File:Imaging and reflectance spectroscopy for the evaluation of effective camouflage in the SWIR (IA imagingndreflect109453165).pdf

The emergence of SWIR (short-wave infrared) sensors and ongoing development of multi-spectral imagers that operate across four wavebands (visible, NIR, SWIR and MWIR) pose new challenges for current camouflage, concealment and deception technologies. For one, they render ineffective conventional camouflage material that worked well in the visible part of the spectrum. The aim of this thesis is to propose means to provide effective camouflage across the visible and SWIR spectrums. A system was developed for combined imagery and spectral reflectance measurements for the visible and the SWIR regions. The system utilizes an InGaAs focal plane array with a response range from 400 to 1700 nm. Experiments were conducted to study the reflectance of materials (e.g. foliage and current camouflage materials) across the two spectrums. From these experiments, the desired properties for camouflage materials were established. It is then proposed that a layer of nanomesh be used to complement current camouflage material in order to maintain the reflectance contrast between various dyes in the SWIR. The modified camouflage material would be reinforced with fibers tuned to absorb radiation around 1.4 m wavelength. This would mimic the SWIR reflectance behavior exhibited by water contained in foliage. The proposed material will enhance the survivability of future warriors by providing effective camouflage across the visible and SWIR spectrums.