GB1398443A - Method and system for guiding a spinning missile - Google Patents

Abstract

1398443 Guiding missiles SOCNATIONALE INDUSTRIELLE AEROSPATIALE 27 Oct 1972 [29 Oct 1971 22 Dec 1971] 49711/72 Heading H4D [Also in Division F3] A method of, and system for guiding a missile towards a target involves the use of polarized radiation. In one embodiment, the radiation emitted from a pyrotechnic source 1, Fig. 6, carried by the missile is passed through a polarizing filter 4 rotating with the missile and is received by a direction-finder unit 10 after having passed through a rotating or stationary, ground-based polarizing filter 5. The signal from the unit 10 is processed in a corrective network 11 and a directional error measuring system 12 from which directional error voltages V x and V y are sent to the missile by a micro-wave link or conductor wires. The filter 5 has four sectors of different polarities and this enables the angular position of the missile to be determined. In another embodiment, Fig. 9, the missile M and target C are illuminated by a ground-based source E. The radiation from a pyrotechnic source 1 carried by the missile is again passed through a polarizing filter 4 and is reflected by a ground-based mirror 30 on to a dichroic screen 31 together with radiation reflected from the target. The radiation from the pyrotechnic source passes through the screen and is received by a direction-finder unit 10M after passing through a polarizing filter 5 and modulating disc 14M. However, the radiation reflected from the target is reflected from the screen 31 on to a mirror 32 and thence into a direction-finder unit 10C after passing through a modulating disc 14C. The correction signals V x and V y are sent to the missile as before. In another embodiment, Fig. 10, the radiation from a ground-based pyrotechnic source E<SP>1</SP> 1 passes through the filter 4 after being reflected from a mirror 33 carried by the missile M. This radiation and the unmodulated radiation reflected from the target C is received by a direction-finder unit 10 after passing through a polarizing filter 5 and modulating disc 14. In a further embodiment, Fig. 11, the radiation from a ground-based pyrotechnic source E<SP>1</SP> 1 is passed through a polarizing filter 4 and is reflected from a target C into a direction-finder unit 10 on the ground and a similar unit 10M forming part of a homing device in the nose of the missile. Respective polarizing filters 5, 5M and modulating discs 14, 14M are provided. The unit 10 guides the missile until the homing device takes over. The pyrotechnic source, Fig. 1, comprises a screen of tantalum 2 which emits radiation R 1 when heated by a pyrotechnic tracer 1 which emits neither gases nor particles. A glass thermal protection plate coated with MgO, Al 2 O 3 or corundum is placed before a polarizing filter 4. Visible, I.R. or U.V. radiation is emitted by the pyrotechnic source. The modulating discs associated with the directionfinder units may, in a modification of the units, be replaced by a mosaic of lead sulphide cells.