GB1605131A

GB1605131A - Camouflage

Info

Publication number: GB1605131A
Application number: GB40801/77A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-01-05
Filing date: 1977-09-30
Publication date: 1981-12-16
Also published as: IT1155756B; NL7710906A; NL187993B; FR2488387B1; DE2700202C1; FR2488387A1; IT7847527A0; NL187993C

Description

(54) IMPROVEMENTS IN OR RELATING TO CAMOUFLAGE (71) I, GUNNER PUSH, a citizen of the German Federal Republic, of Bannholzweg .12, 6903 Neckargemund-Dilsberg, German Federal Republic, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to camouflage. A camouflage which is effective from the visible spectral range into the far IR range, such as is needed for military vehicles of all kinds, for military equipment, personnel, accommodation etc.

Camouflage paints known to date offer a satisfactory protection in the visible and near IR range of the spectrum. If heat-picture equipment or IR line-scanning methods are used for reconnaissance, however, then objects which are painted with camouflage colours available today can be clearly recognized in the majority of cases. This applies even when the objects are covered with camouflage nets which are painted with camouflage colours introduced today. This is primarily because the camouflage colours which exist today have an emissive power of more than 90% in the far IR range i.e. in the spectral range 3 to 5 am wavelength (window II of the atmosphere) and in the spectral range 8 to 14 ,,am wavelength (window III). In the majority of cases this is considerably greater than that of the natural background.

The invention is based on recognition of the fact that the emissive power of camouflage colours in the windows II and III is influenced not only by the pigments of the paint, but decisively by the binding agents.

Whereas black and dark pigments have a comparatively high emissive power even in the far IR range, pigments which imitate natural chlorophyll have a comparatively low emissive power. The lacquer binders hitherto used, however, have a very high emissive power in the window III, while the emissive power fluctuates in the window II, depending on the kind of binder used. If metallic objects, such as vehicles, re painted with known camouflage paints, then because of their different emissive powers, they will appear darker than the natural background in the window II and lighter in the window III. Thus the camouflage effect in the visible optical Spectral range is no longer present in either window. It is therefore an object of the invention to provide a camouflage paint of the kind referred to at the beginning, which offers reliable protection both in the visible range against the known remote observation equipment and remote cameras and in the IR range against heat-picture equipment.

According to the present invention there is provided a camouflaged object comprising a body having a surface which is highly reflecting in the spectral ranges 3 ,,am to 5 ,am (window II) and 8 to 14 ,,am (window III), and a coating of a camouflage paint on the highly reflecting surface, the camouflage paint comprising a pigment having camouflage properties in the visible and near IR range and a binding agent, the paint having an emissivity less than 90% in the spectral ranges 3 to 5 ,,am and 8 to 14 pm.

A camouflaged object according to the invention reflects radiation in the visible and near IR range from 0.5 to 2 llum wavelength (window I of the atmosphere) because the pigmentatiaon of the camouflage paint is precisely like that of former camouflage paints and has their known satisfactory reflecting properties, approximating to the reflection curve of chlorophyll.

The natural emission in the windows II and III is largely reduced by the binding agent employed in the paint.

A priming paint applied to the body prior to applying the camouflage paint may comprise colours which are highly reflecting, in the manner of a clean metal surface, alternating with colours having a black effect in the longwave IR range.

A "structuring" of the emission power in the windows II and III is thus possible, i.e.

an area of an object to which the paint is applied is broken into irregular patterns of different emissive power, giving rise to an image that does not show the contours of a uniformly warm object or the iso-thermal areas of unevenly heated targets and cannot therefore be detected by optical equipment or with heatreconnaissance equipment.

In a further development of the invention, a priming paint for the camouflage paint is made highly reflecting and "structuring" is obtained by using a camouflage paint comprising pigments having different absorbing and/or scattering properties.

Known pigments for use in camouflage paints for the visible optical spectral range have different absorption and/or scattering properties, depending on the visible optical colour, so that the emissive power, and hence a "structuring" of the camouflage in the heatimage range, is possible by suitably selecting the visible optical pigment colour.

In a further development of the invention, the primary paint for the camouflage paint is made highly reflecting and "structuring" is effected by a camouflage paint with uniform pigmentatiati which is used with locally different thicknesses. The structuring is caused by the fact that the absorption or emission coefficient is determined, in the majority of cases, by the thickness of the layer of paint, that is to say the number of pigment molecules which are embedded in the layer, because the absorption of the pigment should be low.

Suitably, the binding agent of the priming paint and/or of the camouflage paint has a high absorption in the range from about 5.5 to 7.5 clam, for heat developed by the vehicle or equipment is emitted in this spectral range, between the atmospheric windows II and III.

This radiation is not visible by thermal observation, however, because the atmosphere does not transmit radiation over a great distance in this spectral range.

Broadband camouflage is obtained with the aid of camouflage nets which do not differ in their visible optical properties from the former ones but have the textile trimming of the camouflage nets first coated with a reflecting paint and then provided with camouflage paint ,having the above-mentioned characteristics.

,Such camouflage nets, in contrast to those at present in use, have the necessary "structuring" ,even in the windows II and III.

Thermal insulation mats to reduce the temperature contrast can also be treated in the above manner at their outside and then appear structured even in the windows II and III of the atmosphere. The characteristic of thermal insulation mats that they heat up considerably more than the natural environment, because of their high thermal insulation effect with solar radiation, and therefore appear light to heat-picture equipment, is prevented in that the hot parts of the object are camouflaged by thermal insulation mats and the whole camouflaged object is camouflaged by one of the above-mentioned camouflage nets, which is disposed at a distance, rendering air convection possible.

