GB1030852A - Improvement in radio guidance systems for aircraft - Google Patents

Abstract

1,030,852. Radio navigation. BRITISH AIRCRAFT CORPORATION (OPERATING) Ltd. March 8, 1963 [March 16, 1962], No. 10283/62. Heading H4D. In an aircraft landing system for enabling a craft of the kind capable of hovering to be flown to a given position to a high accuracy, the craft is provided with an automatic navigation system including directional guidance means, a programme unit for controlling the guidance means in accordance with a predetermined programme to guide the craft generally in the direction of the given point, and radio transmitting and receiving means; and the ground station equipment includes transmitting means comprising an angularly adjustable aerial for transmitting to the craft range-determining signals and positional information signals, receiving means for receiving range-determining signals from the aircraft, and computing means for deriving positional information, and computing means for deriving positional information relating to the craft from the received range-determining signals, the successive positional information signals being applied from the computer to the transmitting means to provide repeated correction of the craft navigation system. The aircraft may be a drone (i.e. unmanned) capable of vertical take-off and landing and programmed by a unit 12, operating through an auto-pilot 10, to carry out a reconnaissance mission and return to a landing point. Data gathered on the mission is recorded in unit 16 and transmitted to the ground station via C-bonded transmitter 20 when the drone is within radio range of the ground station. The ground station transmits radar signals through an X-band transmitter 32, and on the drone the X-band receiver 38, together with units 40, 42, 18 and the transmitter 20 form a transponder unit so that the range can be derived from the C-band receiver 24 at the ground station. The bearing is derived from the aerials 26 and 34 and computer 46 calculates positional information from the range and bearing and transmits this information to the drone through the X-band transmitter 32 at intervals between the ranging signals; at the drone the positional information is used to correct the position calculated by the computer 14 which controls the auto-pilot. When the drone is 100 metres above the launching and landing vehicle and within a horizontal radius of 20 metres, signals from a beacon 58 are received of a phasesensitive receiver 54 on the landing vehicle. On receipt of these signals a radio link 62-64 causes transmitter 32 to be switched-off, and the cessation of transmitter 32 causes a switch 68 to operate in the drone disconnecting the computer 14 from the auto-pilot. Thereafter the drone is controlled by signals from the landing vehicle transmitted by X-band transmitter 74 as a result of information derived from the receiver 54.