GB2343737A

GB2343737A - Weapons decoys

Info

Publication number: GB2343737A
Application number: GB9906195A
Authority: GB
Inventors: Robert Alistair Borrell
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-03-05
Filing date: 1999-03-05
Publication date: 2000-05-17
Anticipated expiration: 2019-03-05
Also published as: GB9804547D0; GB2343737B; GB9906195D0

Abstract

A decoy 1 for a laser guided weapons system has a laser diode 2 as a source of laser radiation and a laser radiation scattering means comprising a sphere 4 of laser radiation transparent material and four mirrors 6a-d mounted on the surface of the sphere 4. Laser radiation from the diode 2 is scattered by the mirrors 6a-d in a manner that minimises the scattered radiation used to guide laser guided weaponry.

Description

Weapons Decoys The invention relates generally to the field of laser guided weaponry and in particular to a decoy or target for laser guided bombs, missiles and other projectiles.

Laser guided weapons are now apparently commonplace and received considerable publicity during the so-called Gulf Conflict between Iraq and Allied forces in the early 1990's. Laser guidance systems were said to have been used by the Allies to accurately drop bombs from planes on to target buildings. It is understood that the bombs were guided by scattered laser radiation emanating from the target. The scattered radiation is believed to have been generated by"illuminating"the target with laser radiation, and a separate plane was equipped for this purpose. It is also known to use laser guided weaponry against movable targets such as helicopters or tanks.

The object of the invention is to provide a decoy for counteracting laser guided weaponry.

A decoy may also serve as a target.

The invention provides a laser guided weaponry decoy comprising a laser radiation source and laser radiation scattering means. The radiation from the laser source is projected on to the laser radiation scattering means so as to produce scattered laser radiation which mimics the scattered radiation relied upon by laser guided weaponry. The source may operate in conjunction with a detector capable of recognising the guided weaponry laser radiation, the wavelength of the radiation and its pulse width modulation, thereby enabling duplicate to be emitted from the source. The decoy can therefore be used to divert a laser guided weapon away from an intended target. For example, a tank may have a decoy mounted on one of its antennae and the decoy will be activated, on detection that the tank has been made a target for a missile launched from a helicopter, so as to lure the missile away from the body of the tank. The scattered radiation from the decoy can be adjusted to overpower any scattered radiation produced by the weapons system of the l The radiation scattering means may comprise at least one mirror. Each of the at least one mirrors is individually capable of scattering laser radiation incident upon it but when there are two or more mirrors these may be so positioned that the scattered light from one of them impinges upon one or more of the others and is thereby scattered further. The radiation from the laser source may be incident upon the first mirror from where it is scattered either into space or on to one of the other mirrors. The radiation may be visible or invisible, and the source may be tunable so as to operate over a range of frequencies. The radiation may be scattered in all directions as the direction of the illuminating may be unknown.

The or each mirror may be supported in relation to the laser source either on or within a body through which laser radiation may pass. For instance, the mirrors may be mounted, equidistantly spaced, on the surface of a sphere made from material transparent to laser radiation, may be suspended within a mesh cage or by any means which enables laser radiation to impinge upon the mirrors and to pass through and out of the body.

The laser radiation source may be a laser diode mounted in, on or close to the body, or may be an alternative laser device with an optical fibre for transmitting the radiation to or into the body. The laser source may also have a lens or similar diverging means associated with it for spreading or increasing the width of the beam of laser radiation it produces so as to enhance the subsequent scattering effect.

It will be appreciated that the invention may be used as a decoy not only with laser guided weaponry but also, for example, with so-called forget and fire type weaponry which homes in on the infra-red radiation emanating from, say, a targets exhaust.

The invention will now be described with reference to the sole figure 1 of the drawings in which one preferred embodiment of a decoy according to the invention is illustrated.

Illustrated generally at 1 is a decoy for a laser guided weapons system having a laser diode 2 as a source of laser radiation and a laser radiation scattering means comprising a sphere 4 of laser radiation transparent material and four mirrors 6a-d mounted on the surface of the sphere 4. Each mirror 6 is fixed into a correspondingly shaped recess in the surface of the sphere 4. A detector 10 recognises guided weaponry laser radiation when if illuminates the object to which the decoy 1 is attached and also identifies the wavelength and pulse width of the radiation from this, the diode 2 emits radiation which has identical characteristics to the illuminating radiation.

Laser radiation from the diode 2, which is held against the sphere 4, is projected through the body of the sphere 4 on to the first mirror 6a which is mounted diametrically opposite the diode 2 with its reflective surface 8a facing towards the spheres centre. The reflective surface 8a is convex as to scatter the incident radiation. The majority of the scattered radiation passes out of the sphere, but a proportion of it impinges on the three equidistantly spaced remaining mirrors 6b-d from where it is scattered further, either towards another mirror or out of the sphere. The second, third and forth mirrors 6b-d have convex surfaces against the sphere 4.

Claims

Claims 1. A laser guided weaponry decoy comprising a laser radiation source artd laser radiation scattering means.
2. A decoy according to claim 1 wherein the radiation scattering means comprises at least one mirror.
3. A decoy according to claim 2 wherein each of the at least one mirrors individually scatters laster radiation incident thereon.
4. A decoy according to claim 3 wherein there are two or more mirrors each positioned to enable the scattered light from one mirror to impinge upon one or more of the other mirrors and thereby scatter further.
5. A decoy according to any of claims 1 to 4 wherein the radiation is visible or invisible.
6. A decoy according to any of claims 1 to 5 wherein the source may be tunable.
7. A decoy according to any of claims 2 to 4 wherein the or each mirror is supported in relation to the source either on or within a body through which laser radiation may pass.
8. A decoy according to claim 7 wherein the or each mirror is mounted equidistantly spaced on the surface of a sphere made from material transparent to laser radiation, suspended within a mesh cage or by any means which enables laser radiation to impinge upon the mirrors and to pass through and out of the body.
9. A decoy according to claim 7 or claim 8 wherein the source may be a laser diode mounted in, on or close to the body, or may be an alternative laser device with an optical fibre for transmitting the radiation to or into the body.
10. A decoy according to any preceding claim wherein the source has a lens or similar diverging means associated with it for spreading or increasing the width of the beam of laser radiation emitted.
11. A decoy substantially as herein described with reference to the sole figure 1 or the drawings.