The influence of rain on small aperture LiDAR sensors

Abstract

The influence of rain on pulsed LiDAR systems with a miniaturized aperture and small laser beam cross sections was investigated based on two situations deemed critical to the system's performance. Firstly, discrete rain drops appearing very close to the laser aperture could lead to a complete deflection of the laser beam when the drop and the beam overlap. However, our semi-probabilistic, semi-analytical model indicates that the rate of deflected scan events is negligible. Secondly, the emitter surface could be covered with drops of various size degrading the performance. We found an optimum ratio between drop diameter and laser beam diameter, favoring larger laser beams. In conclusion, the effect was found to be non critical.