Use of pure-rotational Raman scattering in measurements with a mobile Mie-Raman lidar

Abstract

Small-sized mobile lidars mainly use single-frequency sounding with registration of elastic backscattered radiation on aerosols. Mie-Raman lidars are used to correctly reconstruct the optical characteristics of an aerosol. The method most widely used in such lidar measurements for evaluating optical properties is the method of recording vibrational Raman scattering on nitrogen molecules. The disadvantages of this method are the low backscattering cross section and the significant frequency shift of the Raman vibrational component. These problems are solved by using purely rotational Raman scattering, which is characterized by a higher backscattering cross section, and a much smaller frequency shift, which practically eliminates the dependence on the Angstrom exponent. The paper presents the practical implementation of pure-rotational Raman measurements in the mobile lidar "LOSA-A2".