Three Color Desert pattern

Military camouflage is the use of camouflage by an armed force to protect personnel and equipment from observation by enemy forces. In practice, this means applying colour and materials to military equipment of all kinds, including vehicles, ships, aircraft, gun positions and battledress, either to conceal it from observation (crypsis), or to make it appear as something else (mimicry). The French slang word ''camouflage'' came into common English usage during World War I when the concept of visual deception developed into an essential part of modern military tactics. In that war, long-range artillery and observation from the air combined to expand the field of fire, and camouflage was widely used to decrease the danger of being targeted or to enable surprise. As such, military camouflage is a form of military deception.

Camouflage was first practiced in simple form in the mid 18th century by rifle units. Their tasks required them to be inconspicuous, and they were issued green and later other drab colour uniforms. With the advent of longer range and more accurate weapons, especially the repeating rifle, camouflage was adopted for the uniforms of all armies, spreading to most forms of military equipment including ships and aircraft. Many modern camouflage textiles address visibility not only to visible light but also near infrared, for concealment from night vision devices. Camouflage is not only visual; heat, sound, magnetism and even smell can be used to target weapons, and may be intentionally concealed. Some forms of camouflage have elements of scale invariance, designed to disrupt outlines at different distances, typically digital camouflage patterns made of pixels. Camouflage patterns also have cultural functions such as political identification.

Camouflage for equipment and positions was extensively developed for military use by the French in 1915, soon followed by other World War I armies. In both world wars, artists were recruited as camouflage officers. Ship camouflage developed via conspicuous dazzle camouflage schemes during WWI, but since the development of radar, ship camouflage has received less attention. Aircraft, especially in World War II, were often countershaded: painted with different schemes above and below, to camouflage them against the ground and sky respectively.

Military camouflage patterns have been popular in fashion and art from as early as 1915. Camouflage patterns have appeared in the work of artists such as Andy Warhol and Ian Hamilton Finlay, sometimes with an anti-war message. In fashion, many major designers have exploited camouflage's style and symbolism, and military clothing or imitations of it have been used both as street wear and as a symbol of political protest.

Principles

Military camouflage is part of the art of military deception. The main objective of military camouflage is to deceive the enemy as to the presence, position and intentions of military formations. Camouflage techniques include concealment, disguise, and dummies, applied to troops, vehicles, and positions.

Vision is the main sense of orientation in humans, and the primary function of camouflage is to deceive the human eye. Camouflage works through concealment (whether by countershading, preventing casting shadows, or disruption of outlines), mimicry, or possibly by dazzle. In modern warfare, some forms of camouflage, for example face paints, also offer concealment from infrared sensors, while CADPAT textiles in addition help to provide concealment from radar.

Compromises

While camouflage tricks are in principle limitless, both cost and practical considerations limit the choice of methods and the time and effort devoted to camouflage. Paint and uniforms must also protect vehicles and soldiers from the elements. Units need to move, fire their weapons and perform other tasks to keep functional, some of which run counter to camouflage. Camouflage may be dropped altogether. Late in the Second World War, the USAAF abandoned camouflage paint for some aircraft to lure enemy fighters to attack, while in the Cold War, some aircraft similarly flew with polished metal skins, to reduce drag and weight, or to reduce vulnerability to radiation from nuclear weapons.

No single camouflage pattern is effective in all terrains. The effectiveness of a pattern depends on contrast as well as colour tones. Strong contrasts which disrupt outlines are better suited for environments such as forests where the play of light and shade is prominent, while low contrasts are better suited to open terrain with little shading structure. Terrain-specific camouflage patterns, made to match the local terrain, may be more effective in that terrain than more general patterns. However, unlike an animal or a civilian hunter, military units may need to cross several terrain types like woodland, farmland and built up areas in a single day. While civilian hunting clothing may have almost photo-realistic depictions of tree bark or leaves (indeed, some such patterns are based on photographs), military camouflage is designed to work in a range of environments. With the cost of uniforms in particular being substantial, most armies operating globally have two separate full uniforms, one for woodland/jungle and one for desert and other dry terrain. An American attempt at a global camouflage pattern for all environments (the 2004 UCP) was however withdrawn after a few years of service. On the other end of the scale are terrain specific patterns like the "Berlin camo", applied to British vehicles operating in Berlin during the Cold War, where square fields of various gray shades was designed to hide vehicles against the mostly concrete architecture of post-war Berlin.

Other functions

Camouflage patterns serve cultural functions alongside concealment. Apart from concealment, uniforms are also the primary means for soldiers to tell friends and enemies apart. The camouflage experts and evolutionary zoologists L. Talas, R. J. Baddeley and Innes Cuthill analyzed calibrated photographs of a series of NATO and Warsaw Pact uniform patterns and demonstrated that their evolution did not serve any known principles of military camouflage intended to provide concealment. Instead, when the Warsaw Pact was dissolved, the uniforms of the countries that began to favour the West politically started to converge on the colours and textures of NATO patterns. After the death of Marshal Tito and the breakup of what had been Yugoslavia, the camouflage patterns of the new nations changed, coming to resemble the camouflage patterns used by the armies of their neighbours. The authors note that military camouflage resembles animal coloration in having multiple simultaneous functions.

