Patent attributes
A sensor is used to sense a property relating to each one of a plurality of different elevational locations within a vertical plane that is normal to a length of an aircraft. The vertical plane passes through the doorway of the aircraft, and at least some of the plurality of different elevational locations are disposed outside a known surface boundary of the aircraft. A variation in the sensed property between two elevational locations is detected, the variation indicative of an elevational position of the known surface boundary. An elevational position of the doorway of the aircraft is determined based upon a known relationship between the known surface boundary and the doorway, and based upon the indicated elevational position of the known surface boundary. The determined elevational position of the doorway is used to guide an aircraft engaging portion of the movable bridge into elevational alignment with the said doorway.
