THERMAL AND VISUAL CAMOUFLAGE

Abstract: The invention relates to means for providing thermal camouflage of irregular emission pattern as a supplement to camouflage within the visual and near infra-red region. According to the invention, this camouflage means comprises a supplementary set of material pieces (12) of desired configuration which are intended to be fastened in a desired pattern onto existing masking material (10), for example a net. The emission coefficient of the material pieces (12) differs substantially from the emission coefficient of the masking material (10), preferably by a difference of at least about 0.3. The invention also relates to masking material on which such material pieces are attached.

Description: Thermal and Visual Camouflage The present invention relates to means for creating thermal camouflage of irregular emission pattern as a supplement to camouflage within the visual and near infra-red region of the spectrum. One object of the invention is to provide simple camou¬ flaging means which in addition to possessing good camouflage properties within the visual and near infra¬ red region will also provide satisfactory thermal camouflage protection, i.e. will have the ability to hide heat-radiating objects from discovery by thermo- cameras, or at least make such discovery difficult. This object is achieved in accordance with the present invention in that said means consist of a supplementary kit which comprises material pieces of arbitrary config¬ uration intended for attachment in any desired pattern to existing masking material, such as a net, tarpaulin, covers and the like, said material pieces having an emission coefficient which differs substantially from the emission coefficient of the masking material, preferably by a coefficient difference of at least about 0.3. By dividing an existing masking material, which may consist of a net framework having attached thereto so-called garnishing material made, for in¬ stance, from leaf-cut, softened PVC-foil or the like having a high emission coefficient of 0.90 or higher for instance, into an irregular emission pattern, by attaching material pieces of low-emissivity over the highly emissive garnishi material, it is possible to achieve with the inventive camouflaging means effective masking of the radiation-emitting object within the visual, near infra-red and thermal region of the radiation spectrum. This enables an existing camouflage net to be complemented, simply and inexpensively, in a manner to render discovery of the camouflaged object impossible, or to render such disclosure difficult, within the visual, near infra-red and thermal region with the use of thermocameras. The material pieces are preferably in the form of laminates which comprise at least one internal, lowly- emissive metal layer, for instance an aluminium layer, whose outer surfaces exhibit a pigmented masking layer which is transparent to radiation within the thermal region, for instance polyethylene. The laminates may also include a reinforcing layer, so as to impart the requisite mechanical strength to said laminate. The material pieces preferably have an irregular con- figuration and an area of about 1-2 m 2. The material pieces are fastened onto existing masking or camouflage material, for instance a net, in a desired irregular pattern, with the aid of appropriate fasteners or by gluing or welding. In a manner conven¬ tional with masking-net garnishing material, the mate- rial pieces may be provided with so-called leaf-cuts or eyelid cuts, so as to give the material pieces a three dimensional, irregular pattern. In order to obtain with the masking material an appropriate, thermally irregular pattern, the total area of the material pieces will preferably be about 30-40% of the total area of the masking material. The invention also relates to masking material for camouflaging objects against detection within the visual, near infra-red and thermal region, wherein a material body which includes visual and near infra-red camouflaging garnishing material is augmented with a plurality of material pieces which are attached in a desired pattern on the material body and which have any desired configuration and an emission coefficient which differs by at least about 0.3 from the emission coef¬ ficient of the remainder of the masking material. The masking material may comprise a net, a cloth, a tar- paulin, a cover or the like. The invention will now be described in more detail with reference to the accompanying drawing, which illus¬ trates schematically a masking net onto which a plura- lity of material pieces have been attached for the purpose of masking objects against thermal radiation. Shown in the drawing is a masking net 10 which com¬ prises a net framework, not shown in detail, on which conventional masking garnishing is attached to provide camouflage within the visual and near infra-red region. This garnishing may consist of pieces of fabric, strips or pieces of camouflage-pigmented foil material, for example PVC, having a relatively high emission coeffi- cients e >0.90. In order to augment such conventional masking nets with camouflage which can also be used to camouflage within the thermal spectral region in order to render dif- ficult or impossible the discovery of heat-emitting objects covered by the net by means of ther ovision cameras, it is proposed in accordance with the present invention that- the existing masking net 10 is complemented with a set of material pieces 12 whose emission coefficient differs from the emission coeffi- cient of the net. This difference in emission coeffi¬ cient could preferably be greater than about 0.3, so as to create an irregular, camouflaging emission pattern. The material pieces 12 suitably consist of a laminate of one or more metal layers, a stiffening reinforcement and an outermost thermally transparent layer which exhibits a dull camouflage colour. The material pieces will preferably have an emission coefficient e of about 0.4-0.6. The material pieces 12 have any desired and varying configuration and are attached to the net 10 by means of appropriate fasteners 14, in the pattern desired. In the illustrated embodiment, six material pieces 12 are fastened to the net 10 by means of a plurality of clamps 14, such that the material pieces 12 will cover an area equal to about 30-40% of the net area, so as to provide an appropriate masking effect against thermal radiation. Each material piece will preferably have an 2 area of from 1-2 m . The material pieces may be leaf-cut and/or eyelid cut in a conventional manner, such as to obtain a three dimensionally irregular pattern of said material pieces.

Claims: Claims 1. Means for supplementing camouflage within the visual and near infra-red range with thermal camouflage having an irregular emission pattern, c h a r a c ¬ t e r i z e d in that said means comprises a supple¬ mentary set of material pieces (12) of desired con¬ figuration which are intended for attachment in a desired pattern to existing masking material (10) such as a net, cloth, tarpaulin, cover or the like, and in that the material pieces (12) have an emission co¬ efficient which differs substantially from the emission coefficient of the masking material (10) preferably by a coefficient difference of at least about 0.3. 2. Means according to Claim 1, c h a r a c ¬ t e r i z e d in that the material pieces (12) have a relatively low emission coefficient and are intended to be attached to masking material (10) of relatively high emission coefficient, or vice versa. 3. Means according to Claim 1 or 2, c h a r a c ¬ t e r i z e d in that the material pieces (12) have the form of a laminate which comprises at least one internal lowly-emissive metal layer and an outermost camouflage-pigmented layer which is thermally trans¬ parent. 4. Means according to any one of Claims 1-3, c h a r a c t e r i z e d in that the material pieces (12) are provided with so-called leaf-cuts and/or eyelid cuts so as to obtain a three di ensionally irregular pattern of material pieces. 5. Means according to any one of Claims 1-4, c h a r a c t e r i z e d in that the total area of the material pieces (12) is preferably equal to about 30-40% of the area of the masking material (10). 6. Masking material, such as netting, cloth, tarp¬ aulins, covers or the like constructed to camouflage within the visual, near infra-red and thermal region, comprising a material body provided with garnishing material which camouflages within the visual and infra¬ red region, c h a r a c t e r i z e d in that said material is provided with a plurality of material pieces (12) of desired configuration which are attached to said material body in a desired pattern, said mater¬ ial pieces (12) having an emission coefficient which differs by at least about 0.3 from the emission coeffi¬ cient of the remainder of the masking material, such as to provide an irregular emission pattern and therewith also a masking material which exhibits good thermal masking properties.

Inventors: WALLIN ERIK, WALLIN, ERIK
Applicants: BARRACUDA TECH AB, BARRACUDA TECHNOLOGIES AB
Application year: 1991
Main classification: F41H3
IPC codes: F41H3