Weather-Dependent Detection Performance and Dynamical Response of an FC-III Coherent Doppler Wind LiDAR During Low-Visibility Events at Yinchuan Hedong International Airport

Airport low visibility is spatially heterogeneous, whereas point observations of meteorological optical range (MOR) and runway visual range (RVR) provide certified surface visibility observations but limited information on low-level dynamics and the approach direction of attenuation boundaries. We combined FC-III coherent Doppler wind-LiDAR and automatic observations with 4176 matched low-visibility hourly instances collected at Yinchuan Hedong International Airport from 2020 to 2025 to describe site-specific variation in the spatial coverage of quality-controlled valid wind profile data. Two-dimensional kernel density estimates characterize full-range distributions, while cross-category correlations are evaluated only within a common MOR interval with event-block bootstrap uncertainty. Dust storm and snow samples retained positive conditional associations, whereas rain, fog, and mist showed weaker, negative, or statistically uncertain associations after accounting for event-level dependence. Case analyses illustrate directional contraction of the valid data boundary during dust and fog events. Directional valid range is neither a certified visibility metric nor a contingency observation for MOR/RVR; it is used only to describe the spatial evolution of quality-controlled valid LiDAR-data coverage at this site.