Modeling apparent camouflage-pattern color using segment-weighted spectra

ABSTRACT

Camouflage patterns for military applications, typically upon base materials such as dyed fabrics, consist of highly detailed camouflage patternings that are characterized by combined refectance spectra. The complexity of these camouflage patterns establishes a need for modeling camouflage-pattern reflectance for pattern evaluation as a function of distance. A metric for pattern evaluation is the apparent-camouflage-pattern reflectance spectrum, which is the total reflectance due to all contributions from component segments, within a wavelength range of interest, for light reflected from sufficiently large fabric samples (≥1m²), as a function of standoff distance. This follows in that camouflage patterns tend to lose contributions to the total reflectance from component segments, having less coverage, with increasing standoff distance. Eventually, with increasing distance, reflectance of pattern segments having more coverage combine to produce the “apparent spectrum” of the camouflage pattern at far field. The physical characteristics of camouflage-pattern reflectance spectra are based on far-field and diffuse scattering properties of electromagnetic waves. Accordingly, a modeling approach can be developed to simulate camouflage-pattern spectra using diffuse-reflectance theory, which is based on decomposition of camouflage-pattern reflectance with respect to component segments of camouflage patterns. This paper presents a modeling approach and prototype simulations of camouflage-pattern reflectance within the visible range of wavelengths, which are relevant for evaluating camouflage fabrics with respect to realistic field conditions. A significant aspect of this modeling approach is that it can be extended for simulation of a wide range of factors influencing detection of camouflaged targets.

KEYWORDS:

• Camouflage patterns
• apparent color
• diffuse reflectance
• camouflage modeling

Acknowledgement

Funding for this project was provided by the Office of Naval Research (ONR) through the Naval Research Laboratory’s Basic Research Program.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Scott Ramsey

Scott Ramsey received the MS degree in Forensic Chemistry from Michigan State University (2004), and BS degrees in Biology (1995) and Chemistry (2000) from Florida State University and the University of North Florida, respectively. He is currently a Senior Research Scientist at the Naval Research Laboratory, Washington, DC, where he has been for over 13 years, and has many publications, patents and awards. His expertise includes multispectral signature characterization and environmental testing of both fielded and prototype combat uniform systems, and also develops and incorporates into camouflage fabrics innovative visible and thermal signature reduction capabilities.

Troy Mayo

Troy Mayo is Lead Technician of the Signature Technology Office, Naval Research Laboratory, Washington, DC. He is responsible for spectral-signature quality control evaluations for all fielded warfighter gear, and for a wide range of spectral analysis programs, which include testing prototype combat uniform fabrics for thermal signature performance and durability.

Christopher A. Howells

Christopher A. Howells received the MS degree in Engineering Physics from George Mason University (2005), and BS degree in Physics from San Francisco State University (2000). He is currently Regulatory Analyst at the US Nuclear Regulatory Commission, Washington, DC, and Major in the US Army Reserve, 807th Medical Deployment Support Command. His recent studies concern quantum-mechanics-based calculations of electronic structure and modeling of diffuse reflectance for composites materials.

Andrew Shabaev

Andrew Shabaev received the PhD degree in Physics from American University, Washington, DC (1999), CSc in Physics and Mathematics from Ioffe Institute, St. Petersburg, Russia (1989), and MS degree in Physics and Engineering from Polytechnical University, St. Petersburg (1985). He is currently Senior Research Physicist with Leidos at the Naval Research Laboratory, Washington, DC, where he has been for over 17 years. His expertise is theoretical physics and has many publications and awards. His recent studies concern molecular-dynamics modeling and density functional theory.

Samuel G. Lambrakos

Samuel G. Lambrakos received the PhD degree in Physics from the Polytechnic Institute of New York University in 1983. He is currently a Research Physicist at the Naval Research Laboratory, Washington, DC, where he has been for over 35 years. His expertise is computational physics in general and has many publications, patents and awards. His recent studies concern computational materials physics and inverse spectral analysis.