Air Fronts: Air Defense FM 5-20F; Camouflage of Antiaircraft Artillery - 1. The Antiaircraft Artillery Camouflage Problem

CHAPTER 1: THE ANTIAIRCRAFT ARTILLERY CAMOUFLAGE PROBLEM

Camouflage of AAA is complicated by the distinctive pattern of AAA installations when seen from the air, by the need for a clear field of fire overhead, and by the difficulty in teaching personnel to visualize how they and their installations appear from the air.

ENEMY OBSERVATION

Aerial observation is either direct visual observation from aircraft, or indirect observation through aerial photography. Because the purpose of camouflage is to baffle enemy observation, and because things on the ground look different when seen from the air, it is essential that all personnel learn how AAA is identified from the air. The more that troops learn the aerial viewpoint, by studying aerial photo-graphs or by flying, the more successful is their camouflage.

FIGURE 1 (1) and  (2).—The shape of a 40-mm emplacement, exposed in the open, is conspicuous because it is unrelated to its surroundings. If its shape is made to blend with a familiar and easily recognized ground pattern, such as this rectangular foundation, it immediately loses its identity, becoming hard to discover.

SHADOW

When an object matches its background it is revealed not by its shape but by the shadow it casts. Shadows, even those which appear weak on the ground, are frequently the darkest part of the landscape when seen or photographed from the air. The characteristic "star" shape of a large-caliber AA gun seen from the air is made as much by the gun itself as by the shadow it casts. For camouflage, shadows of military objects must be concealed, obliterated, or disguised as the shadows of non-military objects.

FIGURE 2.-To function properly, this SCR 268 must remain in open. It is well sited in low thick ground cover, which appears dark from the air and absorbs cast shadows.

FIGURE 3 (1) and (2).—Photo insets show vertical and oblique views of "star" shape formed by shadows of AA guns. Color drawings show AA gun occupying a grassy area, which has been excessively trampled down in the vicinity of gun. The smooth ground surface which has resulted is lighter than the undisturbed grass and causes shadows to appear darker and more prominent. In (2) natural materials are placed irregularly around gun to break up its cast shadows.

TEXTURE

Conspicuousness from the air is further increased by the contrast between the surface texture of an object and the surface texture of its background.

Texture is the degree of roughness or smoothness of an object's surface. A rough surface casts shadows on itself and appears dark. A smooth surface reflects light rays and appears light. Where two surfaces are exactly the same color but of different textures, the surface with the rougher texture appears darker.

FIGURE 4 (1).—A landscape with a variety of texture. Smooth-surfaced road and adjacent areas of exposed soil appear almost white. Area at lower center, thickly covered with low scrub growth, appears darker than field of grass, which is smoother in texture. Tall trees are even darker. Battery is easily identified in open field because the light background accents the dark shadows that are inherent in open em-placements. In such emplacements, the circular shadow of the pit absorbs the star-shape of the gun outriggers.
(2)—A better choice of battery position is shown in overlay at right. Field of fire seems to be good; access is provided by existing tracks; low thick growth helps to absorb shadows and is a source of camouflage material for covering parapets.

FIGURE 5 (1) and  (2).

TRACKS

In most cases the "spoor" of an army (tracks and spoil) is seen before the military installation itself. Obvious changes in terrain pattern are easily spotted by the enemy observer. Tracks are the most noticeable and telltale signs of occupation. A maze of unnecessary tracks in figure 5 (1) draws attention to the area and to a badly sited 40-mm position. The prominent track leading off to the left was made by three round-trips of one truck in grass about 9 inches high. Turning loops are always conspicuous.

In figure 5  concealment of the position is much improved. Gun emplacement and power plant are located in a patch of low scrub instead of on a flat plain background. Access is restricted to tracks which run past emplacement, power plant, and machine-gun site. Necessary new tracks to any position are kept to a minimum. It is essential that new tracks be extended beyond the position either to an innocent-looking termination or to a decoy position. Traffic is maintained throughout so the false and real sections are worn equally.

FIGURE 6 (1) and (2) .

SPOIL

Excavated earth, called spoil, is almost always much lighter in color than the undisturbed ground surface. A parapet around the average emplacement forms an easily discernible ring which contrasts in color with the surroundings and shadows within the emplacement (fig. 6) .

Spoil must always be covered or carried away. Natural materials, such as grass, branches, and shrubs, are a satisfactory means of concealing spoil if placed in their natural growing position. The disadvantage of this type of camouflage is that usually materials must be replaced every day or two as they wither and fade.

FIGURE 7.-A 37-mm position in the Pacific theater, camouflaged with scattered palm fronds. They darken immediate surroundings so shadows cast within emplacement do not contrast sharply with white beach.

SHINE

A perfectly smooth surface reflects practically every light ray that hits it, giving a bright sensation to the eye. This high reflection is called shine. It attracts attention instantly and must be prevented.

FIGURE 8.-A searchlight and trailer in the Pacific theater are sited near good natural concealment. Searchlight is rolled out on beach only at night. During daylight it is kept under cover to prevent reflections from its glass and metal surfaces.

FIGURE 9.-A search-light covered with a tarpaulin on which some local moss and branches are placed. Shape of unit is broken up and any possibility of shine from metal or glass surfaces is avoided. It would be wasted effort to cover searchlight with brush only, allowing smooth parts to shine through.

FIGURE 10.-Common breaches of camouflage discipline:

CAMOUFLAGE DISCIPLINE

Camouflage discipline begins with the preliminary reconnaissance and must be maintained throughout the operation. The first footprint or wheel mark must be controlled. Without this measure of security from start to finish, a plan or operation may readily be disclosed to the enemy. It involves: confining movements to designated routes; closing nets when not firing; repairing or changing covering material when necessary; not allowing smoke to appear near a position; keeping ammunition covered; not allowing vehicles to stop in day-light on a road near a position; and, in general, prohibiting any activity which makes the position more visible. Under the fatigue and strain of combat conditions, effective camouflage discipline can be maintained only by thoroughly trained personnel who understand the reasons underlying their actions. Camouflage discipline must be rigidly enforced and personnel guilty of breaches effectively punished.