Measurement and tracking of blowing and falling snow particles using an automotive 1550 nm LiDAR

The prevalence and affordability of fast-scanning commercially available LiDARs are increasing due to the rapid expansion of the autonomous vehicle industry. These LiDAR units can provide > 1 Hz measurements of millions of laser reflections at ranges of hundreds of meters with high precision. In this study we investigate the often overlooked 1550 nm wavelength LiDAR for measurements of airborne blowing and falling snow particles. While reflectance of snow is known to be lower at 1550 nm than shorter wavelengths, the reduced sensitivity of the human eye to this wavelength allows these LiDARs to be produced with much greater laser power, lower beam divergence, and longer range. As exact laser specifications are rarely published due to commercial interests, there is limited potential for estimating the performance of new fast-scanning LiDAR theoretically. In lieu of this, we performed an initial systematic analysis of a 1550 nm LiDAR in controlled blowing and falling snow experiments at the Cryospheric Environment Simulator. We find that commercially available 1550 nm LiDAR can indeed provide reliable high spatiotemporal resolution measurements of volumes of both blowing and falling snow. Furthermore, we find that large falling precipitation particles ( > 1 mm) can be tracked at distances of up to 10 meters away for several seconds. The future implementation of such an instrument in field studies can provide new insights into our understanding of the critical spatial and temporal heterogeneity of turbulent wind–snow processes.