Characteristics of heterodyne lidar echoes in different polydisperse aerosol environments

The characteristics of heterodyne lidar echoes are related to both the polydisperse aerosols and the polarization state of emitted laser. Based on the database of optical properties of aerosols and clouds(OPAC), we have numerically simulated the backscattering process of photons in different polydisperse aerosol environments using the semi-analytic Monte Carlo method. Then, the backscattering properties of five typical aerosol components in four environments are analyzed within the wavelength range of 1.4-2.1 μm, and the emitted lasers are linear polarized light (LPL) and circular polarized light (CPL). The simulation results show that the degree of polarization (DoP) of lidar echoes is larger by using LPL in the four typical aerosol environments and that the returned photon numbers are less affected by the polarization state of emitted laser pulses. Finally, to achieve the same detection performance, the required laser power ratios are discussed in detail under typical humidities, which is of reference value to the designs and performance analyses of heterodyne lidar systems for atmospheric environment observations with long range and high accuracy.