Active hyperspectral imaging

Hyperspectral imaging has emerged as a useful technology for target recognition and anomaly detection. However, passive hyperspectral sensors in the VNIR/SWIR are limited to daytime and fair weather operations. Furthermore, for applications such as material identification, the need for reflectance spectra requires either inscene calibration panels or detailed atmospheric information. Active hyperspectral sensing has the potential to increase the utility of hyperspectral imaging by enabling nighttime operation and non-cooperative conversion to reflectance. At MIT Lincoln Laboratory we have developed an active hyperspectral sensor system to investigate combining active illumination with hyperspectral imaging. Our primary illumination source is a novel broadband ‘white light’ laser, developed at MIT Lincoln Laboratory. Initial phenomenology measurements have revealed an additional benefit of active illumination - enhanced scene contrast due to shadow reduction. We have demonstrated two orders of magnitude decrease in false alarm rates with active illumination versus passive.