Takaheijastimet

Takaheijastimet, also known as counter-illumination devices, are a form of active camouflage used to render objects, such as submarines, less visible against a brighter background when viewed from below. The principle behind takaheijastimet is to emit light from the object's surface in a way that matches the ambient light conditions of the surrounding environment. This effectively cancels out the silhouette that would otherwise be cast against the brighter surface water or sky.

These devices typically employ arrays of lights, often LEDs, strategically placed on the hull of the vessel. These lights are connected to sensors that measure the intensity and color of the light from above. A control system then adjusts the brightness and color of the emitted light to mimic the downwelling light. The goal is to make the object appear as if it blends seamlessly with the background, thus disappearing from an observer's line of sight.

The development of takaheijastimet was driven by the need to improve the survivability of naval vessels, particularly submarines, by reducing their detectability to aircraft and surface ships. While the concept is straightforward, practical implementation faces challenges. Achieving a perfect match to the highly variable and dynamic underwater light field is difficult. Factors such as water turbidity, depth, time of day, and weather conditions all influence the ambient light, requiring sophisticated sensing and control systems. Despite these complexities, takaheijastimet represent a significant advancement in the field of military camouflage and stealth technology.