Hypersectral Imaging for Military and Security Applications: Combining Myriad Processing and Sensing Techniques

Collecting airborne and spaceborne intelligence, surveillance, and reconnaissance (ISR) information is mandatory for addressing the defense challenges posed in the 21st century. A key tool for increasing the information content of ISR is using advanced electrooptical devices, including hyperspectral imaging (HSI). This optical sensing technology offers high spectral resolution covering visible to long-wave infrared (LWIR) wavelengths. The increase in spectral information and spectral degrees of freedom create a unique opportunity to detect difficult targets at the subpixel level, analyze a scene without prior information of the materials to be encountered, distinguish hidden features and camouflage, identify chemical agents in plumes, tag disturbed earth over buried objects, and perform image classification with greatly improved accuracy. This article reviews the military- and security-driven applications of HSI. It analyzes and demonstrates sensing capabilities and advanced methodologies, summarizes the current spaceborne and airborne military HSI technologies, and reviews future technological developments.