Daytime visibility range monitoring through use of a roadside camera

Based on a road meteorology standard, we present a roadside camera-based system able to detect daytime fog and to estimate the visibility range. Two detection algorithms, both based on a daytime fog model, are presented along with a process to combine their outputs. Unlike previous methods, the system takes into account the 3-D scene structure and filters the moving objects from the region of interest through use of a background modelling approach and detects the cause of the visibility reduction. The study of the system accuracy with respect to the camera characteristics leads to a specification of the characteristics of the camera required for the system. Some results obtained using a reduced-scale prototyping of the system are presented. Finally, an outlook to future works is given.