Attenuation Characteristics of a 905-nm Pulsed Laser for Short-Range Transmission in Snowfall Environments

Aiming at the problems of power attenuation and spot expansion of pulsed laser transmission in snowfall environments, based on ray scattering and Fraunhofer diffraction theories, a model of laser transmission attenuation in snowfall environments is established. The model considers the influence of multiple scattering effects by introducing a forward correction coefficient. The Monte Carlo multiple scattering model was used to numerically simulate the attenuation characteristics of a 905-nm pulsed laser in snowfall environments, and an experimental platform for the attenuation characteristics was constructed. The experimental, simulation, and theoretical results show that, in three snowfall environments of 0 < SR < 1, 1 < SR < 2, and 2 < SR < 3, the laser transmittance decreases with the increase of transmission distance, and when the transmission distance is the same, the laser transmittance decreases with the increase in snowfall rate. The influence of transmission distance, simulated photon number, and asymmetry factor on spot extension was studied. The simulation results show that the spot radius increases with the increase in transmission distance, remains almost constant with the increase in the simulated photon number, and decreases with the increase in the asymmetry factor in three snowfall environments.