A non-contact obstacle detection (NCOD) system for an opening in a vehicle includes a cover panel, such as a glass pane, slidable between opened and closed positions within the opening. The system includes one or more infrared time-of-flight (IR-TOF) sensors which measure the length of a beam of infrared light by measuring the time that the infrared light in the beam takes to travel the length of the beam and to reflect back to the sensor. The IR-TOF sensors may be configured to provide a beam of light along either the side edge of the frame parallel to the sliding direction or a terminal edge generally transverse to the sliding direction. Methods are provided for detecting obstacles within the opening of the frame by controllers using the lengths of beams from each of those different beam configurations, and for self-calibrating the system.