Measurement of visibility using lidar in rain

A half-year contradistinctive experiment for visibility detecting has been performed using CSY2 visibility lidar developed by ourselves in Xiaogan of Hubei province and Peking. The output of CSY2 visibility lidar was lower than the outputs of eyeballing and MITRAS meter due to forward scattering caused by raindrop. Based on Marshall-Palmer particle spectral distribution function, the forward scattering effect on 1 064 μm laser propagation of raindrop was analyzed, and a new modified formula for visibility, was proposed, with which measurement error of visibility can be largely reduced in moderate and heavy rain．