High-performance Lightweight (HiLi) Thermal Infrared Hyperspectral Imager

Hyperspectral imaging (HSI) technology’s steady development arc has led to its continued proliferation across Department of Defense for a variety of applications.  While substantive development has taken place across the visible/infrared spectrum, most fielded applications are leveraging visible/near-infrared (VNIR), short-wave infrared (SWIR) and long-wave infrared (LWIR) camera technology for HSI applications.  LWIR HSI stands apart due to its ability to offer true day/night HSI capabilities enabling a wide breadth of potential capabilities including camouflage detection, vehicle detection, chemical plume detection and activities associated with narcotics manufacture among others.  While the capabilities of LWIR HSI are well documented, traditionally, the cost, size, weight and power (C-SWaP) specifications of the technology have limited deployment to specialized platforms and applications.  While offering exceptional performance, these specialized sensors are often large (tens to hundreds of pounds), expensive (millions of dollars), and only suitable relatively large manned/unmanned platforms.  In contrast, there is a dearth of options meeting the goals of the topic description, in particular a sensor payload (gimbal included) weighing less than 10 lbs (allowing for integration onto Group 2 UAS), costing less than $850,000, and offering true hyperspectral imaging capabilities (i.e. hundreds of bands). To fill this capability gap, Spectrum Photonics (Spectrum) seeks to develop a low C-SWaP LWIR HSI payload suitable for deployment on a UAS platform at altitudes up to 10 kft.  The proposed LIghtweight HIgh-performance (LiHi) LWIR HSI sensor will weigh less than 10 lbs and feature more than 250 spectral channels in the LWIR from 7.5-13.0 microns.  The LIHI LWIR HSI sensor will generate real-time information suitable for downlink to ground control.  The HSI capability of our novel compact LWIR system will leverage Spectrum’s Ultra Compact Hyperspectral Imaging System (UCHIS) technology, to embed a LWIR spatial interferometer into a high performance Strained Layer Superlattice (SLS) focal plane array (FPA).  The selection of comparatively low-cost SLS FPA detectors relative to high-performance (and high price) Mercury Cadmium Telluride (MCT) detectors is one of the critical factors that enables Spectrum to meet our cost targets of less than $850,000 per systems in production.  The UCHIS technology reduces the size of the hyperspectral-enabling optic to thin plate which can be integrated into the dewar, enabling the hyperspectral sensor core to be no larger than a conventional broadband infrared camera.  By utilizing a high definition (HD) format, high performance SLS camera in concert with compact spatial interferometry, a high performance, low C-SWaP LWIR HSI sensor can be developed which meets the requisite performance and SWaP goals for deployment on a small UAS.