raman signal of atmospheric molecules to inverse atmospheric temperature and many pure rotational Raman lidars have been established around the world. The addition of all pure rotation Raman spectrum is not dependent on the temperature. Using this feature, we can inverse aerosol extinction without any assumptions. This paper presents a new method of aerosol detection, extraction of pure rotational spectrum of a single branch (J=4and14), coupled with Rayleigh&Mie channel lidar equation, without any requirement of the additional assumptions. We derive the mathematical description of the aerosol backscatter coefficient. Furthermore, we do the error analysis, which shows the total error of atmospheric backscattering coefficient should be less than11.4%with1,600photons counting at8km and less than6.7%below4km.In order to extract the single branch spectrum of the pure rotational Raman scattering, we use the combination of the Interference Filter (IF) and F-P etalon. This article describes the temperature, the pressure and the incidence angle characteristics of the F-P etalon transmittance function. There are also a variety of defects in the production process which influence the performances of F-P etalon significantly.At the end, we compare two wind measurement methods, using iodine vapor filter and Fabry-Perot interferometer, respectively. The results show that, lidar based on double-edge of iodine vapor filter(de-IVF) and the combination of atmospheric molecular Rayleigh scattering and F-P etalon(UV-FPI) can take into account the more content of aerosol at low-altitude detection and less content of aerosol at upper-altitude detection. They are suitable to be made of both high and low altitude wind detection lidar.