a method and apparatus in which the movable system, to determine the orientation of the line of sight of the helmet sight, especially

摘要

A method for determining a line of sight from a sighting device mounted on a helmet provided with a sensor (2) with three orthogonal magnetic coils, in relation to a reference attached to an aircraft and having the form of a transmitter (1) having three orthogonal magnetic coils. According to the method, the cockpit is first magnetically mapped. For this purpose, sets of field measurements detected by the sensor for the fields successively produced by the transmitter's three coils for various known positions and attitudes of the sensor in the cockpit are established and memorized. Then, the cockpit is magnetically modelled on the basis of said measurements. In flight, the matrix of measurements, combined with a transmitter transmission cycle initiated when the pilot confirms a directional line of sight determined in relation to his helmet, allows the orientation of said line of sight in the aircraft reference to be accurately calculated on the basis of the model previously made. The method can be used for sighting from helicopters where the cockpit causes disturbances because of field reflexions from metal components.