Opto-electronic methods for adaptive camouflage

In this paper opto-electronic methods for adaptive camouflage for a soldier are presented. This work is part of the EU funded project ACAMSII, “Adaptive CAMouflage for the Soldier II”, a future soldier system to be developed and implemented that provides adaptive camouflage against all relevant sensor threats, ranging from visible to thermal IR and radar. The assessment of possible technologies for adaptation of the visual signature is presented and discussed. The three most promising technologies will be discussed in detail: LED, OLED and electronic paper. Concerning the optical properties this paper will focus mainly on single colours and intensities, not on pattern generation and evaluation. Optical properties like luminance and the impact of reflectance are studied and compared. Especially the appearance of LEDs embedded in a textile and the impact of reflected ambient light will be analyzed. A discussion of colour space properties as a function of illuminance and surrounding background textile is presented also. It turned out that OLED and electronic paper devices have considerable disadvantages compared to LEDs. Therefor LEDs are the most promising optoelectronic components to be used for adaptive camouflage in the visible spectral range. Concerning the NIR spectral range a discussion of the optical requirements and the application of NIR diodes in clothing will be presented also.