"Radar" is an object detection system which uses radio wave to determinethe range, altitude, direction, or speed of objects. It can be used to detect moving vehicles in car lift application & to start-stop the escalator.

    The radar dish or antenna transmits pulses of radio waves or microwaves which bounce off any object in their path. The object returns a tiny part of the wave's energy to a dish or antenna which is usually located at the same site as the transmitter.