Snow camouflage

Seasons may play a role in some regions. A dramatic change in colour and texture is created by seasonal snowy conditions in northern latitudes, necessitating repainting of vehicles and separate snow oversuits. The Eastern and northern European countries have a tradition for separate winter uniforms rather than oversuits. During the Second World War, the Waffen-SS went a step further, developing reversible uniforms with separate schemes for summer and autumn, as well as white winter oversuits.

Movement

While patterns can provide more effective crypsis than solid colour when the camouflaged object is stationary, any pattern, particularly one with high contrast, stands out when the object is moving. Jungle camouflage uniforms were issued during the Second World War, but both the British and American forces found that a simple green uniform provided better camouflage when soldiers were moving. After the war, most nations returned to a unicoloured uniform for their troops. Some nations, notably Austria and Israel, continue to use solid colour combat uniforms today. Similarly, while larger military aircraft traditionally had a disruptive pattern with a darker top over a lighter lower surface (a form of countershading), modern fast fighter aircraft often wear gray overall.

Digital camouflage

Digital camouflage provides a disruptive effect through the use of pixellated patterns at a range of scales, meaning that the camouflage helps to defeat observation at a range of distances. Such patterns were first developed during the Second World War, when Johann Georg Otto Schick designed a number of patterns for the Waffen-SS, combining micro- and macro-patterns in one scheme. The German Army developed the idea further in the 1970s into Flecktarn, which combines smaller shapes with dithering; this softens the edges of the large scale pattern, making the underlying objects harder to discern. Pixellated shapes pre-date computer aided design by many years, already being used in Soviet Union experiments with camouflage patterns, such as "TTsMKK" developed in 1944 or 1945.

In the 1970s, US Army officer Timothy R. O'Neill suggested that patterns consisting of square blocks of colour would provide effective camouflage. By 2000, O'Neill's idea was combined with patterns like the German ''Flecktarn'' to create pixellated patterns such as CADPAT and MARPAT. Battledress in digital camouflage patterns was first designed by the Canadian Forces. The "digital" refers to the coordinates of the pattern, which are digitally defined. The term is also used of computer generated patterns like the non-pixellated Multicam and the Italian fractal ''Vegetato'' pattern. Pixellation does not in itself contribute to the camouflaging effect. The pixellated style, however, simplifies design and eases printing on fabric.

Non-visual

With the birth of radar and sonar and other means of detecting military hardware not depending on the human eye, came means of camouflaging against them. Collectively these are known as stealth technology. Aircraft and ships can be shaped to reflect radar impulses away from the sender, and covered with radar-absorbing materials, to reduce their radar signature. The use of heat-seeking missiles has also led to efforts to hide the heat signature of aircraft engines. Methods include exhaust ports shaped to mix hot exhaust gases with cold surrounding air, and placing the exhaust ports on the upper side of the airframe. Multi-spectral camouflage attempts to hide objects from detection methods such as infrared, radar, and millimetre-wave imaging simultaneously.

Auditory camouflage, at least in the form of noise reduction, is practised in various ways. The rubberized hull of military submarines absorbs sonar waves and can be seen as a form of auditory camouflage. Some modern helicopters are designed to be quiet. Combat uniforms are usually equipped with buttons rather than snap fasteners or velcro to reduce noise.

Olfactory camouflage is said to be rare; examples include ghillie suits, special garments for military snipers made from strips of hessian cloth, which are sometimes treated with mud and even manure to give them an "earthy" smell to cover the smell of the sniper.

Magnetic camouflage in the form of " degaussing" coils has been used since the Second World War to protect ships from magnetic mines and other weapons with magnetic sensors. Horizontal coils around the whole or parts of the ship generate magnetic fields to "cancel out" distortions to the earth's magnetic field created by the ship.

History

Reconnaissance and riflemen

Ship camouflage was occasionally used in ancient times. Vegetius wrote in the 4th century that "Venetian blue" (bluish-green, like the sea) was used for camouflage in the years 56–54 BC during the Gallic Wars, when Julius Caesar sent his scout ships to gather intelligence along the coast of Britain. The bluish-green scout ships carried sailors and marines dressed in the same colour.

The emphasis on hand-to-hand combat, and the short range of weapons such as the musket, meant that recognition and cohesion were more important than camouflage in combat clothing well into the baroque period. The introduction of infantry weapons with longer range, especially the Baker rifle, opened up new roles which needed camouflaged clothing. In the colonial Seven Years' War (1756–1763), the rifle-armed Rogers' Rangers wore gray or green uniforms. John Graves Simcoe, one of the unit's later commanders, noted in 1784:

The tradition was continued by British Rifle Regiments who adopted rifle green for the Napoleonic Wars.

During the Peninsular War, Portugal fielded light infantry units known as ''Caçadores'', who wore brown-jackets which helped conceal them. The brown color was considered to be more adequate for a concealment in the landscape of most of Portuguese regions, in general more arid than the greener landscapes of Central and Northern Europe. Other nations soon followed suit, dressing their rifle regiments and sometimes also light troops in suitable drab tones, usually variations of green or gray.

The first introduction of drab general uniform was by the British Corps of Guides in India in 1848. Initially the drab uniform was specially imported from England, with one of the reasons being to "make them invisible in a land of dust". However, when a larger quantity was required the army improvised, using a local dye to produce uniform locally. This type of drab uniform soon became known as khaki (Urdu