| 摘要 |
<p>Road stud 10 comprises lens 44, optical input 22, and light sensor 42. The lens has a surface which defines an interface between the lens and an external environment of the road stud. The optical input receives incoming light from a vehicle and directs it through the lens along a predetermined path towards the lens surface so as to be reflected and/or refracted thereby. The light sensor senses light which has been reflected and/or refracted by the lens surface and outputs sensed light data so as to provide information about the refractive index of the external environment, thereby enabling inference of information about the moisture content of the external environment. The sensed light data may include information about the location of the sensed light. The road stud may also include an incoming light sensor 24 for normalizing the processing.</p> |
