Land-based vehicle including an arrangement for monitoring objects in or about a vehicle which includes a source from which illumination is emitted into an area in or about the vehicle, a receiver arranged to receive illumination reflected from an object in the path of the illumination, a light-regulating component arranged in front of the receiver to regulate reception of illumination by the receiver, and circuitry coupled to the source, the receiver and the light-regulating component. The light-regulating component is modulated to enable a determination of a distance between an object from which the illumination has been reflected and the receiver. The circuitry obtains information about objects from which the received illumination has been reflected other than distance information and associates with the objects distances between the objects and the receiver. This improves the ability to control vehicular systems based on the presence of objects in or about the vehicle.