US Patent 10403107 Passive optical detection method and system for vehicles

A system, method, and apparatus are discussed for a passive optical camera-based system to detect a presence of one or more vehicles with one or more cameras. A detection algorithm is applied to recognize of the presence of the one or more vehicles using one or more imaging processors and the one or more cameras to detect fluctuations in light intensity from scattered light and/or reflections off of that vehicle. Those scattered light and/or reflections are captured in images contained in a set of frames from the one or more cameras.