Narcissus-Enabled Compact Thermal Hyperspectral Imager
Jay Bixler | 20-ERD-005
Current thermal infrared hyperspectral imaging (HSI) systems require cooling the spectrally dispersing optics as well as the detector to cryogenic temperatures. To do this requires a custom dewar to house multiple optical components at high vacuum and connection to a large cryocooler to reach cryogenic temperatures. The resulting sensor system weighs hundreds of pounds and requires, at minimum, a general-aviation airplane to field. To produce a sensor with significantly reduced size, weight, and power (SWAP), a novel optical design exploiting optical narcissus was developed, allowing much of the optical system to operate at room temperature. The as-built sensor has a weight of 20 pounds and a performance level comparable to much larger sensors. The sensor has flown several demonstration flights on a drone with remote substance detection and identification. The sensor can operate for one hour on battery power, much longer then the available drone flight time.
This project demonstrated a low SWAP sensor for detecting thermal infrared spectral signatures. As-built sensor SWAP was reduced by a factor of 10x to 20x compared to current thermal HSI sensors, while maintaining sub-microflick sensitivity over a multispectral bandpass. Infrared signatures can provide information on a wide variety of activities germane to the security interests of the U.S. Any process that involves IR-emitting substances (just about everything) is a potential target. The reduction in sensor SWAP will enable a significant increase in deployment opportunities, e.g., small electric drones, handheld monitoring units, and small satellites, as there are many more small platforms available than the large, manned general-aviation and larger platforms currently used for these sensors.