Abstract: The present invention is directed to a light detecting system for accurately determining the lateral position of a moving object, such as a vehicle, relative to a point or points in advance of the object's current position along a desired path. In a preferred embodiment, no moving parts are required to illuminate a field of view in advance of the object's travel. Further, by providing separate range and angle detection channels, relatively compact overall size is actually achieved. Separation of these two channels permits integrating charge-coupled devices (CCD's) to be used in the relatively slow angle detection channel, while a single detector (e.g., single photodiode) is used in the relatively fast, range detection channel.