Abstract
This study describes a parametric model of diffuse reflectance for the purpose of simulating the spectral response of near-infrared (NIR, 0.7–0.9 μm) and shortwave infrared (SWIR, 0.9–1.7 μm) absorbing dyes for minimizing NIR-SWIR reflectance of dyed fabrics. This model is purely phenomenological, but is optimal with respect to numbers of parameters. This model establishes ground-work for development of a prediction tool, which when given the constituent materials available, will enable rapid optimization of NIR/SWIR band contrast matching of composite systems, (e.g. uniforms and ancillary gear) for a given specification of NIR-SWIR reflectance. This model adopts absorption coefficients for NIR/SWIR absorbing dyes whose absorption spectra span the NIR/SWIR spectral range. Military camouflage fabric consisting of 50/50 nylon/cotton blend in a ripstop weave printed with four-color digital pattern was used as the test substrate for NIR/SWIR dye application. The results of this study provide validation of the parametric model within reasonable error, for practical applications including simulating NIR/SWIR spectral responses corresponding to fixed dye and dye blend concentrations in prototype camouflage fabrics.