Research on airborne near-infrared polarized lidar detection of supercooled clouds

Aiming at detecting the distribution of supercooled clouds, a near-infrared airborne polarized coaxial micro-pulse lidar system is designed. The system uses 1550nm laser excitation, which can effectively reduce the extinction of small-scale aerosol particles in the cloud, thereby improving the detection range and efficiency of large-scale cloud particles. The phase state of cloud particles is distinguished by the depolarization ratio of non-spherical particles. At the same time, a lidar inversion algorithm for cloud water content is proposed, combined with airborne temperature data and tropospheric characteristics, to invert the spatial distribution of supercooled clouds. Based on the standard atmosphere model and cloud particle spectrum data of airborne instruments, the detection performance of polarization micropulse lidar with different excitation wavelengths in two kinds of tropospheric clouds is simulated and analyzed. The results show that the detection distance in the lower cloud is about 1.1 km, while the upper layer The detection distance in the cloud can reach up to 1.5 km.