A Sensor for Visibility Determination under Fog Conditions

In this paper, we describe a sensor approach utilizing commercial highway cameras for visibility determination under fog conditions. We achieved this by creating an engineered object in the field of view (FOV) of the camera that utilized two measurement approaches (contrast and light evaluation) via image processing. We employ the Koschmieder’s law to estimate visibility conditions from fog measurements, and scattering profile to estimate visibility conditions from visible measurements of a modulated light. The contrast measurements are used during the daytime, and light evaluations during night. We discuss the merits and challenges of such an approach.