Combination of Roadside and In-vehicle Sensors for Extensive Visibility Range Monitoring

Fog is a local meteorological phenomena which drastically reduces the visibility range. Fog detection and visibility range estimation are critical tasks for road operators who need to warn the drivers and advise them on speed reductions. To achieve this task, fixed sensors are quite accurate but they have a reduced spatial cover. Mobile sensors are less accurate, but they have a good spatial cover. Based on the combination of roadside sensors and in-vehicle devices (sensors or fog lamps), a data fusion framework is presented aiming at taking the advantages of both fixed and mobile sensors for the extensive detection and estimation of the fog density. The proposed solution is implemented by means of a local dynamic map fed by vehicle to infrastructure (V2I) communication, which gives a coherent view of the road environment.