Whereas the thermal contrast, that is to say the contrast between the hot parts and the natural background, is reduced by the thermal insulation mats, the superimposed camouflage net prevents heating of the object or of the thermal insulation mat by the solar radiation, because the trimming, cut in sickle shape in known manner, and structured thermally by the above method, is heated by solar radiation like the natural foliage and is cooled by wind and/or air convection.

The shade effect of the camouflage net on the thermal insulation mats has the effect that these cannot in any case be heated differently from the natural environment by solar radiation at the outside. The thermal structuring of the camouflage net achieved by the means according to the invention has the effect that its emissive power is not uniform but differs locally. Thus the thermal structures of the whole object to be camouflaged are broken up. Therefore, the geometrical configuration of the camouflage net can no longer be detected by heat-image processes.

WHAT I CLAIM IS: 1. A camouflaged object comprising a body having a surface which is highly reflecting in the spectral ranges 3 pm to 5 Can (window II) and 8 to 14 Uam (window III), and a coating of a camouflage paint on the highly reflecting surface, the camouflage paint comprising a pigment having camouflage properties in the visible and near IR range and a binding agent, the paint having an- emissivity less than 90% in the spectral ranges 3 to 5 Eam and 8 to 14 ,zun.

2. A camouflaged object as claimed in claim 1, wherein the said surface of the body has a priming paint applied thereto, the priming paint comprising colours which are highly reflecting.

3. A camouflaged object as claimed in claim 2, wherein the priming paint comprises colours which are highly reflecting alternating with colours whch have a black effect in the longwave IR range.

4. A camouflaged object as claimed in claim 2, wherein the camouflage paint includes pigments which have different absorption and/or scattering properties, whereby, in use, an area to which the paint is applied is broken up into irregular patterns of different emissive powers.

5. A camouflaged object as claimed in claim 2, wherein an area to which the paint is applied is broken up into irregular patterns of different emissive powers by a camouflage paint with uniform pigmentation and with locally different thicknesses.

6. A camouflaged object as claimed in any one of the preceding claims, wherein the bind

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. of unevenly heated targets and cannot therefore be detected by optical equipment or with heatreconnaissance equipment. In a further development of the invention, a priming paint for the camouflage paint is made highly reflecting and "structuring" is obtained by using a camouflage paint comprising pigments having different absorbing and/or scattering properties. Known pigments for use in camouflage paints for the visible optical spectral range have different absorption and/or scattering properties, depending on the visible optical colour, so that the emissive power, and hence a "structuring" of the camouflage in the heatimage range, is possible by suitably selecting the visible optical pigment colour. In a further development of the invention, the primary paint for the camouflage paint is made highly reflecting and "structuring" is effected by a camouflage paint with uniform pigmentatiati which is used with locally different thicknesses. The structuring is caused by the fact that the absorption or emission coefficient is determined, in the majority of cases, by the thickness of the layer of paint, that is to say the number of pigment molecules which are embedded in the layer, because the absorption of the pigment should be low. Suitably, the binding agent of the priming paint and/or of the camouflage paint has a high absorption in the range from about 5.5 to 7.5 clam, for heat developed by the vehicle or equipment is emitted in this spectral range, between the atmospheric windows II and III. This radiation is not visible by thermal observation, however, because the atmosphere does not transmit radiation over a great distance in this spectral range. Broadband camouflage is obtained with the aid of camouflage nets which do not differ in their visible optical properties from the former ones but have the textile trimming of the camouflage nets first coated with a reflecting paint and then provided with camouflage paint ,having the above-mentioned characteristics. ,Such camouflage nets, in contrast to those at present in use, have the necessary "structuring" ,even in the windows II and III. Thermal insulation mats to reduce the temperature contrast can also be treated in the above manner at their outside and then appear structured even in the windows II and III of the atmosphere. The characteristic of thermal insulation mats that they heat up considerably more than the natural environment, because of their high thermal insulation effect with solar radiation, and therefore appear light to heat-picture equipment, is prevented in that the hot parts of the object are camouflaged by thermal insulation mats and the whole camouflaged object is camouflaged by one of the above-mentioned camouflage nets, which is disposed at a distance, rendering air convection possible. Whereas the thermal contrast, that is to say the contrast between the hot parts and the natural background, is reduced by the thermal insulation mats, the superimposed camouflage net prevents heating of the object or of the thermal insulation mat by the solar radiation, because the trimming, cut in sickle shape in known manner, and structured thermally by the above method, is heated by solar radiation like the natural foliage and is cooled by wind and/or air convection. The shade effect of the camouflage net on the thermal insulation mats has the effect that these cannot in any case be heated differently from the natural environment by solar radiation at the outside. The thermal structuring of the camouflage net achieved by the means according to the invention has the effect that its emissive power is not uniform but differs locally. Thus the thermal structures of the whole object to be camouflaged are broken up. Therefore, the geometrical configuration of the camouflage net can no longer be detected by heat-image processes. WHAT I CLAIM IS:

1. A camouflaged object comprising a body having a surface which is highly reflecting in the spectral ranges 3 pm to 5 Can (window II) and 8 to 14 Uam (window III), and a coating of a camouflage paint on the highly reflecting surface, the camouflage paint comprising a pigment having camouflage properties in the visible and near IR range and a binding agent, the paint having an- emissivity less than 90% in the spectral ranges 3 to 5 Eam and 8 to 14 ,zun.

ing agent of the priming paint and/or of the camouflage paint has a strong absorption in the range from about 5.5 to 7.5 pm.

7. A camouflaged object as claimed in any one of the preceding claims and substantially as hereinbefore described.